Interbody implant and method

An interbody endcap includes a wall having a first surface connected to an interbody implant and a second surface including an arcuate portion configured for engagement with a vertebral endplate surface. The second surface extends outwardly from the interbody implant to at least adjacent a perimeter of the vertebral endplate surface. Systems and methods are disclosed.

TECHNICAL FIELD

The present disclosure generally relates to medical devices for the treatment of musculoskeletal disorders, and more particularly to a surgical system that includes an interbody implant and a method for treating a spine.

BACKGROUND

Spinal disorders such as degenerative disc disease, disc herniation, osteoporosis, spondylolisthesis, stenosis, scoliosis and other curvature abnormalities, kyphosis, tumor, and fracture may result from factors including trauma, disease and degenerative conditions caused by injury and aging. Spinal disorders typically result in symptoms including pain, nerve damage, and partial or complete loss of mobility.

Non-surgical treatments, such as medication, rehabilitation and exercise can be effective, however, may fail to relieve the symptoms associated with these disorders. Surgical treatment of these spinal disorders includes fusion, fixation, corpectomy, discectomy, laminectomy and implantable prosthetics. In procedures, such as, for example, corpectomy and discectomy, fusion and fixation treatments may be performed that employ implants to restore the mechanical support function of vertebrae. This disclosure describes an improvement over these prior art technologies.

SUMMARY

In one embodiment, an interbody endcap is disclosed. The interbody endcap includes a wall having a first surface connected to an interbody implant and a second surface including an arcuate portion configured for engagement with a vertebral endplate surface. The second surface extends outwardly from the interbody implant to at least adjacent a perimeter of the vertebral endplate surface. In some embodiments, systems and methods are disclosed.

In one embodiment, the interbody endcap includes a wall having a first surface including a first mating part disposed for engagement with a second mating part of an interbody implant such that the first surface is aligned with the interbody implant such that the wall is disposable in an interlocking configuration with the interbody implant. At least one of the mating parts includes a relatively movable member that is engageable with the other of the mating parts to dispose the wall and the interbody implant in the interlocking configuration. The wall further has a second surface configured for engagement with a vertebral endplate surface.

DETAILED DESCRIPTION

The exemplary embodiments of the surgical system and related methods of use disclosed are discussed in terms of medical devices for the treatment of musculoskeletal disorders and more particularly, in terms of a surgical system that includes an interbody implant and a method for treating a spine.

In one embodiment, the surgical system includes a corpectomy or vertebral body replacement (VBR) implant having extended or widened endcaps and various connection mechanisms for connecting the widened endcaps to either static or expandable implants. In one embodiment, the implant is configured for disposal in a defect in an intervertebral space. In one embodiment, the endcaps are extended and contoured for nested engagement with concave endplates of vertebral bodies. In one embodiment, the endcaps extend out from the center of the defect to the apophyseal ring of a vertebral endplate surface. A majority of the force transferred from the vertebral endplate surfaces to the implant will transfer to the edges of the endcap, which will be in contact with the apophyseal ring or cortical rim of the annulus fibrosis. In one embodiment, a stronger connection between the endcaps and the implant or centerpiece is provided to resist a moment imparted during lateral or sagittal bending of the vertebrae. The various connection mechanisms provided may also be useful for connecting non-extended or non-widened endcaps that have a diameter, length and/or width that approximates a corresponding diameter, length and/or width of the static or expandable implant to which they are attached.

In one embodiment, the endcaps will have a specific length-to-width aspect ratio so as to span the endplates of the vertebral bodies. In one set of exemplary embodiments, the length-to-width aspect ratio of the endcaps will range from 1.1-1 to 1.8-1. In other embodiments the length-to-width aspect ratio of the endcaps may have a greater range from 1-1 to 3-1. In such embodiments, the length of the endcaps may be in a range from 20 mm to 50 mm. In one embodiment, the endcap outer surfaces will have a convex shape. In one embodiment, the endcaps will be connected to the implant centerpiece via a rotate and lock connection mechanism. In one embodiment, the endcaps will be fixed to existing endcaps that are fixed to the expandable or static implant. In one embodiment, the endcaps will be attached to existing endcaps that are articulatingly connected to the expandable or static implant. In one embodiment, the implant is an expandable cage. In one embodiment, the endcap can be connected to an outer body of the implant or a fixed or articulating endcap already connected to a movable inner body of the implant.

In one embodiment, implant end surfaces each include approximately 8 posts extending therefrom configured for mating engagement with spring fingers of endcaps. In one embodiment, a tab of each spring finger is in nested engagement with an undercut or slot of each post. In one embodiment, approximately two spring fingers of an endcap fits into slots defined in pegs extending from end surfaces of an implant. In one embodiment, the spring fingers are wire cut forming a finger of approximately 0.6 millimeters (mm). In one embodiment, a rotate and lock connection is provided. In one embodiment, an endcap is locked to an implant via rotating the endcap into slots defined in approximately 8 pegs extending from a centerpiece of an implant.

In one embodiment, the implant includes a threaded hole located between circumferentially disposed spikes. The endcap also includes a hole through which a set screw is used to connect the endplate to the implant. An underside of the endcap includes indentations corresponding to each spike extending from the implant. The spikes and/or set screws counteract torsion.

In one embodiment, the implant includes a hexagonal hole therethrough. A stem of the endcap includes a correspondingly shaped hex shape fitted with the implant so as to allow for multiple rotational positions to be chosen. The hex geometry resists torsional forces. In one embodiment, the stem of the endcap includes a pair of fingers defining a keyhole shaped recess that allows the fingers to flex and matingly engage a correspondingly-shaped connecting feature in the implant. In one embodiment, flexible wires, such as, for example, Nitinol wires are embedded into the implant and capture an engaging feature disposed at a bottom end of the stem of the endcap.

In one embodiment, the stem of the endcap is similar to a quick connect hose fitting. In one embodiment, splines are disposed on an outer surface of the implant and an underside of the endcap. The splines resist relative rotation of the implant and endcap. Snap fingers and/or set screws maintain contact between the two splined surfaces. In one embodiment, the splines extend down a bone graft hole into a core of the implant. Ridges on the stem of the endcap allow for a plurality of rotational positions and to counteract torsion.

In one embodiment, the endcap includes a separate connecting/locking component. A set screw is threaded through the endcap locking the endcap to the implant. In one embodiment, a snap ring captures the set screw. In one embodiment, the underside of the endcap includes indentations, depressions or through holes to mate with spikes extending from the implant to counteract torsion. In one embodiment, a lower portion of the connecting component includes a cog-like shape. The cog-shaped component matingly engages with a correspondingly shaped hole in the implant. When rotated, the teeth of the cog can engage a series of undercuts to hold the endcap onto the implant. In one embodiment, the endcap includes an external ring that is independently rotatable relative to the implant and the endcap. The ring threadably engages the implant and includes a projection or flange affixed to the endcap whereby connecting the endcap and implant.

In one embodiment, the implant includes a first endcap fixed to the implant. This endcap includes a series of through holes circumferentially disposed. An underside of a second endcap includes one or more features that protrude downward that are configured for engagement with the through holes of the first endcap. Each of the connecting features includes fingers defining a keyhole-shaped recess that matingly engage with the first endcap. In one embodiment, a rotatable central cam is disposed on the endcap. The cam engages one or multiple pivotable arms. When the cam engages the pivotable arms, the arms are forced into a locked position to interface with features extending from the implant. The interface includes, for example, undercuts, recesses, protrusions, or friction fits. The endcap may include through holes or recesses on its underside to correspond to spikes extending from the implant. In one embodiment, the implant includes only one endcap. In one embodiment, the implant includes one or more endcaps that extend uni-laterally from a central body portion of the implant, such as, for example, a cage. For example, only one side of the endcap is extended and can be employed with a partial corpectomy.

In one embodiment, one or all of the components of the surgical system are disposable, peel-pack, pre-packed sterile devices used with an implant. One or all of the components of the surgical system may be reusable. The surgical system may be configured as a kit with multiple sized and configured components.

The following discussion includes a description of a surgical system and related methods of employing the surgical system in accordance with the principles of the present disclosure. Alternate embodiments are also disclosed. Reference is made in detail to the exemplary embodiments of the present disclosure, which are illustrated in the accompanying figures. Turning toFIGS. 1-5, there is illustrated components of a surgical system, such as, for example, a spinal implant system10in accordance with the principles of the present disclosure.

Spinal implant system10is employed, for example, with a minimally invasive procedure, including percutaneous techniques, mini-open and open surgical techniques to deliver and introduce instrumentation and/or an implant, such as, for example, a corpectomy implant, at a surgical site within a body of a patient, for example, a section of a spine. In some embodiments, system10may be employed with surgical procedures, such as, for example, corpectomy and discectomy, which include fusion and/or fixation treatments that employ implants, in accordance with the principles of the present disclosure, to restore the mechanical support function of vertebrae.

System10includes an implant, such as, for example, a spinal implant20. Spinal implant20includes an interbody implant, such as, for example, a corpectomy cage12having a member, such as, for example, an outer body14and an inner body16. Body14has a tubular configuration. Body14is substantially cylindrical and extends between an end17and an end18and defines a longitudinal axis A1therebetween. End17defines a substantially planar surface. End18defines a substantially planar surface including a mating part21. In one embodiment, mating part21includes a relatively movable member that is engageable with a mating part24of an endcap22, to be described below.

Wall34defines openings42configured to facilitate delivery and/or introduction of an agent, bone graft and/or other materials into cavity38, for employment in a fixation or fusion treatment used for example, in connection with a corpectomy. In one embodiment, the agent may include therapeutic polynucleotides or polypeptides and bone growth promoting material, which can be packed or otherwise disposed on or about the surfaces of the components of spinal implant system10, including cage12. The agent may also include biologically active agents, for example, biologically active agents coated onto the exterior and/or interior of cage12and/or applied thereto for gradual release such as by blending in a bioresorbable polymer that releases the biologically active agent or agents in an appropriate time dependent fashion as the polymer degrades within the patient. Suitable biologically active agents include, for example, BMP and cytokines. In some embodiments, openings42may have various configurations, such as, for example, those described herein.

The planar surface of end17defines an opening44that communicates with cavity38. Opening44has a rectangular configuration and is configured to provide access to cavity38. Opening44facilitates disposal of a member, such as, for example, inner body16with cavity38, as described herein. The planar surface of end18defines an opening46, as shown inFIG. 2, which communicates with cavity38. Opening46has a rectangular configuration and is configured to provide access to cavity38. In some embodiments, opening44and/or opening46may have various configurations, such as, for example, those described herein.

Body16has a tubular configuration. Body16is substantially rectangular and extends between an end48and an end50and extends along longitudinal axis A1. End48defines a substantially planar surface including a mating part118, similar to mating part21described above with regard to body14. In one embodiment, mating part118includes a relatively movable member (not shown) that is engageable with a mating part120of an endcap54, to be described below. In some embodiments, end48can include a surface that may be rough, textured, porous, semi-porous, dimpled and/or polished such that it facilitates engagement with endcap54. In other embodiments, body16may have a variety of alternative cross-sectional configurations including, but not limited to: round; oval; “U” or “C” shaped; and combinations thereof.

Body16includes a tubular wall56. Wall56includes an inner surface57that defines an axial cavity58extending between ends48,50. In some embodiments, wall56defines a rectangular cross-section of cavity58. In some embodiments, the cross-section geometry of cavity58may have various configurations, such as, for example, those described herein. In some embodiments, inner surface57is smooth or even. In some embodiments, inner surface57may be rough, textured, porous, semi-porous, dimpled and/or polished.

Wall56defines lateral openings60that communicate with cavity58. Openings60are configured to provide access to cavity58. In one embodiment, openings60facilitate delivery and/or introduction of an agent into cavity58. In some embodiments, openings60may have various configurations, such as, for example, those alternatives described herein.

The planar surface of end48defines an opening (not shown) that communicates with cavity58. The opening has a circular configuration and is configured to provide access to cavity58. In one embodiment, the opening facilitates delivery and/or introduction of an agent and/or an implant, such as, for example, bone graft and/or other materials with cavity58. The planar surface of end50defines an opening64that communicates with cavity38and cavity58. Opening64has a rectangular configuration and is configured to provide access to cavity38and cavity58. In some embodiments, opening64may have various configurations, such as, for example, those described herein.

Implant20further includes an interbody endcap22connected to end18of body14. Endcap22includes a wall66having a rectangular configuration. In some embodiments, wall66has various configurations, such as, for example, oval-shaped, arcuate, crescent, horseshoe, hook-shaped and/or those alternatives described herein. Wall66includes a pair of short sides68and a pair of long sides70. Short sides68extend to at least a perimeter, such as, for example, an apophyseal ring AR of a vertebral endplate surface E1of a vertebral body V1. In some embodiments, short sides68and/or long sides70could be tapered, sloped, angled, or curved, including convex, bi-convex and concave.

Wall66has a surface72and a surface74. Wall66has a non-uniform thickness defined between surfaces72,74. Surface72extends outwardly from cage12to at least adjacent apophyseal ring AR of vertebral endplate surface E1. Surface72includes an arcuate portion76configured for engagement with vertebral endplate surface E1of vertebral body V1. Arcuate portion76is disposed in a nested engagement with vertebral endplate surface E1. Surface72extends between an end78and an end80such that arcuate portion76is disposed between ends78,80. Ends78,80each include a substantially planar configuration oriented transverse to axis A1. Surface72is sized and dimensioned such that ends78,80are disposed adjacent opposing ends of apophyseal ring AR or cortical rim of vertebral endplate surface E1. In one embodiment, surface72is sized and dimensioned such that only one of ends78,80is disposed adjacent an end of apophyseal ring AR. Surface72includes a plurality of fixation elements, such as, for example, spikes82configured to engage vertebral tissue. In some embodiments, surface72can include a surface that may be rough, textured, porous, semi-porous, dimpled and/or polished such that it facilitates engagement with vertebral tissue, such as, for example, vertebral endplate surface E1. In some embodiments, surface72can include an opening corresponding to the size and cross-section geometry of body14to deliver an agent, such as, for example, bone graft to vertebral endplate surface E1. In some embodiments, the vertebral tissue may include intervertebral tissue, endplate surfaces and/or cortical bone.

In one embodiment, endcap22extends uni-laterally from body14such that only one side of endcap22is extended and can be employed, for example, with a partial corpectomy. Surface72is sized and dimensioned such that one of ends78,80extends outwardly from arcuate portion76. The uni-laterally extended endcap22can be used in a partial corpectomy where vertebral tissue on a lateral side of a vertebral body has been removed and vertebral tissue on the contralateral side of the vertebral body remains intact such that one of ends78,80is disposed in contact with apophyseal ring AR on the lateral side and the other one of ends78,80is disposed with the vertebral tissue on the contralateral side.

Surface74includes mating part24, as shown inFIGS. 3-4, engaged to mating part21of cage12. Mating part24is disposed for engagement with mating part21of cage12such that surface74is aligned with cage12such that wall66is disposable in an interlocking configuration with cage12. Surface74is connected to cage12via rotational interlock of mating parts21,24. Mating part24includes a relatively movable member that is engageable with mating part21of body14of cage12to dispose wall66and cage12in the interlocking configuration. The movable member includes a plurality resiliently biased members88that are rotatably aligned with corresponding slots32of mating part21of cage12for disposal of wall66and cage12in the interlocking configuration. Members88extend radially inward from inner circular surface84of endcap22. Members88include a first portion90having a ramped configuration and a second portion92. Portion92extends between an end94having a protrusion, such as, for example, a spike98and an end96having a protrusion, such as, for example, a spike100. To connect endcap22with end18of body14, endcap22is rotated, in a direction shown by arrow A inFIG. 4, such that portion90engages peg26and at least one of member88and peg26deflect such that portion92and slot32are rotatably aligned. Peg26is captured between spikes98,100to dispose wall66and cage12in the interlocking configuration.

Implant20includes an interbody endcap54, similar to endcap22described above. Endcap54is connected to end48of body16via a similar mating engagement as described above with regard to endcap22and end18of body14. Endcap54includes a wall102having a rectangular configuration. Wall102includes a pair of short sides104and a pair of long sides106. Short sides104extend to at least a perimeter, such as, for example, an apophyseal ring AR of a vertebral endplate surface E2of a vertebral body V2. Wall102has a surface108and a surface110. Surface108extends outwardly from cage12to at least adjacent apophyseal ring AR of vertebral endplate surface E2of vertebral body V2. Surface108includes an arcuate portion112configured for engagement with vertebral endplate surface E2of vertebral body V2. Arcuate portion112is disposed in a nested engagement with vertebral endplate surface E2.

Surface110or underside of endcap54is connected to end48of body16. Surface110includes an inner surface114defining a cavity116configured for disposal of end48of body16. Cavity116has a circular configuration. Surface110includes mating part120, similar to mating part24described above, engaged to mating part118of cage12, similar to mating part24described above. Mating part120is disposed for engagement with mating part118of cage12such that surface110is aligned with cage12such that wall102is disposable in an interlocking configuration with cage12. Surface110is connected to cage12via rotational interlock of mating parts118,120. In some embodiments, endcaps22,54are connected to opposite ends18,48, respectively, of cage12via welding.

Cage12is selectively movable between a first, collapsed and/or nested configuration (not shown) and a second, expanded configuration, as shown, for example, inFIGS. 1 and 5, to restore vertebral spacing and provide distraction and/or restore mechanical support function of vertebrae. In some embodiments, opening44facilitates axial translation of body16relative to body14for selective expansion and/or contraction of bodies14,16between a collapsed and/or nested configuration and an expanded configuration. In some embodiments, cage12is disposed in a collapsed, telescopic configuration for delivery and implantation adjacent a surgical site and bodies14,16are expanded in vivo. In some embodiments, cage12can be expanded prior to implantation adjacent a surgical site. In some embodiments, cage12can be disposed to engage adjacent vertebral soft tissue and bone surfaces to restore height and provide support in place of removed vertebrae and/or intervertebral tissue.

In one embodiment, expansion and/or contraction of cage12is facilitated by engagement of respective helical gear surfaces of bodies14,16such that relative rotation of bodies14,16causes axial translation of body16relative to body14. In one embodiment, expansion and/or contraction of cage12is facilitated by engagement of a tool with one of bodies14,16to cause axial translation of body16relative to body14. In one embodiment, expansion and/or contraction of cage12is facilitated by free hand manipulation of bodies14,16to cause axial translation of body16relative to body14. In one embodiment, expansion and/or contraction of cage12is facilitated by engagement of respective pinion gear and rack surfaces of bodies14,16to cause axial translation of body16relative to body14. In some embodiments, expansion and/or contraction of cage12is facilitated by various configurations, such as, for example, mechanical, pneumatic and/or hydraulic components disposed with the surfaces of cage12, for example, disposed within cavity38. In some embodiments, cage12is configured for continuous expansion, which includes incremental expansion. In some embodiments, incremental expansion may include discrete increments of a particular linear dimension. In some embodiments, the increments of linear dimension may include a range of approximately 0.1-1.0 mm.

In operation, implant20is disposed in a first, collapsed orientation (not shown) such that body14and body16are disposed in a concentric configuration with longitudinal axis A1and disposed in a telescopic arrangement for delivery and implantation adjacent a surgical site. Bodies14,16are seated concentrically such that substantially all of body16is disposed within body14. Endcap22is connected with body14of cage12. Endcap22is rotated, in a direction shown by arrow A inFIG. 4, such that portion90of mating part24engages peg26of mating part21and at least one of member88and peg26deflects such that portion92and slot32are rotatably aligned. Peg26is captured between spikes98,100to dispose wall66and cage12in the interlocking configuration. In the interlocking configuration, mating parts21,24of cage12and endcap22, respectively, are matingly engaged. Endcap54is matingly engaged to end48of body16of cage12via a similar method. In the interlocking configuration, endcaps22,54are prevented from rotating such that implant20is steady upon insertion between vertebrae.

Cage12is delivered to the surgical site adjacent vertebrae V with a delivery instrument (not shown) including a driver via the protected passageway for the arthrodesis treatment. The driver delivers cage12into a prepared vertebral space S, between vertebra V1and vertebra V2. Cage12is manipulated such that surface72of endcap22engages vertebral endplate surface E1and surface108of endcap54engages vertebral endplate surface E2. Sides68of endcap22are aligned with opposite ends of apophyseal ring AR of vertebral body V1and arcuate portion76is in nested engagement with vertebral endplate surface E1. Sides104of endcap54are aligned with opposite ends of apophyseal ring AR of vertebral body V2and arcuate portion112is in nested engagement with vertebral endplate surface E2.

Body16is axially translated relative to body14for selective expansion in vivo to an expanded configuration, as shown inFIG. 5, and described herein. As such, cage12expands within vertebral space S. In the expanded orientation, as shown inFIG. 5, body14and endcap22are disposed to engage adjacent vertebral soft tissue and bone surfaces, as will be described, to restore height and provide support in place of removed vertebrae and/or intervertebral tissue.

Implant20is configured for axial expansion along axis A1. In one embodiment, implant20may expand in an arcuate configuration along a curvature relative to axis A1. In some embodiments, all or only a portion of implant20may be arcuately expanded, such as one or all of bodies14,16may include a curvature relative to longitudinal axis A1.

In one embodiment, implant20is expanded at a selected amount of spacing and/or distraction between vertebrae such that endcap22engages vertebral endplate surface E1and endcap54engages vertebral endplate surface E2to restore vertebral spacing and provide distraction and/or restore mechanical support function. In one embodiment, implant20is expanded, as discussed herein, progressively and/or gradually to provide an implant configured to adapt to the growth of a patient including the vertebrae. In some embodiments, the height of implant20may also be decreased over a period of time and/or several procedures to adapt to various conditions of a patient.

In some embodiments, implant20provides a footprint that improves stability and decreases the risk of subsidence into tissue. In some embodiments, implant20provides height restoration between vertebral bodies, decompression, restoration of sagittal and/or coronal balance and/or resistance of subsidence into vertebral endplates.

In assembly, operation and use, system10including implant20, similar to that described with regard toFIGS. 1-5, is employed with a surgical procedure, such as, for example, a lumbar corpectomy for treatment of a spine of a patient including vertebrae V. System10may also be employed with other surgical procedures, such as, for example, discectomy, laminectomy, fusion, laminotomy, laminectomy, nerve root retraction, foramenotomy, facetectomy, decompression, spinal nucleus or disc replacement and bone graft and implantable prosthetics including plates, rods, and bone engaging fasteners for securement of implant20.

System10is employed with a lumbar corpectomy including surgical arthrodesis, such as, for example, fusion to immobilize a joint for treatment of an applicable condition or injury of an affected section of a spinal column and adjacent areas within a body. For example, vertebrae V include first vertebra V1and second vertebra V2. A diseased and/or damaged vertebra and intervertebral discs are disposed between vertebrae V1and V2. In some embodiments, system10is configured for insertion within vertebral space S to space apart articular joint surfaces, provide support and maximize stabilization of vertebrae V.

In use, to treat the affected section of vertebrae V, a medical practitioner obtains access to a surgical site including vertebrae V in any appropriate manner, such as through incision and retraction of tissues. In some embodiments, system10may be used in any existing surgical method or technique including open surgery, mini-open surgery, minimally invasive surgery and percutaneous surgical implantation, whereby vertebrae V is accessed through a mini-incision, or sleeve that provides a protected passageway to the area. Once access to the surgical site is obtained, corpectomy is performed for treating the spine disorder. The diseased and/or damaged portion of vertebrae V, and diseased and/or damaged intervertebral discs are removed to create vertebral space S.

A preparation instrument (not shown) is employed to remove disc tissue, fluids, adjacent tissues and/or bone, and scrape and/or remove tissue from endplate surface E1of vertebra V1and/or endplate surface E2of vertebra V2. Implant20is provided with at least one agent, similar to those described herein and as described above, to promote new bone growth and fusion to treat the affected section of vertebrae V.

Implant20is disposed in a first, collapsed orientation (not shown) such that body14and body16are disposed in a concentric configuration with longitudinal axis A1and disposed in a telescopic arrangement for delivery and implantation adjacent a surgical site. Bodies14,16are seated concentrically such that substantially all of body16is disposed within body14. Endcap22is connected with body14of cage12. Endcap22is rotated, in a direction shown by arrow A inFIG. 4, such that portion90of mating part24engages peg26of mating part21and at least one of member88and peg26deflects such that portion92and slot32are rotatably aligned. Peg26is captured between spikes98,100to dispose wall66and cage12in the interlocking configuration. In the interlocking configuration, mating parts21,24of cage12and endcap22, respectively, are matingly engaged. Endcap54is matingly engaged to end48of body16of cage12via a similar method. In the interlocking configuration, endcaps22,54are prevented from rotating such that implant20is steady upon insertion between vertebrae.

Cage12is delivered to the surgical site adjacent vertebrae V with a delivery instrument (not shown) including a driver via the protected passageway for the arthrodesis treatment. The driver delivers cage12into a prepared vertebral space S, between vertebra V1and vertebra V2. Cage12is manipulated such that surface72of endcap22engages vertebral endplate surface E1and surface108of endcap54engages vertebral endplate surface E2. Sides68of endcap22are aligned with opposite ends of apophyseal ring AR of vertebral body V1and arcuate portion76is in nested engagement with vertebral endplate surface E1. Sides104of endcap54are aligned with opposite ends of apophyseal ring AR of vertebral body V2and arcuate portion112is in nested engagement with vertebral endplate surface E2.

Body16is axially translated relative to body14for selective expansion in vivo to an expanded configuration, as shown inFIG. 5. As such, cage12expands within vertebral space S. In the expanded orientation, as shown inFIG. 5, body14and endcap22are disposed to engage adjacent vertebral soft tissue and bone surfaces, as will be described, to restore height and provide support in place of removed vertebrae and/or intervertebral tissue.

Implant20engages and spaces apart opposing endplate surfaces E1, E2and is secured within vertebral space S to stabilize and immobilize portions of vertebrae V in connection with bone growth for fusion and fixation of vertebrae V1, V2. Fixation of implant20with endplate surfaces E1, E2may be facilitated by the resistance provided by the joint space and/or engagement with endplate surfaces E1, E2. A lock can be provided to prevent body16from axially translating relative to body14to fix implant20in a selected expanded and/or contracted orientation, including those described herein.

In some embodiments, implant20may engage only one vertebral endplate. In some embodiments, an agent(s), as described herein, may be applied to areas of the surgical site to promote bone growth. Components of system10including implant20can be delivered or implanted as a pre-assembled device or can be assembled in situ. Components of system10including implant20may be completely or partially revised, removed or replaced in situ. In some embodiments, one or all of the components of system10can be delivered to the surgical site via mechanical manipulation and/or a free hand technique.

In one embodiment, implant20may include fastening elements, which may include locking structure, configured for fixation with vertebrae V1, V2to secure joint surfaces and provide complementary stabilization and immobilization to a vertebral region. In some embodiments, locking structure may include fastening elements such as, for example, rods, plates, clips, hooks, adhesives and/or flanges. In some embodiments, system10can be used with screws to enhance fixation. In some embodiments, system10and any screws and attachments may be coated with an agent, similar to those described herein, for enhanced bony fixation to a treated area. The components of system10can be made of radiolucent materials such as polymers. Radiomarkers may be included for identification under x-ray, fluoroscopy, CT or other imaging techniques.

In one embodiment, system10includes a plurality of implants20. In some embodiments, employing a plurality of implants20can optimize the amount vertebral space S can be spaced apart such that the joint spacing dimension can be preselected. The plurality of implants20can be oriented in a side by side engagement, spaced apart and/or staggered.

In some embodiments, the use of microsurgical and image guided technologies may be employed to access, view and repair spinal deterioration or damage, with the aid of system10. Upon completion of the procedure, the non-implanted components, surgical instruments and assemblies of system10are removed and the incision is closed.

In one embodiment, as shown inFIG. 9, system10includes implant20, similar to that described above with regard toFIGS. 1-5, having an endcap322, similar to endcaps22,54described above, and a cage312, similar to cage12described above. Endcap322includes a mating part324. Mating part324includes a relatively movable member, such as, for example, a relatively rotatable screw member326engageable with a threaded cavity328of a mating part320of cage312. Mating part324includes a hexagonal member340engageable with a hexagonal inner surface342of mating part320. Screw member326extends through hexagonal member340and into threaded cavity328. Surface274is rotatably aligned with cage312such that mating parts320,324are rotatably aligned.

In one embodiment, as shown inFIG. 10, system10includes implant20, similar to that described above with regard toFIGS. 1-5, having an endcap422, similar to endcaps22,54described above, and cage412, similar to cage12described above. Endcap422includes a mating part424. Mating part424includes a relatively movable member, such as, for example, a relatively rotatable screw member426, similar to screw member326described above with regard toFIG. 9. Screw member426is engageable with a threaded cavity428of a mating part420of cage412. Mating part424includes a splined outer surface440. Individual splines of splined surface440are oriented substantially parallel with longitudinal axis B1. Splined surface440has a cylindrical configuration. Splined surface440is engageable with a splined inner surface442of mating part420of cage412. Individual splines of splined surface442are oriented substantially parallel with longitudinal axis B1. Splined surface442has a cylindrical configuration configured for disposal of splined surface440. In some embodiments, surface472of endcap422includes splines engageable with splines on a surface473of cage412. In some embodiments, splined surfaces440,442are variously configured, such as, for example, oval, oblong, triangular, square, hexagonal, polygonal, irregular, uniform, non-uniform and/or tapered.

In one embodiment, as shown inFIG. 11, system10includes implant20, similar to that described above with regard toFIGS. 1-5, having an endcap522, similar to endcaps22,54described above, and a cage512, similar to cage12described above. Cage512includes a mating part520, similar to mating part320described above with regard toFIG. 9. Mating part520includes a relatively movable member, such as, for example, Nitinol wires526extending in cross-sectional plane P2of cage512. Nitinol wires526have a substantially parallel orientation relative to one another and are disposed on opposite ends of an inner surface528of mating part520. Inner surface528defines a cavity530having a hexagonal cross section configuration configured for disposal of a correspondingly shaped outer surface532of a mating part524of endcap522. Mating part524includes a circumferential recess534configured for disposal of Nitinol wires526. Outer surface532has a hexagonal configuration such that inner and outer surfaces528,532are matingly engageable. In some embodiments, surfaces528,532are variously configured, such as, for example, those alternatives herein described. In some embodiments, recess534is a pair of recesses disposed in opposite ends of outer surface532. To engage endcap522with cage512, a surface574of endcap522and cage512are rotatably aligned and outer surface532is positioned within cavity530. Nitinol wires526deflect outwardly away from one another during insertion of mating part524into cavity530. Upon insertion of mating part524into cavity530, Nitinol wires526deflect inwardly towards one another into recess534to capture endcap522in cavity530.

In one embodiment, as shown inFIG. 12, system10includes implant20, similar to that described above with regard toFIGS. 1-5, having an endcap622, similar to endcaps22,54described above, and a cage612, similar to cage12described above. Endcap includes surfaces672,674, similar to surfaces72,74described above with regard toFIGS. 1-5. Endcap622includes a passageway636extending between surfaces672,674. Endcap622includes a biasing member, such as, for example, an annular member630disposable in an annular notch634of endcap622. Endcap622includes protrusions640extending into passageway636. Endcap622includes a mating part624. Mating part624includes a relatively movable member, such as, for example, a rotatable screw member626, similar to screw members326,426described above with regard toFIGS. 9-10. Screw member626includes a screw head638. Screw member626is disposable in passageway636and with a threaded inner cavity628of a mating part620of cage612.

To connect endcap622with cage612, screw member626is rotated such that screw member626axially translates through passageway636. Screw member626overcomes the resilient bias of annular member630such that annular member630deflects and/or deforms about head638of screw member626, in the direction shown by arrow B inFIG. 12. Annular member630expands such that screw member626passes through passageway636of endcap622. Upon seating of screw head638with protrusions640of endcap622, annular member630is resiliently biased and collapses, in the direction shown by arrow C inFIG. 12, to resist and/or prevent movement of screw member626back out of passageway636. Endcap622includes a plurality of circumferentially disposed channels642that extend between surfaces672,674of endcap622. Cage612includes a plurality of circumferentially disposed spikes644disposable with channels642such that relative rotation of endcap622and cage12is resisted.

In one embodiment, as shown inFIG. 13, system10includes implant20, similar to that described above with regard toFIGS. 1-5, having an endcap722, similar to endcaps22,54described above, and a cage712, similar to cage12described above. Endcap722includes a mating part724. Mating part724includes a relatively movable member, such as, for example, a circumferential ring726. Ring726includes a flange728engageable with endcap722. Ring726includes a threaded inner surface730threaded with a threaded outer surface732of mating part720of cage712such that the rotation of ring726matingly engages endcap722and cage712.

In one embodiment, as shown inFIG. 14, system10includes implant20, similar to that described above with regard toFIGS. 1-5, having a endcap822, similar to endcaps22,54described above, and a cage (not shown), similar to cage12described above. Endcap822includes a mating part824, similar to mating part24described above. Mating part824includes a relatively movable member, such as, for example, a pair of arms826extending from surface872of endcap822and being substantially parallel with a longitudinal axis C1. Arms826include a rounded end828configured for disposal in a correspondingly shaped inner surface of the cage (not shown). Arms826define a cavity830having a keyhole configuration such that arms826are moveable. In some embodiments, cavity830is variously configured, such as, for example, those alternatives herein described. To connect endcap822with the cage, arms826are positioned into contact with the mating part of the cage such that arms826deflect inward. Endcap822is translated within the cage and arms826deflect outward such that rounded end828engages the correspondingly shaped inner surface of the cage to interlock the cage and endcap822.

In one embodiment, as shown inFIG. 15, system10includes implant20, similar to that described above with regard toFIGS. 1-5, having an endcap (not shown), similar to endcaps22,54described above, and a cage912, similar to cage12described above. The endcap includes a mating part (not shown) having a cog-shaped configuration configured for mating engagement with a mating part920of cage912. Mating part920includes an inner surface924having a cog-shaped cross section configuration. Inner surface924includes a series of annularly disposed recesses926corresponding to teeth (not shown) of the cog-shaped mating part of the endcap. Mating part920includes a plurality of undercuts930, shown in phantom inFIG. 15, which intersect recesses926such that rotation of endcap and/or cage912orients the teeth of the mating part out of recesses926and into undercuts930to interlock the mating parts of cage912and the endcap.

In one embodiment, as shown inFIG. 16, system10includes implant20, similar to that described above with regard toFIGS. 1-5, having an endcap1022, similar to endcaps22,54described above, and a cage (not shown), similar to cage12described above. Endcap1022includes a mating part1024. Mating part1024includes a relatively movable member, such as, for example, a pair of arms1026extending from surface1072of endcap1022and being substantially parallel with a longitudinal axis D1. Arms1026are configured for disposal in a correspondingly shaped inner surface of the cage (not shown). Arms1026define a cavity1030such that arms1026are moveable. To connect endcap1022with the cage, arms1026are positioned into contact with a mating part of the cage such that arms1026deflect inward. Endcap1022is translated within the cage and arms1026deflect outward such that arms1026engage the correspondingly shaped mating part of the cage.

In one embodiment, as shown inFIG. 17, system10includes implant20, similar to that described above with regard toFIGS. 1-5, having an endcap1122, similar to endcaps22,54described above, and a cage1112, similar to cage12described above. Endcap1122includes a mating part1124. Mating part1124includes a relatively movable member, such as, for example, a plurality of circumferentially disposed pairs of legs1126. Each pair of legs1126extend between an end1128connected to surface1172and an end1130including a flange1132. Flanges1132on each leg are oriented outwardly from one another. Legs1126are disposable with a plurality of circumferentially disposed channels1134, shown in phantom, in cage1112. To connect endcap1122with cage1112, each pair of legs1126are positioned within a channel1134such that legs1126deflect inwardly towards one another. Upon translation of legs1126through channels1134, legs1126deflect outwardly away from one another and flanges1132engage an underside1136of cage1112such that endcap1122and cage1112are matingly engaged.

In one embodiment, as shown inFIG. 18, system10includes implant20, similar to that described above with regard toFIGS. 1-5, having an endcap1222, similar to endcaps22,54described above, and a cage1212, shown in phantom, similar to cage12described above. Endcap1222includes a mating part1224. Mating part1224includes a relatively movable member, such as, for example, a rotatable cam lock1226and a pair of pivotable arms1228. Arms1228extend between an end1230pivotally engageable with a surface1274of endcap1222and an end1232having a notch1234. A mating part1220of cage1212includes a projection1236configured for disposal in notch1234of arms1228. Rotation of cam lock1226causes cam lock1226to engage arms1228such that arms1228pivot about end1230such that projection1236engages notch1234to interlock endcap1222and cage1212. In some embodiments, projection1236and notch1234are variously configured, such as, for example, oval, oblong, triangular, rectangular, square, polygonal, irregular, uniform, non-uniform, variable and/or tapered.

In one embodiment, as shown inFIGS. 19 and 20, system10includes implant20, similar to that described above with regard toFIGS. 1-5, having endcaps1322,1354, similar to endcaps22and54described herein, and a cage1312, similar to cage12described herein. Endcap1322includes a wall1366having a surface1372configured for engagement with vertebral tissue and a surface1374configured for engagement with cage1312. Endcap1322includes a mating part1324. Mating part1324includes a relatively movable member, such as, for example, at least two resiliently biased latches1326,1327disposable with a mating part1321of cage12. Latches1326,1327extend from surface1374of cage1312. Mating part1321includes at least two notches, such as, for example, indentations1332in an outer surface1328of cage1312each configured for disposal of latches1326,1327. Latches1326,1327engage indentations1332in a snap fit engagement such that endcap1322and cage1312are connected. In one embodiment, at least an end1342of cage1312has a hexagonal-shaped cross section configuration, countersink feature, or any of the configurations described herein, such that relative rotation of endcap1322and cage1312is resisted and/or prevented. In some embodiments, end1342has various cross section configurations, such as, for example, those alternatives described herein.