Systems for and methods of preparing a sacroiliac joint for fusion

A surgical preparation tool for preparing a sacroiliac joint for a surgical procedure comprising a trial tool assembly and a cutting tool configured to releasably and slidably couple with the trial tool assembly, wherein the trial tool assembly is configured to guide the cutting tool during distal-proximal translation such that as the cutting tool distally advances relative to an implant trial of the trial tool assembly, at least a portion of a cutting element of the cutting tool extends generally over and perpendicularly outward from a first top surface of a body of the implant trial.

TECHNICAL FIELD

Aspects of the present disclosure relate to medical apparatus and methods. More specifically, the present disclosure relates to devices and methods for preparing a sacroiliac joint for fusion.

BACKGROUND

The sacroiliac joint is the joint between the sacrum and the ilium of the pelvis, which are joined by ligaments. In humans, the sacrum supports the spine and is supported in turn by an ilium on each side. The sacroiliac joint is a synovial joint with articular cartilage and irregular elevations and depressions that produce interlocking of the two bones.

Pain associated with the sacroiliac joint can be caused by traumatic fracture dislocation of the pelvis, degenerative arthritis, sacroiliitis an inflammation or degenerative condition of the sacroiliac joint, osteitis condensans ilii, or other degenerative conditions of the sacroiliac joint. Currently, sacroiliac joint fusion is most commonly advocated as a surgical treatment for these conditions. Fusion of the sacroiliac joint can be accomplished by several different conventional methods encompassing an anterior approach, a posterior approach, and a lateral approach with or without percutaneous screw or other type implant fixation. However, while each of these methods has been utilized for fixation and fusion of the sacroiliac joint over the past several decades, substantial problems with respect to the fixation and fusion of the sacroiliac joint remain unresolved.

A significant problem with certain conventional methods for fixation and fusion of the sacroiliac joint including the anterior approach, posterior approach, or lateral approach may be that the surgeon has to make a substantial incision in the skin and tissues for direct access to the sacroiliac joint involved. These invasive approaches allow the sacroiliac joint to be seen and touched directly by the surgeon. Often referred to as an “open surgery”, these procedures have the attendant disadvantages of requiring general anesthesia and can involve increased operative time, hospitalization, pain, and recovery time due to the extensive soft tissue damage resulting from the open surgery.

A danger to open surgery using the anterior approach can be damage to the L5 nerve root, which lies approximately two centimeters medial to the sacroiliac joint or damage to the major blood vessels. Additionally and as seen inFIG. 1, which depicts a conventional fusion procedure (immobilization of the articular surfaces of the sacroiliac joint in relation to one another) on a sacroiliac joint1, one or more screws or implants2are implanted transversely across the articular surfaces3and through the sacrum4and the ilium bones5. That is, the joint1is immobilized by placement of a fusion device2transverse to or across a plane defined by articular surfaces3of the sacroiliac joint space.

Use of trans-sacroiliac and S1 pedicle-iliac bone implants can also involve the risk of damage to the lumbosacral neurovascular elements. Damage to the lumbosacral neurovascular elements as well as delayed union or non-union of the sacroiliac joint by use of these procedures may require revision surgery to remove all or a portion of the implants or repeat surgery as to these complications.

Another significant problem with conventional procedures utilizing minimally invasive small opening procedures can be that the procedures are technically difficult, requiring biplanar fluoroscopy of the articular surfaces of the sacroiliac joint and extensive surgical training and experience. Despite the level of surgical training and experience, there is a substantial incidence of damage to the lumbosacral neurovascular elements. Additionally, sacral anomalies can further lead to malplacement of implants leading to damage of surrounding structures. Additionally, these procedures are often performed without fusion of the sacroiliac joint, which does not remove the degenerative joint surface and thereby does not address the degenerative condition of the sacroiliac joint, which may lead to continued or recurrent sacroiliac joint pain.

Another significant problem with conventional procedures can be the utilization of multiple trans-sacroiliac elongate implants, which do not include a threaded surface. This approach requires the creation of trans-sacroiliac bores in the pelvis and nearby sacral foramen, which can be of relatively large dimension and which are subsequently broached with instruments, which can result in bone being impacted into the pelvis and neuroforamen.

The creation of the trans-sacroiliac bores and subsequent broaching of the bores requires a guide pin, which may be inadvertently advanced into the pelvis or sacral foramen, resulting in damage to other structures. Additionally, producing the trans-sacroiliac bores, broaching, or placement of the elongate implants may result in damage to the lumbosacral neurovascular elements, as above discussed. Additionally, there may be no actual fusion of the articular portion of the sacroiliac joint, which may result in continued or recurrent pain requiring additional surgery.

Another substantial problem with conventional procedures can be that placement of posterior extra-articular distracting fusion implants and bone grafts may be inadequate with respect to removal of the articular surface or preparation of cortical bone, the implant structure and fixation of the sacroiliac joint. The conventional procedures may not remove sufficient amounts of the articular surfaces or cortical surfaces of the sacroiliac joint to relieve pain in the sacroiliac joint. The conventional implant structures may have insufficient or avoid engagement with the articular surfaces or cortical bone of the sacroiliac joint for adequate fixation or fusion. The failure to sufficiently stabilize and fuse the sacroiliac joint with the conventional implant structures and methods may result in a failure to relieve the condition of sacroiliac joint being treated. Additionally, conventional methods of driving apart a sacrum and ilium may lead to mal-alignment of the sacroiliac joint and increased pain.

Improvements to sacroiliac joint fusion involve systems and methods for non-transverse delivery of an implant into the sacroiliac joint are described in U.S. patent application Ser. No. 12/998,712, filed May 23, 2011 entitled SACROILIAC JOINT FIXATION FUSION SYSTEM; Ser. No. 13/236,411, filed Sep. 19, 2011 entitled SYSTEMS FOR AND METHODS OF FUSING A SACROILIAC JOINT; and Ser. No. 13/475,695, filed May 18, 2012, entitled SYSTEMS FOR AND METHODS OF FUSING A SACROILIAC JOINT; and Ser. No. 13/945,053, filed Jul. 18, 2013, entitled SYSTEMS FOR AND METHODS OF FUSING A SACROILIAC JOINT; and Ser. No. 13/946,790, filed Jul. 19, 2013, entitled SYSTEMS FOR AND METHODS OF FUSING A SACROILIAC JOINT; and Ser. No. 14/216,975, filed Mar. 17, 2014, entitled SYSTEMS AND METHODS FOR FUSING A SACROILIAC JOINT AND ANCHORING AN ORTHOPEDIC APPLIANCE; and Ser. No. 14/447,612, filed Jul. 31, 2014, entitled SYSTEMS FOR AND METHODS OF FUSING A SACROILIAC JOINT. All of application Ser. Nos. 12/998,712, 13/236,411, 13/475,695, 13/945,053, 13/946,790, 14/216,975, and Ser. No. 14/447,612 are herein incorporated by reference in their entirety. In certain instances, it may be desirable to prepare the surfaces of the sacroiliac joint prior to implantation of the fusion device, e.g., the intraarticular or extra-articular surfaces. While surgical preparation tools may exist for procedures in other areas of the body, tools for preparing the sacroiliac joint for fusion are lacking. Thus, the systems and methods discussed herein address the challenges in preparing the sacroiliac joint for fixation and fusion.

SUMMARY

One implementation of the present disclosure may take the form of a surgical preparation tool for preparing a sacroiliac joint having a sacrum and an ilium for a surgical procedure. In one embodiment, the tool may include a trial tool assembly and a cutting tool.

The trial tool assembly may include an implant trial at a distal end of the trial tool assembly and a trial shaft coupled to and extending proximally from the implant trial. The implant trial may include a body comprising a first length extending along a longitudinal axis from a proximal to a distal end, a top surface, a bottom surface generally opposite the top surface, a first side surface, and a second side surface generally opposite the first side surface. The implant trial may be configured to be delivered non-transversely into the sacroiliac joint such that the first top and first bottom surfaces oppose either the sacrum or the ilium.

The cutting tool of the surgical preparation tool may be configured to releasably and slidably couple with the trial tool assembly. The cutting tool may include a first cutting element at a distal end of the cutting tool and a cutting shaft extending proximally from the cutting element. The first cutting element may include a second length extending from a proximal to a distal end. The trial tool assembly is configured to guide the cutting tool during distal-proximal translation such that as the first cutting element distally advances relative to the implant trial, at least a portion of the first cutting element extends generally over and perpendicularly outward from the first side surface of the body of the implant trial.

Another implementation of the present disclosure may take the form of a surgical preparation tool for preparing a sacroiliac joint having a sacrum and an ilium for a surgical procedure. In one embodiment, the tool may include a trial tool assembly and a drill guide assembly.

The trial tool assembly may include an implant trial at a distal end of the trial tool assembly and a trial shaft coupled to and extending proximally from the implant trial. The implant trial may include a body comprising a first length extending along a longitudinal axis from a proximal to a distal end, a first top surface, a first bottom surface generally opposite the first top surface, and a thickness defined between the first top and first bottom surfaces. The implant trial may be configured to be delivered non-transversely into the sacroiliac joint such that the first top and first bottom surfaces oppose either the sacrum or the ilium.

The drill guide assembly may be configured to releasably and slidably couple with the trial tool assembly. The drill guide assembly may include a drill guide at a distal end of the cutting guide and a drill guide shaft extending proximally from the drill guide. The drill guide may include a first passageway that is configured to guide a drill bit during distal-proximal translation of the drill bit relative to the drill guide assembly. The trial tool assembly may be configured to guide the drill guide assembly during distal-proximal translation such that as the drill guide distally advances relative to the implant trial, the drill guide is positioned in an orientation to deliver the drill bit generally over at least a portion of the first top surface of the body of the implant trial.

Yet another implementation of the present disclosure may take the form of a method of surgically preparing a sacroiliac joint having a sacrum and an ilium for a surgical fusion procedure.

In one embodiment, the method may include approaching a sacroiliac joint space with a joint preparation tool that may include an implant trial assembly and a cutting tool. The implant trial assembly may include an implant trial at a distal end of the joint preparation tool and an implant trial shaft extending proximally from the implant trial. The implant trial may include a length extending from a proximal end to a distal end of the implant trial, a first top surface, and a first bottom surface generally opposite the first top surface. The cutting tool may be configured to releasably and slidably couple with the trial tool assembly. The cutting tool may include a cutting element at a distal end of the cutting tool and a cutting shaft extending proximally from the cutting element. The cutting element may include a second length extending from a proximal to a distal end, wherein the trial tool assembly is configured to guide the cutting tool during distal-proximal translation.

The method may also include delivering a portion of the implant trial non-transversely into the sacroiliac joint space. The implant trial may be oriented in the sacroiliac joint space such that the first top and bottom surfaces are generally coplanar with a joint plane of the sacroiliac joint space.

The method may further include causing the cutting tool to be distally driven relative to the trial tool assembly such that the cutting element makes a cut extending into the sacrum or the ilium.

Another implementation of the present disclosure may take the form of a surgical system for preparing a sacroiliac joint having a sacrum and an ilium for a surgical procedure. In one embodiment, the system may include a joint preparation tool and a first anchoring arm.

The joint preparation tool may include a rasping head at a distal end of the joint preparation tool, a shaft extending proximally from the rasping head, and a longitudinal axis extending from a proximal to a distal end of the joint preparation tool. The rasping head may include a length extending from a distal to a proximal end of the rasping head, a top surface, and a bottom surface opposite the top surface.

The first anchoring arm may include a proximal end and a distal end, where the distal end of the first anchoring arm may be configured to engage a proximal end of an anchor element, the first anchoring arm may be operably coupled to the joint preparation tool in an arrangement such that a longitudinal axis of the anchor element is generally transversely aligned with the longitudinal axis of the joint preparation tool when the distal end of the first anchoring arm is engaged with the proximal end of the anchor element, wherein the first anchoring arm is configured to deliver the anchor element across the sacroiliac joint according to the arrangement.

Another implementation of the present disclosure may take the form of a surgical preparation tool for preparing a sacroiliac joint having a sacrum and an ilium for a surgical procedure. In one embodiment, the tool may include a trial tool assembly and a cutting tool assembly.

The trial tool assembly may include an implant trial at a distal end of the trial tool assembly and a trial shaft coupled to and extending proximally from the implant trial. The implant trial may include a body comprising a first length extending along a longitudinal axis from a proximal to a distal end, a first top surface, a first bottom surface generally opposite the first top surface, and a thickness defined between the first top and first bottom surfaces. The implant trial may be configured to be delivered non-transversely into the sacroiliac joint such that the first top and first bottom surfaces oppose either the sacrum or the ilium.

The cutting tool may be configured to releasably and slidably couple with the trial tool assembly. The cutting tool may include a cutting element at a distal end of the cutting tool and a cutting shaft extending proximally from the cutting element. The cutting element may include a second length extending from a proximal to a distal end. The trial tool assembly may be configured to guide the cutting tool during distal-proximal translation such that as the cutting element distally advances relative to the implant trial, at least a portion of the cutting element extends generally over and perpendicularly outward from the first top surface of the body of the implant trial.

DETAILED DESCRIPTION

Implementations of the present disclosure involve a system for preparing a sacroiliac joint for fusion. In particular, the system may include a preparation tool for removing articular cartilage from the sacroiliac joint space, abrading of the articular surfaces to enhance boney fusion, and removal of portions of the cortical, subchondral or cancellous bone for implantation of a fusion device. The preparation tool may include an anchoring arm that is configured to direct an anchoring element for transverse delivery through the sacroiliac joint space. The anchor may be delivered into the joint space before, during, or after the joint space is prepared for implant delivery. Alternatively, an implant may not be delivered into the joint and instead, e.g., bone paste or slurry may be introduced into the prepared sacroiliac joint before or after anchor placement. And, the anchor may be delivered cranial, caudal, or in-line with the eventual placement of the implant. The preparation tool is configured to quickly, accurately and reliably prepare the joint space for insertion of an implant.

I. System for Fusion of the Sacroiliac Joint

To begin a detailed discussion of a system10for delivering an implant12into the sacroiliac joint, reference is made toFIGS. 2A-3.FIG. 2Ais an isometric view of the system10.FIG. 2Bis the same view asFIG. 2A, except an implant assembly14of the system10is separated from a delivery tool16of the system10.FIG. 3is the same view asFIG. 2A, except the system10is shown exploded to better illustrate the components of the system10.

As can be understood fromFIGS. 2A and 2B, the system10includes a delivery tool16and an implant assembly14for implanting at the sacroiliac joint via the delivery tool16, the implant assembly14being for fusing the sacroiliac joint. As indicated inFIG. 3, the implant assembly14includes an implant12and an anchor element18(e.g., a bone screw or other elongated body). As discussed below in greater detail, during the implantation of the implant assembly14at the sacroiliac joint, the implant12and anchor element18are supported by a distal end20of the delivery tool16, as illustrated inFIG. 2A. The delivery tool16is used to deliver the implant12into the sacroiliac joint space. The delivery tool16is then used to cause the anchor element18to extend through the ilium, sacrum and implant12generally transverse to the sacroiliac joint and implant12. The delivery tool16is then decoupled from the implanted implant assembly14, as can be understood fromFIG. 2B. As illustrated inFIG. 3, the delivery tool16further includes a proximal end22opposite the distal end20, an arm assembly24, a handle26, an implant retainer28, a sleeve30and a trocar or guidewire32. While in the embodiment ofFIGS. 2A-3, the delivery tool16is fixed and non-adjustable and configured to deliver the anchoring element18in a single orientation relative to the implant12, the delivery tool16may be adjustable and configured to deliver the anchoring element18within a range of orientations relative to the implant12that will orient the anchoring element18either within a bore of the implant12, or adjacent implant12as described in U.S. patent application Ser. No. 14/447,612, filed Jul. 31, 2014, entitled SYSTEMS FOR AND METHODS OF FUSING A SACROILIAC JOINT, which is hereby incorporated by reference in its entirety.

In particular embodiments, first and second articular faces of the implant12may be selected to match the contour of the joint space of the sacroiliac joint within which the implant12is to be inserted. For example, the sacral, medial or first articular face of the implant may be configured to be generally convex to match the contour of a sacral auricular boney surface or to match the contour of an extra-articular region of a sacrum (e.g., a sacral fossa). In one aspect and referring to portions of the anatomy shownFIG. 48C, the sacral, medial or first articular face of the implant12may be generally a surface negative of the articular surfaces1016of the extra-articular region3007and/or articular region1044of the sacrum1004. As another example, the lateral, iliac or second articular face of the implant12may be configured to be generally concave to match the contour of an iliac auricular boney surface or to match the contour of an extra-articular region of an ilium (e.g., an iliac tuberosity). In one aspect, the lateral, iliac or second articular face of the implant12may be generally a surface negative of the articular surfaces1016of the extra-articular region3007and/or articular region1044of the ilium1005.Referring toFIGS. 54A-54E, in one embodiment the implant9010includes a first planar member9012extending a first top length of the implant and comprising a first planar top surface9014that extends between a first sacral side edge9016and a first ilium side edge9018that is opposite of and substantially parallel with the first sacral side edge, the side edges being substantially perpendicular to first planar top surface, the side edges extending the first top length of the implant and disposed a first thickness9020from a first bottom surface9022that is opposite the first planar top surface, the first planar top surface also extending between a substantially perpendicular proximal end edge9024and a tapered distal end edge9026, the tapered distal edge including a sloped taper9028along the first thickness between the first planar top surface and the first bottom surface such that the first top length is shorter than a first bottom length that extends a length of the first bottom surface, the tapered distal edge also including an inward tapering9030of the side edges towards a distal end of the implant, the side edges including a taper9032at a proximal end of the implant such that the first thickness substantially linearly increases until the side edges meet with the proximal end edge.The implant further includes a second planar member9034that is opposite the first planar member, the second planar member extending a second top length of the implant and comprising a second planar top surface9036that extends between a second sacral side edge9038and a second ilium side edge9040that is opposite of and substantially parallel with the second sacral side edge, the side edges being substantially perpendicular to the second planar top surface, the side edges extending the second top length of the implant and disposed a second thickness9042from a second bottom surface9044that is opposite the first planar top surface and opposed to the first bottom surface, the second planar top surface also extending between a substantially perpendicular proximal end edge9046and a tapered distal end edge9048, the tapered distal edge including a sloped taper9050along the second thickness between the second planar top surface and the second bottom surface such that the second top length is shorter than a second bottom length that extends a length of the second bottom surface, the tapered distal edge also including an inward tapering9052of the side edges towards the distal end of the implant, the side edges including a taper9054at a proximal end of the implant such that the second thickness substantially linearly increases until the side edges meet with the proximal end edge.The implant further includes a distal end member9056that couples the respective tapered distal end edges of the first planar member and the second planar member, the distal end member extending perpendicularly between the first planar member and the second planar member and including a distal front edge9058, a proximal edge9060opposite the distal front edge, and a pair of distal end member side surfaces9062between the distal front edge and the proximal edge, the proximal edge including a width that is larger than a width of the distal front edge such that the pair of distal end member side surfaces tapers or narrows9064towards the distal front edge, the distal front edge including a distal most point9066that slopes toward each of the respective first planar top surface and the second planar top surface, the sloping of the distal front edge smoothly transitioning9068with the sloped taper between the first planar top surface and the first bottom surface as well as the sloped taper between the second planar top surface and the second bottom surface, the distal front edge and the proximal edge both defining radial curves9069.The implant further includes a proximal end member9070that couples the respective proximal end edges of the first planar member and the seond planar member, the proximal end member including a proximal side9072that is in-line and parallel with the first and the second proximal end edge and a distal side9074that is opposite the proximal side, the distal side including a curve9076that is a mirror of the radial curve of the proximal edge of the distal end member, the proximal end member including an axial bore9078through the proximal end member, the proximal end member being slightly larger and including a similar shape to the axial bore, the axial bore being threaded and configured to mate with an implant insertion tool, wherein a bone graft or anchoring window9080is defined between the proximal edge of the distal end member and the distal side of the proximal end member, the window including a stadium shape that extends perpendicularly through a longitudinal axis of the implant, the window being adapted to receive bone graft or an anchoring element to anchor the implant to the articular surfaces.In certain embodiments, the distal end member side edges and the proximal edge meet at a corner where the corner is perpendicular or rounded. Similarly, other meeting points between respective edges can be straight edges (e.g., perpendicular) or rounded.In still other embodiments, among other figures, the first sacral side edge9016and the first ilium side edge9018taper inward from the proximal end9024to the distal end9026of the implant such that the first planar top surface9014and the second planar top surface9016defines a truncated isosceles triangle with the side edges forming sides of equal length.While reference is made to the embodiment of the implant9010inFIGS. 54A-54E, the reference numerals are similarly applicable to the implant9010inFIGS. 55A-55E.

A system as described inFIGS. 2A-3may be used in a surgical procedure via a posterior approach, as seen inFIGS. 4-5. As can be understood fromFIG. 4, which is a posterior-inferior view of a sacroiliac joint36with a patient40shown in broken line, the delivery tool16is positioned to deliver the implant12into a caudal region34of the sacroiliac joint36and the anchoring element18through the ilium5and into the bore38of the implant12. Referring toFIG. 5, the implant12and anchoring element18have been inserted into the caudal region34of the sacroiliac joint36and the delivery tool16has been removed.

With further reference to the boney anatomy shown inFIG. 48C, a system as described herein may be used in a surgical procedure via an anterior approach (e.g., such that the surgical pathway includes traversing an anterior boundary segment3004and/or traversing an anterior-inferior corner3010) and may further include positioning an implant into a sacroiliac joint such that: 1) the implant longitudinal axis a) is generally parallel to a sacroiliac joint inferior boundary segment3002, or b) points towards a posterior superior iliac spine, or c) point towards a posterior inferior iliac spine, or d) points toward a sacroiliac extra-articular region; or, 2) the distal end of the implant generally lies within a) a caudal region of the sacroiliac joint articular region, or b) an extra-articular portion of the sacroiliac joint, or c) a cranial portion or cephlad region of the sacroiliac joint articular region.

Additionally, a system as described herein may be used in a surgical procedure via an approach which includes a surgical pathway which transverses a sacroiliac joint inferior boundary segment3002, e.g., as described in U.S. patent application Ser. No. 13/945,053, filed Jul. 18, 2013, entitled SYSTEMS AND METHODS OF FUSING A SACROILIAC JOINT, which is hereby incorporated by reference in its entirety. A surgical procedure via this pathway may further include positioning an implant into a sacroiliac joint such that: 1) the implant longitudinal axis a) is transverse to a sacroiliac joint inferior boundary segment3002, or b) points towards a posterior superior iliac spine, or c) point towards a posterior inferior iliac spine, or d) points toward a sacroiliac extra-articular region, or e) points towards a sacroiliac joint anterior boundary segment3004, or f) points towards either superior boundary segment corner3014or3012or somewhere in-between; or, 2) the distal end of the implant generally lies within a) a caudal region of the sacroiliac joint articular region, or b) an extra-articular portion of the sacroiliac joint, or c) a cranial portion or cephlad region of the sacroiliac joint articular region.

Furthermore, in an aspect, an implant12may be inserted along a generally arcuate path. Accordingly, a surgical preparation technique and tools may be utilized while operating in an arcuate path. The implant arcuate path may follow and generally match the surgical preparation arcuate path and the path arc may include a radius of between approximately 3 cm to 6 cm. The portion of the path having an arcuate path including a radius of between approximately 3 cm to 6 cm may reside substantially in the plane of the sacroiliac joint or in a plane in close proximity and generally parallel thereto. Furthermore, the arcuate path may generally or substantially reside in sacroiliac joint articular region1044. Additionally, an implant may be selected for use during the procedure which substantially matches the radius or curvature of the arcuate or curved insertion path or surgical preparation path.

According to a particular aspect, after drilling or otherwise producing an opening through an ilium (or sacrum) leading toward or into a sacroiliac joint, a sleeve may guide (alone or along with another cannulated tool, e.g., a needle) a bone paste, bone marrow aspirate, stem cells, allograft or any biocompatible material or substance into the sacroiliac joint space via a path with a trajectory which may be generally transverse to the plane of the sacroiliac joint. The sleeve may be caused to form a seal with a bone defining the sacroiliac joint, e.g. the ilium. The seal may be created by impacting a proximal end of sleeve which may, for example, cause the sleeve to slightly penetrate the cortex of the outer table of the ilium. Alternatively, a cannulated tool such as a large gauge needle or tube may either be interference fit within a hole in the ilium or the needle or tube may have a threaded distal end which may be threaded into the bore formed in the ilium. A plunger or bone tamp may be forced through a sleeve to advance the bone paste or other material into the sacroiliac joint space, adjacent/around the implant and/or into the bone graft window of the implant.

Subsequently, an anchor such as a bone screw may be advanced via the sleeve into engagement with an opening formed in the ilium and driven across the sacroiliac joint and further into the sacrum. Alternatively, a bone plug may positioned into the opening formed in the ilium in order to occlude the passageway between the outer cortex of the ilium and the implanted bone paste or other material positioned which had be positioned generally in the plane of the joint.

As such, the systems and methods described herein are directed to preparing the sacroiliac joint for surgical fusion procedures of this type and others.

II. System for Preparing the Sacroiliac Joint for Fusion

Various surgical preparation tools and assemblies will be discussed herein. These tools and assemblies may be used by themselves or in combination with each other. Additionally, features of a particular embodiment are non-limiting and may be incorporated into any or all other embodiments without departing from the teachings in this disclosure.

A. Joint Preparation Tool with Interchangeable Heads

To begin a detailed discussion of the surgical preparation tools for preparing a sacroiliac joint for a fusion, reference is made toFIG. 6, which is an isometric view of a first embodiment of a joint preparation tool50with interchangeable tooling heads52. Each of the tooling heads52described herein may be used by themselves, with one or more subcomponents of tool50, with the completed tool50, or with any other tool of the systems disclosed herein or incorporated herein. As seen in the figure, the joint preparation tool50includes a slap hammer assembly54and a cutting tool assembly56. The slap hammer assembly54includes a proximal handle58that translates distal-proximal on a shaft60. The cutting tool assembly56includes a distal handle62. To better illustrate the components of the joint preparation tool50, reference is made toFIG. 7, which is an exploded side view of the tool50. As seen in the figure, a distal end64of the shaft60of the slap hammer assembly54is coupled to a proximal end66of a shaft68of the tooling head52via a connector70having dual-female threaded ports72. The distal end64of the shaft60and the proximal end66of the shaft68have thread features74that correspond and engage with the dual-female threaded ports72. In other embodiments, the connector70may include dual-male threaded ends and the shafts60,68may include corresponding female threaded ports. The distal handle62includes a lumen76extending through the handle62that is slightly larger than an outer diameter of the shaft68of the tooling head52. The distal handle62may be slidably positioned over the shaft68of the tooling head52and locked in place with a pair of set screws78. Thus, the distal handle62may be positioned as far proximally such that it abuts the connector70, as far distally so as not to interfere with the distal end of the tooling head52, or at any point in between.

Reference is now made toFIG. 8, which is an isometric and cross-sectional view of the first embodiment of the joint preparation tool50. As seen in the figure, the proximal handle58further includes a lumen80extending through the handle58that is slightly larger than an outer diameter of the shaft60of the slap hammer assembly54. The proximal handle58is configured to slide or translate distal-proximal on the shaft60between a proximal stop feature82and a distal stop feature84. In this way, a surgeon may grasp the distal handle62with one hand and the proximal handle58with the other hand. To facilitate distal driving of the tooling head52, the surgeon may distally slide the proximal handle until it makes contact with the distal stop feature84. The contact with the stop feature84will cause a force to be transmitted down the shaft68of the tooling head52such that head52will advance in the direction of the force. This type of driving of the tooling head52may be useful to advance a distal end86of the tooling head52into the sacroiliac joint.

Additionally, the proximal stop feature82may be configured such that an additional handle may be coupled to or integral with proximal stop feature82. The additional handle may be in-line with shaft60and extend proximally from the proximal stop feature82.

To facilitate backing-out of the tooling head52, the surgeon may proximally slide the proximal handle until it makes contact with the proximal stop feature82. This contact will cause a force to be transmitted proximally, which may aid in backing the tooling head52out from within the sacroiliac joint, for example.

As stated above, the first embodiment of the joint preparation tool50is configured to be used with a variety of interchangeable tooling heads52. In certain embodiments and referring toFIGS. 9A-9B, the tooling head52may include a cutting element88at the distal end86of the tooling head52. The cutting element88includes an aperture90at a distal most end of the tooling head52that extends between a distal edge92and a proximal edge94. The distal edge92forms a boundary of the aperture90and, in this embodiment, the distal edge92is blunt. Opposite the distal edge92is the proximal edge94, which, in this embodiment, is angled, sharp, and configured for cutting during “backing-out” of the preparation tool50from the sacroiliac joint.

In this embodiment, the aperture90is rectangular and is defined by a pair of generally parallel sidewall members102that extend generally tangentially from the surface of the shaft68of the tooling head52. Adjacent and extending generally perpendicular between the parallel sidewall members102is a top wall member104. Opposite the top wall member104is an inner wall member106that may communicate with an opened end of a lumen108that extends through the shaft68of the tooling head52. Additional tooling (e.g., guidewire, suctioning device, irrigation, a (centreless/shaftless/flexible/etc.) screw conveyor, an auger, Archimedes' screw, or their various combinations) may communicate through the lumen108for interaction with the portion of the patient's body in contact with the distal end86of the tooling head52.

A tooling head52with a cutting element88as described inFIGS. 9A-9Bmay be useful, for example, during the initial preparations of the sacroiliac joint. That is, the cutting element88may be initially and carefully advanced into the sacroiliac joint via the slap hammer assembly54. Once at an appropriate depth into the caudal region of the joint, the cutting element88may be more aggressively backed-out by the application of force by the proximal handle58against the proximal stop feature82. In this way, the force used to cut the articular cartilage is applied in the safer, proximal direction. Applying force distally requires care because advancement of the cutting element88too far (i.e., outside of the sacroiliac joint) can risk damage to, for example, the ventral sacroiliac joint ligament or the neurovascular structures in proximity to the joint.

Other arrangements of the cutting element88are possible and contemplated by this disclosure. For example, the distal edge92may be sharp and configured for cutting, while the proximal edge94may be blunt. Additionally and as seen inFIG. 10, which is an isometric view of the proximal edge94of the cutting element88, the side wall members102are parallel, but the top wall member104and, thus, the distal edge,92, the proximal edge94, and the aperture90are rounded. As seen in the figure, the proximal edge94is sharpened along its radial edge96and is configured to cut during a “backing-out” of the cutting element88.

Other arrangements of the top wall member104and side wall members102are possible. For example, the side wall members102may converge to a blade-like point. The particular arrangement of the top wall member104and side wall members102may be chosen based on the density of the boney surface to be prepared. And, as will be discussed later, the tool50may be used oriented perpendicular to the articular surfaces of the sacroiliac joint in order to make “keel-cuts” into the bone of either or both of the sacrum or the ilium. Such keel-cuts may match or generally match a shape of an implant to be implanted into the joint. Alternatively, the keel-cuts may be sized smaller than portions of an implant to be implanted into the joint such that a portion of the implant when implanted may extend beyond the keel-cut void and further into the prepared bone. Alternatively, a keel-cut may be created in only one bone, for example, the ilium, and may generally match the shape of an implant to be implanted while the second bone, e.g., the sacrum, may have no keel-cut or a keel-cut which is significantly undersized in comparison to the shape or size of the feature of the implant which is to be implanted into the sacrum. Thus, the shape of the top wall member104and the side wall members102may be influenced by the type and configuration of the implant that is chosen for the fusion procedure.

Referring now toFIG. 11, which is an isometric view of another embodiment of a tooling head52, the head52may include a curette-type closed distal end86and an opened proximal end98that defines a cup-shape. The tooling head52may include a pair of generally parallel side wall members102and a rounded top wall member104. A proximal edge94bounds the opened proximal end98and may or may not be sharpened. As best seen inFIG. 12, which is an isometric and cross-sectional view of the tooling head52, the tooling head52defines an inner cavity100that is configured to gather cartilage or other material when scooping or backing the distal end86of the tooling head52out of the sacroiliac joint. While not depicted in this embodiment, the tooling head52may include an opening in the vicinity of the cavity100that communicates with a lumen that extends through the shaft68of the tooling head52. In certain instances, it may be advantageous to use the cup-shaped tooling head52ofFIGS. 11-12to gather and remove biological material that was cut or abraded from the articular surfaces of the sacroiliac joint by the opened tooling head52ofFIGS. 9-10. In other instances, however, the closed tooling head52ofFIGS. 11-12may be used without previous preparation of the joint.

Referring now toFIG. 13, which is a side view of another embodiment of the tooling head52, the head52may include two cutting elements88opposite each other. Each cutting element88may be as described with reference toFIGS. 9A-9B,FIG. 10orFIGS. 11-12. In particular, each cutting element88includes parallel side wall members102, a top wall member104extending generally perpendicular between the parallel side wall members102, a distal edge92, a proximal edge94opposite the distal edge92, and an aperture90extending between the distal and proximal edges92,94. In this embodiment, the distal edge92is blunt and the proximal edge94is sharpened such that the tooling head52is configured to cut or abrade cartilage or other material in the sacroiliac joint during backing-out of the tooling head52from the joint. An arrangement with two cutting elements as shown inFIG. 13may be useful, for example, to prepare the plane of the joint as well as in making parallel side-cuts or keel-cuts into the surfaces of the ilium and sacrum. To prepare the plane of the joint, each of the cutting elements88may be oriented such that neither projects into the sacrum or the ilium. Rather, the cutting elements88are oriented vertically within the articular space. On the other hand, to prepare the sacrum and/or the ilium for a subsequent delivery of an implant, the cutting elements88may be oriented to project into the bone of the sacrum and ilium, and for example oriented perpendicularly with the plane of the joint such that the cutting elements protrude generally perpendicularly into the sacrum and the ilium to make cuts that match a shape of a portion of an implant that will be implanted in the joint.

Referring toFIG. 14A, which is a side view of a tooling head52, the shaft68may include a gradual taper from the proximal end66of the tooling head52to the distal end86. As seen in the figure, the shaft68extends along a straight longitudinal axis between the distal and proximal ends86,66. Other arrangements of the shaft68, however, are possible. For example and as seen inFIG. 14A, the shaft68may include a dogleg110along the shaft68. In this example, the distal and proximal ends86,66of the shaft68extend along parallel axes, but a mid-portion112of the shaft68extends non-parallel to the distal and proximal ends86,66. The dogleg110at the mid-portion112of the shaft68defines an angle A between the proximal end66and the dogleg110and an angle B between the dogleg110and the distal end86of the shaft68. Also, the proximal end66and distal end86may be offset by a distance D1, which, in certain instances, may be within a range of about 10 mm to about 25 mm or from about 15 mm to 70 mm. In certain embodiments, angle A may be within a range of about 90 degrees to about 165 degrees or from about 120 degrees and 150 degrees, and angle B may be within a range of about 90 degrees to about 165 degrees or from about 120 degrees and 150 degrees.

Referring toFIG. 14B, which is a close-up of the distal end86of the tooling head52, a distance D2 is defined between the top wall member104and an opposite radial edge114of the shaft68of the tooling head52. In certain instances, distance D2 may be within a range of about 4 mm to about 5.5 mm, from about 4.5 mm to about 6 mm, from about 5 mm to about 6.5 mm, from about 5.5 mm to about 8 mm, from about 7.5 mm to about 10 mm, from about 9 mm to about 11.5 mm and from about 11 mm to about 15 mm. A distance D3 is defined by a length of the top wall member and in certain instances D3 may be within a range of about 1.5 mm to about 2.5 mm, from about 2 mm to about 3.5 mm, from about 3 mm to about 4.75 mm, from about 4.25 mm to about 6 mm, from about 5 mm to about 6.75 mm, from about 5.5 mm to about 8 mm, from about 7.5 mm to about 10 mm, from about 9 mm to about 11.5 mm and from about 11 mm to about 15 mm. Angle C is defined between the shaft68of the tooling head52and the extension of the proximal edge94of the side wall member102. In certain instances, angle C may be within a range of about 15 degrees to about 35 degrees, from about 30 degrees to about 45 degrees, from about 40 degrees to about 65 degrees, from about 60 degrees to about 75 degrees, from about 70 degrees to about 100 degrees, from about 90 degrees to about 135 degrees, from about 120 degrees to about 155 degrees, from about 150 degrees to about 170 degrees, from about 160 degrees to about 175 degrees, and from about 170 degrees to about 180 degrees (e.g., substantially in-line with shaft68).

As stated above, the first embodiment of the joint preparation tool50is configured to be used with a variety of interchangeable tooling heads52. Additionally, the tooling heads52may be used independently from the joint preparation tool50. In certain embodiments and referring toFIGS. 15A-15D, the tooling head52may include an elongate shaft116coupled with an ellipsoidal head118at a distal end120of the tooling head52. A proximal end119of the tooling head52may include threading (not shown) in order to couple with the connector70of the joint preparation tool50described previously. In this embodiment, the ellipsoidal head118is a triaxial ellipsoid shape (semi-axes lengths C>B>A), however, the head118may be other shapes without departing from the teachings of this disclosure. As seen in the figures, the ellipsoid head118includes a rasp band122around one half of the circumference of the ellipsoid head118. The rasp band122may include a rough surface texture, or geometrically repeating or non-repeating pattern that is configured to abrade a boney surface of a patient (e.g., articular surface of the sacroiliac joint). In this particular embodiment, the rasp band122is a repeating cone-shaped pattern that is in the plane AB but is bounded on one side by axis A. While no rasp band122is depicted on the opposite side of the ellipsoid head118, such a side may include a similar or different type of rasp band122. For example, a less rough or “less aggressive” rasp band122may be included on the side opposite of the current rasp band122or simply on one half of the currently depicted rasp band122. In this way, the tooling head52may be used to simultaneously rasp two surfaces with different rasp bands122. In practice, such a tooling head52may be used to abrade the surfaces of the sacrum and the ilium in preparation for delivery of a joint implant. Since the sacrum is generally a softer bone than the ilium, the sacrum may require less abrasion than the ilium. Thus, the tooling head52with the ellipsoid head118having rasp bands122of differing roughness on opposite sides of the head118may be beneficial to rasp the illium with a rasp band122having greater roughness and the sacrum with a rasp band122having less or no roughness.

Reference is now made toFIGS. 16-17, which are isometric views of tooling heads52with bisected ellipsoidal heads124and bisected shafts126. The bisected ellipsoidal head124includes an ellipsoid shaped surface128on one side and a planar surface130opposite the ellipsoid shaped surface128. The planar surface130extends a length of the shaft126from a distal end to a proximal end120,119. InFIG. 16, the bisected ellipsoidal head124includes a small rasp band132on a portion of the intersection of the planar surface130and the ellipsoidal shaped surface128. In this embodiment, the small rasp band132includes a single row of teeth or other geometrically repeating pattern; however, the small rasp band132may include other surfaces configured to abrade or rasp a surface. InFIG. 17, the bisected ellipsoidal head124includes a rasp band134that is similar to that as described inFIGS. 15A-15D. That is, the rasp band134wraps around the entirety of the ellipsoid shaped surface128and includes a rough surface texture, or geometrically repeating or non-repeating pattern that is configured to abrade a boney surface of a patient (e.g., articular surface of sacroiliac joint). This type of tooling head52may be useful, for example, when a single surface of a pair of opposed surfaces requires rasping. As such, the tooling head52may be used, for example, to rasp the ilium only while orienting the planar surface130generally parallel with a plane defined by the sacrum. Alternatively, the tooling head52may be oriented to rasp the sacrum while orienting the planar surface130in-line with the ilium.

Moving on, the discussion will focus onFIGS. 18-23and additional types and configurations of tooling heads52that are applicable for use with the joint preparation tool50. Additionally and as discussed previously, the tooling heads52discussed herein may also be used independently from the joint preparation tool50.

Reference is now made toFIGS. 18A-18D, which depict a tooling head52with a planar rasping head136at a distal end138. The planar rasping head136is configured to prepare a joint or boney surface for subsequent delivery of an implant. More particularly, the planar rasping head136may be used to abrade or roughen a joint surface, such as the sacroiliac joint, by removing cartilage from the joint and causing the boney surface of the sacrum and the ilium to hemorrhage, which may contribute to subsequent bone growth and fusion of the sacrum and the ilium.

As seen in theFIGS. 18A-18B, the planar rasping head136is coupled to a shaft140that extends to a handle142at a proximal end144of the shaft140. A proximal end146of the handle142includes an impact plate148that is configured to be struck with a hammer, mallet, or other device in order to drive the planar rasping head136distally. While this embodiment is depicted with a handle142attached to the proximal end144of the shaft140, the shaft140could, alternatively, be coupled to the connector70of the joint preparation tool50described previously.

As seenFIGS. 18A-18D, the planar rasping head136is a planar member that includes a pair of planar surfaces150opposite of and generally parallel to each other. Alternatively, the pair of planar surfaces150may be non-parallel (not shown) and may taper. The planar surfaces150are disposed between a side edge152that wraps around the planar rasping head136. A distal tip158of the planar rasping head136is rounded, although, in other embodiments, the distal tip may be pointed, flat, or otherwise. The planar rasping head136includes a rasping surface154on the planar surfaces150and the side edge152. The rasping surface154may include ridges156in a chevron pattern, as seen in the figures, or other surfaces configured to roughen or abrade a biological surface. The rasping surface154may, for example, include geometrically repeating or non-repeating features (e.g., cones, pyramids, bubbles, spines, notches, teeth) formed by machining, surface treating, or otherwise.

As seen inFIG. 18A, the planar rasping head136may include a width W18 in a range of about 13 mm to about 19 mm. In certain instances, the width W18 may be 13 mm, 16 mm, or 19 mm. As seen inFIG. 18B, the planar rasping head136may include a thickness T18 between the planar surfaces150in a range of about 5 mm to about 7 mm. In certain instances, the thickness T18 may be 5 mm, 6 mm, or 7 mm.

Moving on, reference is made toFIGS. 19A-19D, which depict a tooling head52with a planar rasping head160at a distal end162of the tooling head52that includes a single perpendicularly extending cutting element164. The planar rasping head160is a planar member that includes a planar top surface166, a planar bottom surface168opposite the top surface166, and a side edge186extending between the top and bottom surfaces166,168. The distal end162of the rasping head160includes a double chamfered tip184. Both the top and bottom surfaces166,168and the side edge168include a rasping surface170that is configured to abrade or roughen a boney surface or a joint. The rasping surface170may include a series of ridges172in a chevron pattern or otherwise, as described previously. The tooling head of this embodiment may also include a handle142, an impact plate148, and a shaft140, among other features, as described in previous embodiments.

As seen in the figures, the cutting element164extends generally perpendicularly upward from a central portion of the top surface166. The cutting element164is a planar member with opposite side surfaces174and a top surface176that includes a cutting element feature178, which, in this embodiment, includes a series of teeth180with a rounded blade-tip182at the distal most end. The planar rasping head136is configured to prepare a joint or boney surface for subsequent delivery of an implant. More particularly, the bottom surface168of the planar rasping head136may be used to abrade or roughen a joint surface, such as the sacroiliac joint, by removing cartilage from the joint and causing the boney surface of the sacrum and the ilium to hemorrhage, which may contribute to subsequent bone growth within the joint space. The top surface166with the cutting element164, on the other hand, may be used to cut into either the sacrum or the ilium in order to make way for a portion of an implant (e.g., keel or wing member) that will protrude into the bone of the sacrum or ilium. As previously described with reference toFIG. 5, an implant may include keels that extend generally perpendicularly into each of the ilium and the sacrum. Thus, a tooling head52such as seen inFIGS. 19A-19Dmay be useful in preparing a “keel-cut” into either or both of the sacrum or ilium such that when the implant12is delivered into the sacroiliac joint, the keels may be delivered and positioned within the keel-cuts made by the tooling head52with the planar rasping head160with the perpendicularly extending cutting element164. While the tooling head52is described with a single perpendicularly extending cutting element164, the head52may include a second cutting element (not shown) extending opposite the first cutting element164on the bottom surface168of the rasping head160. In this way, the tooling head52may perform dual keel-cuts simultaneously in both the sacrum and the ilium. In such an embodiment, the cutting element feature178may be different for each cutting element164since the ilium is a generally harder bone than the sacrum, which is generally softer.

As seen inFIG. 19A, the planar rasping head160may include a width W19 in a range of about 11 mm to about 17 mm. In certain instances, the width W19 may be 11 mm, 14 mm, or 17 mm. Also seen inFIG. 19A, the cutting element164may include a thickness T19A of about 2.5 mm. As seen inFIG. 19B, the planar rasping head160may include a thickness T19B between the planar surfaces166,168in a range of about 5 mm to about 7 mm. In certain instances, the thickness T19B may be 5 mm, 6 mm, or 7 mm. Also as seen inFIG. 19B, the planar rasping head160and the cutting element164may have a combined thickness TC19B in a range of about 5.5 mm to about 7.5 mm. In certain instances, the combined thickness TC19B may be about 5.5 mm, 6.5 mm, or 7.5 mm.

Moving on, reference is made toFIGS. 20A-20C, which depict a tooling head52with a planar rasping head160at a distal end162of the tooling head52that includes a single perpendicularly extending cutting element164. This embodiment includes similar features to the tooling head52described in reference toFIGS. 19A-19D, except that the present embodiment includes a smooth surface188instead of a rasping surface on the top surface, bottom surface, and side edges166,168,186. The present embodiment of the tooling head52may be useful in a surgical preparation when the articular surfaces of the sacroiliac joint need not be rasped, but merely require keel-cuts into the sacrum and/or the ilium in preparation for delivery of an implant.

Reference is now made toFIGS. 21A-21C, which depict a tooling head52with a planar rasping head190with a pair of perpendicularly extending cutting elements192extending from side edges194of the head52. In this embodiment, the planar rasping head190is a planar member that includes a planar top surface196, a planar bottom surface198opposite the top surface196, both of which include a smooth surface texture200. The planar rasping head190also includes a double chamfered tip202at a distal end204of the rasping head190. Tip202may terminate distally in-line with the chamfered tip of cutting element216. Alternatively, tip202may extend a distance distally beyond the distal most portion of the chamfered tip of cutting element216, for example, said distance may be from about 1.5 mm to about 2.5 mm, from about 2 mm to about 3.5 mm, from about 3 mm to about 4.75 mm, from about 4.25 mm to about 6 mm, from about 5 mm to about 6.75 mm, from about 5.5 mm to about 8 mm, from about 7.5 mm to about 10 mm, from about 9 mm to about 11.5 mm and from about 11 mm to about 15 mm which may permit placement of a tip202within the plane of the joint thereby aligning cutting elements192to project toward or into the bone of the sacrum or ilium. Each of the cutting elements192includes an inner surface206that faces the smooth surface texture200, an outer surface208opposite the inner surface206that is smooth and lies flush with the side edge194, and a top surface210that includes a cutting element feature212that includes a series of teeth214. A distal end of the cutting elements192includes a chamfered tip216. Additionally, the tooling head52of the present embodiment may have similar features as described in the previous embodiments. The dimensions of the present embodiment may be similar to that as described in reference toFIGS. 19A-19D.

Such a tooling head52with a pair of cutting elements192may be used to perform dual keel-cuts in either or both of the ilium and sacrum for delivery of an implant with dual keels such as described in U.S. patent application Ser. No. 14/447,612, filed Jul. 31, 2014 and entitled SYSTEMS FOR AND METHODS OF FUSING A SACROILIAC JOINT, which is hereby incorporated by reference in its entirety. To prepare the sacroiliac joint for delivery of a dual keel implant, the tooling head52with the pair of cutting elements192may be inserted into the sacroiliac joint of a patient with the cutting elements oriented towards the ilium, for example, and the tooling head52may be advanced distally in the caudal region of the joint such that the cutting elements192cut into the boney surface of the ilium. Once at a far end of the caudal region, the tooling head52may be proximally withdrawn and repeated if desired. After sufficiently cutting into the ilium, the tooling head52may be withdrawn from the joint. Next, the tooling head52may be rotated one hundred and eighty degrees such that the cutting elements are oriented towards the sacrum. The tooling head52may then be advanced into the sacroiliac joint and make keel-cuts into the sacrum as described previously with reference to the ilium. Once the tooling head52is removed from the joint, the implant may then be delivered into the joint such that the implant keels are positioned within the keel-cuts made with the cutting elements192of the tooling head52.

Continuing on, reference is made toFIGS. 22A-22D, which depict a tooling head52with a planar rasping head190at a distal end204of the tooling head52that includes a pair of perpendicularly extending cutting element192. This embodiment includes similar features to the tooling head52described in reference toFIGS. 21A-21C, except that the present embodiment includes a rasping surface218instead of a smooth surface on the top and bottom surface196,198of the rasping head190. The rasping surface218may be as described previously and may include a series of ridges220in a chevron pattern. A planar rasping head190of this embodiment may be useful for simultaneously rasping the intra-articulating surfaces of the sacroiliac joint to remove cartilage or abrade the boney surfaces and make dual keel-cuts into either the sacrum or the ilium for the subsequent delivery of an implant having similarly featured keels.

Reference is now made toFIGS. 23A-23D, which depict a tooling head52with a box osteotome head222. As seen in the figures, the box osteotome head222includes a planar top member224, a planar bottom member226generally parallel to and opposite of the planar top member224, a pair of side members228that extend generally perpendicularly between the top and bottom members224,226, and a pair of coaxially aligned openings230in the top and bottom members224,226. In this embodiment, the openings230are bounded by four edges236; however, the configuration of the openings230may include a different number of edges236and shapes. The box osteotome head222defines a cavity232therein that is bounded by inner surfaces242of the top, bottom, and side members224,226,228. The cavity232is open on a distal end234of the box osteotome head222. A distal edge of the distal end234of each of the top, bottom, and side members224,226,228form a curved cutting edge238that includes an inward bevel240such that outer surfaces244of the members224,226,228extend further distally than the inner surfaces242.

As seen in the figures, the tooling head52additionally includes a shaft246that is four-sided, a handle248coupled to a proximal end250of the shaft246, and an impact plate252at a proximal end254of the handle248. The tooling head52of this embodiment may additionally include features as described in the previous embodiments without limitation.

The box osteotome head222may be useful in a surgical procedure where a section of bone or cartilage is to be removed. The box osteotome head222may be distally advanced into the sacroiliac joint and bone and/or cartilage in contact with the cutting edge238will be cut and urged via the inward bevel240within the cavity232. After an appropriate cut has been made, the box osteotome head222may be proximally removed from the joint space and the biological material within the cavity232may be removed through one or both of the coaxially aligned openings230in the top and bottom members224,226. The box osteotome head222may be used with the joint preparation tool50, as described previously, or independently.

As seen inFIG. 23A, the box osteotome head222may include a width W23 in a range of about 13 mm to about 19 mm. In certain instances, the width W23 may be 13 mm, 16 mm, or 19 mm. As seen inFIG. 23B, the box osteotome head222may include a thickness T23 between the outer surfaces244of the top and bottom members224,226in a range of about 5 mm to about 7 mm. In certain instances, the thickness T23 may be 5 mm, 6 mm, or 7 mm.

With reference toFIG. 23C, the shape of cavity232may generally match the shape of the implant which may be subsequently implanted into the void created by the head222. In certain aspects, the cross sectional shape and dimensions of the cavity232may substantially match the corresponding cross sectional shape and dimensions of the implant to be implanted at the joint in the void created by head222.

B. Joint Preparation Tool with Anchoring Arm

Reference is now made toFIG. 24A, which is a side view of a first embodiment of a joint preparation tool256attached to an anchoring arm assembly258. The anchoring arm assembly258may be similar to as described in U.S. patent application Ser. No. 14/447,612, mentioned previously, and hereby incorporated by reference in its entirety. The joint preparation tool256may be similar to those described previously and may include a tooling head260as also described previously. As seen inFIG. 24A, the tooling head260includes a rasping head284with a pair of perpendicularly extending cutting elements262extending from side edges of the head260. The tooling head260is attached to a handle286at a proximal end of the tool256. Regarding the anchoring arm assembly258, it includes an extension member264that extends from the joint preparation tool256. A distal portion of the extension member264includes a pair of guide collars272that are configured to securely support and position an anchoring tool274. The anchoring tool274includes a tubular shaft276that is secured within the guide collars272via a set screw278. The anchoring tool274further includes a rotationally engaged handle280at a proximal end of the tool274that is configured to rotationally extend and retract an anchoring element282that is coupled to a distal portion of the tool274. The anchoring arm assembly258is configured to orient the anchoring element282in a single orientation relative to the rasping head284. That is, the anchoring arm assembly258or, more particularly, the orientation of the guide collars272relative to the rasping head284is fixed and nonadjustable once the anchoring arm assembly258is affixed to the joint preparation tool. In this and other embodiments, the orientation of the anchoring element282may be such that, when delivered into the joint space, the anchoring element282will be positioned cranial (above) to the rasping head284, caudal (below) to the rasping head284, or in-line with and distally of the rasping head284.

Turning toFIG. 24B, reference is made to a pre-assembled state of the joint preparation tool256and the anchoring arm assembly258. As seen in the figure, the extension member264is coupled to and extends from a sleeve266that includes a lumen extending therethrough. The sleeve266is configured to receive a shaft268of the joint preparation tool256through the lumen. The sleeve266may be secured to the joint preparation tool256by any type of fastening mechanism such as, for example, corresponding threading on the sleeve266and a proximal portion270of the shaft268of the tool256. The rasping head284may be fixed to the shaft268of the joint preparation tool256or the head284may be releasably coupled to the shaft268.

Moving on to another embodiment of a joint preparation tool256attached to an anchoring arm assembly258, reference is made toFIG. 25. The joint preparation tool256is identical to the tool256ofFIGS. 24A-24B. The anchoring arm assembly258of the present embodiment is similar to the assembly258inFIGS. 24A-24B, except that the assembly258in the present embodiment includes a trio of guide collars272. Each guide collar272is configured to orient a tool (not shown) in a specific trajectory T1, T2, T3 relative to the rasping head284of the joint preparation tool256. T1 may, for example, orient an anchoring tool, as described previously, to deliver an anchor element cranial to the rasping head284. T2 may, for example, orient an anchoring tool to deliver an anchor element distally, in-line with the rasping head284. T3 may, for example, orient an anchoring tool to deliver an anchor element caudal to the rasping head284. T2 may alternatively orient an anchoring tool to deliver an anchor element in-line with and towards a central portion of the rasping head284. In such an orientation, the rasping head may include an opening (not shown) on its planar surface that extends proximally from a distal edge of the rasping head284such that the rasping head284is pronged or fork-shaped. While the anchoring arm assembly258is described as coupling to an anchoring tool that delivers an anchoring element that may be a screw, the assembly258may couple with other types of tools. For example, the guide collars272may couple with a syringe barrel that delivers a bone paste or other biomaterial into the joint space to facilitate fusion of the boney surfaces of the joint.

While the anchor arm assemblies258of the various embodiments are described with reference to a joint preparation tool with a shaft attached with a handle at a proximal end of the tool, the anchor arm assemblies258may be used with other embodiments of the joint preparation tool. For example, the anchor arm assemblies258may be coupled with the joint preparation tool50with the slap hammer assembly54as described previously.

In another aspect, for example as shown and described in U.S. Provisional Patent Application 61/860,185, the anchor arm assembly258may be provided in the form of two or more linked structural elements thereby providing an adjustable elongate shape. For example, anchor arm assembly258may be telescoping and may include a first section ending in the first arm end and a second section ending in the second arm end; both sections may have matched circular arc shapes with a common center.For example,FIG. 56AandFIG. 56Bare side views of a telescoping anchor arm assembly258. Referring toFIG. 56A, the anchor arm assembly258may include a first section4102ending in a first arm end3802and a second section4104ending in a second arm end3804; both sections4102and4104may have matched circular arc shapes with a common center4110as illustrated inFIG. 56A. In an aspect, the second section4104may have a hollow cross-section with a central lumen (not shown), and the first section4102may he shaped and dimensioned to fit within the central lumen by sliding along the arc length of the second section4104,FIG. 56Billustrates the anchor arm assembly258with a portion of the first section4102nested within the central lumen of the second section4104, resulting in a shorter elongate shape. The second section4104includes the second arm end3804as well as a sliding attachment fitting4106at an end of the second section4104opposite to the second arm end3804. The sliding attachment fitting4106may slide along the first section4102to adjust the relative position of the first arm end3802and second arm end3804as illustrated inFIG. 56B. The elongate shape of the anchor arm assembly258and the sliding attachment fitting4106may he locked into a fixed position using a locking mechanism including, but not limited to, a set screw4108as illustrated inFIG. 56A. Any other known locking mechanism may be used to lock the adjustable anchor arm assembly258into a locked position including, but not limited to clamps, pegs, compression fittings, and any combination thereof. In this aspect, the shorter elongate shape illustrated inFIG. 56Bmay result in a change in the angle4112between the anchor element18and/or anchoring tool274and the implant12and/or tooling head260. The adjustability of the anchor arm assembly258may further facilitate fine-tuning the entry paths of the various components during formation of the implant assembly14, or delivery of the anchor element18relative to the tooling head260, to account for variability in patient morphology and/or to avoid injury to vulnerable tissues including, but not limited to, nerves and/or blood vessels.

In an aspect, the second section may have a hollow cross-section with a central lumen, and the first section may be shaped and dimensioned to fit within the central lumen by sliding along the arc length of the second section. A portion of the first section may be nested within the central lumen of the second section, resulting in a shorter elongate shape. The second section includes the second arm end as well as a sliding attachment fitting at an end of the second section opposite to the second arm end. The sliding attachment fitting may slide along the first section to adjust the relative position of the first arm end and second arm end. The elongate shape of the anchor arm assembly258and the sliding attachment fitting may be locked into a fixed position using a locking mechanism including, but not limited to, a set screw. Any other known locking mechanism may be used to lock the adjustable anchor arm assembly258into a locked position including, but not limited to clamps, pegs, compression fittings, and any combination thereof. In this aspect, the shorter elongate shape may result in a change in the angle between the anchor and/or anchor guide and the implant body and/or implant guide. The adjustability of the anchor arm assembly258may further facilitate fine-tuning the entry paths of the various components during placement of the one or more anchors to account for variability in patient morphology and/or to avoid injury to vulnerable tissues including, but not limited to, nerves and/or blood vessels.

In other aspects, the anchor arm assembly258includes a straight horizontal segment and a straight vertical segment. The vertical segment includes the second arm end as well as a sliding attachment fitting at an end of the vertical segment opposite to the second arm end. The sliding attachment fitting may slide in a horizontal direction along the horizontal segment to adjust the relative position of the first arm end and second arm end. The position of the sliding attachment fitting may be locked into place using any known locking mechanism described previously above including, but not limited to, a set screw.

In various other aspects, the anchor arm assembly258may be made adjustable by the incorporation of any other adjustable elements known in the art. Non-limiting examples of suitable adjustable elements include: two or more hinged or jointed subsections of the anchor arm assembly258, two or more telescoping subsections of the anchor arm assembly258, one or more bendable subsections of the anchor arm assembly258having limited deformability, and any combination thereof. In other additional aspects, different sizes of fixed-geometry anchor arm assembly258may be used to provide a suitable range of installation tool geometries to account for differences in patient morphologies, differences in orthopedic surgical procedures, and any other variable factor governing the selection of an anchor arm assembly258geometry.

C. Joint Preparation Tool with Translating and Rotation Inhibiting Distal Handle Assembly

Reference is now made toFIG. 26A, which is a side isometric view of a joint preparation tool800having a proximal handle802and a distal handle assembly804that is slideably attached to a shaft806of a tooling head808. The distal handle assembly804is configured to translate on the shaft806along a set trajectory that inhibits rotation of the handle assembly804relative to the proximal handle802and shaft806. The tooling head808may be similar to the various embodiments previously described and the joint preparation tool800may be configured to couple with any of the tooling heads described herein. In this embodiment, there is a cutting element812at a distal end810of the tooling head808. Referring to the distal handle assembly804, it includes a coupler member816that releasably secures to the shaft806of the tooling head808. Proximal to the coupler member816is a handle818that is coupled to the coupler member816via an adjustable socket assembly820.

With continuing reference toFIG. 26A, the joint preparation tool800may be further configured to have an indicator803coupled to or integral with a component (e.g., the proximal handle802) of the joint preparation tool800. The indicator803may indicate a position or orientation of the cutting element812when the cutting element is positioned out of view of the surgeon (e.g., in a joint space). Alternatively, an indicator803may be fixed to a portion of the patient's skeleton to act as a reference during the course of the procedure. The indicator803may be configured as a body visible to a human user during the course of employing the joint preparation tool800or one of its components. Additionally, the body may be configured to be visible to a user while using fluoroscopy or CT scan (e.g., the body may comprise a material which is radiopaque) or be identifiable by an O-arm® Surgical Imaging System from Medtronic or similar device or a StealthStation® S7® surgical navigation system by Medtronic which has both optical and electromagnetic tracking options, or a StealthStation i7′™ also by Medtronic. The indicator803may be used as a reference guide when directly viewed by the human user or when identified by a computer, surgical robot or imaging system. According to an aspect, the indicator803may be a reference array and may include 3 or 4 balls supported in a predetermined spaced apart arrangement and connected to one another by a frame. The frame may be coupled to a component of the tool800or may be separately coupled to a portion of the patient's skeleton or may be coupled to a delivery tool16of a system10.

In another aspect, the indicator803may indicate the position of the cutting element812supported by the tooling head808when the tooling head808may be obscured from view by the patient's soft tissues, by the positioning of the tooling head808within the joint, or by aspects of the operating environment which may otherwise obfuscate the arrangement or position of elements of the various components of the joint preparation tool800. For example, the indicators803may be elongate cylinders extending radially from a proximal handle802(or shaft of a tooling head806) longitudinal axis and projecting towards one or more outer cutting blades. In an aspect, the indicators803(when coupled to the tool800) have a longitudinal axis which is parallel to a cutting element axis which is defined as being coincident with the tooling head axis and also coincident with a point along a tip of an outer cutting blade856.

As such, the indicator803may permit a surgeon to align an outer cutting blade with the bone of an ilium and a second outer cutting blade with the bone of the sacrum. Alternatively or additionally, an indicator803may permit a surgeon to align an outer cutting blade856to be generally in-line with a plane of a sacroiliac joint.

As seen inFIG. 26B, which is a cross-sectional view of the coupler member816of the distal handle assembly804and the shaft806of the tooling head808, the shaft806is hexagonal and includes six outer surfaces840that are configured to matingly slide within and against matching inner surfaces814of the coupler member816. The inner surfaces814of the coupler member816are hexagonal and sized slightly larger than the six outer surfaces840of the shaft806in order to facilitate sliding of the distal handle assembly804relative to the shaft806. As seen in the figure, the coupler member816includes two sections that are held together by fasteners (e.g., bolt, screw)822. In this way, the coupler member816is releasably secured to the shaft806via the fasteners822. And, when the coupler member816is secured to the shaft806, the coupler member816, along with the socket assembly820and the handle818, are in a fixed position relative to the tooling head808and the proximal handle802. That is, the distal handle assembly804may translate on the shaft806of the tooling head808, but the distal handle assembly804may not rotate relative to the shaft806.

In one aspect, coupler member816may be caused to disengage matching inner surfaces814from outer surfaces840of the shaft806such that rotation between shaft806and coupler member816may be permitted. For example, coupler member816may be distally displaced relative to shaft806such that surfaces814and840disengage and then coupler member816may be rotated relative to shaft806to a different desired position and then coupler member816may be proximally displaced relative to shaft806such that inner surfaces814reengage the outer surfaces840.

Reference is now made toFIG. 26C, which is an isometric front view of the joint preparation tool800with the distal handle assembly804in an exploded view. As seen in the figure, the socket assembly820is releasably secured to the coupler member816via a fastener824that is fitted within a passageway826through a socket member828of the socket assembly820. The fastener824may be threaded and may engage with corresponding threads in the coupler member816. The socket member828is coupled to the handle at a proximal end830of the socket member828and includes a socket opening832at a distal end834of the member828. The socket opening832leads to the passageway826and includes a six-sided inner surface836that may be engaged with a matching male-end of a six-sided member838on the coupler member816. As such, the socket member828may engage with and be secured to the six-sided member838in one of six orientations such that the handle818extends at differing orientations relative to the shaft806of the tooling head808and the proximal handle802. This adjustability may be useful for a surgeon to appropriately position the handle818for a particular surgical procedure.

The present embodiment of the joint preparation tool800with a translating and rotation inhibiting distal handle assembly804may be useful to prevent inadvertent rotating of the cutting element812out of a desired cutting trajectory. For example, since the ilium is generally a harder bone than the sacrum, there may be a tendency for the cutting element812to deflect from being driven into the ilium by twisting into the joint space where this is less resistance. Such twisting of the tooling head808may be damaging to the patient and may inaccurately prepare the joint surfaces for fusion.

In operation, the cutting element812at the distal end810of the tooling head808may be distally driven into a joint (e.g., sacroiliac joint) while a surgeon controls the trajectory of delivery. More particularly, a surgeon may grasp the handle818of the distal handle assembly804with one hand and the proximal handle802with the other hand. At this initial stage, the joint preparation tool800may be oriented as shown inFIG. 26A, which depicts the distal handle assembly804in a distal position. The surgeon may then urge the proximal handle802distally while maintaining a stabilizing force on the distal handle assembly804. As the cutting element812is urged into the joint, the distal handle assembly804may displace proximally relative to the shaft806of the tooling head808as the surgeon maintains the stabilizing force on the assembly804. At this stage of the procedure, the joint preparation tool800may be oriented as shown inFIG. 26D, which depicts the distal handle assembly804in a proximal position. In this way, the stabilizing force exerted on the distal handle assembly804ensures that the cutting element812is not caused to inadvertently rotate out of alignment during the delivery of the head808into the joint space.

Additionally, the coupler member may house a brake shoe which in turn may carry a brake block or pad. The brake shoe may be coupled to a brake caliper. The brake caliper may be manipulated by a user acting upon a lever which may be configured with an ergonomic lever handle and which may be coupled to the distal handle assembly804. Such a braking system may resist longitudinal and rotational forces between shaft806and coupler member816.

Moving on, reference is made toFIG. 26E, which is an up-close side view of the cutting element812. As seen in the figure, the cutting element812includes a central cutting blade or central guide842and a pair of outer cutting blades844. The cutting element812also includes a front and back wall member846that extends between and couples the outer cutting blades844with the central cutting blade842. The front and back wall members846may include a distal beveled edge848extending between the outer cutting blades844.

Referring toFIG. 26F, which is a cross-sectional side view of the cutting element812, it can be seen that the shaft806of the tooling head808tapers into the central cutting blade842. In between opposite sides of the central cutting blade842and the outer cutting blades844are passageways850that extend from the distal beveled edge to a proximal edge852of the cutting element812. In operation, as the cutting element812is distally advanced within a joint space articular cartilage and/or bone may be cut with the distal beveled edge848and the central and outer cutting blades842,844such that the severed bone/cartilage is caused to funnel through the passageway850to make way for additional bone/cartilage to be cut.

Such a cutting element812may be oriented within the joint plane or perpendicular to the joint plane. When oriented perpendicular to the joint plane, one of the outer cutting blades844may be positioned to cut the ilium and one of the outer cutting blades844may be positioned to cut the sacrum while the central cutting blade is positioned within the plane of the joint. Thus, as the tool800is distally advanced the cutting element812may make keel cuts into the sacrum and the ilium. The distal handle assembly804, as discussed previously, may be useful to provide a stabilizing force that ensure the cutting element812does not inadvertently twist or rotate given the differences hardness of the sacrum and ilium.

The cutting element812may be modified, as inFIG. 26G, to include an elongated central cutting blade842. Such a cutting element812may be useful when the cutting element is oriented perpendicular to the joint plane, as described previously, in that the elongated central cutting blade842may urge the cutting element812to stay within the joint plane as opposed to easily cutting into one of the boney surfaces of the joint. The tip854of the elongated central cutting blade842may be blunt to further urge the central cutting blade842to remain within the joint plane.

As seen inFIG. 26G, sample dimensions of the cutting element812may be as follows. The outer cutting blades may extend a distance D4 from the distal edge848to a distal tip856of about 0 mm to about 1.75 mm, from about 1.5 mm to about 2.5 mm, from about 2 mm to about 3.5 mm, from about 3 mm to about 4.75 mm, from about 4.25 mm to about 6 mm, from about 5 mm to about 6.75 mm, from about 5.5 mm to about 8 mm, from about 7.5 mm to about 10 mm, from about 9 mm to about 11.5 mm, and from about 11 mm to about 13 mm. In certain embodiments, the distance D4 may be about 1 mm, 3 mm, or 5 mm. The elongated central portion842may extend a distance D5 from the distal edge848to the tip854of about 3 mm to about 4.75 mm, from about 4.25 mm to about 6 mm, from about 5 mm to about 6.75 mm, from about 5.5 mm to about 8 mm, from about 7.5 mm to about 10 mm, from about 9 mm to about 11.5 mm, from about 11 mm to about 13 mm, and from about 12.5 mm to about 15 mm. In certain embodiments, the distance D5 may be about 5 mm, 6.5 mm, or 8 mm. The elongated central portion842may extend a distance D6 beyond that of the distal tips856of the outer cutting blades by about 3 mm to about 15 mm. In certain embodiments, the distance D6 may be about 5 mm, 6.5 mm, or 8 mm. A distance D7 between the distal and proximal edges848,852may be about 1.5 mm to about 2.25 mm, from about 2 mm to about 3.5 mm, from about 3 mm to about 4.75 mm, from about 4.25 mm to about 6 mm, from about 5 mm to about 6.75 mm, from about 5.5 mm to about 8 mm, from about 7.5 mm to about 10 mm, from about 9 mm to about 11.5 mm, from about 11 mm to about 13 mm, and may even range up to 40 mm-60 mm. In certain embodiments, the distance D7 may be 3.5 mm, 7.5 mm, 15 mm, 30 mm 40 mm or 45 mm. A distance D8 may be defined between one of the outer cutting blades844and the elongated central cutting blade842. D8 may be in a range of about 2.25 mm to about 2.75 mm, from about 2 mm to about 3.5 mm, from about 3 mm to about 4.75 mm, from about 4.25 mm to about 6 mm, from about 5 mm to about 6.75 mm, from about 5.5 mm to about 8 mm, from about 7.5 mm to about 10 mm, from about 9 mm to about 11.5 mm, from about 11 mm to about 13 mm. In certain embodiments, the distance D8 may be about 6 mm, 8 mm, or 10 mm.

While the cutting element is shown inFIGS. 26E-26Gas including a certain configuration of cutting blades, other arrangements are possible and contemplated herein. For example, a cutting element812may include serrated cutting blades and may include additional or fewer cutting blades than are depicted in the figures. In one aspect, there may be four passageways850arranged into two pairs. The first pair may be arranged such that the first and second passageways are positioned and aligned relative to one another similar to the configuration inFIGS. 26F-26Gsuch that a back wall member846of the first passageway is generally coplanar with a back wall member846of the second passageway and forming a first plane. The second pair of passageways850may also have a relationship between each of the second pair passageways850similar to the first and second passageways of the first pair of passageways such that a back wall member846of the first passageway of the second pair is generally coplanar with a back wall member846of the second passageway of the second pair and forming a second plane. The second pair of passageways may be arranged relative to the first pair of passageways such that the first plane formed by the first pair of back wall members is generally perpendicular to the second plane formed by the second pair of back walls.

D. Joint Preparation Tool with Trial Fit Implant and Cutting Tool with Translating Cutting Element

The discussion of preparing the sacroiliac joint, among other joints, for implant delivery will now focus on additional tools that may be used independently from or in combination with the previously mentioned tools.

1. Trial Fit Assembly and Cutting Tool with Offset Shafts

To begin, reference is made toFIG. 27, which is an isometric side view of a joint preparation tool assembly300that is configured to test-fit an implant size and make a transverse cut into either or both the sacrum and ilium to make way for a keel of an implant that is configured to extend into the bone. As seen in the figure, the joint preparation tool assembly300includes a trial tool assembly302and a cutting tool304that is configured to translate relative to the trial tool assembly302in order to make the transverse keel-cuts into the patient's bone.

The trial tool assembly302includes an implant trial306at a distal end308of the assembly302. The implant trial306is a planar member with a tapered tip310that includes a width312that corresponds with a width of an implant that may be subsequently delivered into a joint. The implant trial306may be removably coupled with a shaft314that extends proximally. The shaft314is removably attached to a handle assembly316at a proximal end318of the shaft314. The handle assembly316includes a coupler320configured to removably attach to the shaft314of the trial tool assembly302. The coupler320is attached to a handle shaft410that extends to a gripping handle322.

As mentioned previously, the implant trial306is used to gauge the size of the joint space so that an implant size may be chosen that best fits the joint space. Thus, the system described herein may include implant trials306of various sizes and configurations in order to gauge the size of the joint space. In operation, a surgeon may begin a surgical procedure by test-fitting the smallest size of implant trial306into the patient's joint to determine the fit. If the size of the implant trial306is too small, then the surgeon may remove the implant trial306and deliver a larger size implant trial306into the joint. Once an appropriate size of implant trial306is received within the joint, the surgeon may use the cutting tool304to deliver transverse keel-cuts into the boney surfaces in preparation for the implant delivery.

The cutting tool304is slidably coupled to the shaft314of the trial tool assembly302and configured to slide distal-proximal on the shaft314. The cutting tool304is slidably coupled to the shaft314via a distal and a proximal collar324that extend around the shaft314of the trial tool assembly302. The collars324are separated by a gap and are attached to a cutting tool shaft326that extends proximally. The cutting tool shaft326includes a curved mid-portion328such that the shaft326angles away from the shaft314of the trial tool assembly302. A proximal end330of the cutting tool shaft326includes an impact plate332that is configured for being hit with a hammer or similar device to drive the cutting tool304distally. In this way, the surgeon may securely hold the handle322of the trial tool assembly302with one hand and strike the impact plate332with the other hand.

Reference is now made toFIG. 28, which is an isometric view of an opposite side of the joint preparation tool assembly300. As seen in the figure, a distal end334of the cutting tool304includes a cutting element336that extends within a guide338formed in a top surface340to the tapered tip310of the implant trial306when the cutting element336translates relative to the implant trial306. A distal tip344of the cutting element extends to the tapered tip310of the implant trial306when the shaft326of the cutting tool304abuts a proximal end346of the implant trial306. The cutting tool304is configured to maintain an orientation relative to the guide338when the cutting element336is proximally retracted or distally extended towards the guide338via a channel342formed in the shaft314of the trial tool assembly302.

For a detailed discussion of the cutting tool304, reference is made toFIGS. 29-30, which are isometric views of the cutting tool304. As seen inFIG. 29, the cutting tool304includes a protrusion348on each inner surface350of the collars324that extend around the shaft314of the trial tool assembly302. The protrusion348is configured to fit within the channel342formed in the shaft314of the trial tool assembly302such that the shaft314cannot rotate when the protrusion348is fitted within the channel342. Reference is now made toFIG. 30, which is a close-up view of the distal end334of the cutting tool304. As seen in this figure, the protrusion348is semi-hemispherical and extends a length of the collars324. Other shapes for the protrusion348are possible and contemplated herein.

Turning to the distal end334of the cutting tool304and still referring toFIG. 30, the cutting element336is a six-sided, box-type chisel with planar outer surfaces360that distally terminates in a beveled cutting edge362that forms a distal opening364that extends to lumen extending through the cutting element336. While this embodiment of the cutting element336includes a six-sided, box-type chisel, other arrangements and designs of cutting tool elements336are contemplated herein. For example, a rectangular, box-type chisel, knife blade, or saw may be used without departing from the teachings of the disclosure.

Continuing withFIG. 30, the cutting element336further includes a cutting element guide352that extends off of the cutting element336and extends just proximally from the distal tip334of the cutting element336to a proximal end354of the cutting element336. The cutting element guide352includes a rounded head356and a neck358that is thinner than a widest part of the head356. Alternatively, cutting element guide352and guide channel366may have complementary dovetail or flaring tenon and mortise configurations. As seen inFIG. 31, which is an isometric view of the cutting element336and implant trial306with a cross-section at the proximal end354of the cutting element336, the cutting element guide352is received within a guide channel366that is a corresponding shape to that of the cutting element guide352. In particular, the guide channel366includes a neck region368and a head region370that are only slightly larger than the corresponding neck358and head356of the cutting element guide352. The guide channel366extends from a proximal surface372to a distal surface374of the implant trial306. In this way, as the cutting tool304and, more particularly, the cutting element336are translated distally, the cutting element guide352is received within the guide channel366, which ensures that the cutting element336remains within the guide338on the top surface340of the implant trial306during a cutting operation. Stated differently, the guide channel366prevents rotation and other errant movement of the cutting element336during a cutting operation such that the cutting element336remains reliably within the guide338to perform repeatable and accurate cuts into the patient's bone.

Still referring toFIG. 31and also extending through the implant trial306from the proximal surface372to a distal surface374is a bore376that is configured receive a guidewire or similar device to guide the implant trial306into a joint space, for example. As best seen inFIGS. 32-33, which are respective front and back views of the implant trial306, both the bore376and the guide channel366extend through the implant trial306parallel to a longitudinal axis of the implant trial306. While shown in the figures as generally linear, the longitudinal axis of the implant trial306may be curved and may further include an arcuate portion with a radius between from about 3 cm and about 6 cm and may be about 2 cm, 2.5 cm, 3 cm, 3.5 cm, 4 cm, 4.5 cm, 5 cm, 5.5 cm, 6 cm, 6.5 cm and 7 cm. In one aspect, while shown in the figures as generally linear, the guide channel366may be curved and may further include an arcuate portion with a radius that matches the curved implant trial306. The radius of the arcuate portion of the guide channel366may be between from about 3 cm and about 6 cm and may be about 2 cm, 2.5 cm, 3 cm, 3.5 cm, 4 cm, 4.5 cm, 5 cm, 5.5 cm, 6 cm, 6.5 cm and 7 cm. In another aspect, while shown in the figures as generally linear, the implant trial306may be curved and may further include an arcuate portion with a radius between from about 3 cm and about 6 cm and may be about 2 cm, 2.5 cm, 3 cm, 3.5 cm, 4 cm, 4.5 cm, 5 cm, 5.5 cm, 6 cm, 6.5 cm and 7 cm. In yet another aspect, the implant trial306and the guide channel366may both include a matching radius.

Still referring toFIGS. 32-33, while the guide338is centered between opposite side surfaces378of the implant trial306, the bore376and the head region370of the guide channel366are offset from a center point between the opposite side surfaces378. As seen in the figures, the guide338is an extrusion with a bottom surface380that is generally perpendicular to a pair of side surfaces382. The bottom surface380adjoins one of the side surfaces382to form a perpendicular angle between the two surfaces while the opposite pair of surfaces are transected by the guide channel366extending about one hundred and thirty-five degrees from each of the bottom surface380and the side surface382.

Reference is now made toFIG. 33and the proximal end346of the implant trial306. As seen in the figure, the channel342in the shaft314of the trial tool assembly302mirrors a portion of the circumference of the bore376extending through the implant trial306. In this way, the trial tool assembly302may be delivered into a sacroiliac joint, or other joint, of a patient by way of a guidewire (not shown) being received through the bore376of the implant trial306which was previously delivered into the joint. The channel342in the shaft314provides a passageway for the guidewire when the trial tool assembly302is advanced into the joint. Subsequently, when it is appropriate to use the cutting tool304with the trial tool assembly302, the channel342provides the function of guiding the cutting tool304in an appropriate orientation by aligning the protrusion348within the collars324of the cutting tool304within the channel342of the shaft314of the trial tool assembly302.

As seen inFIGS. 43E and 43F, the implant trial306may have a locking means which reversibly secures the trial306within the joint during certain steps in the procedure. For example, the proximal surface372of the implant trial306may have at least one passageway307which communicates with either a top of bottom surface340which is configured to receive an anchoring member305which may be proximally acted upon to reversibly transition from a recessed condition to a deployed condition. The recessed condition, as seen inFIG. 43E, is such that the anchoring member305is recessed within the passageway307or simply not extending beyond the top surface340and thereby not engaging a bone defining the joint and thereby not preventing movement of the implant trial306relative to the joint. The deployed condition, as seen inFIG. 43F, is such that the anchoring member305projects out of the passageway307from the top surface340thereby engaging a bone of the joint which may prevent or at least limit the movement of the implant trial306during the course of the procedure. The anchoring member305may be a spike, pin, dart, screw or other suitable locking or restraining member.

As further seen inFIG. 34, which is a front view of the trial tool assembly302, an outer surface384of the shaft314of the trial tool assembly302lies flush with one of the outer surfaces378of the implant trial306. As discussed previously, the proximal end318of the shaft314in configured to engage with a handle assembly316. To facilitate the coupling of the shaft314and the handle assembly316, the shaft314includes a notch or indent386within the outer surface384of the shaft314. Proximally from the notch386is a stop feature388that defines a partial planar resection or flattening390of the outer surface378of the shaft314.

For a discussion of the engagement of the handle assembly316with the shaft314, reference is made toFIG. 35, which is a cross-sectional isometric view of the handle assembly316and the proximal end318of the shaft314. As seen in the figure, the coupler320includes a cylindrical sidewall404and a flat impacting end412at a proximal end414of the coupler320. Opposite the proximal end414, a distal end394of the coupler320includes an opening392that is configured to receive the proximal end318of the shaft314. The opening392includes a passageway that extend partially through the coupler320and includes a proximal inner surface396that is sized slightly larger than the proximal end318of the shaft314. The inner surface396includes a planar inner surface portion398that matches the planar surface390of the shaft314such that when the shaft314is inserted into the opening392, the planar surface390of the shaft314lies flush and opposed with the planar inner surface398of the opening392in a single orientation. When the shaft314is fully inserted into the opening392, the stop feature388abuts a corresponding feature400on the inner surface396of the opening392, which prevents further extension of the shaft314into the opening392. Also, when the stop feature388abuts the corresponding feature400, the notch386is aligned with a lock feature402that extends through a bore in the cylindrical sidewall404of the coupler320. The lock feature402includes a tubular member that is configured to extend through the sidewall404and into the notch386while still being partially positioned in the sidewall404in order to lock the shaft314in place relative to the coupler320. The lock feature402may be engaged and disengaged from within the notch386by activation of a set screw406or similar mechanism. In this embodiment, the set screw406is maintained within the sidewall404of the coupler by a retainer408that inhibits movement of the set screw406from full retraction outside of the sidewall404. The function of the lock feature402and the set screw406may be accomplished with many different mechanisms and methods. For example, the set screw406may be substituted for a mechanical switch that forces the lock feature402into the notch386when the switch is engaged. This and other such mechanisms are possible and contemplated by this disclosure.

Turning now toFIGS. 36A-36B, reference is made to another embodiment of the cutting tool304. As seen inFIG. 36A, the cutting tool304include a similar shaft326with a curved mid-portion328, distal and proximal collars324for receiving a shaft of a trial tool assembly, and an impact plate332at a proximal end330of the cutting tool304as described with reference to the previous embodiment of the joint preparation tool assembly300. The present embodiment differs, however, from the previously described embodiment of the joint preparation tool assembly300in that it includes a saw-blade type cutting element416at a distal end334of the cutting tool304. Referring toFIG. 36B, which is a close-up isometric view of the distal end334of the cutting tool304, the cutting element416extends from a planar distal surface418of the tool304and includes opposite side surfaces420, a bottom surface422, and a top surface424that includes a series of teeth426arranged in a saw tooth shape that is configured to cut during a distal extension of the cutting tool304. The series of teeth426extend generally perpendicularly from a top surface430of the shaft326. At a distal end334of the cutting tool304, the top surface424of the cutting element416tapers towards the bottom surface422to form a rounded, tapered distal tip428.

In certain embodiments of the cutting tool304, the cutting element416may include a width W416 between the opposite side surfaces within a range of about 1 mm to about 1.25 mm, from about 1 mm to about 1.75 mm, from about 1.5 mm to about 2.25 mm, from about 2 mm to about 2.75 mm, from about 2.5 mm to about 3 mm, from about 2.75 mm to about 4.25 mm, from about 4 mm to about 5 mm, from about 4.75 mm to about 6 mm, from about 5.75 mm to about 7 mm, and from about 6.5 mm to about 7.5 mm. In certain instances, the width W416 may be about 1.5 mm, 1.75 mm, 2 mm, 2.75 mm, 3 mm or 3.5 mm X. In certain embodiments, the cutting element416may include a length L416 from the planar distal surface418to the tapered distal tip428within a range of about 10 mm to about 15 mm, from about 13 mm to about 20 mm, from about 17.5 mm to about 30 mm, from about 25 mm to about 37.5 mm, from about 35 mm to about 40 mm, from about 37 mm to about 50 mm. In certain instances, the length L416 may be about 27 mm, 30 mm, 37 mm, or 40 mm. In certain embodiments, the cutting element may include a height H416 from the bottom surface422to the series of teeth426within a range of about 2.25 mm to about 2.65 mm, from about 2.5 mm to about 3 mm, from about 2.75 mm to about 4.25 mm, from about 4 mm to about 5 mm, from about 4.75 mm to about 6 mm, from about 5.75 mm to about 7 mm, from about 6.5 mm to about 7.5 mm, from about 7 mm to about 8.75 mm, from about 8.5 mm to about 9.75 mm and from about 9.5 mm to about 11.25 mm. In certain instances, the height H416 may be about 3.25 mm, 4 mm, 4.5 mm, 5 mm or 5.25 mm.

The cutting tool304ofFIGS. 36A-36Bis configured to be used with the trial tool assembly302as described previously. The cutting tool304inFIGS. 36A-36Bmay be useful, for example, in making a keel-cut into either the sacrum or the ilium after the implant trial of the trial tool assembly is delivered non-transversely into the sacroiliac joint. Since the cutting element416extends generally perpendicular from the shaft326of the cutting tool304, when the implant trial is positioned non-transversely within the sacroiliac joint, the series of teeth426will be oriented generally perpendicularly to the sacrum/ilium such that a distal extension of the cutting tool304will provide a cut into the bone that may match a keel or wing member of an implant to be subsequently implanted into the joint space.

Reference is now made toFIGS. 36C-36E, which depict an alternative implant trial306and cutting element416. As seen inFIG. 36C, the cutting element416may include interconnected teeth764forming a chain that are configured to rotate around a portion of the implant trial306. The interconnected teeth764may be segmented into individual teeth764and each segmented tooth764may be in-line and linked with one another via rivets766or similar mechanisms. The interconnected teeth764may be configured similar to a tooth on a chainsaw and dimensioned as herein described, however, the overall length of each tooth764will be a fraction of the total length L416 of the cutting element segment assembly. For example, if the assembly comprises three teeth764, than the length of each tooth will be approximately one third of the overall length L416 of the cutting element segment assembly. In an aspect, an assembly comprises fifteen teeth764with each tooth approximately 2 mm in length. In one aspect, the teeth764are configured similar to chipper teeth or an OREGON no. 10 chipper chain, one of many STIHL saw chains or even a full-chisel chain. In other aspects, the teeth764may be configured as other linked-chains known in the art.

The interconnected teeth764may be configured to rotate through a portion of a length of the implant trial306such that a portion of the teeth764extend above a top surface768of the implant trial306. Thus, in operation and during rotation, the interconnected teeth764are configured to deliver a cut (e.g., keel-cut) into a joint bone when the implant trial306is positioned within a joint space. The interconnected teeth764opposite the top surface768, may extend outward from a bottom surface of the implant trial306such that rotation of the interconnected teeth764delivers simultaneous cuts to opposing bones in a joint space. Or, alternatively, the teeth764opposite the teeth764on the top surface768may remain housed within a passageway within the body of the implant trial306such that the teeth764only contact a joint bone that opposes the top surface768.

Referring toFIG. 36D, which is a top view of an implant trial306that is suitable for use with the cutting element416described previously, the implant trial306may include a first guide or channel338formed in the top surface768and a second guide or channel (not shown) formed in the bottom surface of the implant trial306, which is opposite the top surface768and not shown inFIG. 36D. And, at a distal end774of the implant trial306, there may be a passageway770communicating between implant trial top and bottom surfaces768. The passageway770may be configured and dimensioned to receive the interconnected teeth764as they run distal-proximal along the first and second guides338through the passageway770. Such a configuration of the interconnected teeth764with the implant trial306having a passageway770at the distal end774may permit use of a rotating chain of teeth while protecting a patient's tissue that is distal to the distal end774of the implant trial306.

Referring now toFIG. 36E, which is an isometric view of an arcuate implant trial306coupled with a shaft780, the teeth764may be linked together such that they pivot relative to one another with a pivot axis which is generally perpendicular to the length of the trial guide338and perpendicular to the top surface768of the implant trial306. Such a configuration would permit a saw chain of interconnected teeth764to travel an arcuate path via an arcuate trial guide path772formed on a generally planar implant trial top surface768where the opposite side surfaces776of implant trial306are curved and have a radius of approximately 2 cm to about 8 cm. In this arrangement a cutting tip of the interconnected teeth764remains oriented perpendicular to the top surface768of the implant trial306; however, the orientation of the pivot766is altered from the previous embodiment. As described previously, the interconnected teeth764may travel along the arcuate trial guide path772until the teeth764enter the passageway770at the distal end774of the implant trial306. The teeth764may then exit the passageway770and travel proximally on the arcuate trial guide path772formed on the bottom surface778of the implant trial306. In this arrangement, the interconnected teeth746may include an additional pivot766oriented generally perpendicular to the previously described pivot766such that the additional pivot766enables movement of the chain of interconnected teeth764to travel through the passageway770. Alternatively, the implant trial306may not include a passageway770and the teeth764may simply translate distally-proximally within the guide paths772.

Other cutting elements416are possible and contemplated herein. For example, the cutting element416may include a serrated or smooth knife blade. And, the joint preparation tool assembly300may include a series of cutting tools304, each cutting tool304with progressively larger (e.g., wider) blades that may or may not be used in succession to make larger and larger cuts until a desired cut size is made for subsequent implant delivery.

2. Trial Fit Assembly and Cutting Tool with Coaxially Aligned Shafts

Turning now to another embodiment of a joint preparation tool assembly450, reference is made toFIG. 37. As seen in the figure, the joint preparation tool assembly450includes a trial tool assembly452and a cutting tool454that translates on a shaft456of the trial tool assembly452. The cutting tool454includes a tubular shaft458having an outer surface460, an inner surface462, and a hollow interior space464. The tubular shaft458also includes a series of apertures466extending from the outer surface460to the inner surface462of the shaft458. The apertures466provide for easier and improved steam cleaning compared with a tubular shaft without apertures. The apertures466also reduce weight of the assembly450, among other benefits. The tubular shaft458or, more particularly, the hollow interior space464is configured to receive the shaft456of the trial tool assembly452such that the shafts456,458are coaxially aligned. At a proximal end468, the cutting tool454includes a handle470. At a distal end472, the cutting tool454includes a cutting element474, which, in this embodiment, is a box-type chisel as described previously.

Regarding the trial tool assembly452, the assembly includes an implant trial476at a distal end478of the assembly. As seen inFIG. 38, which is an isometric view of the cutting tool454and the trial tool assembly452in an uncoupled state, it can be seen that the trial tool assembly452is similar to and may include the same or different features of the joint preparation tool assembly300discussed previously inFIGS. 27-35. That is, the trial tool assembly452includes the implant trial476at the distal end478of the assembly, a guide480on a top surface482of the implant trial476, and a guide channel484that is configured to guide the cutting element474during translation of the cutting element474within the guide480of the implant trial476.

To couple the trial tool assembly452and the cutting tool454, the shaft456of the trial tool assembly452is received through a pair of collars486on the cutting tool and is translated proximally such that the shaft456is received within the tubular shaft458of the cutting tool454. As seen inFIG. 38, the cutting tool454includes a protrusion488within each of the collars486that fit within a corresponding channel490formed within an outer surface492of the shaft456of the trial tool assembly452. The interaction of the protrusion488and the corresponding channel490ensures that the trial tool assembly452maintains its orientation relative to the cutting tool454during distal-proximal movement. As the trial tool assembly452is proximally retracted within the tubular shaft458of the cutting tool454, a cutting guide element494of the cutting tool454will engage with and be received within the guide480of the implant trial476. The interaction of the cutting guide element494and the guide480and guide channel484further ensures that the orientation of the cutting tool454and the trial tool assembly452will be maintained during a cutting stroke of the cutting tool454during a surgical procedure.

3. Trial Fit Assembly, Cutting Tool, and Trial Impact Rod with Coaxially Aligned Shafts

Turning now to another embodiment of a joint preparation tool assembly500, reference is made toFIG. 39, which depicts the individual components of the assembly500in an uncoupled state. As seen in the figure, the joint preparation tool assembly500includes a trial tool assembly502, a trial impact rod assembly504, a handle assembly506, and a cutting tool508.

In one aspect, the trial impact rod assembly504is configured to be used in conjunction with the trial tool assembly502to provide stability during delivery of a distal end510of the trial tool assembly502into a joint of a patient. In particular, slidable coupling of the trial impact rod assembly504and the trial tool assembly502adds stability and rigidity to the assembly500by reducing potential bending, among other movements, of the trial tool assembly502shaft512during a striking of the handle assembly506.

In another aspect, the cutting tool508is configured to be used in conjunction with the trial tool assembly502to deliver a transverse keel-cut into a bone of a joint. For example, the distal end510of the trial tool assembly502may be delivered non-transversely into a sacroiliac joint of a patient with stabilizing support from the trial impact rod assembly504and, then, once the trial impact rod assembly504is decoupled from the trial tool assembly502, the cutting tool508may be may be slidably coupled with the trial tool assembly502and used to transversely cut into either or both of the sacrum and the ilium to make way for subsequent delivery of an implant having transversely extending members that match the cuts made into the sacrum/ilium. In each of the examples described above, the handle assembly506may be coupled to a proximal end of the trial impact rod504or the cutting tool508and a device (e.g., hammer, mallet) may be used to strike the handle assembly506in order to distally drive the assembly500.

To begin the discussion of the components of the joint preparation tool assembly500, reference is made to the trial tool assembly502inFIG. 39. As seen in the figure, the trial tool assembly502includes an implant trial514at the distal end510of the assembly502. The implant trial514is a planar member with a top surface516, a bottom surface518that is opposite the top surface516, and opposite side surfaces520. The top surface516includes a channel522that guides a cutting element524of the cutting tool508. The channel522extends from a tapered distal tip526to a proximal end528of the implant trial514and is coaxial with a shaft channel530that extends the length of the shaft512from the proximal end528of the implant trial514to a proximal end532of the shaft512. In this way, the cutting element524of the cutting tool508may be guided along the shaft channel530while the cutting element524is proximal of the implant trial514. And, when the cutting element524is distally advanced it will also be guided by the channel522in the top surface516of the implant trial514. Shaft channel530may simply be a planar surface along shaft512and aligned with a corresponding planar surface of channel522.

As seen inFIG. 39, the shaft512of the trial tool assembly502is centrally positioned on a proximal surface534of the implant trial514. On the proximal surface534of the implant trial514and on either side of the shaft514are bores536that extend distally through a portion of the implant trial514. The bores536are configured to receive a corresponding pair of stud members538on a distal end540of the trial impact rod assembly504. When the stud members538are received within the bores536, the implant trial514is correctly aligned with the distal end540of the trial impact rod504. Alternatively, the bores may be studs and the studs bores.

Now the discussion will focus on the trial impact rod assembly504ofFIG. 39. As seen in the figure, the trial impact rod assembly504includes a tubular shaft542that couples or transitions to an implant trial extension member544at the distal end of the trial impact rod assembly504. The implant trial extension member544is a planar member that includes the stud members538on a planar distal surface546of the member544. The shaft512of the trial tool assembly502is configured to be received within an interior space548in the tubular shaft542and the stud members538are configured to be received within the bores536on the proximal surface534of the implant trial514. In this arrangement, when the shaft512of the trial tool assembly502is fully received within the tubular shaft542of the trial impact rod assembly504, the proximal surface534of the implant trial514and the distal surface546of the implant trial extension member544abut each other. The implant trial extension member544acts as a natural extension of the implant trial514such that when the implant trial514is delivered into a patient's joint, the distal end540of the trial impact rod assembly504may also be delivered into the joint space without stoppage. Stated differently, the implant trial extension member544includes top and bottom surfaces550,552and opposite side surfaces554that align with and provide a smooth transition between (i.e., coplanar) the top, bottom, and opposite side surfaces516,518,520of the implant trial514. Alternatively, implant trial extension member544may have a transition which intentionally interferes with a bone of the joint in order to act as a stop. The stop feature may be adjustable or fixed.

At a mid-portion570of the trial impact rod assembly504, a screw-lock572is rotatably coupled to the tubular shaft542and configured to frictionally lock or support the shaft512of the trial tool assembly502when the shaft512is received within the tubular shaft542of the trial impact rod assembly504. The screw-lock572may function to lock the shaft512in place in many ways. For example, the screw-lock572may rotationally advance on a pair of threaded push-locks (not shown) that extend through the tubular shaft542such that when the screw-lock572is rotationally engaged over the push-locks, the push-locks are caused to extend further through the tubular shaft542and into contact with the shaft512of the trial tool assembly502. Such contact with the shaft512of the trial tool assembly502may cause sufficient friction to securely support the positioning of the shaft512within the tubular shaft542.

Also as seen inFIG. 39, a proximal end556the trial impact rod assembly504includes a handle engagement mechanism558that includes a pair of block-like members560with four generally perpendicular sidewalls562separated by mid-section member564with four slightly concave sidewalls566that are generally coplanar with a pair of corresponding sidewall562of the pair of block-like members560. The handle engagement mechanism558is configured to be received and secured within a distal opening568in the handle assembly506. The distal opening568extends to a cavity586for housing and securing of the handle engagement mechanism558.

Moving on, reference is made to the cutting tool508inFIG. 39. As seen in the figure, the tool508includes a shaft590that is coupled to the cutting element524at a distal end592of the cutting tool508. The cutting element524is a planar member with generally parallel opposite sides and a top surface598that extends outward and distally from an outer surface594of the shaft590. The cutting element524includes a series of teeth596on the top surface598of the cutting element524. The cutting element in this embodiment is similar to as described in reference toFIGS. 36A-36B. Alternatively, the cutting element524may be as described in other portions of this disclosure. For example, the cutting element524may include a box chisel, serrated knife blade, etc.

The shaft590of the cutting tool508is tubular and includes an internal passageway600that is configured to receive the shaft512of the trial tool assembly502. When the shaft512is fully received within the tubular shaft590of the cutting tool508, the cutting element524or, more particularly, a bottom surface602and a portion of opposite sidewall surfaces604of the cutting element524are guided by and positioned within the channel522on the top surface516of the implant trial514. The cutting tool508may include a protrusion (not shown) on the internal passageway600of the shaft590that is configured to engage with and be guided by the shaft channel530of the trial tool assembly502. When the implant trial514is delivered into a joint of a patient, a distal stroke of the cutting element524relative to the implant trial514is configured to make a keel-cut perpendicular to a plane defined by the joint for the subsequent delivery of an implant having matching keels or wing members.

Referring to a proximal end606of the cutting tool508, the shaft590is coupled or transitions to a handle engagement mechanism608that is similar to the mechanisms558on the trial impact rod assembly504. The handle engagement mechanism608includes a pair of block-like members610with four generally perpendicular sidewalls612separated by a smaller mid-section member614with four slightly concave sidewalls616that are generally coplanar with a pair of corresponding sidewall612of the pair of block-like members610. The handle engagement mechanism608is configured to be received and secured within the distal opening568in the handle assembly506. As stated previously, the distal opening568extends to the cavity586for housing and securing of the handle engagement mechanism608.

Referring to the handle assembly506inFIG. 39, the assembly506includes a coupler574that is configured to receive and support the handle engagement mechanisms558,608on the trial impact rod assembly504and the cutting tool508within the distal opening568. The coupler574includes a cylindrical sidewall576and a flat impact plate578that is opposite the distal opening568and configured to be struck with a hammer, mallet, or similar device in order to distally drive the joint preparation tool assembly500within a joint. Extending from and attached to the cylindrical sidewall576is a shaft580that further extends to a handle582.

Still referring to the handle assembly506ofFIG. 39, the coupler574includes a camming mechanism584that is configured to securely support the trial impact rod assembly504or the cutting tool508when the proximal end of the assembly504or tool508is positioned within the cavity586of the handle assembly506. The camming mechanism584includes a handle588that transitions to a camming head having a cam-shaped surface. The camming head is coupled to the coupler574by an axle that extends through an aperture in the cylindrical sidewall576and is configured such that when the camming head is rotated about the axle, the cam-shaped surface contacts and locks against one of the concave sidewalls566,616that is positioned adjacent the aperture. When the camming head is rotated in an opposite direction, the cam-shaped surface disengages with the concave sidewalls566,616such that the trial impact rod assembly504or the cutting tool508may be removed from the cavity586in the coupler574.

Reference is now made toFIGS. 40A-C, which are isometric views of the trial tool assembly502and the trial impact rod assembly504coupling together. As seen inFIG. 40A, the tubular shaft542of the trial impact rod assembly504is coaxially aligned with the shaft512of the trial tool assembly502such that the shaft512may be received within the interior space548of the tubular shaft542. In this arrangement, as seen inFIG. 40B, which is a close-up view of the engagement of the implant trial514with the distal end540of the trial impact rod assembly504, the stud members538on the trial impact rod504are aligned and configured to be received within the bores536on the proximal surface534of the implant trial514. As seen inFIG. 40C, once the trial tool assembly502is received within the trial impact rod assembly504, the screw-lock572may be rotationally engaged to frictionally support the shaft512of the trial tool assembly502, which, in turn, securely supports the positioning of the trial tool assembly502relative to the trial impact rod assembly504.

Reference is now made toFIG. 41, which is an isometric view of the trial impact rod assembly504and the trial tool assembly502coupled together with the handle assembly506in close proximity. As seen in the figure, the handle engagement mechanism558is positioned to be received within the distal opening568in the handle assembly506. Also, a guidewire618is positioned to be received within the channel522on the top surface516of the implant trial514. After being received within the channel522, the guidewire618may be further received within and guided by the shaft channel530in the shaft512of the trial tool assembly502. In this way, the guidewire618may be delivered into a joint of a patient and the assembly500including the impact rod assembly504and the trial tool assembly502may be delivered into the joint via the guidewire618being received within the channel522. Once the handle assembly506is coupled to the trial impact rod assembly504, a mallet may be used to impact the handle assembly506in order to sufficiently drive the distal end510of the trial tool assembly502into the joint. And, once the implant trial514is sufficiently delivered within the joint space, the handle assembly506may be decoupled with the trial impact rod assembly504. Next, the screw-lock572on the trial impact rod assembly504may be loosened so that the assembly504may be slidably removed from the trial tool assembly502, which remains within the joint space. At this point, the guidewire618may be removed. Alternatively, the guide wire may be removed at any time during the procedure.

Reference is now made toFIGS. 42A-42B, which are isometric views of the trial tool assembly502and the cutting tool508coupling together. As seen inFIG. 42A, the shaft512of the trial tool assembly502is coaxially aligned with and configured to be received within the internal passageway600of the shaft590of the cutting tool508. The cutting element524is aligned with and guided by the channel522on the top surface516of the shaft512as the cutting tool508is distally advanced relative to the trial tool assembly502. That is, the bottom surface602and a portion of the opposite sidewall surfaces604are fitted and guided within the channel522such that rotation of the cutting tool508relative to the trial tool assembly502is restricted.

As seen inFIG. 42B, once the trial tool assembly502is coupled with the cutting tool508, the handle assembly506may be coupled with the handle engagement mechanism608on the cutting tool508. The handle assembly506may be struck with a mallet in order to distally drive the cutting element524relative to the implant trial514in order to make a keel-cut transverse to the joint. The cutting tool508may be distally driven relative to the implant trial514until a distal edge620of the shaft590abuts the proximal surface534of the implant trial514. At this point, the distal end592of the cutting element524is positioned at the distal tip526of the implant trial514.

Once the keel-cut has been made, the handle assembly506and the cutting tool508may be decoupled from the trial tool assembly502(either together or individually). Then, the trial tool assembly502may be removed from the joint space for subsequent delivery of an implant that matches the space that was cleared by the implant trial514and the cutting tool508.

While the joint preparation tool assembly500as described in the previous figures includes an implant trial514with a single channel522and a cutting tool508with a single cutting element524, the assembly500may include implant trials514and cutting tools508with multiple channels522and cutting elements524. For example, a certain joint preparation tool assembly500may include an implant trial514with channels522on a top and bottom surface516,518and a cutting tool508with cutting elements524on opposite sides of the shaft590such that the assembly500may deliver simultaneous, dual keel-cuts into a joint space (e.g., into both sacrum and ilium). As another example, a certain joint preparation tool assembly500may include an implant trial514with a pair of channels522on both a top and a bottom surface516,518and a cutting tool508with a pair of cutting elements524on opposite sides of the shaft590in order to make quad keel-cuts into the bones defining the sacroiliac joint space to make way for an implant having an I-beam shape as described in U.S. patent application Ser. No. 14/447,612, mentioned previously, and hereby incorporated by reference in its entirety. Other embodiments of the assembly500are contemplated and within the scope of the present disclosure.

As further examples of alternative configurations of the implant trial514and cutting element524, reference is made toFIGS. 43A-43D, which are respective front views of implant trials514with various configurations of cutting elements524channels522. As seen inFIG. 43A, the channel522is formed by one of the side surfaces520that extends from the proximal end528of the implant trial514to the distal end510of the trial tool assembly. The channel522includes a neck portion622and a bulb-end portion624that is wider than the neck portion622. In this way, once the cutting element524is received within the channel522, the cutting element524is restrained from movement out of the channel522except by distal-proximal translation of the cutting element524relative to the implant trial514.

Regarding the cutting element524, it includes an implant trial engagement end626and a cutting end628. The engagement end626includes a neck member630that extends to a bulb-member632that is slidingly and matingly received within the channel522by distally translating the cutting element524such that the engagement end626of the cutting element524is engaged and fitted within the channel522at the proximal end528of the implant trial514. The channel522described herein may include additional mechanisms to restrain the cutting element524during distal-proximal translation. The description of a channel522having a neck portion622and a bulb portion624is illustrative and not intended to be limiting.

Regarding the cutting end628of the cutting element524, as seen inFIG. 43A, the cutting end628transitions generally ninety degrees from the implant trial engagement end626and extends generally parallel with the side surface520of the implant trial514. In particular, the cutting end628terminates in a cutting tip634that extends beyond the top surface516of the implant trial514. In this way, as the cutting element524is distally translated, the patient's bone (e.g., sacrum or ilium) that abuts the top surface516of the implant514will be cut.

Referring toFIG. 43B, the cutting element524may be a T-shaped member and include a pair of cutting tips634where one cutting tip extends beyond the top surface516and one cutting tip extends beyond the bottom surface518of the implant trial514. In this arrangement, the cutting element524may be used to deliver simultaneous cuts into opposing bones defining a joint (e.g., sacrum and ilium). And, referring toFIG. 43C, the cutting element524may include two T-shaped members wherein one T-shaped member is on each side surface520of the implant trial. In this arrangement, the cutting element524may be used to deliver dual-keel cuts into each of the sacrum and ilium. Such cuts may be useful for delivery of an implant having a pair of keels that are configured to extend into the sacrum and ilium.

And, while this discussion has focused on cutting elements524with cutting tips634, other cutting devices that include a similar implant trial engagement end may be used with the implant trial514of the present discussion. For example and as seen inFIG. 43D, the cutting element524includes a T-shaped member with a cutting tip634as previously described on one side surface520and a box-chisel636on the opposite side surface520. The box-chisel636may be useful, for example, to clear the plane of the joint while the T-shaped member with the cutting tips634may be useful for cutting into the sacrum and ilium to prepare for the subsequent delivery of a matching implant. Similarly, instead of the box chisel636as shown and positioned inFIG. 43D, a drill guide collar710may be positioned and arranged in place of the box chisel; however, the collar would be positioned adjacent the proximal surface of the implant trial as inFIG. 44by aligned with one or both opposite side surfaces520. In an aspect, the drill guide collar may have a slot like configuration similar to the collar shown inFIGS. 47A and 47Bexcept that the slot length is positioned near the implant trial opposite side surface520as just described regarding the drill guide collar710in place of the box chisel ofFIG. 43D. In an aspect with the slot length parallel to the implant trial opposite surface520, a milling cutter bit may be passed immediately adjacent surface520while sweeping in a plane generally parallel to the surface520and in doing so the milling bit may be caused to project beyond top and bottom surfaces of the implant trial—effectively preparing a cut similar to that prepared by the cutting end628ofFIG. 43B. In yet another aspect, a guide collar including a slot aperture may align a milling bit with an opposite surface520yet the slot length may extend generally perpendicularly away from the surface520, thereby permitting preparation along the joint plane by safely milling from a reference surface520and perpendicularly directing the motion of the bit away from the surface520(e.g., the other opposite surface520may be facing the sciatic notch).

These are only some versions of alternative embodiments of the implant trial514and cutting element524that are applicable to all joint preparation tools described herein. Other arrangements of channels522on different surfaces of the implant trial514are possible and contemplated herein. Additionally and alternatively, the implant trial514and cutting element524described in reference toFIGS. 43A-43Dmay include other features described in reference to the previous embodiments. For example, the implant trial514of the present embodiment may additionally include a cutting element as described previously that extends over the top surface of the implant trial. Also, the cutting element524of the present embodiment may include a cutting element guide as described previously that is configured to fit within a reciprocally shaped opening in the implant trial.

4. Trial Fit Assembly and Cutting Tool with Drill Guiding System

Turning now toFIGS. 44-47, reference is made to an additional embodiment of a joint preparation tool assembly700. As seen inFIG. 44, the joint preparation tool assembly700includes a trial tool assembly702, a drill guide704, and a handle assembly706.

In one aspect, the joint preparation tool assembly700is configured to guide a drill bit708during distal-proximal translation of the drill bit708relative to the drill guide704and trial tool assembly702. In particular, the drill guide704is similar to as described previously with respect to the various embodiments of the cutting tool, except that the drill guide704includes a guide collar710at a distal end712of the drill guide712as opposed to a cutting element. The guide collar710is a tubular member that is positioned to guide the drill bit708above a channel714formed in a top surface716of an implant trial718, which is located at a distal end720of the trial tool assembly702, when the distal end712of the drill guide704abuts a proximal end722of the implant trial718.

As seen inFIG. 44, the handle assembly706is releasably secured to a proximal end724of a shaft726of the trial tool assembly702. The handle assembly706includes drill shank guide728that is formed within a body730of the handle assembly706and is configured to receive and guide a drill bit shank732during distal-proximal translation of the drill bit708. The drill shank guide728is a cylindrical or partially cylindrical opening or cutout that is sized slightly larger than a diameter of the drill bit shank732. In this way, as the drill bit shank732is translated distal-proximal a distal end734of the drill bit708is guided to be received within, and further guided by, an internal passageway736defined within the guide collar710.

Moving on toFIG. 45, reference is made to the various components of the joint preparation tool assembly700in an uncoupled state. As seen in the figure, the drill guide704is similar to previously described embodiments of the cutting tool in that it includes a pair of collars738with protrusions740extending radially inward from inner walls742of the collars738. The protrusions740are configured to fit within and be guided by a groove744formed within the shaft726of the trial tool assembly702. The drill guide704additionally includes a drill guide element746at distal end712of the drill guide704that is configured to slidingly engage with and be guided by a reciprocally shaped opening748formed within the implant trial718.

Turning now toFIG. 46, reference is made to the various components of the joint preparation tool assembly700in a coupled state. As seen in the figure, the drill bit708may include a stop feature750that limits a depth that the distal end734of the drill bit708may distally extend relative to the implant trial718. The stop feature750may be permanently fixed (e.g., welded) or may be adjustable based on the needs of a particular surgical procedure.

In operation, the joint preparation tool assembly700may function as follows. The trial tool assembly702may be delivered into the sacroiliac joint of a patient with or without guidance by a guide wire. The drill guide704may be slidingly engaged with the shaft726of the trial tool assembly702by fitting the proximal end724of the shaft726within and through the collars738such that the protrusions740(not shown inFIG. 46) are fitted within the groove744of the shaft726. The drill guide704may be translated distally while being guided by the collars738of the trial tool assembly702. As the drill guide704approaches the implant trial718, the drill guide element746will engage with, and be further guided by, the reciprocally shaped opening748formed in the implant trial718. The drill guide704will continue its distal translation until the distal end712of the drill guide704abuts the proximal end722of the implant trial718. At this point, the guide collar710is adjacent the channel714on the top surface716of the implant trial718.

Next, the drill bit708or, more particularly, the drill bit shank732may be fitted within the drill bit shank guide728in the handle assembly706. The drill bit708may then be distally advanced while being guided by the drill bit shank guide728until the distal end734of the drill bit708engages with and is caused to enter the internal passageway736of the guide collar710. At this point the drill bit708may be further distally advanced to deliver a bore into a patient's bone or cartilage while being guided by the collar710on the drill guide704and by the drill bit shank guide728on the handle assembly706.

Reference is now made toFIGS. 47A-47B, which are alternative configurations for the guide collar710. As seen inFIG. 47A, the guide collar710may include generally parallel sidewalls752that are generally perpendicular to a lower collar wall754. Defined between the sidewalls752and the lower collar wall754is a slot or opening756that is open on a top side758. Thus, as the drill bit708is distally translated relative to the guide collar710, the sidewalls752prevent the drill bit708from angling laterally in a direction towards one of the side surfaces of the implant trial718. The drill bit708, however, is free to angle towards or away from the top surface716of the implant trial718. In this way, the drill bit708(i.e., with a drill bit configured for milling) may be used to mill or machine a portion of a patient's bone that abuts the top surface716of the implant trial718.

The guide collar710ofFIG. 47Bis similar to the collar ofFIG. 47A, except that the guide collar710inFIG. 47Bincludes a top wall member760on the top side758of the guide collar710. In this way, the guide collar710restrains the movement of the drill bit708as it angles away from the top surface716of the implant trial718. Otherwise, the guide collar710functions very similarly to the collar ofFIG. 47A. It is noted that a proximal opening762on the guide collar710may be sized larger than the drill bit708a particular amount such that the drill bit708may be angled slightly downward towards the implant trial718. The exact size of the opening762may be chosen such that the drill bit708can angle somewhat downward towards the top surface716of the implant trial718without contacting the top surface716.

Other mechanisms are possible to guide the drill bit708during distal-proximal movement in drilling or milling a patient's bone. The aforementioned embodiments are merely exemplary and are not intended to be limiting. Additionally and alternatively, the trial tool assembly702and drill guide704discussed in the present embodiment may include features described in previous embodiments. For example, while not discussed previously, the drill guide704may include an alignment guide that is similar to the cutting guide element discussed previously. The alignment guide may extend distally from the guide collar710and be received within a reciprocally shaped opening in the implant trial718.

III. Methods of Preparing the Sacroiliac Joint for Fusion

The following discussion will focus on various methods of preparing a sacroiliac joint for a surgical fusion procedure utilizing the tools and devices discussed previously. While the discussion focuses on fusing the sacroiliac joint, the methods discussed herein are not limiting; rather, the methods are applicable to the preparation of other joints as well.

A. Preoperative Planning for a Surgical Fusion Procedure

Prior to any joint preparation, a surgeon or other medical person may select a suitable procedure to fuse the sacroiliac joint. The procedure may include fusing the joint with or without delivering an implant in the joint space. If the surgeon selects a procedure involving delivery of an implant within the joint space, the surgeon will select an implant configuration for delivery into the sacroiliac joint of the patient based on preoperative or intraoperative data. The data may be the result of post-processing of raw or other imaging data (e.g. CT or MRI DICOM files). The post-processing may include the use of a software program (e.g., 3DSLICER available from http://www.slicer.org) that may be used for medical image processing and 3D visualization of image data. Other data may include the patient's weight, activity level, and general health.

The preoperative or intraoperative data may assist in the planning and selecting of desirable anchor trajectories (e.g., starting and stopping points on patient's soft tissue and near or within bone tissue), anchor dimensions (e.g., length, diameter, head size, washer, thread pitch), implant types and dimensions, and joint preparation tool types, dimensions, and configurations. A particularly system for preparing and fusing the sacroiliac joint may be selected, for example, for a hypermobile joint, which may include an implant or fusion system that is resistant to the expected forces present at that particular patient's sacroiliac joint. The determination of fixation sufficiency may be calculated based on the patient's data and also on the performance results of various bench and/or finite element analysis (“FEA”) tested implant assembly configurations. For example, a calculated anchor and/or implant trajectory may be considered and determined from certain patient imaging and post-processing data with an overlayed implant assembly. Further, the implant assembly footprint within the joint plane may be selected as a lower percent of total joint surface to permit sufficient boney fusion across the joint while maintaining a sufficient implant sacral and iliac face surface area to prevent implant subsidence.

Specific measurements and characteristics of the patient's anatomy may influence the selection of a particular joint fusion system. For example, the patient's bone density may be measured at numerous locations in proximity to and surrounding the elements of the implant assembly. Lower bone density (e.g., osteopenia, osteoporosis) corresponding to a T-score lower than −1, sacroiliac joint instability, or hypermobility may require the use of an implant assembly with a greater amount of keel (i.e., the material cross section as defined by thickness of the keel and its length along implant longitudinal axis and also keels extending a greater distance into both bones defining the sacroiliac joint) and anchor extending across the sacroiliac joint and into the ilium and sacrum. Additionally, the relative angles between the implant longitudinal axis and anchor or anchors, and also the relative angles between multiple anchors (e.g., parallel, divergent, convergent) may be preselected based on the patient's anatomy.

A comparison of the preoperative or intraoperative data (e.g., sacroiliac joint surface area, joint mobility, loading, bone density, desirable anatomic pathways) and the selected implant assembly and joint preparation tools may be conducted to ensure or validate compatibility before the manufacture ships the implant system and/or before the surgeon employs the system in a surgical procedure. After implant assembly and preparation tools validation, the selected assemblies may be shipped to the surgeon and the surgeon may proceed with the surgical fusion procedure utilizing the selected assemblies.

B. Fusion of the Sacroiliac Joint via Implant Delivery

In order to fully understand the steps to prepare the sacroiliac joint for a fusion procedure, this section will detail one, among many, methods of fusion a sacroiliac joint for which the preparation tools discussed herein may be beneficial. To begin, reference is made toFIGS. 48A-48B, which depict various bone landmarks adjacent, and defining, the sacroiliac joint1000of a patient1001.

Reference is first made toFIG. 48A, which is a right lateral view of a hip region1002of a patient1001lying prone, wherein the soft tissue1003surrounding the skeletal structure1006of the patient1001is shown in dashed lines. Delivery of an implant into the sacroiliac joint1000and, thus, preparing of the joint1000for delivery of the implant are via a posterior approach to the hip region1002.FIG. 48B, which is an enlarged view of the hip region1002ofFIG. 48A, depicts a lateral view of the patient's hip region1002reveals certain features of the ilium1005, including the anterior superior iliac spine2000, the iliac crest2002, the posterior superior iliac spine2004, the posterior inferior iliac spine2006, the greater sciatic notch2008extending from the posterior inferior iliac spine2006to the ischial spine2010, and the tubercle of iliac crest2012.

Still referring toFIG. 48B, the sacroiliac joint articular region1044roughly defines an L-shape that includes a caudal region1086and a cranial region1087. Access into the caudal region1086of the sacroiliac joint is via the posterior inferior access region2016that extends between corners defined by the superior end2018and the inferior end2022. Access into the cranial region1087may be accomplished by continual, anterior travel in the caudal region1086until the articular region1044turns superiorly into the cranial region1087.

To begin a discussion of implant delivery into the sacroiliac joint articular region1044, reference is made toFIG. 48C, which is a close-up lateral side view of the hip region1002of a patient1001with a nearest ilium1005removed in order to show the sacroiliac joint boundary3000defined along the sacrum1004and outlining the sacroiliac joint articular region1044, and an implant25positioned for implantation within the sacroiliac joint articular region1044.

As seen inFIG. 48C, boundaries along the sacroiliac joint articular region1044include an inferior boundary segment3002, an anterior boundary segment3004, a superior boundary segment3006, and a posterior boundary segment3008. The inferior boundary segment3002is immediately adjacent, and extends along, the sciatic notch2024.

The inferior boundary segment3002and anterior boundary segment3004intersect to form an anterior-inferior corner3010. The anterior boundary segment3004and superior boundary segment3006intersect to form an anterior-superior corner3012. The superior boundary segment3006and posterior boundary segment3008intersect to form a superior-posterior corner3014. The posterior boundary segment3008and posterior inferior access region2016intersect to form a superior-posterior corner3016of the posterior inferior access region2016. The inferior boundary segment3002and posterior inferior access region2016intersect to form an inferior-posterior corner3018of the posterior inferior access region2016.

The inferior boundary segment3002extends between corners3010and3018. The anterior boundary segment3004extends between corners3010and3012. The superior boundary segment3006extends between corners3012and3014and provides an access into the cranial portion1087of the sacroiliac joint. The posterior boundary segment3008extends between corners3014and3016. The posterior inferior access region2016extends between corners3016and3018and provides an access into the caudal region1086of the sacroiliac joint. The posterior boundary segment3008separates articular region1044and extra-articular region3007, which includes the sacral fossa on the sacrum1004and the corresponding iliac tuberosity on the ilium1005and defined by the extra-articular region boundary3009.

In one aspect and as seen inFIG. 48C, the implant25may be delivered via an implant arm111of a delivery tool into the caudal region1086of the sacroiliac joint articular region1044. As shown via the implant25and implant arm110shown in solid lines, in one embodiment, the implant25enters the posterior inferior access region2016, and is further advanced into the caudal region1086of the sacroiliac joint articular region1044, in an orientation such that the implant arm110and wide planar members51are in the joint plane and the longitudinally extending edge3050of the wide planar member51next to the inferior boundary segment3002is generally parallel to, and immediately adjacent to, the inferior boundary segment3002. Thus, the distal end43of the implant is heading generally perpendicular to, and towards, the anterior boundary segment3004.

As shown inFIG. 48Cvia the implant25and implant arm110shown in dashed lines, in one embodiment, the implant25enters the posterior inferior access region2016, and is further advanced into the caudal region1086of the sacroiliac joint articular region1044, in an orientation such that the implant arm111and wide planar members51are in the joint plane and the longitudinally extending edge3050of the wide planar member51next to the inferior boundary segment3002is somewhere between being generally parallel to the inferior boundary segment3002(as illustrated by the solid-lined implant25inFIG. 48C) or forming an angle AJ with the inferior boundary segment3002of up to approximately 50 degrees. Thus, the distal end43of the implant shown in dashed lines can be said to head anywhere from generally perpendicular to, and towards, the anterior boundary segment3004to heading generally towards the superior-anterior corner3012, or points in between.

In one embodiment, the implant25may be first directed into the joint space as illustrated by the solid-lined implant25inFIG. 48Cafter which the implant25is rotated within the joint space to be positioned somewhere between, and including, angled position depicted by the dashed-lined implant25. In other embodiments, the implant25may be first directed into the joint space as illustrated by the dashed-lined implant25inFIG. 48Cafter which the implant25is rotated within the joint space to be positioned somewhere between, and including, the parallel position depicted by the solid-lined implant25. Thus, an implant25may be delivered non-transversely (i.e., within the joint and not across the joint) into the caudal region1086, the cranial portion1087, or partially within each of the caudal and cranial regions1086,1087of the sacroiliac joint articular region1044. Further details of the implant delivery can be found in related applications, mentioned previously, such as U.S. patent application Ser. No. 12/998,712, which is incorporated by reference herein in its entirety.

C. Utilization of the Tools and Assemblies Described Herein to Prepare the Sacroiliac Joint for Fusion

Now that an overview of the relevant anatomical landmarks and an example fusion procedure has been described, the discussion may now focus on preparing the sacroiliac joint for a fusion procedure. In doing so, reference will be made toFIGS. 49A-49D, among additional figures, which are steps in the methodology and illustrated in the same transverse cross section taken in along a plane extending medial-lateral and anterior posterior. In this cross section, articular surfaces1016are covered by a thick layer of articular cartilage with a joint space existing between them, theFIGS. 49A-49Dare simplified for illustrative purposes and do not show these features to scale.

Now referring primarily toFIG. 49A, an embodiment of the method can include the step of placing a patient under sedation prone on a translucent operating table (or other suitable surface). The sacroiliac joint1000can be locally anesthetized to allow for injecting a radiographic contrast1046(as a non-limiting example, Isoview 300 radiographic contrast) under fluoroscopic guidance into the inferior aspect of the sacroiliac joint1000to outline the articular surfaces1016of the sacroiliac joint1000) defined between the sacrum1004and ilium1005, the sacroiliac joint1000having an interarticular region1044. Injection of the radiographic contrast1046within the sacroiliac joint1000can be accomplished utilizing a tubular member1047(e.g., a syringe needle) having first tubular member end1048which can be advanced between the articulating surfaces1016of the sacroiliac joint1000and having a second tubular member end1049which removably couples to a hub1050. The hub1050can be configured to removably couple to a syringe barrel1051or other device to contain and deliver an amount of radiographic contrast1046. In the example of a syringe barrel1051, the syringe barrel1051can have an internal volume capable of receiving an amount of the radiographic contrast1046sufficient for outlining the articular surfaces1016of the sacroiliac joint1000, for example, under lateral fluoroscopy. A plunger1052can be slidingly received within the barrel1051to deliver the radiographic contrast1046through the tubular member1047into the sacroiliac joint1000. The tubular member1047can have a gauge in the range of about 16 gauge and about 20 gauge and can further be incrementally marked on the external surface to allow determination of the depth at which the first needle end1048has advanced within the sacroiliac joint1000. As the first needle end1048advances into the sacroiliac joint1000the radiographic dye1046can be delivered from within the syringe barrel1051into the sacroiliac joint1000to allow visualization of the sacroiliac joint1000and location of the tubular needle1047within the sacroiliac joint1000.

Now referring primarily toFIG. 49B, once the first tubular member end1048has been sufficiently advanced into the sacroiliac joint1000and the articular surfaces1016of the sacroiliac joint1000have been sufficiently visualized, the hub1050can be removed from the tubular member1047leaving the tubular member1047fixed within the sacroiliac joint1000as an initial guide for tools subsequently used to locate or place the sacroiliac joint implant non-transversely between the articulating surfaces1016of the sacroiliac joint1000(e.g., locate the implant non-transversely to the joint plane1030generally defined by the articulating surfaces1016of the interarticular region1044of the sacroiliac joint1000) or in removal of a portion of the sacroiliac joint1000within the region defined by the articular surfaces1016to generate an implant receiving space1029. Alternately, one or more guide pins1013can be inserted along substantially the same path of the tubular member1047for fixed engagement within the sacroiliac joint1000and used in subsequent steps as a guide(s).

Now referring primarily toFIG. 49C, a small incision1053can be made in the skin at the posterior superior, or as to certain embodiments inferior, aspect of the sacroiliac joint1000, extending proximal and distal to the tubular member1047along the line of the sacroiliac joint1000to provide a passage to access the interarticular space between the articulating surfaces1016(seeFIG. 49B) of the sacroiliac joint1000. More specifically, the small incision1053can be made along the joint line of the sacroiliac joint1000in the tissue covering the posterior inferior access region2016of the sacroiliac joint articular region1044. A cannulated probe1054can be slidingly engaged with the tubular member1047(or guide pin1013) extending outwardly from the sacroiliac joint1000(while the sacroiliac joint may be shown in the figures as being substantially linear for illustrative purposes, it is to be understood that the normal irregular features of the sacroiliac joint have not been removed). The cannulated probe1054can have a probe body1054of generally cylindrical shape terminating in a spatulate tip1055at the end advanced into the sacroiliac joint1000. A removable cannulated probe handle1056couples to the opposed end of the probe body1054. The spatulate tip1055can be guided along the tubular needle1047or guide wire1013into the posterior portion of the sacroiliac joint1000and advanced to the anterior portion of the sacroiliac joint1000under lateral fluoroscopic visualization. The cannulated probe handle1056can then be removed providing the generally cylindrical probe body1054extending outwardly from the sacroiliac joint1000through the incision1053made in the skin.

Alternatively, the probe1054can be used to guide, advance or place a needle, guide wire or other instrument up to, near, or into the joint.

Additionally, in particular embodiments, probe handle1056or the opposed end of the probe body1054, or both, can be configured to have an interference fit or a luer lock hub to communicate with a syringe barrel1051in order to advance contrast, in situ curable biocompatible materials, stem cells, or etc through the cannulated probe1054or cannulated probe handle1056.

Now referring primarily toFIG. 49D, a passage from the incision1053(seeFIG. 49C) to the sacroiliac joint1000can be generated by inserting a cannula1057into the incision. A soft tissue dilator1058having a blunt end1059can be advanced over the probe body1054, or a plurality of soft tissue dilators of increasing size, until the blunt end1059of the soft tissue dilator1058and the corresponding cannula end contact the posterior aspect of the sacroiliac joint1000. More specifically, in one embodiment, the ends of the dilator1058and cannula1057contact the joint line2019of the sacroiliac joint1000at the posterior inferior access region2016of the sacroiliac joint articular region1044. The soft tissue dilator1058can be removed from within the cannula1057. The external surface of the cannula1057can be sufficiently engaged with the surrounding tissue to avoid having the tissue locate with in the hollow inside of the cannula1057. A non-limiting embodiment of the cannula1057provides a tubular body having substantially parallel opposed side walls which terminate in a radius at both ends (lozenge shape) into which a plurality of different jigs can be inserted. Alternatively, as a non-limiting example, according to particular embodiments, cannula1057and corresponding dilators1058and alignment jigs1060can be configured to have tubular bodies with an elliptical or circular cross section.

In some embodiments, the cannula1057may be additionally configured to have within or near its walls a light source such as, for example, a fiberoptic or a LED light source to assist in visualization of the working area. Also, in some embodiments, irrigation and suction tubing may communicate with the inside passage of cannula1057.

At this stage, additional tools and methods may be employed to provide access to the sacroiliac joint1000as described in U.S. patent application Ser. No. 13/475,695 filed May 18, 2012 entitled “SYSTEMS FOR AND METHODS OF FUSING A SACROILIAC JOINT,” which is hereby incorporated by reference in its entirety. For example, drill jigs may be further advanced over the probe body1054to align a drill or other joint preparation tool. Accordingly, the discussion will now focus on employing the tools and devices described in previous sections of this application.Now referring primarily toFIGS. 49E-49G, a cannula alignment jig1060can be advanced over the probe body1054(or guide pins1013) and received within the cannula1057. Substantially, identical cross hairs1063,1064can be disposed on the upper jig surface1065and the lower jig surface1066. Alignment of the cross hairs1063,1064under x-ray with the sacroiliac joint1000can confirm that the cannula1057has proper orientation in relation to the paired articular surfaces1016of the sacroiliac joint1000. The cannula1057properly oriented with the paired articular surfaces1016can then be disposed in fixed relation to the sacroiliac joint by placement of fasteners through the cannula1057into the sacrum1004or the ilium1005.Now referring toFIGS. 49H and 49I, a first drill jig1067can be advanced over the probe body1054(or guide pins1013) and received within the cannula1057. The probe body1054(or guide pins1013) extending outwardly from the sacroiliac joint1000passes through a drill guide hole1068of the first drill jig1067(or a plurality of guide pins1013can extend through a corresponding plurality of guide pin holes1069). The drill guide hole1068can take the form of a circular hole as shown in the Figures, a slot, or other configuration to restrict the movement of a drill bit1062within the drill jig1067and provide a guide for a drill bit1062in relation to the sacroiliac joint1000. Guide pin holes1069can receive guide pins which can be positioned between the articular surfaces1016of the sacroiliac joint1000to demarcate the zone of desired treatment or safe working zones while using, for example, lateral fluoroscopy. As a non-limiting example, a first guide pin1013can be advanced through a first guide pin hole1069, or alternatively a guide pin1013is first inserted into the sacroiliac joint1000and subsequently a guide jig1067is advanced over the guide pin1013, the first guide pin1013can enter near inferior end2022of the posterior inferior access region2016of the sacroiliac joint articular region1044via the sacroiliac joint line2019to border a portion of the greater sciatic notch2008thereby allowing a medical person, computer guided surgical system, or other observer to more easily highlight under x-ray a border which should not be crossed during the procedure due to the presence of nerve and other structures. Additionally, as a non-limiting example, first guide pin1013can configured as an electrode, insulated from the operator and the patient's soft tissues, and may be connected to a monitor to signal to an operator or surgeon when implant12, configured with a stimulating electrode (NM), e,g., as shown and described in U.S. Provisional Patent Application 61/860,185, comes into contact with first guide pin. Similarly, a second guide pin1013can be placed in another guide pin hole1069to demarcate a second limit to a desired zone of treatment, or safe working zone. For example, a second guide pin1013can enter near the superior end2018of the posterior inferior access region2016of the sacroiliac joint articular region1044via the sacroiliac joint line2019to be positioned to border an area of the sacroiliac joint1000such as a transition zone between the extra-articular3007and the interarticular region1044which, for example, has been highlighted by contrast material as above described.Referring to FIGS,49J-49R, a cannula1057may be used to facilitate access to the surgical region during a procedure to implant the implant assembly14(not shown). In one embodiment, the cannula1057may be used in conjunction with a sacroiliac joint repair procedure via a known surgical access region including, but not limited to, the posterior inferior access region2016as illustrated inFIGS. 49J-49R. The cannula1057may include a cannula body1057H forming a wall enclosing an internal volume1057J, which opens to a proximal opening1057A and a distal opening105713. Upon insertion of the cannula1057within the surgical access region, the internal volume1057J may be maintained, thereby functioning as an opening through which surgical instruments, appliances, fasteners, and any other associated surgical equipment or supplies may be inserted or removed and through which the surgical procedure may be visually monitored.The outer surface of the cannula body1057H may include one or more contoured regions or projections to enhance the close fit of the cannula1057between the skeletal structures surrounding the surgical access region2016. The outer surface of the body1057H may form a cannula sacral contour1057C on one side and may additionally form a cannula iliac contour1057D on a side opposite to the cannula sacral contour1057C. The cannula1057may also include a distal projection1057E which extends distally beyond the cannula sacral contour1057C and may be shaped to fit within a portion of the greater sciatic notch2008(seeFIG. 49P). In addition, the outer distal surface of the cannula body1057H may form a PSIS contact area1057F to enhance the fit of the portion of the cannula1057contacting the posterior superior iliac spine (PSIS)2004(seeFIG. 49N).The cannula body1057H may further define one or more additional bores configured to reversibly receive handles and/or fasteners used to situate the cannula within the surgical region and/or to reversibly receive fasteners used to fix the cannula in place within the surgical region during the surgical procedure. The cannula body1057H may define a fastener bore1057K passing through the cannula body1057H from the outer surface into the internal volume1057J of the cannula1057. The cannula bore may open at one end to a cannula fastener bore proximal opening1057G, which may be in communication with the internal volume1057J of the cannula1057. The cannula bore may also open at an opposite end to a cannula fastener bore distal opening1057L which may be further configured to permit a fastener1057Z to i) extend generally perpendicular to the cannula PSIS contact area1057F; and/or, ii) be in a divergent relation relative to distal projection1057E. Furthermore, the cannula1057may have a handle1057Y extending from the cannula body1057H for inserting, removing, and/or otherwise manipulating the cannula1057during a surgical procedure. As illustrated inFIG. 49J, the handle1057Y may be reversibly attached to the cannula body1057via a handle bore1057M formed with the cannula body1057H. The handle bore1057M may be provided with fastener features including, but not limited to, threads, that may cooperatively engage corresponding fastener features at a distal end1057N of the handle1057Y in order to implement the reversible attachment of the handle1057Y to the cannula1057.Referring again toFIGS. 49J to 49R, a surgical procedure employing the cannula1057may be conducted using a method described herein below. A cannula1057may be positioned near a sacroiliac joint line2019and in an area including the posterior inferior access region2016such that the sacroiliac joint line2019may be visible and/or accessible via a cannula proximal opening1057A, as illustrated inFIG. 49O. The cannula1057may be further positioned to align the distal extension1057E with a portion of the greater sciatic notch2008, as illustrated inFIG. 49P. The cannula1057may be further positioned to align the cannula PSIS contact area1057F with a portion of a posterior superior iliac spine2004as illustrated inFIG. 49N. The cannula1057may then be disposed in fixed relation to the sacroiliac joint by placement of fasteners1057Z through the cannula1057into the sacrum1004or the ilium1005, as illustrated inFIG. 49P.

In certain embodiments of the method, an amount of articular cartilage or other tissues from between the articular surfaces of the sacroiliac joint1000can be removed sufficient to allow embodiments of the sacroiliac joint implant to be implanted in replacement of the removed articular cartilage or tissue. Because the method removes the degenerative articular cartilage or tissue between the articular surfaces of the sacroiliac joint1000, the articular surfaces of the sacroiliac joint1000can remain intact or substantially intact allowing the sacroiliac joint implant to be non-transversely located between the articular surfaces of the sacroiliac joint1000.

Reference is now made toFIG. 50A, which depicts a joint preparation tool4000including a tooling head4002, as described inFIGS. 9-10, approaching the sacroiliac joint1000. The joint preparation tool4000, in particular, includes a cutting element4004that outwardly extends from a shaft4006at the distal end of the tooling head4002. The cutting element4004includes a sharpened proximal edge4008such that a cutting stroke occurs with a proximal retraction of the joint preparation tool4000.

As seen inFIG. 50A, the joint preparation tool4000is oriented relative to sacroiliac joint articular region1044such that the outwardly extending cutting element4004is positioned parallel to the joint plane1030. That is, each of the side walls the cutting element4004is oriented between the articular surfaces of the joint1000and the proximal edge4008is, initially, oriented transversely across the joint plane1030. As illustrated inFIG. 50B, the joint preparation tool4000is advanced into the sacroiliac joint articular region1044in the previously described orientation.

Now reference is made primarily toFIG. 50C, which is a similar view to that ofFIG. 48C, except that instead of an implant being delivered into the sacroiliac joint1000, the joint1000is being prepared for implant delivery. As seen in the figure, the distal end of the tooling head4002may enter the posterior inferior access region2016and extend into the caudal region1086of the sacroiliac joint articular region1044. As an example and as seen by the solid line depiction of the tooling head4002, the head4002may be delivered into the caudal region1086such that the shaft4006is generally adjacent and parallel to the inferior boundary segment3002. At a sufficient depth, the joint preparation tool4000may be rotated within the joint plane (as seen by the broken line depiction of the joint preparation tool4000) such that the shaft4006angles the cutting element4004towards the cranial region1087of the articular region1044. This and other movements will cause the proximal edge4008of the cutting element4004to cut into or shear the articular cartilage from the articular surfaces of the sacroiliac joint articular region1044.

As another example of preparing the articular region1044once the tool4000is positioned within the articular region1044, reference is made toFIG. 50D, which depicts the joint preparation tool4000fully in into the articular region1044such that the shaft4006of the tooling head4002is adjacent and parallel to the inferior boundary segment3002and the cutting element4004is adjacent the anterior-inferior corner3010. In this orientation, the cutting element4004extends from the shaft4006towards the cranial region1087of the articular region1044. It is noted that insertion of the tool4000into the articular region1044causes an initial abrasion to the articular cartilage in the portions of the articular region1044where the tool4000is inserted. To further prepare the articular region1044, a force F1 may be applied to joint preparation tool4000in a direction perpendicular to the extension of the shaft4006and in a direction towards the cranial region1087. As seen inFIG. 50E, which depicts the joint preparation tool4000moved superiorly according to the applied force F1, the cutting element4004is now in contact with additional articular cartilage that was not previously abraded by the insertion of the tool4000into the articular region1044. At this point, a force F2 may be applied proximally on the joint preparation tool4000.

As seen inFIG. 50F, the force F2 and the proximal retraction of the tooling head4002from the articular region1044will cause articular cartilage in-line with the cutting element4004to be cut or otherwise sheared from the articular surfaces of the articular region1044leaving a prepared joint surface4010. At this point, the joint preparation tool having a curette-type tooling head may be used to remove the abraded articular cartilage in the joint space by any number of methods.

The previously mentioned steps may be repeated in order to increase the size of the prepared joint surface4010as may be needed for a particular surgical procedure. For example, a joint preparation tool4000having a tooling head4002with a larger outwardly extending cutting element4004may be subsequently used to prepare an even larger joint surface4010.

Now primarily referring toFIG. 51A, the joint preparation tool4000previously described may be used to make keel-cuts generally perpendicularly into the sacrum1004and/or the ilium1005. As seen in the figure, which is a transverse cross section of the sacrum1004and the ilium1005taken in along a plane extending medial-lateral and anterior posterior, the joint preparation tool4000may be delivered into the sacroiliac joint articular region1044, as described previously inFIGS. 50A-50B, such that the cutting element4004extends from the shaft4006of the tooling head4002parallel to the joint plane1030. In this orientation, the proximal edge4008of the cutting element4004extends across the joint plane1030. Once the joint preparation tool4000is at a sufficient depth within the articular region1044, as seen inFIG. 51A, the shaft4006of the tool4000may be rotated such that the cutting element extends within either the sacrum1004or the ilium1005(cutting element extends within ilium1005inFIG. 51A) and is oriented perpendicular to the joint plane1030. Next, a force F3 may be proximally applied (e.g., via a slap hammer assembly) to the joint preparation tool4000such that the proximal edge4008of the cutting element4004cuts a channel, groove, or other feature as defined by the shape of the proximal edge4008into the bone of the ilium1005. As seen inFIG. 51B, the proximal retraction of the joint preparation tool4000forms a receiving space4012within the bone of the ilium1005for use in a particular fusion procedure. WhileFIG. 51Bdepicts the cutting element4004only partially retracted from the articular region1044, the cutting element4004may be fully retracted such that the keel-cuts forming the receiving space4014extend to the proximal end of the joint line1030.

Alternatively and as seen inFIG. 51C, which is the same asFIG. 51Bexcept the shaft4006of the joint preparation tool4000is rotated about ninety degrees, the tooling head4002may be removed from the articular region1044after the ninety degree rotation by a proximal force F4. Thus, the tooling head4002is removed from the joint without performing a full keel-cut that would extend the receiving space4012to the proximal end of the joint line1030. Turning toFIG. 51D, which depicts the receiving space4012after the joint preparation tool4000has been proximally withdrawn; the receiving space4012may be filled with a biological material4014such as an alto/auto-graft, synthetic biologic, or scaffold, among other materials. Next, a bone tamp4016or other device may be used to apply a distal force F5 along the joint line1030so as to compress the biological material4014into the receiving space4012. As seen inFIG. 51E, the bone tamp4016may be compressed along the joint line1030up to a depth of the keel-cut, among other possible depths, such that the biological material4014may compress across the articular surface of the sacrum1004and the groove formed in the receiving space4012.

In certain embodiments of the method, keel-cuts can be made in either or both of the sacrum1004and the ilium1005and such a decision will be based on the particular fusion procedure and the type and configuration of an implant to be delivered into the joint. For example, an implant having coplanar wing member may require dual keel-cuts where both the sacrum1004and the ilium1005are cut for the subsequent delivery of the implant. In such an example and referring toFIG. 52A, a joint preparation tool4000having a tooling head4002with dual-cutting elements4004, as described in reference toFIG. 13, may be employed. Similar to as discussed previously, the joint preparation tool4000having dual-cutting elements4004may be delivered into the sacroiliac joint articular region1044with the outwardly extending cutting elements4004positioned within the joint plane1030such that the proximal edges4008extend across the joint line1030. Once the joint preparation tool4000is delivered into the articular region1044at an appropriate depth, as seen inFIG. 52A, the tool4000may be rotated about ninety degrees such that the cutting elements extend generally perpendicularly into the sacrum1004and the ilium1005. Next, as seen inFIG. 52B, the joint preparation tool4000may be proximally retracted by a force F6 (e.g., via a slap hammer) such that the dual-cutting elements4004form opposing channels4018in the sacrum1004and the ilium1005that match the shape of an implant to be delivered in the surgical procedure.

In certain embodiments, the dual-cutting elements4004are identical in shape and size. In other embodiments, the dual-cutting elements4004may be differently configured based on the physical characteristics of the bone type to be cut, the implant to be delivered, etc. That is, since the ilium1005is generally a harder bone than the sacrum, a different type of cutting edge configuration may be used on one of the cutting elements4004.

Now the discussion will focus on methods of preparing the sacroiliac joint1000for a surgical fusion procedure with a joint preparation tool assembly including a trial tool assembly and a cutting tool as described in reference toFIGS. 27-47.

Referring primarily toFIG. 53A, a trial tool assembly4022having an implant trial4024at a distal end of the assembly4022may be delivered into the sacroiliac joint articular region1044of a patient. The trial tool assembly4022may be guided into the articular region1044by a guide wire (not shown) that was previously delivered into the joint by previously described methods. In particular, the guide wire may be received within a bore that extends from a distal end to a proximal end of the implant trial4024. The implant trial4024may be delivered within the joint plane1030such that the planar top and bottom surfaces4026are parallel to the joint plane1030and the opposite side surfaces4028of the implant trial4024are perpendicular to the joint plane1030.

The implant trial4024may be forcibly delivered into the articular region1044by using a hammer or mallet to strike an impact plate (not shown) at a proximal end of the joint preparation tool assembly4020. And, in certain embodiments, a trial impact rod assembly (not shown) may be used in conjunction with the trial tool assembly4022to provide stiffness during the forceful delivery of the implant trial4024within the articular region1044.

The implant trial4024is used to determine an appropriate fit of an implant. So, implant trials4024of increasingly larger size may be delivered into the articular region1044until an implant trial4024is chosen that appropriately fits the top and bottom surfaces4026of the implant trial4024against the articular surfaces of the articular region1044.

Referring primarily toFIG. 53B, which depicts the implant trial4024positioned within the articular region1044, a cutting tool4030may be slidingly engaged with a shaft4032of the trial tool assembly4022and translated distally on the shaft4032. As seen inFIG. 53Band as described previously, the cutting tool4030is guided along the shaft4032in a single orientation such that it will be guided within a channel (not shown) on the top surface4026of the implant trial4024. The channel is configured to guide the cutting tool4030such that a cutting element4034of the cutting tool4030extends generally perpendicular to the top surface4026of the implant trial4024. Thus, as seen inFIG. 53C, as the cutting element4034advances distally into the channel of the implant trial4024and within the articular region1044, the cutting element4034extends and cuts into the articular surface of either the sacrum1004or the ilium1005. A reciprocating motion may be employed.

While, as seen inFIG. 53C, the cutting element4034extends and cuts into the ilium1005during a distal stroke of the cutting tool4030, the process may be similarly performed with respect to the sacrum1004. Alternatively, a cutting tool4030with dual-cutting elements4034may be employed to deliver simultaneous and opposing cuts into both the sacrum1004and the ilium1005. In such an embodiment of the joint preparation tool assembly4020with dual-cutting elements4034(and, thus, dual-channels in the implant trial4024) the individual cutting elements4034may be the same or different. The individual cutting elements4034may, for example, be different types and configurations of cutting elements4034since the ilium1005is a generally harder bone than the sacrum1004. Additionally, cutting tools4030with increasingly larger cutting elements4034may be employed such that initial cuts are smaller and of a shallower depth into the articular surfaces while subsequent cuts are larger and of a deeper depth into the articular surfaces of the sacrum1004and ilium1005.

After employing the joint preparation tool4020to make appropriate keel-cuts, as seen inFIG. 53D, the tool4020may be removed from the articular region1044leaving one or more channels4036that match an implant to be delivered into the joint1000.

As stated previously, the various tools and assemblies discussed herein may be used independently or in combination with each other. Thus, in certain embodiments and at various steps within the methodology the anchor arm assembly258, as discussed in reference toFIGS. 24-25, may be employed with any of the joint preparation tools to deliver an anchoring element282across the sacroiliac joint. The anchoring arm assembly258may, for example, orient the anchoring element282to be delivered first through the ilium, transversely across the joint line of the sacroiliac joint, and then through the sacrum. Alternatively, the anchoring arm assembly258may orient the anchoring element282to be delivered first through the sacrum, transversely across the joint line of the sacroiliac joint, and then through the ilium.

Understandably, other instruments can be utilized separately or in combination during the course of any of the steps of the methodology, .e.g., for the removal of articular cartilage or tissue between articular surfaces, such as any of the tools previously described or any of: endoscopy tools, box chisels, side cutting router bits, burs, flexible burs and bits, hole saws, key hole saw, medical bone chainsaw osteotome, curettes, lasers (e.g., C02, Neodymium/Y AG (yttrium-aluminum-garnet), argon, and ruby), electrosurgical equipment employing electromagnetic energy (the cutting electrode can be a fine micro-needle, a lancet, a knife, a wire or band loop, a snare, an energized scalpel, or the like) where the energy transmitted can be either monopolar or bipolar and operate with high frequency currents, for example, in the range of about 300 kHz and about 1000 kHz whether as pure sinusoidal current waveform where the “crest factor” can be constant at about 1.4 for every sinus waveform, and a voltage peak of approximately 300 V to enable a “pure” cutting effect with the smallest possible coagulation effect or as amplitude modulated current waveforms where the crest factor varies between 1.5 and 8, with decreasing crest factors providing less of a coagulation effect. Electrosurgical waveforms may be set to promote two types of tissue effects, namely coagulation (temperature rises within cells, which then dehydrate and shrink) or cut (heating of cellular water occurs so rapidly that cells burst). The proportion of cells coagulated to those cut can be varied, resulting in a “blended” or “mixed” effect. Additionally, a fully rectified current, or a partially rectified current, or a fulguration current where a greater amount or lateral heat is produced can be employed to find the articular surfaces of the joint and aid in advancing a probe or guide wire into a position in between the articulating surfaces. These currents can effectively degrade the cartilage and allow advance into the joint without grossly penetrating much beyond the cartilage.

The foregoing merely illustrates the principles of the embodiments described herein. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements and methods which, although not explicitly shown or described herein, embody the principles of the embodiments described herein and are thus within the spirit and scope of the present disclosure. From the above description and drawings, it will be understood by those of ordinary skill in the art that the particular embodiments shown and described are for purposes of illustrations only and are not intended to limit the scope of the present disclosure. References to details of particular embodiments are not intended to limit the scope of the disclosure.