Systems and methods for spinal fixation

A spinal stabilization system, method, and a surgical kit having a surgical extender apparatus for implanting a surgical screw are disclosed. The extender includes a housing having a distal end and a proximal end, a hollow interior passageway disposed between the distal end and the proximal end, a channel disposed along an exterior surface of the housing at least partially between the distal end and the proximal end and configured to at least partially expose the hollow interior passageway, an interior locking mechanism disposed on an interior surface of the housing and substantially adjacent the proximal end, wherein the interior locking mechanism is configured to allow attachment of at least one surgical tool, and at least one flexible member disposed substantially adjacent the distal end. The housing is configured to accommodate placement of a surgical screw implant. The surgical screw implant is secured to the housing using a mating feature in the surgical screw implant. The at least one flexible member is configured to retain the surgical screw implant. The mating feature is configured to control axial movement of the surgical screw implant.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to the field of spinal surgery. In particular, the present invention relates to the field of surgical access to the spine.

Spinal fusion is a procedure that promotes fusing or growing together of two or more vertebrae in the spine. Spinal fusion can be performed to:straighten a spine deformed by scoliosis, neuromuscular disease, cerebral palsy, or other disorder;prevent further deformation;support a spine weakened by infection or tumor;reduce or prevent pain from pinched or injured nerves;compensate for injured vertebrae or disks.

One of the goals of spinal fusion procedure is to unite two or more vertebrae to prevent them from moving independently of each other. This may be done to improve posture, increase ability to ventilate the lungs, prevent pain, or treat spinal instability and reduce the risk of nerve damage. According to the American Academy of Orthopedic Surgeons, approximately a quarter-million spinal fusions are performed each year, half on the upper and half on the lower spine.

The spine is a series of individual bones called vertebrae, separated by cartilaginous disks. The spine includes seven cervical (neck) vertebrae, 12 thoracic (chest) vertebrae, five lumbar (lower back) vertebrae, and the fused vertebrae in the sacrum and coccyx that help to form the hip region. While the shapes of individual vertebrae differ among these regions, each is essentially a short hollow tube containing the bundle of nerves known as the spinal cord. Individual nerves, such as those carrying messages to the arms or legs, enter and exit the spinal cord through gaps between vertebrae. The spinal disks act as shock absorbers, cushioning the spine, and preventing individual bones from contacting each other. Disks also help to hold the vertebrae together. The weight of the upper body is transferred through the spine to the hips and the legs. The spine is held upright through the work of the back muscles, which are attached to the vertebrae. While the normal spine has no side-to-side curve, it does have a series of front-to-back curves, giving it a gentle “S” shape. The spine curves in at the lumbar region, back out at the thoracic region, and back in at the cervical region.

One of the types of spinal fusion procedures is a posterior spinal fusion surgery. This procedure is performed posteriorly, or from the back of patient, as opposed to anteriorly, or through the abdomen. There are three know posterior fusion techniques (all three are typically performed with pedicle screw fixation). The first is a posterolateral gutter fusion surgery. This type of spinal fusion involves placing bone graft in the posterolateral portion of the spine (a region just outside the back of the spine). The second is a posterior lumbar interbody fusion (“PLIF”) surgery. A PLIF involves placing bone graft and/or spinal implant (e.g., cage) directly into the disc space in the front of the spine. The third is a transforaminal lumbar interbody fusion (“TLIF”) surgery. A TLIF is essentially like an extended PLIF, as it also involves expanding the disc space by removing one entire facet joint (whereas a PLIF usually involves gaining access to the disc space by removing a portion of the facet joints on each side of the spine).

There have been various approaches and systems for performing posterior spinal surgery. Some conventional systems further include titanium construction that is compatible with current CT and MRI scanning technology, low profile implant systems, top-loading and top-tightening systems, and other parameters. Some systems also include cross-connectors that allow one-piece implant to be applied to a dual-rod construct for a top-loading approach.

The conventional devices and systems have a number of disadvantages. These devices do not provide flexibility when adjusting the devices either prior to, during, or after their placement into the patient. Thus, these devices force a surgeon to utilize a specific configuration, leaving very little room for adjustment in accordance with patient's physiological characteristics and needs.

In some embodiments, the present invention relates to a minimally invasive bone screw placement system that allows a surgeon to implant one or more bone screws into the spine and connect he screws with a wire or any other device, wherein the system does not require any incisions in excess of the bone screw incisions.

SUMMARY OF THE INVENTION

In some embodiments, the present invention is directed to a spinal stabilization system for stabilizing a spine using at least one a surgical screw implant configured to be implanted into the spine. The system includes a housing configured to accommodate placement of the surgical screw implant, the surgical screw implant is secured to the housing using a first mating feature in the surgical screw implant, a locking feature contained within the housing and configured to retain the surgical screw implant for implantation. The first mating feature is configured to control axial movement of the surgical screw implant.

In some embodiments, the present invention relates to a method of stabilizing spine of a patient including implanting a surgical screw implant having a housing configured to accommodate placement of a surgical screw implant, the surgical screw implant is secured to the housing using a first mating feature in the surgical screw implant, a locking feature contained within the housing and configured to retain the surgical screw implant for implantation, wherein the first mating feature is configured to control axial movement of the surgical screw implant. The method includes implanting the surgical screw implant coupled to the housing into a bone, manipulating the surgical screw implant and the housing to orient the housing in a predetermined manner, advancing a wire through the housing, and using the wire, connecting the surgical screw implant with another surgical screw implant.

In some embodiments, the present invention relates to a surgical stabilization system using at least one screw implanted into a bone of a patient, wherein the screw includes a head, wherein the head is configured to include a second mating feature that can be configured to include a plurality of openings and a plurality of recessed edges. The system includes a hollow housing having a wall surrounding an interior of the hollow housing, an open proximal end, and an open distal end, wherein the wall is disposed between the proximal end and the distal end. The distal end is secured to the surgical screw and the surgical screw is delivered via the proximal end. The housing includes a flexible portion having a first mating feature disposed along the wall of the housing and adjacent the distal end. The flexible indenting portion is configured to retain the surgical screw within the housing.

In some embodiments, the present invention relates to a surgical extender apparatus for implanting a surgical screw. The apparatus includes a housing having a distal end and a proximal end, a hollow interior passageway disposed between the distal end and the proximal end, a channel disposed along an exterior surface of the housing at least partially between the distal end and the proximal end and configured to at least partially expose the hollow interior passageway, an interior locking mechanism disposed on an interior surface of the housing and substantially adjacent the proximal end, wherein the interior locking mechanism is configured to allow attachment of at least one surgical tool, and at least one flexible member disposed substantially adjacent the distal end. The housing is configured to accommodate placement of a surgical screw implant. The surgical screw implant is secured to the housing using a mating feature in the surgical screw implant. The at least one flexible member is configured to retain the surgical screw implant. The mating feature is configured to control axial movement of the surgical screw implant.

In some embodiments, the present invention relates to a method of implanting a surgical screw implant into a bone of a patient using a an extender device having a housing configured to accommodate placement of a surgical screw implant, the surgical screw implant being secured to the housing using mating feature in the surgical screw implant, wherein the housing includes a flexible member contained within the housing and configured to retain the surgical screw implant. The method includes implanting the surgical screw implant into a bone of the patient, attaching the screw extender device to the surgical screw and, inserting a screw locking device along the long axis of the screw extender.

In some embodiments, the present invention relates to a surgical kit for stabilizing the spine of a patient. The kit includes a screw extender configured to be coupled to a surgical screw, wherein the screw extender includes a housing having a distal end and a proximal end, a hollow interior passageway disposed between the distal end and the proximal end, a channel disposed along an exterior surface of the housing at least partially between the distal end and the proximal end and configured to at least partially expose the hollow interior passageway, an interior locking mechanism disposed on an interior surface of the housing and substantially adjacent the proximal end, wherein the interior locking mechanism is configured to allow attachment of at least one surgical tool, and at least one flexible member disposed substantially adjacent the distal end. The housing is configured to accommodate placement of a surgical screw implant. The surgical screw implant is secured to the housing using a mating feature in the surgical screw implant. The flexible members are configured to retain the surgical screw implant. The mating feature is configured to control axial movement of the surgical screw implant.

In some embodiments, the present invention relates to a distraction/compression tool for use with a screw extender system having at least two hollow screw extender housings configured to be coupled to respective screw assemblies implanted into vertebrae. The tool includes a housing having a first screw extender holding portion, a second screw extender holding portion pivotally coupled to the first screw extender holding portion, each screw extender holding portion includes a base configured to hold a screw extender housing, a multi-directional threading mechanism configured to secure bases of the screw extender holding portion. Rotation of the threading mechanism in one direction causes distraction of the screw extender housings coupled to the bases and rotation of the threading mechanism in another direction causes compression of the screw extender housings.

In some embodiments, the present invention relates to a method for compressing/distracting screw extender system using the above distraction/compression tool, wherein the screw extender system includes at least two hollow screw extender housings configured to be coupled to respective screw assemblies implanted into vertebrae. The method includes rotating the threading mechanism to compress/distract screw extender housings.

In some embodiments, the present invention relates to a rod inserter tool for use with a hollow screw extender housing configured to be coupled to a screw assembly implanted into vertebrae. The tool includes a handle coupled to a curved shaft at a proximal end of the curved shaft. The shaft includes a static shaft portion configured to be permanently coupled to the handle, a sliding shaft portion configured to be slidably coupled inside the handle and further configured to slide along the static shaft portion, a rod holding mechanism formed by the static shaft portion and a sliding shaft portion and configured to be disposed at a distal end of the curved shaft. By translating the sliding shaft portion along the static shaft portion toward the distal end of the shaft, the rod holding mechanism is configured to secure a rod.

In some embodiments, the present invention relates to a method for inserting a rod using the above rod inserter tool in combination with a hollow screw extender housing configured to be coupled to a screw assembly implanted into vertebrae. The method includes securing the rod in the rod holding mechanism, and advancing the secured rod using the rod inserter tool through the screw extender housing and toward the corresponding screw assembly.

In some embodiments, the present invention relates to a re-attachment guide tool for re-attaching a hollow screw extender housing, having at least one open channel disposed in a wall of the screw extender housing, to a screw assembly implanted into a vertebrae. The tool includes at least one guide shaft configured to be coupled to a screw assembly, a main assembly having a handle coupled to a flat shaft at a proximal end of the flat shaft, a hollow housing coupled to the flat shaft at a distal end of the flat shaft and configured to accommodate insertion of the screw extender housing, and a hollow interior disposed inside the handle and the flat shaft and configured to accommodate insertion of the at least one guide shaft. The flat shaft is configured to have a predetermined thickness that allows coupling of the screw extender housing using the at least one open channel in the screw extender housing.

In some embodiments, the present invention relates to a method for re-attachment of a hollow screw extender housing to a screw assembly implanted into a vertebrae using the above re-attachment guide tool, wherein the hollow screw extender housing includes at least one open channel disposed in a wall of the screw extender housing. The method includes coupling the at least one guide shaft to the screw assembly, placing the main assembly over the at least one guide shaft, securing the main assembly to the screw assembly, coupling the screw extender housing to the flat shaft of the main assembly, translating the screw extender housing toward the distal end of the flat shaft, and, re-attaching the screw extender housing to the screw assembly.

In some embodiments, the present invention relates to a rod reducer tool for use with a screw extender housing secured to a screw assembly implanted into a vertebrae. The tool includes a hollow shaft having a proximal and a distal end and configured to accommodate insertion of the screw extender housing, a rotating handle coupled to the hollow shaft at the proximal end of the hollow shaft, a first threading mechanism disposed inside the handle, a second threading mechanism coupled to the handle and disposed inside the hollow shaft for coupling to the screw extender housing. The first threading mechanism is configured to allow independent rotation of the handle with respect to the hollow shaft. Rotation of the handle is configured to translate the hollow shaft along the screw extender housing that has been inserted into the hollow shaft through interaction of the second threading mechanism with a threading mechanism disposed on the screw extender housing.

In some embodiments, the present invention relates to a method for reducing a rod using the above rod reducer tool used in connection with a screw extender housing secured to a screw assembly implanted into a vertebrae. The method includes inserting the screw extender housing inside the hollow shaft, translating the rod reducer tool along the screw extender housing toward the screw assembly, and rotating the rotating handle to advance the rod reducer tool toward the screw assembly, thereby reducing the rod.

In some embodiments, the present invention relates to a screw extender removal tool for removing a screw extender housing having flexible portions disposed at a distal end of the screw extender housing, wherein the screw extender housing is coupled to a screw assembly. The tool includes an external shaft having a proximal end and a distal end, wherein a plurality of protrusions are disposed on an external surface at the distal end of the external shaft, the external shaft having an internal shaft disposed in a hollow interior of the external shaft, a handle coupled to the proximal end of the shaft, wherein the handle includes a spring-loaded mechanism pivotally coupled to the internal shaft. Upon actuation of the spring-loaded mechanism, the internal shaft is translated in the hollow interior of the external shaft to extend beyond the distal end of the external shaft. The external shaft is configured to be inserted into the screw extender housing coupled to the screw assembly. Then, using the handle, rotated to push apart the flexible portions of the screw extender housing. Upon actuation of the spring loaded mechanism, further configured to extend the internal shaft beyond the distal end of the external shaft in order to remove the screw extender housing from the screw assembly.

In some embodiments, the present invention relates to a method for removing a screw extender housing from a screw assembly using the above screw extender removal tool, wherein the screw extender housing includes flexible portions disposed at a distal end of the screw extender housing and the screw extender housing is coupled to a screw assembly. The method includes inserting the screw extender remover tool into the screw extender housing coupled to the screw assembly, using the handle, rotating the screw extender remover tool to push apart the flexible portions of the screw extender housing using the plurality of protrusions, and upon actuation of the spring loaded mechanism, extending the internal shaft beyond the distal end of the external shaft, and, removing the screw extender housing from the screw assembly.

In some embodiments, the present invention relates to a rod inserter tool for use with a hollow screw extender housing configured to be coupled to a screw assembly implanted into vertebrae. The tool includes a handle, a main housing configured to include a rod holding mechanism adjacent to a distal end of the main housing for holding a rod, wherein the handle is coupled to the main housing adjacent to a proximal end of the main housing, a secondary housing configured to be slidably disposed along the main housing and further configured to secure the rod to the distal end of the main housing, and a lateral housing configured to be slidably disposed along the main housing and further configured to change orientation of the rod upon being actuated by the handle.

In some embodiments, the present invention relates to a method of inserting a rod using a rod inserter tool described above in combination with a hollow screw extender housing configured to be coupled to a screw assembly implanted into vertebrae. The method includes coupling the rod to the distal end of the main housing of the rod inserter tool, advancing the rod toward the screw assembly implanted into vertebrae along the screw extender housing coupled to the screw assembly, securing to rod to the screw assembly, and releasing the rod from the rod inserter tool.

DETAILED DESCRIPTION OF THE INVENTION

In some embodiments, the present invention allows a surgeon using conventional stab wounds to place bone screws. This is typically accomplished using a Jamshiti needle followed by progressive dilation. Once the bone has been prepared, the bone screw is implanted.

After implantation, the bone screw is manipulated for orientation by the extender. This “extender” extends out of the stab wound and allows the surgeon to control the implanted screw. Once two or more screws are implanted, the surgeon will place the wire inserters onto the screw extender. The wire components are designed to guide a wire down the axis of the screw extender. Once the desired depth is reached, the wire will exit out of the screw extender and puncture the muscle and create a path to join the adjacent bone screw.

Once the wire bridges the gap between the screws, an instrument that has been previously placed down the adjacent extender grabs the wire and pulls the distal portion of the wire to the surface. Attached to the proximal portion of the wire is a rod. By pulling on the distal portion of the wire, the rod is drawn down the extender and pulled across the gap between the screws. The “button” feature on the proximal portion of the rod prevents the rod from being overly pulled past the extender. In some embodiments, the extenders along with screws and the wire inserters are disposed at the surgical site prior to advancement of the wire.

Set screws can be placed, final tightened and the guide wire can be removed. This provides a minimally invasive placement of fusion hardware.

FIGS. 1a-cillustrate an exemplary embodiment of a screw extender device100, according to some embodiments of the present invention.FIG. 1aillustrates the screw extender device100being coupled to a screw.FIG. 1billustrate the screw extender device100by itself andFIG. 1cillustrates a cross-sectional cut out of the screw extender device shown inFIG. 1b. Screw extender device100includes a housing110that is coupled to a screw implant120using first mating features (or as shown inFIGS. 1a-c, the indented features)105disposed on the head of the screw122. The indented features105are configured to control axial and torsional movement. The housing110has a proximal end102and a distal end104. The housing110further includes a partially open channel112, which permits insertion and passage of a rod toward from the proximal end102toward the distal end104of the housing110. In some embodiments, as will be discussed below, the housing110can be configured to include a partially open channel112and/or a fully open channel, whereby the fully open channel is configured to stretch from the proximal end102to the distal end104. The open channel is configured as a hollow interior or passageway119of the housing110. The hollow interior119is configured to allow passage of instruments, rods, implants, etc. through the screw extender device during surgery. To allow such passage, the housing110includes an opening108disposed at the proximal end102and a similar opening disposed at the distal end104. The sizes of the openings can be substantially similar to the size of the interior119. The openings allow passages of instruments, tools, rods, implants, etc. during surgical procedures. In some embodiments, the screw extender housing110is configured to have a cylindrical shape. As can be understood by one skilled in the art, other shapes of the housing110are possible.

The distal end104of the housing110is configured to be coupled to the head of the screw122. The distal end104includes second mating features (as shown inFIGS. 1a-c, protrusions)115(as shown inFIGS. 1b-c) that are configured to mate with the first (or indented) features (or openings)105disposed on the head of the screw122. In the following description ofFIGS. 1a-22b,the terms “protrusion(s)”, “indentation(s)”, “first mating feature(s)”, “second mating feature(s)” will be used interchangeably, and thus, in some embodiments, the present invention can include a first mating feature that is a protrusion and a second mating feature that is an indentation configured to mate with the protrusions, whereas in some embodiments, a first mating feature can be an indentation and a second mating feature can be a protrusion with which the first mating feature mates. Hence, the terms “protrusion(s)” and “indentation(s)” are to mean “indentation(s) or protrusion(s)” are to be interpreted as such. Further, the terms “protrusion(s)” and “indentation(s)” are used in this description for illustrative non-limiting purposes only. The protrusions115are configured to flex as the screw120(a portion117of the screw is shown inFIGS. 1a-c) is coupled to the extender housing110. In some embodiments, protrusions115are configured to be spring-loaded or otherwise be any locking feature, wherein upon insertion of the screw, the protrusions115are configured to retract toward the interior wall of the extender housing110and then protract toward the indented features105upon protrusions115being aligned with the features105. Upon coupling, the protrusions115are configured to snap into indented features105, thereby locking the screw to the screw extender housing110and creating a rigid structure. The interior walls of the housing110can further configured to include threading131disposed near the proximal end104. The threading131is configured to allow securing of various tools to the extender housing110during surgical procedures. As can be further understood by one skilled in the art, the terms “threading” or “thread” are used in this description ofFIGS. 1a-22cfor exemplary non-limiting purposes and instead of threading components together, other means of compression and/or distraction and/or other ways of coupling can be used.

In some embodiments, the screw120can be a poly-axial screw that allows a surgeon to manipulate (rotate, tilt, etc.) the combination of the screw120coupled to the housing110once the screw is implanted into a bony matter (e.g., vertebrae) of the patient. The screw120further includes threading124on a threaded shaft of the screw that is configured to assist in insertion of the screw into a bony matter. The threaded shaft is coupled to the head of the screw122. The head of the screw122includes a passageway126that is configured to be wide enough to accommodate placement and securing of a rod. The passageway126is configured to be aligned with the channel112so as to create a continuous channel between the screw and the screw extender. In some embodiments, the passageway126can be configured to include threading138disposed on passageway's interior surfaces. The threading138allows placement of set screws (not shown inFIGS. 1a-c) to secure a rod once it is installed into the screw.

FIGS. 2a-billustrate another exemplary screw extender system200, according to some embodiments of the present invention.FIG. 2aillustrates the screw extender housing being coupled to the screw andFIG. 2billustrates the screw extender housing being uncoupled from the screw. As shown inFIGS. 2a-b, a screw220is configured to be coupled to a screw extender housing210. The screw extender housing210is configured to be an elongated tube that includes openings at both of its ends202(proximal),204(distal) for coupling to the screw220at one end204and for insertion of surgical instruments at the other end202. The housing210further includes slots or channels212that extend along at least a portion of the housing210and are further configured to accommodate placements of rod(s). Additionally, the housing210further includes indentor portions or screw-locking features240, which are configured to secure the screw220to the screw extender device housing210. In some embodiments, the housing210includes two indentor portions240(second portion is not shown inFIG. 2a). The indentor portions240are configured to be fixed to the housing210at a location237, which is disposed toward the screw-coupling end204. In some embodiments, the indentor portions240are configured to be welded at a location237. Once the screw220is loaded into the extender device (See,FIG. 2a), the indentor portions240are configured to engage the screw220using protrusions242that are disposed on an interior wall of the indentor portions240and are further configured to protrude into the interior of the housing210. In some embodiments, the indentor portions240are configured to be flexible.

The indentor portions240are configured to engage an opening251in the head of the screw220, as shown inFIG. 2b.Upon insertion of the screw220into the extender device housing210, the indentor portions240are configured to spread apart from the center of the housing210. In some embodiments, the indentor portions240are configured to be spring-like devices that pull apart upon application of external mechanical pressure. Once the screw220is inserted into the housing210, the indentor portions240are configured to snap into openings251of the screw220. Upon snapping into openings251, the indentor portions240rigidly secure the screw220to the housing210.

Similarly to the screw extender shown inFIGS. 1a-c, the screw extender housing210includes an interior passageway219that is configured to be exposed by the channel212(either fully or partially stretching along the length of the housing210). The channel212is configured to be aligned with a passageway226disposed on the head of the screw222so as to create a continuous channel between the between the channel212and the passageway226for passing of tools, instruments, rods, etc.

FIGS. 3a-cillustrate another exemplary screw extender housing310, according to some embodiments of the present invention. The extender housing310includes two channels312and332that are configured to expose the interior319of the screw extender housing310. The channel312is configured to be partially open (i.e., partially stretch out between proximal and distal ends) and channel332is configured to be fully open (i.e., connect the proximal and distal ends), as illustrated inFIGS. 3band3c,whereinFIG. 3cis a top cross-sectional view of the extender housing310. The housing310further includes a gripping feature (or features)391that is configured to be disposed along edges of the channel312and/or channel332, as shown inFIGS. 3a-b. The gripping feature391is configured to assist in providing additional support to the distractor/compressor device shown inFIGS. 14a-eand discussed below. In some embodiments, the gripping feature391is configured to form a small cavity disposed along edges of the channels. In some embodiments, the gripping features391can have a shape of a semi-circular cavity. The gripping features391can be configured to be disposed along the entire length of the channels312and/or332or along a portion of the channels.

Similarly to the screw extenders shown inFIGS. 1a-2b,the screw extender housing300can include interior threads331disposed adjacent the proximal end302of the screw extender housing300. The screw extender housing310further includes a locking feature340disposed toward the distal end304for interlocking with a screw in a similar fashion as the screw extender shown inFIGS. 2a-b.

FIG. 3dis a cross-sectional view of a portion of the distal end304of the screw extender housing310.FIG. 3dfurther illustrates in the locking feature340having a protrusion371that is configured to mate with an opening disposed on a head of the screw (not shown inFIG. 3d), similar to the feature240shown inFIGS. 2a-c. The locking feature340further includes a stopping mechanism379that is configured to prevent a screw extender removal tool (shown inFIGS. 8a-8dand discussed below) from over rotating once it is placed inside the screw extender housing's interior for the purposes of removing the screw extender housing from the screw. In some embodiments, the stopping mechanism379is configured to prevent rotation of the screw extender removal tool by more than 90 degrees. As can be understood by one skilled in the art, the stopping mechanism can prevent any angle of rotation.

As can be understood by one skilled in the art, the channels formed by the screw extender housing channels and the screw do not need to be continuous. For example, a channel on the extender housing can have multiple discontinuities disposed throughout the housing. As can be also understood by one skilled in the art, the screw extender housing can be configured to include one or more first mating features (or indentors, or indented features, or indentor portions, etc.) upon release of one of them, the extender housing can be configured to disengage from the screw.

FIG. 4a-billustrate an exemplary screw400configured to be used with screw extenders shown inFIGS. 1a-3dand discussed above, according to some embodiments of the present invention. The screw400includes a distal end404, a proximal end402, a shaft421having threads424disposed along its length, and a head of the screw408coupled to the shaft421. The head of the screw includes a passageway426that is sized and configured to accommodate placement and securing of a rod. To secure the rod inside the screw head408, the rod is placed into an interior space425created by the passageway426and then a set screw (not shown) is placed on top of the rod and secured using threads415disposed on the interior walls of the passageway426. The passageway426can be configured to include recessed edges420(a, b, c, d) that are configured to accommodate placement of the screw extender housing (shown inFIG. 5). The head of the screw further includes openings410that are configured to receive protrusions of the locking features disposed on the screw extender housing (as shown inFIGS. 2a-3b).

Referring toFIG. 5, to further secure the screw500(similar to the screw400) to the extender device housing512, the housing512includes a plurality of protrusions510(a, b, c, d). The protrusions510are configured to engage recessed edges509(a, b, c, d), respectively, of the head528of the screw514. In some embodiments, the protrusions510are configured to wrap around the recessed edges509. Such interaction of screw's recessed edges509and extender's protrusions510further secures the screw514to the extender housing512and prevents displacement of the screw514from the housing512. This configuration also allows the surgeon (or any other medical professional) to controllably apply various forces to the screw (e.g., during placement of an implant, etc.), such translational, axial, torsional, or any other forces. As can be understood by one skilled in the art, the screw514and the housing512can have any number of recessed edges509and corresponding protrusions510. Additionally, the screw514can have any number of openings (not shown inFIG. 5, but shown inFIGS. 4a-b) and the housing512can have any number of corresponding indentor portions540that interact with the openings.

As stated above, the screw extender aids in the placement of, for example, pedicle screws during spinal fusion procedures. In some embodiments, the surgeon (or other medical professional) attaches the screw extender to the pedicle screw and maintains control of the screw from an exterior (for example, from outside of the skin incision). The screw extender provides strong attachment so that axial, lateral, and torsional forces can be applied to the screw extender. The surgeon typically applies these forces to screw extenders to manipulate the vertebra to which pedicle screws are attached.

In some embodiments, the screw extender has a center-less tubular body. The extender includes various securing features, for example, flexible indenters, for holding the screw in an axial plane along the axis of the screw and the extender, where the securing features engage the recessed edges of the screw. In some embodiments, the screw extender indenters are flexible and are fixed to the main body of the screw extender at only one location (as shown inFIG. 3a). This allows the screw extender indenters to flex out of the way and allow the screw to be released from the screw extender. As stated above, extender's tubular body is also partially slotted to allow a rod to be placed in the typical fashion.

In other embodiments, the system includes a screw extender remover tool shown inFIGS. 8a-d.FIGS. 8a-billustrate one embodiment of a screw extender remover tool800andFIGS. 8c-dillustrate another embodiment of a screw extender remover tool850.

Referring toFIGS. 8a-b, the remover tool800includes a shaft833disposed between a distal end864and a handle862. In some embodiments, the handle862is configured to have a rounded shape. As can be understood by one skilled in the art, the handle can be configured to have any desired shape. The shaft833further includes a threaded portion823disposed substantially adjacent to the handle862and a stopping mechanism821disposed between the handle and the threaded portion823. The shaft833is configured to fit into the interior passageway819of the extender housing810, as shown inFIG. 8a.The threaded portion823is configured to interact with an interior threaded portion825of the screw extender housing810upon insertion of remover tool800into the screw extender housing810, as shown inFIG. 8b.Upon insertion of the remover tool800, the threaded portions823and825are configured to interact with each other and a surgeon (or any other medical professional) begins to rotate the remover tool in a downward direction (e.g., clockwise direction) in order to advance the remover tool toward the screw. The remover tool is advanced until the stopping mechanism821prevents its further advancement toward the screw. In some embodiments, the length of the remover tool's shaft can be appropriately selected so that upon full insertion of the remover tool, its distal end864is configured to interact with flexible plates817containing protrusions815and to push the plates817apart, thereby causing disengagement of the screw extender housing810from the screw. The stopping mechanism821is further configured to prevent over-insertion of the remover tool and thus, damage to the screw.

Thus, to remove or disengage the extender housing810from the screw, a threaded shaft833is inserted down the long axis of the extender housing. This threaded shaft833engages the threads825of the extender housing and forces the distal indented ends of the extender apart. This mechanism releases the bone screw by releasing the tabs or flexible plates817in the screw extender from its mating hole in the screw.

FIGS. 8c-dillustrate an alternate embodiment of the remover tool850, according to some embodiments of the present invention. The remover tool850includes a shaft853, a stopping mechanism857, and a handle851. In some embodiments, the handle851can be configured to be cannulated on the inside to allow passage of additional devices through it, as shown inFIGS. 18a-c. Such additional devices can be configured to be used to assist in removal of the screw extender from the screw in the event that the remover tool850is unable to disengage from the screw.

As shown inFIGS. 8c-d, the remover tool850is configured to fit inside the extender housing820and to be advanced toward the distal end of the housing upon application of a downward force by the surgeon (or any other medical professional). The stopping mechanism857is configured to prevent over-insertion of the remover tool850and thus, damage to the screw. The remover tool850further includes at least one protrusion861extending from an outer surface of the shaft853of the remover tool850substantially adjacent the distal end of the shaft853of the remover tool. The protrusions861are configured to interact with the flexible portions840of the extender housing810when the remover tool850is fully inserted into the screw extender housing (i.e., the stopping mechanism857is configured to interact with a proximal end of the screw extender housing) and rotated by the surgeon. Upon interaction of the protrusions and flexible locking features, the protrusions861are configured to push on the flexible locking features840, thus pushing them away for the interior passageway of the screw extender and thereby unlocking the screw extender housing from the screw. In some embodiments, a stopping mechanism379shown inFIG. 3dprevents over-rotation of the remover tool once it is inserted into the housing of the screw extender. The stopping mechanism379can be a protrusion disposed on an inner surface of the extender housing substantially adjacent to the flexible indenters. The stopping mechanism379can be further disposed in the path of the rotating protrusions861, thus, preventing rotation of the remover tool beyond a particular point. In some embodiments, the stopping mechanism379is configured to prevent rotation of the remover tool by more than 90 degrees. The stopping mechanism is configured to assist the surgeon in determining when the flexible members have been pushed apart and thus it is safe to remove the extender housing.

FIG. 6illustrates a closer view of the interaction of the distal end of the remover tool679(which is similar to the remover tool850) with the extender housing610. As shown, the distal end of the remover tool679includes protrusions675that are configured to extend away from the surface of the remover tool679. The flexible portions640(a, b) (similar to those shown inFIGS. 2a-3c) include protrusions642(a, b), respectively, that are configured to be removed from the openings in the screw upon rotation of the remover tool and subsequent interaction of the protrusions675of the remover tool with the flexible portions640.

Thus, for the surgeon to remove the screw extender610from the screw (which is typically done after completion of a procedure), the screw extender remover device679is used. In addition to the components shown inFIGS. 8c-d, the remover device679includes a tip having protrusions or ramps675. The ramps675are configured to be disposed around the perimeter of the tip. The shaft and the tip of the remover device can be cylindrical in order to match the cylindrical housing610of the extender device600. As can be understood by one skilled in the art, the shaft and the tip have any other shape and can correspond to the shape of the housing610.

In some embodiments, the tip can be smaller than the shaft (e.g., the diameter of the tip is smaller the diameter of the shaft). The shaft is also sized to fit inside the housing610of the extender device600. The stopping mechanism or a stopper rim823(see,FIGS. 8c-d) that acts as a stopper and limits the depth at which the remover device679can be placed into the housing610, thereby controlling the depth that the ramps675can engage the screw extender's indentor portions640(shown inFIG. 6).

The ramps675are configured to protrude away from the surface of the tip. The ramps675interact with the indentor portions640of the housing610, as illustrated inFIGS. 6-7b,whereinFIGS. 7a-billustrate a bottom view of the remover tool interacting with the indentor portions. To remove the extender device600from the screw, the remover device679is inserted into the hollow housing610via its proximal end (not shown inFIGS. 6-7b). In some embodiments, the ramps675of the remover device679can be aligned with the channels619during insertion of the remover device679into the housing610. As such, during insertion, the ramps675slide down the channels619(as shown inFIG. 6). The insertion of the device679continues until the stopper rim of the remover device (not shown inFIG. 6) comes in contact with the proximal end of the extender housing. At this point, the device679is rotated about 90 degrees (in any direction) by gripping the handle of the remover device (shown inFIG. 8c-d) and twisting it in an appropriate direction. By rotating the handle, the ramps675come in contact with the indentor portions640. Due to flexible nature of the indentor portions640, the ramps675are configured to push the indentor portions640towards exterior portion of the housing610of the extender device600. As the portions640are pushed apart, the indentor protrusions642disengage from the openings of the screw. Once the protrusions642are removed from the openings in the head of the screw, the extender device600becomes loose and can be removed from the screw. In some embodiments, the extender device600and the remover device610can be removed at the same time. As can be understood by one skilled in the art, other ways of removing the screw extender housing from the screw are possible.

FIGS. 18a-cillustrate an exemplary supplemental screw extender remover device1810, according to some embodiments of the present invention. In the event that a surgeon is unable to disengage the screw extender device from the screw, the device1810can assist the surgeon in pushing the screw extender away from the screw. As shown inFIGS. 18a-c, the supplemental remover device1810includes a shaft1803disposed between the distal tip1807and a handle1801. The supplemental remover device1810is configured to have a smaller diameter than that of the remover tool850. The shaft1803of the device1810is configured to be longer than that of the remover tool850. The remover tool850includes an interior cannulated portion (not shown inFIGS. 18a-c) that is disposed within the remover tool850and that further accommodates insertion of the device1810, as shown inFIGS. 18a-b. The device1810further includes a threaded portion1805configured to be disposed substantially adjacent the handle1801. The threaded portion1805is configured to interact with a threaded portion disposed inside the handle851of the device850.

Thus, in the event that the surgeon cannot remove the screw extender device1802from the screw1807using just the remover tool850, the surgeon inserts the device1810through an opening in the handle851of the remover device850and pushes the device1810along the interior channel (i.e., cannulated portion) of the remover device850, until threaded portion1805comes in contact with an interior threaded portion of the remover device850. At this time, the surgeon begins to rotate the device1810along the threaded portion, thereby protruding the tip1807of the device1810beyond the distal tip of the remover device850. Thus, the tip1807comes in contact with the screw1804and effectively pushes the screw extender1802along with remover tool1810away from the screw, thus, allowing the surgeon to remove the screw extender.

In some embodiments, the screw extender system of the present invention can be utilized for delivery of a percutaneous wire, which can then be utilized for advancement of a rod. Initially, to perform a spinal surgery using the screw extender device of the present invention, the surgeon initially makes an incision at a location where a first screw along with a first screw extender device is to be implanted. Another incision can be made at another location where a second screw along with a second screw extender are to be implanted. As can be understood by one skilled in the art, the surgeon can make as many incisions as are necessary for creating a spinal stabilization system according to the present invention. Once, the incisions are made, the surgeon can couple the screw extenders with the screws and advance this combination toward the bony matter (e.g., vertebrae) for subsequent insertion. Once the screw-extender-and-screw combination are inserted, the surgeon is able to manipulate to the screw extenders and the screws for insertion of percutaneous wires and/or rods and/or other tools and device. In some embodiments, the screws can be poly-axial screws that allow the surgeon to manipulate the screw extenders in any direction while the screw extenders are rigidly attached to the screws.

FIGS. 9a-9hillustrate exemplary percutaneous wire insertion devices900and950, according to some embodiments of the present invention. The devices900and950are configured to be inserted into the screw extender's hollow interiors for guiding a percutaneous wire along and between the screw extenders. Referring toFIGS. 9a-cand9h,a first percutaneous wire insertion device900is illustrated. The device900includes a shaft920disposed between a proximal end902and a distal end904. The device900is configured to be cannulated and thus includes an interior channel941configured to be disposed between an opening at the proximal end902and an opening930disposed at the distal end904of the device900. In some embodiments, the opening930is configured to be placed on the side of the device900so as to accommodate advancement of the wire toward another screw extender.

In some embodiments, the device900further includes two parts927aand927bthat are configured to be coupled using a nut or any other locking mechanism922that is configured to be placed adjacent the proximal end902of the device900. The two-part configuration is provided for ease of removal of the device900from the screw extender. The two parts927are configured to be coupled using hook features932and933disposed at the distal end902of the device and the nut922disposed adjacent the proximal end904of the device900. The nut922further includes threading924that is configured to interact with the threading disposed at a proximal end of the screw extender on the screw extender's inner surface.

To secure the device900inside a screw extender device, the surgeon inserts the assembled device900with the distal end904into the screw extender's proximal end and slides the device900along the interior passageway of the screw extender until the threads924of the device900begin to interact with the screw extender's interior threads disposed at the proximal end of the screw extender. At this point, the surgeon begins rotation of the nut922, thereby screwing the nut922into the screw extender without rotation of the shaft920of the device900. Upon insertion of the device900into the screw extender, the distal end904of the device900is configured to fit within the passageway of the head of the screw. This allows proper alignment of the opening932toward another screw extender. In some embodiments, upon placement of the screws and respective screw extenders, the surgeon can manipulate the screw extenders (coupled to the screws) so that the channels disposed on the extenders' exterior surfaces are aligned toward each other. The device900can be inserted with the opening930pointed toward the second screw extender that has been already installed into patient's vertebrae. During insertion of the wire through the device900, the wire is advanced along the interior channel941, out of the opening930and toward the second extender through patient's muscle tissue.

As stated above, the device900is configured to be separated into to portions927aand927b.In some embodiments, the portion927ais configured to include the channel941for advancing the wire along the device900. The channel941is configured to begin at the proximal end of the device900and protract through the entire length of the portion927atoward the opening930disposed on the side of the device900. In some embodiments, the channel941is configured to be curved to accommodate bending of the wire during advancement.

In some embodiments, the device900can include a balancing feature925configured to extend away from the surface of the shaft920. The feature925is configured to prevent the device900from wobbling once it is inserted into the interior passageway of the screw extender.

The second device950, shown inFIGS. 9d-g, is configured to include a shaft951disposed between a distal end914and a proximal end912. In some embodiments, the shaft can be configured to have a unitary structure as opposed to a two-part structure of the device900. The device950further includes a nut or any other locking mechanism947disposed substantially adjacent the proximal end of the device950. The nut947further includes threading948configured to interact with the threading disposed at a proximal end of the screw extender on its interior wall. The nut is configured to be coupled to the shaft951at the proximal end912. The device950further includes a wire-pinching or a wire-holding mechanism957disposed at the distal end914of the device950and that is configured to pinch or secure the wire once the wire is advanced from the first screw extender (containing device900) through patient's muscle tissue. The wire-pinching mechanism957includes an opening959. Upon advancement of the wire from the first screw extender and through the muscle tissue, the opening959is configured to receive the wire, which is then secured by the wire-pinching mechanism957. The wire-pinching mechanism957is controlled by a knob or any other locking feature945disposed at the proximal end912of the device950. The knob945is configured to be coupled to a shaft955that is inserted through the interior of the shaft951of the device950. The shaft955is configured to have a smaller diameter than the diameter of the shaft951. The shaft955further includes a threading913that is configured to mate with a threading disposed on an interior surface of shaft951(not shown). Upon such mating, the surgeon can begin rotating the knob945, thereby advancing the shaft955through the opening959, as illustrated inFIGS. 9f-g. Upon advancement of the shaft955, the shaft955is configured to decrease available space within opening959, thereby pinning the wire to one of the walls of the opening959.

FIG. 12illustrates an exemplary wire1010, according to some embodiments of the present invention. The wire1010includes a distal tip1210that is configured to lead the wire through the first extender (and the device900), through the patient's muscle tissue, and into the second extender (and the device950). The wire1010also includes a proximal end1212to which a rod1984is attached. The rod1984contains a hole where the wire interlocks with the rod. This attachment can have a thread or a mechanical attachment mechanism. The rod also contains a feature on the far proximal portion of the rod, (the end not attached to the wire). This prevents the rod from being pulled through the screw extender. As can be understood by one skilled in the art, any other ways of coupling the wire to the rod are possible, e.g., any mechanical coupling of the wire and the rod are possible. In some embodiments, such coupling can be configured to allow for a quick release of the rod from the wire.

In some embodiments, the wire1010can be configured to be advanced using a wire-advancement device or a wire advancement gun1100, as shown inFIGS. 11a-b.FIG. 11aillustrates a cross-sectional view of the gun1100andFIG. 11billustrates a perspective view of the gun1100. In some embodiments, the gun1100includes a fixed handle1102, an actuating handle1104, and a barrel1106coupled to the handles1102and1104. The barrel1106is configured to include a loading opening1114disposed at a proximal end of the barrel1106and a discharge opening1112disposed at a distal end of the barrel1106. The wire1010(not shown) is configured to be loaded into the loading opening1114and discharged through the discharge opening1112by advancing the wire through the barrel1106. The actuating handle1104is configured to be spring-resistance-loaded with respect to the fixed handle1102, i.e., upon squeezing the actuating handle1104toward the fixed handle1102, a ratcheting mechanism1110is configured to cause advancement of the wire1010through the barrel1106and then forcing the handle1104to spring back to its original position. In some embodiments, the surgeon, upon squeezing the handle1104multiple times, can advance the wire1010to any desired length. As can be understood by one skilled in the art, other methods and/or instruments of advancing the wire1010are possible and are not limited to the wire advancement device1100shown inFIGS. 11a-b.

FIGS. 10a-eillustrate an exemplary procedure for advancement of wire1010through screw extenders1002and1004. As stated above, prior to advancement of wire1010, a surgeon (or any other medical professional) makes an incision above the location of implantation of a spinal stabilization system (represented by a screws, wires, rods, or any other devices), where the incision is configured to correspond to the location where a first combination of a screw and a screw extender (i.e., screw1006, screw extender1002) are to be implanted into patient's vertebrae. The surgeon can make another incision corresponding to the location where a second combination of a screw and a screw extender (i.e., screw1008, screw extender1004) are to be implanted into patient's vertebrae. Then, the surgeon implants first and second combination. The screw extenders are subsequently aligned so that the channels disposed on their housings (i.e., channels1012disposed on the first screw extender1002and channels1014disposed on the second screw extender1004; wherein channels can be partially open or fully open, as discussed above) are facing each other. Along with the channels, the passageways in the heads of the screws (i.e., passageway1016in the head of the screw1006and passageway1018in the head of the screw1008) are also aligned, thus creating a virtual corridor between the passageways and the channels.

Subsequent to the alignment procedure, devices900and950are inserted into the interior portions of the housings of screw extenders1002and1004, respectively. The devices900and950are then secured using appropriate knobs and threaded portions, as discussed in connection withFIGS. 9a-h. During insertion, the surgeon also aligns devices900and950so that the opening930on the device900is aligned with the opening959of the device950(not shown inFIG. 10a). The wire advancement device1100is loaded with the wire1010and is then coupled to the device900, as shown inFIG. 10a. Upon coupling of the device1100, the opening1112in the barrel of the device1100is aligned with the opening on the device900disposed at a proximal end of the device900so that the wire1010can safely pass through the interior channel941of the device900(not shown inFIG. 10a).

As the surgeon advances the wire1010using the device1100, the wire1010begins to travel along the channel941of the device900and is configured to advance out of the opening930of the device900. Then, the wire1010begins to travel through the muscle tissue toward the second screw extender1004. In some embodiments, the wire1010can be configured to have a sharpened tip in order to pierce through the muscle tissue. As the wire1010is advanced further, it reaches and is passed through the opening959of the device950disposed within the second screw extender1004. As the sufficient length of wire has passed through the opening959, the surgeon actuates the pinching mechanism of the device950, which compresses the wire1010in the device950. The surgeon can observe wire advancement using X-ray.

Once the wire1010is secured in the device950, the surgeon removes the wire-advancement device1100, as illustrated inFIG. 10b. In some embodiments, the device1100can be simply slid off the wire1010. Thus, at this stage, the wire remains secured by the device950and both devices900and950are secured within their respective screw extenders1002and1004. Then, the surgeon removes the nut922by unthreading it along the threads924(as shown inFIGS. 9a-b) and removes the portion927bfollowed by removal portion927aof the device900from the screw extender1002, as shown inFIG. 10c. The device950still remains in the second screw extender1004. Referring toFIGS. 10d-e, the surgeon removes the device950by unscrewing it from the housing of the extender1004. The device950is removed while the wire is being held by the pinching mechanism957. Upon removal of the device950, the wire1010is configured to protract through the first extender1002, through the muscle tissue of the patient disposed between extenders1002and1004, and the second extender1004while being coupled to the removed device950.

In some embodiments, the rod1984(shown inFIG. 104) can be configured to be advanced along with the wire1010(or follow the wire through the screw extender1002and then along the virtual corridor in the muscle tissue created by the wire) for installation between two screws.FIGS. 10f-gillustrate advancement of the rod1984along the wire1010, whereFIG. 10fis a perspective view of the installed rod andFIG. 10gis a cross-sectional view. The rod1984can be configured to include an advancing tip1952disposed at a distal end of the rod1050and a proximal end1954of the rod1984that in some embodiments can be configured to be coupled to a rod inserter (discussed below in detail). The rod's advancing tip1952is configured to travel from the first screw extender1002along the passageway created by the wire1010in the muscle tissue of the patient to reach the second screw extender1004. Once the rod1984is disposed in the passageways of screws1006and1008that are coupled to the respective screw extenders1002and1004, the rod1984can be secured using setscrews1072that can be advanced through the interior of the screw extenders using a setscrew setting device1070, as shown inFIG. 10h. The setscrew setting device1070can be configured to carry a setscrew at its distal tip and then upon insertion into the passageway in the head of the implanted screw begin rotating the setscrew (having appropriate threads) along the threads disposed on the interior of the passageway of the implanted screw. Upon setting the setscrew, the device1070can be released from the setscrew1072and removed from the interior of the screw extender. Upon removal of the setscrew setting device1070, the screw extenders can be removed using the remover tools discussed above.

During installation of the spinal stabilization system of the present invention, the surgeon may wish to compress or distract the screw extenders that are coupled to the screws, which are implanted into patient's bony matter.FIGS. 13a-13fand14a-eillustrate various embodiments of compressor/distractor tools. In some embodiments, the compression motion can be characterized by pushing the distal ends of the screw extenders closer to each other and by pulling the proximal ends of the screw extenders away from each other. The distraction motion can be characterized by pushing the proximal ends of the screw extenders closer to each other and by pulling the distal ends of the screw extenders away from each other (i.e., a reverse of the compression motion).

FIGS. 13a-fillustrate an exemplary compression/distractor tool1300, according to some embodiments of the present invention. The tool1300includes a housing1310, compression/distraction arms1304(a, b), ratchet handle1302, fulcrum1312, and a release handle1320. The arms1304are configured to be coupled to the housing1310using respective shoulders1315(a, b). The arms1304are configured to substantially perpendicularly protrude away from the housing1310in the same direction. The ratchet handle1302is configured to be disposed on the side of the housing1310that is opposite to the side where the arms1304are disposed. The ratchet handle1302is configured to cause movement of the arms1304to and from each other. The ratchet handle1302can be configured to use any conventional ratcheting mechanism for activating such translational movement of the arms1304. In some embodiments, the ratchet handle1302can be configured to have a gripping portion to allow for better gripping of the handle1302. The arms1304further include respective inner cavities1308(a, b) that are configured to accommodate placement of the screw extenders between the arms1304and the fulcrum1312. The fulcrum1312can be configured to have a rhombus shape (as can be understood by one skilled in the art, other shapes are possible) that creates pivot points for the screw extenders being secured between the arms1304and the fulcrum1312. The pivot points are configured to allow tilting of the of the screw extenders either during compression or distraction motions. In some embodiments, the fulcrum1312can be configured to be rotated to allow for variable angle distraction/compression of extenders. In some embodiments, the arms1304can be configured to include respective openings1306(a, b) configured to accommodate insertion of pins1353(a, b), which serve for attachment of an anti-torque device1370(shown inFIG. 13f).

In order to prevent slippage of the screw extenders, an anti-splay device1351(shown inFIG. 15) can be placed over each of the proximal ends of the extender housings prior to performing any distraction/compression. In some embodiments, the anti-splay device can also be anti-torque device. As can be understood by one skilled in the art, the terms “anti-splay” and “anti-torque” are used interchangeably in this description and an anti-splaying device can be configured to have anti-torque capabilities and vise versa. The anti-splay device1351includes a body portion1504coupled to an anti-splay portion1357. The body portion1504is configured to be coupled to the housing of the screw extender using any known methods (e.g., hook-and-slide (shown inFIG. 15), snap-fit, or any other ways). The anti-splay portion1357is configured to interact with the arms of the1304or any other parts (e.g., fulcrum1312) of the device1300, as shown inFIGS. 13e-f. Upon coupling, the anti-splay device1351and the screw extender housing create a unitary structure that can withstand the forces being applied to it during compression/distraction motions. The anti-splay portions1357can be configured to have mesh-like surface that is configured to create friction between components of the device1300and the anti-splay devices1351.

Referring toFIG. 13e,the screw extenders1341(a, b) are configured to be arranged in the device1300for the purposes of compression, i.e., pulling of the proximal ends of the screw extenders apart from each other. For compressing the screw extenders, the anti-splay devices1351(a, b) are coupled to proximal ends of the respective screw extenders1341(a, b). The device1300is configured to be arranged so that the fulcrum1312is disposed above the arms1304(a, b) in relation to the proximal ends of the screw extenders. The screw extenders1341are configured to be arranged between the respective arms1304and the fulcrum1312, as shown inFIG. 13e.Once the screw extenders1341along with anti-splay device1351are secured between the respective arms1304and the fulcrum1312, the handle1302is further rotated to tilt the screw extenders1341about side edges of the fulcrum1312, thereby causing the distal ends of the extenders1341to be pushed together, whereas the proximal ends of the extenders1341are pulled apart. In some embodiments, an anti-torque device1370can be coupled to the pins1353to prevent slippage or any other movement of the extenders while performing compression. To increase the angle of inclination of the extenders1341, the surgeon can continue rotating the handle1302. To release the handle1302after compression, the handle1320is depressed.

FIG. 13fillustrates a reverse motion of distraction. To perform this motion, the device1300is turned upside down in relation to the motion of compression situation, whereby the fulcrum1312is arranged below the arms1304, as shown inFIG. 13f.During distraction, the arms1304are configured to interact with the anti-splay portions1357of the anti-splay devices1351. By rotating the handle1302, the device1300is configured to push the proximal ends of the extenders closer together while pulling the distal ends of the extenders apart. The anti-torque device1370can also be attached to the pins1353to prevent slippage of the device.

In some embodiments, the arms1304can be “powered” by a rack and pinion or a mechanical link system. In some embodiments, the anti-splay device1351further prevents the extenders from splaying, bending, or undergoing flex during activities such as distraction, compression, torsion, and axial loads common in manipulating vertebra during spine surgery.

FIGS. 14a-eillustrate another exemplary compressor/distractor device1480, according to some embodiments of the present invention. The device1480includes a housing1482that includes an elongated opening between two rails1491(a, b) running in parallel to each. The rails1491are configured to be connected at one end using an elevated rounded section1483and at the other end using a connection rod1493. The device1480further includes a crank-and-ratchet mechanism1474that is configured to slide along the rails1491using a sliding mechanism1490disposed within each rail. The rail1491afurther includes a plurality of ratchet teeth1484with which a ratchet wheel1495of the mechanism1474is configured to interact, as shown inFIG. 14c.The mechanism1474further includes a handle1481that is coupled to the ratchet wheel1495and configured to cause rotation of the ratchet wheel1495. The mechanism1474further includes a release handle1482that is configured to allow movement of the mechanism toward the elevated portion1483and prevent a reverse motion of the mechanism1474. Upon depressing of the release handle1482, the mechanism1474is released and is allowed movement (i.e., translation) away from the elevated portion1483.

The elevated portion1483of the device1480includes a spring-loaded locking feature1488having two spring-loaded locking pins1489(a, b) connected by a rod1499. The rod1499and the elevated portion1483are configured to create an opening1485for insertion of a screw extender device, as shown inFIGS. 14d-e. In some embodiments, the screw extender device housing's features391shown inFIGS. 3a-bare configured to interact with the rod1499and prevent movement of the screw extender device inside the opening1485. A second screw extender device can be inserted into an opening created between the rails1491, the rod1499and the mechanism1474. The second screw extender can be secured by translating mechanism1474along the rails1491, until the second screw extender is secured between the rod1499and the mechanism1474. In some embodiments, each of the openings1485and1487are configured to be sized to allow insertion and securing of the screw extenders. The spring-loaded features1489are configured to be locked in using a screwdriver or any other tool. Referring toFIG. 14d,a motion of distraction is shown, whereby the distal ends of the screw extenders are pulled apart. During this motion, the device1480is configured to be secured so that the ratchet teeth1484are facing upwards.FIG. 14eillustrates a motion of compression, whereby the proximal ends of the screw extenders are pulled apart. In this case, the ratchet teeth1484are configured to face downwards. The device shown inFIGS. 14a-eis advantageous as no anti-splay or anti-torque devices are required to maintain stability of the screw extenders during distraction/compression motions.

FIGS. 16a-cillustrate an exemplary caliper tool1600having screw extender attachment barrels1602(a, b) that are coupled to a measuring ruler1604, whereby the measuring ruler1604is configured to be slidably coupled to the barrel1602a(for example) and fixed to the barrel1602b.In some embodiments, the barrels1602are also coupled to respective handles1603(a, b) that are configured to allow a surgeon to easily translate the barrels1602. The barrels1602are configured to be hollow inside and are appropriately sized to accommodate placement of the screw extenders. The caliper tool1600assists the surgeon in determining the length of a rod that is needed to for a particular surgery.

Upon installation of the screw extenders into the vertebrae, the surgeon places the barrels1602over the proximal ends of the screw extenders (as shown inFIG. 16c) and slides one of the barrels1602aalong the ruler1604. The ruler1604is configured to have markings1608indicating an appropriate size of the rod needed for surgery. In some embodiments, the ruler1604can be configured to have a stopping mechanism1607that prevents slippage of the barrels1602from the ruler1604. Once the size of the implant is noted on the rule1604, the caliper tool1600can be removed from the extenders. In some embodiments, the moving barrel1602bcan also include a locking feature1611that the surgeon can use to lock the device upon determining the appropriate size of the rod.

FIGS. 17a-cillustrate an exemplary screw extender guide tool1700for reinstalling the screw extender, according to some embodiments of the present invention. The tool1700can be used in the event that a screw extender is removed from (or for example, accidentally slips off) the installed screw and needs to be re-installed to the screw. The tool1700can be used during any re-installation procedures.

The tool1700includes a hollow housing1702disposed between a distal end1704and a proximal end1706. The proximal end1706is configured to include a handle1708that controls rotation of a threaded portion1710disposed at a distal end1704. The threaded portion1710is configured to interact with the threaded portion inside the head of the screw (not shown inFIG. 17a). Thus, in the event that the screw extender1750is removed from the screw1752(either accidentally or not) and needs to be reinstalled, the tool1700is placed over the wire1754and slid downwards along the wire1754and toward the screw1752. Upon reaching the screw1752, the tool1700is screwed into the head of the screw1752and thus, secured to the screw1752. Once the tool1700is secured to the screw, the extender1750can be advanced along the tool1700for coupling to the screw in a similar fashion as described above. After coupling of the extender1750, the tool1700is unscrewed from the head of the screw1752and removed along the wire1754. In some embodiments, the wire1754can be a guide-wire placed to outline a perimeter of the surgical procedure and guide the surgeon during procedure.

FIGS. 19a-eillustrate various embodiments of a rod inserter device, according to some embodiments of the present invention.FIGS. 19a-billustrate an exemplary a rod inserter tool1910. The rod inserter tool1910includes a handle1912disposed at a proximal end of the tool1910and a shaft1914coupled to the handle1912. At a distal end of the shaft1914, the shaft includes a rack-and-pinion mechanism1920that is configured to slide out of the shaft1914and to rotate a rod1930(that was previously coupled to the mechanism1920) by approximately 90 degrees. As can be understood by one skilled in the art, other angles of rotation are possible. In some embodiments, such rotation is accomplished through rotation of the handle1912that is coupled to rods1925disposed within the shaft1914. Rotation of the handle1912causes the rods1925to push down the rods1927of the rack-and-pinion mechanism1920, thereby causing the rotational motion of the rod1930. Reverse rotation of the handle1912causes reverse rotation of the rod1930.

In some embodiments, the rod1930(which is similar to the rod1984shown inFIG. 19f) includes an opening1979disposed at its distal end and configured to be coupled to an insertion pin of the rack-and-pinion mechanism1920. This allows the rod1930to be held in place by the rod inserter tool1910, while the rod is being inserted into the screw extenders. The rod further includes ratchet teeth1978(shown inFIG. 19f) that are configured to be disposed at the distal end of the rod and further configured to interact with ratchet teeth1922of the mechanism1920. The ratcheting interaction of the rod1930and the mechanism1920provides a controlled rotation of the rod1930.

FIGS. 19c-eillustrate another exemplary rod insertion tool1950, according to some embodiments of the present invention. The tool1950includes a shaft1955disposed between a distal end1957configured to be coupled to a rod1930(in a similar fashion as with the tool1910inFIGS. 19a-b) and a control handle1959. The control handle1959is configured to be threadedly secured inside the shaft1955using threads1961. The control handle1959is further secured to an interior rod1971that is disposed inside the shaft1955and is configured to slide inside the shaft1955. The rod1930is rotatably coupled to the interior rod1971. Upon rotation of the control handle1959, the interior rod1971begins to push on the pivoted connection between rod1930and interior rod1971, thereby causing the rod1930to rotate, as shown inFIGS. 19d-e. In some embodiments, the interior rod1971can be configured to be spring loaded inside the shaft1955using springs1963, which cause the handle1959to spring back upon completion of rotation of the rod1930. In some embodiments, the rod1930can be configured to include a pivot hole1977that is configured to disengage from the interior rod1971upon rotation of the rod1930. Thus, this allows for a release of the rod1930from the interior rod1971.

In some embodiments, the shaft1955further includes a measuring scale1967disposed along a portion of the length of the shaft1955. The scale1967is configured to determine the proper depth of insertion of the inserter tool1950into the screw extender housing.

FIGS. 20a-lillustrate a procedure for rod insertion using a tool1910shown inFIGS. 19a-b. Referring toFIGS. 20a-d, the rod inserter tool1910coupled to the rod1930(pointing towards the screw extender) is inserter into the first screw extender2002. Upon insertion, the rod1930is rotated to being protruding outside the exterior channels of the first screw extender2002and to begin pointing toward the second screw extender2004, as shown inFIGS. 20e-f. Then, the rod1930is advanced into one of the exterior channels of the second screw extender2004, as shown inFIGS. 20g-j. Upon being inserted into the channels of the first and second screw extenders2002and2004, the inserter tool1910is disengaged, as shown inFIGS. 20k-l.FIGS. 20m-oillustrate insertion of the rod1930using the tool1950shown inFIGS. 19c-e.

FIGS. 21a-eillustrate an exemplary rod reducer tool2100for reducing the rod1930toward the implanted screw, according to some embodiments of the present invention. The rod reducer2100includes a rod reducer shaft2102coupled to a handle2104. The handle2104is configured to be rotatably coupled to the shaft2102. The shaft2102is configured to include an interior passage2120for insertion over a screw extender. The reducer further includes handle threads2132and extender threads2135. The extender threads2135are configured to interact with the threads disposed on an interior surface of the screw extender housing2165(as shown inFIG. 21a) and thus are configured to secure the tool2100to the screw extender housing. The handle threads2132are configured to allow rotation of the handle2104once the reducer tool2100is secured to the extender housing2165. In some embodiments, the reducer tool2100includes a window2140disposed on the shaft2102that allows a surgeon to get a visual confirmation that the extender housing2165has been secured to the reducer tool2100.

In some embodiments, the handle2104of the tool2100includes an opening2108that is configured to allow insertion of setscrews or other tools, once the reducer tool2100has aligned the rod1930and it is time to secure to the implanted screw.

FIGS. 22a-billustrate an exemplary rod inserter tool2200, according to some embodiments of the present invention. The tool2200is configured to allow pushing of the rod1930disposed in the channels between two extenders2202and2204toward the implanted screws. The tool220can push the rod1930from a side of one of the extenders (as shown inFIG. 22b) or between two extenders (as shown inFIG. 22a). The scenarios shown inFIGS. 22a-bmay require different types of incisions made. For example, the scenario shown inFIG. 22amay require a surgeon making an incision that connects the two incisions created for the two extenders. In some embodiments, the tool2200includes an elongated shaft2207coupled to scissor-like handles2209at a proximal end and gripping jaws2211at a distal end. The gripping jaws2211are configured to grip the rod1930upon actuation of the handles2209. Once the jaws2211have gripped the rod1930, the surgeon can begin pushing the rod toward the implanted screws.

In some embodiments, components of the present invention can be manufactured from Nitinol or any other suitable materials.

In some embodiments, the above referenced extender devices can be used by a surgeon (or any other medical professional) in a variety of applications. The extender devices can be used subsequent to preparation of a bone for screw-implantation. Screw is implanted using a bone biopsy needle, such as a Jamshidi needle, manufactured by Cardinal Health Inc., Dublin, Ohio, USA, which can be followed by progressive dilation. Once the bone has been prepared, the bone screw is implanted. After implantation, the bone screw can be manipulated for orientation using the extender device. This “extender” extends out of the stab wound and allows the surgeon to control the implanted screw.

The following description illustrates some additional tools that can be used with the screw extender devices that have been discussed above and shown inFIGS. 1-22b.

FIGS. 23a-iillustrate an exemplary compressor-distractor tool2300, according to some embodiments of the present invention.FIGS. 23a-billustrate perspective views of the tool2300;FIG. 23cillustrates the tool2300being coupled to screw extenders that are attached to respective screws implanted into a vertebrae;FIGS. 23d-eillustrate the tool2300being in a compressed state (FIG. 23dis a perspective view andFIG. 23eis a cross-sectional view);FIGS. 23f-gillustrate the tool2300being a distracted state (FIG. 23fis a perspective view andFIG. 23gis a cross-sectional view);FIGS. 23h-iare perspective views of the tool2300being attached to screw extenders along with respective screw assemblies.

Referring toFIGS. 23a-i, the tool2300is configured to apply compressive and/or distractive forces to screw extenders and, ultimately, screw assemblies that have been implanted into vertebra and coupled to the screw extenders. In some embodiments, the tool2300is placed over top portions of two screw extenders that can be adjacent to one another and then, by turning a handle or a knob, the screw extender assemblies can be compressed together or distracted from each other, as shown inFIG. 23c-g.

In some embodiments, the tool2300includes a first screw extender holding portion2302and a second screw extender holding portion2304, as shown inFIGS. 23a-b. Each portion2302,2304can be configured to have a respective base part2303coupled to a respective top part2305. The base part2303is configured to be coupled to a screw extender (not shown inFIGS. 23a-b). The top part2305is configured to protrude away from the base part2303and, in some embodiments, can be further configured to have a curvature. The top parts of the portions2302and2304can be configured to curve toward each other, where portions2302and2304are pivotally coupled to each other at their respective tops, as shown inFIGS. 23a-b.

The portions2302and2304are pivotally coupled to each other using a pivoted connection2306. In some embodiments, a removable handle2308coupled to a rod2307can be inserted through openings at the top of the portions2302and2304to allow pivoting of the portions2302,2304about the rod2307.

The base parts2303of each portion2302and2304include respective screw extender openings2312and2314disposed at the bottom of the respective base parts. The openings2312and2314are configured to receive upper portions of screw extenders, i.e., tool2300is placed on top of the extenders using the openings2312and2314, as shown inFIGS. 23c-i.

The tool2300further includes a multi-threaded screw2310that is configured to further connect the portions2302and2304at their base parts2303. The screw2310is configured to be inserted through openings2309, where the openings2309are configured to be disposed substantially perpendicularly to the openings2312and2314. The screw2310is configured to include multi-directional threading2315and2317that is disposed at opposite ends of the screw. The base parts2303of each portion2302,2304include respective threading mechanisms2319,2321. The mechanism2319is configured to interact with threading2315of the screw2310and mechanism2321is configured to interact with threading2317of the screw2310. The screw2310can be further configured to include a handle2320for rotating the screw once it is inserted through the openings2309. Since threading2315and2317have oppositely disposed threads, rotation of the handle2320and the screw2310in one direction (e.g., clockwise direction2341) causes base parts2303of portions2302and2304to come closer to each other (i.e., compression). Similarly, rotation of the handle2320and the screw2310in an opposite direction (e.g., counterclockwise direction2342) causes base parts2303of portions2302and2304to spread apart from each other (i.e., distraction). Such movement of the base parts2303translates into compression/distraction movement of the screw extender towers inserted into the respective openings2312and2314. Compressed extenders are illustrated inFIGS. 23d-e. Distracted extenders are illustrated inFIGS. 23f-i. Because the screw2310rotates at the same angular velocity, equal rotational force is applied to the portions2302and2304that allows the portions to translate along the length of the screw2310equally in their respective directions (which depends on compression or distraction).

In some embodiments, the fulcrum handle2308can be configured to be removable and can be further configured to accommodate right-handed or left-handed usage. This is advantageous in the event that the portions2302and2304may need to be separated.

As shown inFIG. 23a,the respective top parts2305of the portions2302and2304can be configured to include openings2331that allow access to the screw extender towers that are inserted into the respective openings2312and2314. The surgeon (or other medical professional) can insert instruments or any other tools through the top parts2305and respective openings2331of the tool2300and into the screw extender towers. The openings2331can be also configured to provide a visual indicator of the placement of the screws through the screw extender towers/housings.

As can be understood by one skilled in the art, the tool2300can be configured to compress/distract at least two screw extender towers.

FIGS. 24a-lillustrate an exemplary end-holding rod inserter tool2400, according to some embodiments of the present invention. The tool2400is used during rod insertion procedures and is configured to grip the rod at a distal end by squeezing onto the rod.

Referring toFIGS. 24a-l, the tool2400includes a handle2402coupled to a curved shaft2404. The shaft2404includes a distal end2406configured to secure a rod and a proximal end2408that is coupled to the handle2404. In some embodiments, the rod can be held at an approximately 75 degrees (or any other angle) with respect to the shaft2404. The proximal end2408is configured to have a curved portion2409, which allows the user of the tool2400to conveniently secure and manipulate the rod inside the screw extenders coupled to respective implanted screw assemblies.

The shaft2404is configured to have a stationary or static portion2412and a sliding portion2414. The sliding portion2414is configured to slide on top of the stationary portion2412. The stationary portion2412is configured to be permanently secured to the handle (or inside the handle)2402. Both portions2412and2414have curved proximal ends2409(a, b). The distal end of the stationary portion2412further includes an L-shaped receiving groove2415that, in combination with the distal end of the sliding portion2414, is configured to secure the rod. In some embodiments, as illustrated inFIG. 24l, the distal end of the stationary portion2412can have a male mating feature2451that is configured to interact with a female mating feature2453adisposed on the rod2460. The rod2460can be configured to have another mating feature2453bdisposed oppositely to the mating feature2453aand configured to interact with the distal end of the sliding portion2414(not shown inFIG. 24l). The rod2460is configured to be securely “squeezed” between the mating feature of the stationary portion2412and the sliding portion2414, when the rod is placed into the L-shaped receiving groove2415.

The sliding portion2414is configured to be coupled to a rotary mechanism2420disposed inside the handle2402. The rotary mechanism2420is further coupled to a control knob2425. The rotary mechanism2420further includes a first rod2427that is disposed between and coupled to the knob2425and a threaded nut2429and a second rod2431that is coupled to the threaded nut2429and an interior portion of the curved proximal end of the sliding portion2412. The threaded nut2429is configured to rotate inside and along a threaded portion2433, as shown inFIGS. 24g,24i,and24k.The threaded portion2433is coupled to the sliding portion2414and depending on the movement of the threaded nut2429either pulls or pushes the sliding portion2414along the stationary portion2412, as shown inFIGS. 24gand24k.Rotation and translation of the threaded nut2429along the threaded portion2433is controlled by the control knob2425, whose rotational motion causes the first rod2427to rotate, thereby rotating the threaded nut2429and thus, either pulling towards or pushing away from the control knob2425.

In some embodiments, the stationary portion2412can be configured to have grooved stopper portions2471(a, b) disposed in its shaft, and the sliding portion2414can be configured to have corresponding protrusions2473(a, b) that slide inside the stopper portions2471when sliding portion2414is translated along the stationary portion2412. The stoppers prevent the sliding portion2414from overextending and thus, damaging the rod2460or the tool2400.

Thus, to secure the rod2460to the tool2400, the control knob2425is rotated in one direction (e.g., counterclockwise) to open the L-shaped receiving groove2415at the distal end of the shaft of the tool2400. Thus, such rotation translates the sliding portion2414along the stationary portion2412toward the handle2408, thereby spreading apart the distal ends of the portions2412,2414and forming a gap between the proximal curved ends of the stationary and sliding portions, as shown inFIG. 24k.The rod is then placed into the opened L-shaped receiving groove2415. Optionally, mating features2451and2453aon the stationary portion2412and the rod2460, respectively, can be engaged to further secure the rod. Once the rod2460is in place, the knob2425is rotated in an opposite direction (e.g., clockwise) and the sliding portion2414is translated away from the handle2408and toward the distal end of the stationary portion2412that is holding the rod2460. The sliding portion2414contacts the rod2460and secures it inside the L-shaped receiving groove2415. Optionally, mating features of the sliding portion and the rod can be engaged to provide further stability to the secured rod. In some embodiments, the tool2400can be configured to include a locking mechanism to prevent unintentional translation of the sliding portion2414. The rod2460can be released by performing the above steps in reverse. The mating features are also configured to prevent axial and torsion forces during rod-insertion procedures.

FIGS. 25a-eillustrate an exemplary percutaneous end-holding rod inserter tool2500, according to some embodiments of the present invention. The tool2500is in some respects similar to the tool2400as it allows rod holding during insertion of the rod through the screw extender system. The tool2500includes a handle2502and a curved shaft2504. The shaft2504has a proximal end2509to which a control knob2508is attached and a distal end2511that is configured to secure a rod2560. The proximal end2509is further configured to be permanently coupled to the handle2502. The handle2502is configured to assist the user of the tool2500during rod-insertion procedures. The distal end2511includes a rod-holding mechanism2570. The mechanism2570is configured to clamp the rod2560in a pliers-type fashion. The mechanism2570may include an upper immovable lip2571that is permanently coupled to the distal end of the shaft2504and a pivoting lip2573that is rotatably coupled to the distal end of the shaft2504.

As illustrated inFIG. 25e,in some embodiments, the immovable lip2571can be configured to include a male mating feature2575that is configured to interact with a corresponding female mating feature2576disposed on the rod2560. In some embodiments, the pivoting lip2573can be also configured to include similar mating features that can interact with corresponding mating features disposed on the rod2560(not shown inFIG. 25e). Similarly to the tool2400, the mating features allow better gripping of the rod2560, when the rod2560is placed between the immovable lip2571and the pivoting lip2573. The mating features are also configured to prevent axial and torsion forces during rod-insertion procedures.

The curved shaft2504further includes a slidable rod2520disposed in an interior portion of the shaft2504. The slidable rod2520is coupled to a threaded mechanism2525disposed at the proximal end of the shaft2504. The slidable rod2520is further rotatably coupled to the pivoting lip2573.

To secure the rod2560to the tool2500, the knob2508is rotated in one direction (e.g., counterclockwise), causing the rod2520to be pushed away from the handle2502, and thereby rotating the pivoting lip2573in a downward direction away from the immovable lip2571. The rod2560is inserted into an opening created by the two lips2571,2573. In some embodiments, the mating features on the rod2560and the lip2571can interact with each other. Once the rod2560is inserted, the knob2508is rotated in an opposite direction (e.g., clockwise), thus causing the slidable rod2520to retract toward the handle, and thereby rotating the pivoting lip2573in an upward direction toward the immovable lip2571and the rod2560. In some embodiments, the mating features of the rod2560and the pivoting lip2573can be configured to interact to further secure the rod2560inside the mechanism2570. In some embodiments, the tool2500can be configured to have a stopper mechanism that can be configured to prevent accidental unwinding of the knob2508, which can release the rod2560. As can be understood by one skilled in the art, the tool2500can have both lips2571,2573rotate to secure the rod.

FIGS. 26a-killustrate an exemplary in-situ re-attachment guide tool2600, according to some embodiments of the present invention. In some embodiments, the tool2600is configured to facilitate re-attaching a screw extender to a screw assembly while the latter one is already implanted into vertebrae. This tool can also be useful in the following scenarios: (1) when screw assembly is by itself; (2) when the screw assembly already includes a rod that has been inserted; and (3) when the screw assembly already includes a rod that has been inserted and secured by a setscrew.

FIG. 26aillustrates the tool2600being coupled to a screw extender2601. Screw extenders have been previously discussed above with regard toFIGS. 1-22b.As shown inFIG. 26b,the tool2600can be configured to include two removable shafts2604and2606along with a main assembly2608. The shaft2604is configured to be used when a setscrew has not been attached to a screw assembly being implanted into vertebrae (i.e., scenarios nos. (1) and (2)). The shaft2604has a distal end2605aand a proximal end2605b.The distal end2605aincludes a threaded tip2610that allows screwing the shaft2604into the head of the screw assembly when the setscrew is not installed. The proximal end2605baccommodates placement of a removable knob2611that is configured to rotate the shaft2604during installation into and removal from the screw assembly.

Alternatively, if the setscrew has been already installed into the screw assembly (i.e., scenario no. (3)), the shaft2606can be used. The shaft2606includes a distal end2607aand a proximal end2607b.The distal end2607aincludes a peg2612that is configured to be inserted into the setscrew and that secures the shaft2606to the setscrew. The proximal ends2607band2605bare similar to one another. The knob2611can be configured to be secured to the proximal end2607bof the shaft2606in the same way as with respect to the shaft2604.

Once one of the shafts2604,2606is installed into the screw assembly, as shown inFIGS. 26c-d, the main assembly2608is the placed over the installed shaft. The main assembly2608includes a proximal end2615and a distal end2617and a shaft2619disposed between the proximal end2615and the distal end2617. The proximal end2615includes a handle2618. The distal end2617includes a hollow housing2621that is configured to be placed over a head of an installed screw and further accommodate placement of a screw extender housing. The shaft2619and the handle2618include an interior channel2625, which is used to place the assembly2608over the shaft2604or2606. In some embodiments, the length of the shaft2619or, alternatively, the distance between the distal end of the handle2618and the proximal end hollow housing2621is greater than the length of the screw extender housing that is to be re-attached to the screw.

The hollow housing2621has a diameter that is larger than the diameter of a screw extender housing that is to be re-attached to the screw assembly. In some embodiments, the housing2621can be further configured to have grooved portions disposed at its distal end, where the grooved portions are configured to be placed over the rod that has been previously secured to the screw assembly (if such rod has been installed).

Once the shaft2604or2606and the assembly2608are installed to the screw assembly, the knob2611secures the combination of the shaft2604(or2606) and the assembly2608to the screw, as shown inFIG. 26h.Then, the screw extender housing having an open channel (as illustrated inFIGS. 3a-c) is configured to be slid over the flat shaft2619via its open channel. The thickness of the flat shaft2619can be configured to be less than the width of the screw extender's open channel. Once the screw extender housing is placed over the shaft2619(as shown inFIG. 26i), the extender housing is translated toward the screw assembly (e.g., in a downward fashion) along the shaft2619, thereby inserting the screw extender housing into the hollow housing2621, as shown inFIG. 26j.Upon insertion, the screw extender housing is secured to the screw assembly, as discussed above with regard toFIGS. 1-22b.Once the screw extender housing is secured to the screw assembly, the tool2600is removed. The tool2600can be unscrewed from the screw assembly, if the setscrew is not installed; alternatively, it can be removed from the screw assembly by removal of the assembly2608and the shaft2606, if the setscrew is installed. Once, the tool2600is removed from the screw assembly, the screw extender housing is configured to remain attached to the screw assembly, as shown inFIG. 26k.

FIGS. 27a-gillustrate an exemplary rod reducer tool2700, according to some embodiments of the present invention. In some respects, the rod reducer2700is similar to the rod reducer2100shown inFIGS. 21a-ewith the following differences. In some embodiments, the rod reducer2700includes a threaded reduction mechanism and allows its outer shaft portion to be independent of the spinning or rotating forces. The handle of the rod reducer2700is configured to be attached to an internal thread that engages a screw extender tower. The rod reducer2700includes a collar that is attached to the main shaft and is configured to float within the handle assembly. As such, the rotational threading of the rod reducer2700causes the rod to be forced downward along the screw extender, however, the collar and/or the main shaft of the rod reducer are configured to remain in place. The rod reducer2700is configured to provide counter-rotational forces on the rod and to further provide a better translation of downward forces from the rod reducer to the rod.

Referring toFIG. 27a-f, assuming that a screw extender tower/housing2710is already coupled to the screw assembly2730that has been implanted into the vertebrae and a rod2720has been placed inside the screw extender2710substantially adjacent to the screw assembly, the rod reducer tool2700can be placed over the screw extender tower/housing2710for further securing the rod2730in place. In some embodiments, the rod reducer2700includes a main shaft2702coupled to a handle2704. As shown inFIG. 27c,a cross-sectional view of the rod reducer2700, the rod reducer includes a hollow interior2708that is configured to accommodate placement of the screw extender housing/tower2710(See,FIGS. 27d-e). The handle2704is configured to include an interior threading mechanism2712that is further configured to engage the screw extender housing2710, as shown inFIGS. 27d-e. Upon engaging the screw extender tower, the threading mechanism2712is rotated in a downward fashion using the handle2704, thereby translating the rod reducer2700also in a downward direction toward the screw assembly and the rod. The handle is configured to rotate together with the main shaft2702. In some embodiments, the handle is configured to rotate independently of the main shaft2702, where the main shaft2702does not rotate. Such translation of the rod reducer2700pushes the rod toward the screw assembly, as shown inFIGS. 27e-g. After pushing the rod to the screw assembly, the rod reducer tool2700is removed.

FIGS. 27h-iillustrate an alternate embodiment of a rod reducer tool2750, according to some embodiments of the present invention. The rod reducer tool2750is configured to be similar to the rod reducer tool2700. The tool2750includes a handle2755, a main shaft2757, and a collar2759disposed between the handle2755and the main shaft2757. The handle2757includes a handle shaft2761, a first handle threading2763and a second handle threading2765, wherein the first handle threading2763is disposed at the proximate end of the handle shaft2761and the second handle threading2765is disposed at a distal end of the handle shaft2761. The first handle threading2763is configured to allow spinning of the handle2755about the handle shaft2761during the translational movement of the tool2750along the screw extender tower (not shown inFIGS. 27h-i). The second handle threading2765is configured to engage the screw extender tower in similar fashion as discussed above and shown inFIGS. 27a-g. The collar2759is configured to include a collar threading2767that interacts with a shaft threading2769during rod reduction procedure (i.e., translation of the shaft in a downward fashion along the screw extender tower/housing). The collar2759allows a user to hold the collar2759during the rod reduction procedure and rotate the handle2755to force the tool2750toward the screw assembly and to thereby push the rod toward the screw assembly. It should be noted that during rod reduction procedures, the main shaft2757is static, while handle2755and the collar2759are configured to rotate independently of one another and the shaft2757. In some embodiments, the distal tip of the shaft2757includes two grooved portions2771(a, b) that are configured to accommodate placement of the rod during rod reduction procedures. The grooved portion2771allow better stability of the rod reducer tool2750during the procedure.

FIGS. 28a-eillustrate another exemplary tool, a screw extender remover tool2800, according to some embodiments of the present invention. The tool2800is configured to be used when it is necessary to remove a screw extender tower/housing that has been attached to a screw assembly. This tool is configured to easily release the screw extender from the screw assembly while localizing and minimizing axial forces on the screw assembly.

Referring toFIG. 28e,in some embodiments, the tool2800includes a handle2802coupled to a shaft2804. The handle2802includes a static portion2805and a moving portion2807. The moving portion is resistance-loaded using a spring-like mechanism2809. The mechanism2809allows moving portion2807to be pushed toward the static portion2805against resistance of the mechanism2809and to return portion2807to its original state upon its release. The moving portion2807is coupled to a lever2811, which is in turn coupled to an internal shaft2806disposed within the shaft2804. The shaft2804is configured to have a smaller diameter than the internal diameter of screw extender housing, which is to be removed from the screw assembly. The lever2811is pivotally coupled to both the moving portion2807and the internal shaft2806. Upon squeezing of the portion2807of the handle2802, the pivotal connections of the lever2811rotate and push the internal shaft2806along the interior of the shaft2804and away from the handle2802. This causes the distal end of the internal shaft2806to extend beyond the distal end of the shaft2804. Upon release of the portion2807, the internal shaft2806returns to its original position within the shaft2804.

The shaft2804further includes protrusions2815(a, b) disposed on its outer circumference substantially adjacent the distal end of the shaft2804. The protrusions2815are configured to interact with flexible indentor portions240(see,FIG. 2a) upon insertion of the tool2800into the screw extender housing2820, as shown inFIGS. 28a-e. The protrusions2815are configured to push apart the flexible indentor portions240and thereby free screw extender housing from the locked arrangement with the screw assembly2830. Thus, to remove the screw extender tower/housing from the screw assembly, the tool2800is inserted into the screw extender housing until its distal end is substantially adjacent the setscrew of the screw assembly, the tool2800may be rotated so that the protrusions2815contact and subsequently push apart (i.e., away from the head of the screw assembly) the flexible indentor portions240, then the movable portion2807of the handle2802is squeezed, thereby extending the internal shaft2806beyond the distal end of the shaft2804and pushing the internal shaft2806against the setscrew of the screw assembly and removing the screw extender from the screw assembly, as shown inFIGS. 28a-e. In some embodiments, the shaft2804can be configured to include a stopper2819that contacts the proximal end of the screw extender housing upon insertion of the tool2800and prevents over-insertion of the tool.

FIGS. 29a-fillustrate an exemplary rod inserter tool2900for inserting a connecting element through a diverging exposure of a soft tissue, which is created by the screw extenders, according to some embodiments of the present invention. The tool2900includes a handle2902, a main housing2904, a secondary housing2906, a lateral housing2908, and a switch2910. The handle2902is disposed at the proximal end of the main housing2904. The tool2900further includes a rod holding mechanism (or jaws)2912disposed at a distal end of the main housing2904. The rod holding mechanism2912is configured to secure a rod2950while it is being inserted between two screw extender housings2952and2954that are coupled to installed screws, as shown inFIGS. 29b-d. The main housing2904is disposed between the handle2902and the distal end of the tool2900. The sub housing2906and the lateral housing2908are configured to be disposed along the main housing2904. The tool2900further includes a switching mechanism2914disposed at the proximal end of the tool2900and substantially adjacent to the main housing2904and the handle2902. The switching mechanism2914is further illustrated inFIGS. 29e-f. The switching mechanism2914is configured to release the rod2950once it is installed between two screw extender housings2952and2954.

The rod holding mechanism2912is formed using distal ends of the main housing2904, secondary housing2906, and the lateral housing2908. The distal end of the main housing2904includes an “L-shaped” gripping feature2918that allows placement of the rod in a substantially vertical position with respect to the housings2904,2906,2908, as shown inFIG. 29b.The distal end of the lateral housing2908is configured to push on a portion of the rod that is disposed adjacent to the distal end of the lateral housing2908in order to rotate the rod into a horizontal position, as shown inFIG. 29d.

The housings2904,2906, and2908are configured to be internally coupled to the handle2902and the switching mechanism2914. The handle2902is configured to be spring-loaded having a resistance spring that allows return of the handle2902into an initial state after the user has squeezed the handle2902. The switching mechanism2914includes a lever2920disposed on the handle2902substantially adjacent to the proximal end of the main housing2902. The lever2920is further disposed adjacent to a tab2922. Rotation of the lever2920allows release of the rod from the holding mechanism2912. The lever2920is further interconnected with a holding pin2944, as shown inFIGS. 29e-f. Upon rotation of the lever2920in a downward direction, as shown inFIG. 29e,the pin2944is configured to be pulled in an upward direction, thereby releasing the housing2906from a position, in which it is configured to hold the rod2950(see,FIG. 29d). Once the housing2906is released, the user can pull on the tab2922to release the rod2950from the tool2900(and vice versa).

The tool2900is configured to hold the rod2950at an almost vertical position during insertion. The tool2900further allows manipulating the rod horizontally once the rod is inserted through a small incision in the skin of the patient to install the rod2950between two pedicle screws, as shown inFIGS. 29b-d. The tool2900allows its user (a surgeon or any other medical professional) to grip the rod2950mid-span without requiring a special feature (e.g., a groove for clamping, etc.) to be placed on the rod. The tool2900further allows its user to place the rod2950through an incision having a small opening but diverging as the incision deepens. In some embodiments, the tool2900is configured to combine two motions in different directions by squeezing the tool2900, i.e., it allows holding the rod in semi-vertical orientation and then rotating it into a horizontal position for installation between two pedicle screws.

FIGS. 29b-dfurther illustrate procedure for inserting the rod2950using the tool2900. To install the rod2950, the user loads the rod2950into the tool2900by coupling the rod2950to the rod holding mechanism2912located at the distal end of the tool2900. To load the rod2950, the secondary housing2906is pulled back using the tab2922and the rod2950is placed into the L-shaped gripping feature2918. The secondary housing2906is configured to be spring-loaded (e.g., having a spring disposed inside the secondary housing) and is further configured to return to its original position with respect to the main housing and toward the loaded rod2950. Once the secondary housing2906is returned to its original position, the rod2950is secured at the distal end of the tool2900. Thus, the rod2950is ready to be placed through the incision.

During insertion of the rod, the user may wish to rotate to rod to place it into a horizontal position to secure it to the pedicle screws. In order to rotate the rod2950, the user compresses the handle2902. Handle compression actuates the lateral housing2908, which causes the lateral housing2908to slide along the main housing2902toward the secured rod2950. The distal end of the lateral housing contacts the rod2950and forces the rod to rotate into a substantially horizontal position. During the rotation process, the main housing serves as a fulcrum and continues to hold the rod2950. Further, the secondary housing is configured to be pushed away from the rod and toward the proximal end of the secondary housing upon actuation of the lateral housing and rotation of the rod. Thus, upon fully squeezing the handle2902, the rod2950is configured to rotate to a position that is substantially perpendicular to the axis of the main housing.

Once the rod2950is secured to the pedicle screws, the rod is released. To release the rod2950, the user rotates the switching mechanism from its first position (loading position) to its second position (releasing position), thereby locking the lateral housing2908and the secondary body2906together. Upon locking the two housings together, the user releases the handle2902and the rod2950remains in a horizontal position and free from the secondary and lateral housings2906,2908. At which point, the inserter tool2900can be removed from the incision. To re-grip the rod2950, the user can squeeze the handle2902and rotate the switching mechanism in an opposite direction from its second position to its first position, thereby securing the rod2950to the holding mechanism.

In some embodiments, a surgeon can implement one or multiple tools discussed above and shown inFIGS. 1a-29fin connection with a screw extender system and a screw assembly. In an exemplary procedure, a patient can be positioned prone, lying flat on a radiolucent table. Chest rolls may be used, but it is preferable to avoid knee-to chest positions. Adequate clearance may be provided around the surgical table for use of a fluoroscopic C-arm. In some cases, preoperative planning may determine proper pedicle targeting, including an appropriate entry point and trajectory. For pedicle targeting, fluoroscopic imaging can be used to verify anterior-posterior and lateral images of the spine to adequately delineate pedicle morphology and geometry. After identifying pedicle entry point, a targeting needle is used to initiate the entry point. Entry angle and trajectory can be adjusted using fluoroscopic imaging until proper position is obtained. Once the targeting needle is in place, an inner stylet of the needle can be removed. The needle is cannulated to allow for placement of guidewire. The guidewire is inserted through the needle to a desired depth while observing that the guidewire does not cause any damage. Then, after the guidewire is inserted, the needle is removed. For the purposes of spreading apart the tissue and allowing placement of screw extender housing/towers and tools, variable-diameter dilators are advanced along the guidewire. Upon placement of a larger diameter dilator, a smaller diameter dilator is removed and a cannulated awl is placed over the guidewire through the larger diameter dilator to breach the cortex at the pedicle entry point. The pedicle can be tapped using a cannulated tap tool once the cannulated awl is removed. This completes the pedicle preparation stage of the surgical procedure. At this time, the surgeon can begin insertion of the screw. The cannulated tap tool is removed and further larger-diameter dilators are placed over the guidewire. As stated above, the screw extender housing is attached to a cannulated polyaxial screw (or any other type of suitable screw) prior to being installed on the chosen site. In some embodiments, a screw alignment guide tool can be used to attach the screw to the screw extender. Once the screw extender is coupled to the screw, using a screw driver having an axial handle or a T-handle, the combination of the screw extender and the screw are placed over the guidewire and through the attached dilator. The screw is then inserted into the pedicle using the screw driver. After inserting the screw into the pedicle, the screw driver and the dilator are removed. The above procedure can be repeated for any subsequent screws and screw extenders.

Once the screws with their respective screw extenders are installed at the site, rod insertion procedure can be initiated. Using screw extender calipers3000(such as those shown inFIG. 30) or any other suitable tool, length of the rod is determined. If calipers shown inFIG. 30are used, then rod length can be indicated at the top of the calipers. The rod is then prepared based on these measurements.

A pathway between two installed screws is cleared using a known curved and/or a sharp wand blade. Then, using a rod inserter (FIGS. 22a-b), an end-holding rod inserter (FIGS. 24a-l), the percutaneous end-holding rod inserter (FIGS. 25a-e), a rod inserter (FIGS. 29a-f), or any other rod inserter mechanisms/tools (e.g.,FIGS. 19a-20o) are used to advance the rod along screw extenders toward the implanted screws.

In some embodiments, a rod reducer tool (FIGS. 21a-e,27a-i) can be used to provisionally secure the rod into place. Additionally, compression/distraction tools (FIGS. 13a-14e,23a-i) can be used to adjust distances/angles between screw extender towers.

After the distances/angles are determined, the rod is captured using setscrews that are placed through the screw extender assemblies using a known setscrew inserter tool. The setscrews can be provisionally tightened to secure the rod in place. Then, using a known T-handle torque wrench with a torque wrench shaft and a screw extender anti-torque handle3100(e.g., as shown inFIG. 31), the setscrews are finally tightened. The anti-torque handle is coupled to a proximate end of the screw extender housing and the T-handle torque wrench is inserted into the screw extender housing until it contacts the setscrew. Then, the T-handle torque wrench is turned (e.g., clockwise) to secure the setscrew. In some embodiments, an audible indication (e.g., clicking) can alert the surgeon that the setscrews have been finally tightened.

To remove the screw extenders, screw extender remover tools (e.g.,FIGS. 18a-c,28a-e) are used to disengage the screw extender housing from the implanted screw assembly. In some embodiments, an in-situ screw extender re-attachment tool (e.g.,FIGS. 26a-k) can be used to re-attach the screw extender housings to the screw assemblies.

In a typical surgery, a plurality of bone screws can be implanted using the methods and tools discussed in connection with and shown inFIGS. 1a-31. In some cases, once an appropriate number of screws have been implanted into the bony matter of a patient, a rod and/or wire can bridge gaps between the screws. Placement and manipulation of screws can be accomplished using the extender devices and various surgical tools, as shown inFIGS. 1a-31. Following that, set screws can be tightened and the guide wire can be removed. Typically, the guide wire is removed prior to use of the caliper tool is used. The extender device and use of surgical tools allows a surgeon (or other medical profession) to perform a minimally invasive surgery of placing various fusion devices, such as in the case of spinal fusion procedures.

Although particular embodiments have been disclosed herein in detail, this has been done by way of example for purposes of illustration only, and is not intended to be limiting with respect to the scope of the appended claims, which follow. In particular, it is contemplated that various substitutions, alterations, and modifications may be made without departing from the spirit and scope of the invention as defined by the claims. Other aspects, advantages, and modifications are considered to be within the scope of the following claims. The claims presented are representative of the inventions disclosed herein. Other, unclaimed inventions are also contemplated. The applicant reserves the right to pursue such inventions in later claims.