USRE43526E1 - Rod introduction apparatus - Google Patents

Abstract

An introduction apparatus for approximating a longitudinal member and an implant to permit fixation therebetween. The introduction apparatus having a gripping nose for securely engaging an implant, a lateral approximation mechanism for laterally aligning an implant and an offset longitudinal member, and a reduction mechanism for reducing the vertical distance between the implant and the longitudinal member. The introduction apparatus is provide with a gripping nose actuated by axial movement of a clamping shaft in an outer sleeve. The clamping shaft further includes an axial cannula for passage of a fastener to the implant.

Description

This application is a reissue of U.S. Pat. No. 5,910,141, issued on Jun. 8, 1999, which is hereby incorporated by reference, as if fully set forth herein. U.S. Pat. No. 5,910,141 matured from U.S. application Ser. No. 08/798,092, filed Feb. 12, 1997.

BACKGROUND OF THE INVENTION

1. Description of the Prior Art

The present invention relates generally to instruments used to manipulate orthopedic implants. More particularly, the present invention relates to the manipulation of hone anchoring elements positioned in the spine and longitudinal members interconnecting those elements. While the present invention is particularly useful in spinal surgery, it may find use in other areas of medicine as well.

In many applications, particularly those relating to spinal correction techniques, it is desirable to place a series of implants in a patient's spine prior to inserting a longitudinal member (a rod or a plate) along the spine to interconnect the previously placed implants. On occasion, implants may be vertically spaced from the rod or plate and require a mechanical mechanism to bring the rod or plate into contact with the implant. In the instance of a plate, often the implant is a double threaded bolt with a series of bone screw threads anchoring into the bone and a machine threaded post extending through an opening in the plate. A machine threaded nut slightly larger than the opening in the plate may then be threaded onto the threaded post and tightened to bring the implant closer to the plate. For rod systems, a similar arrangement can be utilized whereby the threaded post of the implant extends through a connector attached to the rod. In these systems a nut is used to draw the implant closer to the connector by progressively threading the nut onto the post of the bone bolt.

Alternatively, it is known to provide a rod introducer mechanism that forces the rod and an implant towards each other. In some cases, the threaded post of a bolt type bone anchor is not long enough to extend through a connector attached to the rod. In this situation a mechanism is used to grasp the bolt and pull it towards the connector until the threaded post extends through an opening in the connector. A threaded nut may then be used to complete the connection to the connector.

In other cases the implant, either a bone screw or spinal hook, includes an open channel to receive the rod. A plug or set screw can be used to close the channel and lock the rod to the implant. In certain surgical techniques a rod is anchored at both ends by at least one implant, resulting in the rod being suspended above a second implant. A mechanism is then required to urge the second implant and rod together to permit connection of the implant to the rod and more particularly to seat the rod within the open channel of the implant. One such instrument marketed by Sofamor Danek Group as part of the Compact CD™ system, is an introducer lever C-6903 which resembles a fork with a pair of offset tines. The tines of this device extend over the vertically spaced rod and under either side of an enlarged portion of the implant. Once in place, the fork handle is moved toward the rod thereby forcing the rod and implant together. One problem with this arrangement is that the fork tines must pass between the implant and the bone, which in many cases may be difficult and may result in damage to the bone. Moreover, the connection between the fork tines and the implant is not a secure engagement and may result in the rod introducer slipping during the procedure of forcing the rod into the implant.

Other types of rod introduction devices have overcome the problems associated with the simple fork device by first achieving a secure attachment to the implant with articulated forceps or the like. Various instruments for gripping and handling implants are commonly known. One such instrument has a pair of articulating branches defining a gripping nose opposite a pair of handles. While many varieties of these forceps exist to accomplish various functions during surgery, some are adapted specifically to securely hold an implant, and in particular, a spinal osteosynthesis implant. The gripping nose of one such configuration utilizes a pair of inwardly facing cylindrical projections disposed at the distal end of the gripping nose. The cylindrical projections are adapted to engage corresponding recesses on an implant, thereby providing a secure grip. Because of the small size of many spinal implants and the accompanying difficulty gaining a secure grip with only manual pressure, such forceps are often utilized in the manipulation and placement of the implants.

In addition to providing a nose for gripping implants, many forceps also provide a locking mechanism to hold the forceps in the gripping position once the implant is gripped. A common example is the provision of one half of a ratchet rack on one articulating branch aligned to engage a second half of the ratchet rack on the other articulating branch. Upon movement of the branches towards one another, the separate halves of the ratchet rack come into engagement thereby preventing separation of the articulating branches. As is common with such arrangements, the articulating branches have sufficient flexibility that they may be flexed with respect to one another, thereby disengaging the ratchet racks.

An alternative forcep locking mechanism is disclosed in U.S. Pat. No. 5,423,855 owned by the Sofamor SNC subsidiary of Sofamor Danek Group. This patent shows forceps having an implant gripping nose as previously discussed. In this configuration, the articulating branches are held in the closed position by a spring biased cap disposed on the end of the branches opposite the gripping nose.

In prior systems, once a secure engagement has been accomplished between the forceps and the implant, a separate apparatus is attached between the forceps and the rod. In one such mechanism marketed by Sofamor Danek Group as the TSRH™ mini-corkscrew, a threaded rod is threadedly coupled at one end to the forceps and engages the rod at the opposite end. Rotation of the threaded rod urges the rod and implant towards each other. In another mechanism marketed by Sofamor Danek Group as an articulated rod pusher C-6211 for use with the Compact CD™ system, forceps grip the implant and a pivoting two piece rod pusher lever is used to urge the rod and implant towards one another. In this device, a lower end of the first member of the rod pusher engages the rod and the upper end of the first member is pivotally attached to the second member of the rod pusher lever. The lower end of a second member engages the forceps while the upper end of the second member is rotated to force the rod and implant towards each other.

U.S. Patent 5,020,519 to Hayes et al. discloses a single mechanism which both grips the rod and has a threaded mechanism to accomplish vertical reduction of the rod into the implant. As this reference discloses, the mechanism must first be attached to the implant and then the rod threaded through the opening between the clamping jaws. This unnecessarily creates a complication for the surgeon, i.e. maintaining both the reduction mechanism and the hook in the desired position while attempting to thread the rod through various implants and the opening in the reduction apparatus. Moreover, once the rod has been reduced into the implant opening, the reduction apparatus interferes with visualizing the implant and rod connection, and with placement of a fastener to hold the rod in the implant.

In addition to the surgical condition where the rod is suspended above the implant, the rod may be laterally offset with respect to the implant. Moreover, in some applications the implant may have an implant opening for receiving the rod which opens to the side, thereby requiring the rod to be laterally introduced into the implant. In these instances, it is often desirable to have mechanical assistance in bringing the rod and implant together to permit securing the rod within the implant. One such device marketed by Synthes Spine as the Universal Spinal System Rod Introduction Pliers is utilized to urge a laterally offset rod into a side opening implant. The Rod Introduction Pliers are used in conjunction with a Hook or Screw Holder device threadedly engaging the implant. One branch of the pliers consists of a barrel while the opposing branch defines a rod engaging surface. In operation, this barrel is placed over the Hook or Screw Hold device and the opposing branch of the pliers engages the offset rod and upon actuation of the plier handles the rod is urged into the implant opening. While this system provides a means to reduce the lateral displacement of the rod, it does not permit the user to additionally reduce any vertical displacement between the rod and the implant. Rather, the barrel of the rod introduction pliers apparently slides freely up and down the hook holder.

In addition to having a need, in some surgical situations, to both laterally approximate the rod to the implant and to vertically reduce the rod into the implant, there is a need to deliver a fastening member to the implant while the rod is securely held in place by the rod reduction apparatus. In some systems, the components required to accomplish reduction are offset with respect to the implant, thereby providing access to the implant to facilitate placement of the fastener once the rod is inserted into the implant. Use of offset instruments to apply force to the rod and implant may impart rotational forces to the implant tending to displace the implant from the desired location. Moreover, in most applications the fastening elements must be relatively small to prevent unnecessary protrusion from the implant. While this is desirable after placement, the small size of the fastener makes handling these items difficult. The difficulty of handling the small fasteners is increased when it is required to place them in the implant that is partially obscured by the rod introduction device. One approach to solving this problem is taken by the Universal Spine System pliers discussed above. In operation, a fastening collar is preloaded over the barrel prior to placement over the hook holder. Once the rod has been inserted into the implant the collar may be advanced over the barrel and engaged with the implant.

One disadvantage to the systems discussed above, is that none of the systems provide both a mechanism for reducing vertical rod offset and lateral rod offset from the bone anchor in a single device. Moreover, many of the systems utilize articulating clamping tips actuated by articulating handles to hold the implants and require a separate apparatus attached to the hook or screw holder to perform manipulation of the rod. It will be appreciated that the various handles extending out of the patient interfere both with vision and work space in an already limited surgical field. Therefore, it is desirable to provide a compact implant holder adapted to perform both vertical and lateral reduction of a rod.

The present invention overcomes the problems associated with the prior art by providing a gripping mechanism and a rod introduction lever for both lateral and vertical approximation in a single convenient instrument.

SUMMARY OF THE INVENTION

One form of the present invention contemplates a multiple action insertion apparatus for engaging a longitudinal member and an implant, comprising an implant holder including a first clamping branch and a second clamping branch cooperable with the first clamping branch to hold to the implant, a reduction mechanism interconnected with the implant holder, the reduction mechanism having a distal end for engaging the longitudinal member, wherein the reduction mechanism urges the longitudinal member into vertical alignment with the implant, and a lateral approximator mechanism interconnected with the implant holder, the lateral approximator mechanism having a distal end disposed adjacent the first and second clamping branches, said distal end adapted to engage the longitudinal member, wherein said lateral approximator mechanism urges the longitudinal member into lateral alignment with the implant.

Still a further form of the present invention contemplates a multiple action insertion apparatus for engaging a longitudinal member and an implant, comprising a device for attaching to an implant having an opening for receiving a rod, a device for lateral approximation of a longitudinal member laterally offset from the implant rod opening, the device for lateral approximation interconnected with the device for attaching, and a device for vertical reduction of a longitudinal member vertically offset from the implant, the device for vertical reduction interconnected with the device for attaching, wherein the device for lateral approximation laterally aligns the longitudinal member over the implant and the device for vertical reduction vertically aligns the longitudinal member with the implant.

Another form of the invention contemplates an implant holder for holding an implant adapted to receive a fastener, comprising a device for gripping the implant, the device for gripping including a gripping end and a handle defining a longitudinal cannula having a distal end adjacent the gripping end, the cannula adapted to receive a fastener cooperable with the implant.

In another aspect, the present invention contemplates an implant holder for gripping an implant, comprising a shaft having a gripping end with a portion, the gripping end defining a first clamping branch and a cooperable second clamping branch, the first and second clamping branches tending to assume an insertion position defining a first distance between the first and second clamping branches, and the first and second clamping branches compressible into a clamping position defining a second distance between the first and second clamping branches, the first distance greater than the second distance, and a sleeve defining an interior channel, the shaft slidably received within the interior channel, the shaft moveable between a first position with the portion extending from the sleeve and a second position with the portion drawn into the sleeve, wherein movement of the shaft within the tubular sleeve from the first position to the second position controls the first and second clamping branches from the insertion position to the clamping position.

Another form of the present invention contemplates an implant holder having a rod reduction mechanism for vertically aligning a longitudinal member and an implant, comprising a device for gripping the implant, a sleeve having an axis and a distal end adapted to engage the longitudinal member, the sleeve having an axial bore sized to receive the device for gripping, the device for gripping slidably received within the axial bore, and a device for axially displacing the sleeve with respect to the device for gripping, whereby the vertical offset longitudinal member is urged into alignment with the implant.

Additionally, the invention includes a method for for interconnecting a longitudinal member and an implant adapted to engage the longitudinal member, comprising the steps of providing an introduction apparatus having an attachment mechanism with a cannula and a vertical reduction mechanism, attaching the introduction apparatus to the implant, operating the vertical reduction mechanism to force the longitudinal member into alignment with the implant, inserting a fastener through the cannula, interconnecting the fastener and the implant, wherein the longitudinal member is securely attached to the implant, and removing the introduction apparatus.

The invention includes an additional method for interconnecting a longitudinal member and an implant adapted to engage the longitudinal member, comprising the steps of providing an introduction apparatus having an attachment mechanism, a lateral approximation lever, and a vertical reduction mechanism, attaching the introduction apparatus to the implant, engaging a laterally offset longitudinal member with one end of the lateral approximator lever, rotating the lever to urge the longitudinal member into lateral alignment with the implant, operating the vertical reduction mechanism to force the longitudinal member into vertical alignment with the implant, and interconnecting the longitudinal member and the implant.

One object of the present invention is to provide an implant holder having a cannula for passage of a fastener to the implant while it is being securely held.

Another object of the present invention is to provide a simple device for gripping the implant and reducing vertical offset between an implant and a longitudinal member.

A further object of the present invention is to provide an implant holder operable in a small lateral area to clamp an implant by axial movement of the holder mechanism.

Still a further object of the present invention is to provide a multiple action insertion apparatus that is capable of gripping an implant, approximating the implant and an laterally offset longitudinal member, and reducing the vertical distance between the implant and the longitudinal member.

Another object of the present invention is to provide a multiple action insertion apparatus that is capable of gripping an implant, approximating the implant and an laterally offset longitudinal member, and reducing the vertical distance between the implant and the longitudinal member wherein the apparatus includes a cannula for insertion of a fastening member.

Related objects and advantages of the present invention will be apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the rod introduction apparatus according to the present invention.

FIG. 2 is a side view of the rod introduction apparatus ofFIG. 1.

FIG. 3 is a bottom plan view of the rod introduction apparatus ofFIG. 1.

FIG. 4 is a side view of the rod introduction apparatus ofFIG. 2 with the rod seated in the implant.

FIG. 5 is a top view of the rod introduction sleeve.

FIG. 6 is a side view of the rod introduction sleeve.

FIG. 7 is a cross-sectional view taken alongsection lines7—7.

FIG. 8 is an end view of the rod introduction sleeve looking into the rod bearing surface.

FIG. 9 is a side view of a rod introduction clamp shaft.

FIG. 10 is a bottom view of the rod introduction clamp shaft.

FIG. 11(a) is a cross-sectional view of the rod introduction clamp shaft taken along section lines11—11.

FIG. 11(b) is a cross-sectional view of the rod introduction clamp shaft showing a threaded plug and driving member extending through the cannula.

FIG. 12 is a perspective view of the rod introduction speed nut.

FIG. 13 is a cross-sectional view of the speed nut ofFIG. 12.

FIG. 14 is a partial side view of a lever mechanism according to another embodiment of the present invention.

FIG. 15 is an alterative embodiment of a rod reduction apparatus according to the present invention.

FIG. 16 is a front view of the clamp shaft of the embodiment ofFIG. 15.

FIG. 17 is a front view of the outer sleeve of the embodiment ofFIG. 16.

FIG. 18 is a side view of the outer sleeve ofFIG. 17.

FIG. 19 is a side view of the clamp shaft ofFIG. 16.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

Referring now toFIG. 1, arod introduction apparatus10 according to the present invention includes anouter sleeve14, aclamp shaft18 and alateral approximator lever12. As will be appreciated by the detailed description that follows, the rod introduction apparatus is a multiple action device having the capability of securely holding an implant (often a hook or a screw), aligning a laterally offset longitudinal member (typically a rod or a plate), reducing the vertical distance between the longitudinal member and the implant, and providing a passage for placement of a fastener into the implant while the implant and longitudinal member are held in alignment. It is understood that all of the features of the apparatus may be used in combination or only a select portion thereof may be utilized, the features utilized will depend on the needs of the surgery being performed.

Referring now toFIGS. 5 through 8,outer sleeve14 includes on its proximal end ashoulder46 extending around the entire circumference of the outer sleeve. Pivot pins24 and25 project from opposite sides of the outer sleeve. The distal end ofouter sleeve14 is therod engagement end40, which defines a pair of diametrically opposedrod engagement arms62 and63. As shown inFIG. 6, these arms have a substantially reducedwidth52 in comparison to diameter ofouter sleeve14, as they extend towards therod engagement end40. Disposed on the distal tip ofrod engagement arm62 is aconcave recess54 having a curvature substantially equivalent to the outside diameter of a rod. A similarconcave recess55 is disposed on the distal tip ofrod engagement arm63 and is in alignment withconcave recess54 to permit a rod to be engaged by both recesses simultaneously. It will be understood thatrod engaging arms62 and63 haveconcave recesses54 and55 in order to hold a portion of the rod and inhibit lateral movement thereof.

FIG. 7 shows a cross-sectional view ofouter sleeve14. The outer sleeve is a hollow substantially cylindrical tube defining aninterior channel48 extending therethrough.Interior channel48 is substantially narrowed adjacent the distal end byinner surfaces60 and61 ofrod engagement arms62 and63, respectively. As shown inFIG. 8, an end view ofouter sleeve14 looking into the distal end, the inner sidewalls ofouter sleeve14 can form a substantially rectangular surface defininginterior channel48.

Referring now toFIGS. 9 through 11,clamp shaft18 is sized to be slidingly received within the interior channel ofouter sleeve14.Clamp shaft18 includes grippingnose22 having a portion extendable beyond the distal end ofouter sleeve14.Gripping nose22 includes afirst clamping branch36 and a second clamping branch separated byspace76. The distance between first clampingbranch36 and second clampingbranch76 changes as the clamping branches are moved from there insertion position, with ramped sidewall portion extending outsideouter sleeve14, to a clamping position with rampedsidewall portions72 and73 engaging bearing surfaces60 and61 respectively. In the preferred embodiment the clamping branches resiliently tend to assume there insertion form unless constrained byouter sleeve14. Preferably, clampingbranches36 and38 have an area of reduced wall thickness defining a void78 adjacent their attachment points to the remainder of clampingshaft18. This area of reduced wall thickness tends to experience the greatest amount of deflection when the clamping branches are in the clamping position. While the preferred embodiment relies on the resiliency of the clamping branches themselves to assume the insertion position, it is contemplated that a mechanical means cooperable with the clamping branches may be utilized to move the clamping branches between the insertion and clamping positions.

Each clamping branch includes a series ofprojections42a and42b to engage correspondingrecesses44a and44b onimplant26. WhileFIGS. 2 and 3show implant26 as a spinal hook, it is contemplated that the clamping branches may be adapted to engage a variety of implants, with or without the use of interengaging projections and recesses. In the preferred embodiment, each branch includes twoprojections42a and42b to engage a corresponding tworecesses44a and44b onimplant26. However, it is contemplated that the number of projections on each clamping branch can vary, depending on the number of mating recesses disposed onimplant26. Moreover, it is contemplated thatimplant26 may contain a series of projections while clamping branches may have corresponding recesses.

Disposed on the opposite end ofclamp shaft18 is T-handle20. Adjacent T-handle20 and spaced by a smoothcylindrical shank portion35, areexternal threads26 adapted to engage an internally threaded nut. Additionally, disposed between thetreads26 and the grippingnose22 is ashoulder86 where clampingshaft18 transitions from a cylindrical cross sectionadjacent threads26 to a substantially rectangular cross section extending to grippingnose22.

Referring now toFIG. 10,clamp shaft18 has a substantially uniform width when viewed from this side, with the exception of a reduced width portion disposed betweenshoulder86 andgripping end22. The reduced width area is defined by sidewalls70 and71 and continues at a reduced width until it begins to increase at rampedportions72 and73. Ramp portions terminate insidewalls74 and75, having the same width as the remainder of theclamp shaft18. In addition to the area of reduced outer width, in the area of reduced outer width, the walls also include reducedthickness sidewalls80 and82. This area of reduced thickness creates void78. It will be understood that in use, asclamp shaft18 is withdrawn intoouter sleeve14, outersleeve side walls60 and61 will engageramps72 and73, respectively, thereby urging clampingbranches36 and38 toward one another and reducing the distance between the clamping branches. Moreover, it will be understood that a major portion of the deformation required to urge clampingbranches36,38 toward one another will occur in the sidewalls defining cavity78.

Referring now toFIG. 11(a),clamp shaft18 has acentral cannula84 extending throughout the entire length of the shaft.Cannula84 has a uniform diameter throughout and is adapted to receive a fastener for placement onto an implant. The internal passage for delivery of the fastening member to the implant provides an important advantage to the surgeon when the rod is being held in alignment with the implant because external passages to the implant may be obstructed or have limited clearance because of the presence of the rod reduction apparatus. In the preferred embodiment, an externally threaded plug88 (FIG. 11(b)) may be placed into the cannula and urged into engagement with an internally threaded opening inhook26. An elongated driving member89 is then inserted throughcannula84 and engaged with threadedplug88 to threadedly insert the plug into a corresponding threaded opening in the implant. Although an externally threaded plug is shown in this embodiment, it is contemplated that an internally threaded nut could be passed throughcannula84 to engage an externally threaded portion of a hook or a screw. The internally threaded nut could then be tightened by engagement of projections on a tightening tool with corresponding recesses in the nut.

Speed nut16 of the present invention is of conventional design (FIGS. 12 and 13) and is rotatably mounted onouter sleeve14.Speed nut16 includes a central threadedopening65 sized to freely slide oversmooth shank portion35 of clampingshaft18.Threads17 are adapted to engagecooperable threads28 on clampingshaft18. Bearingsurface58 surrounds threadedopening65 and forms an internal bearing surface for bearing againstouter sleeve14. Extending through the sidewall of thenut16 are a series ofopenings56 and57 (and a third opening not shown), each adapted to receive a retaining pin. In the preferred embodiment,speed nut16 has a series ofprojections66 on its outer surface for ease of gripping during the turning process.

Preferably, the rod insertion apparatus of the present invention includes a lateral approximator mechanism to bring an implant into alignment with a laterally offset longitudinal member. In the preferred embodiment, the lateral approximator mechanism is alateral approximator lever12 pivotally attached to outer sleeve14 (FIG. 1).Lateral approximator lever12 defines a pair ofkeyways13 and15 (FIG. 3) adapted to selectively engage a pair of pivot pins24 and24 onouter sleeve14. Theproximal end31 oflever12 is configured to be a handle for manually manipulating the lever to urge a laterally offset rod and implant into alignment.

Therod engaging end30 oflever12 is bifurcated into afirst lever arm29 and a second lever arm33. Each arm freely passes over the outer surface ofouter sleeve14.First lever arm29 has arod engaging hook32 disposed at its distal end. Likewise, second lever arm33 has a correspondingrod engaging hook34 disposed at its distal end and in alignment with engaginghook32 permitting both hooks to contact a rod simultaneously. It is contemplated that the extent of lever arm extending distally beyondhooks32 and34 should be minimized in order to limit contact with surrounding anatomical structures during the lateral approximation procedure and the vertical reduction procedure if performed.

The above-described components of the rod introduction apparatus of the present invention are assembled as follows.Clamp shaft18 as shown inFIGS. 9 through 11, is inserted intoouter sleeve14 withsurfaces70 and72 aligned withsurfaces60 and61 of the outer sleeve, respectively.Speed nut16 is then passed over theproximal end29 ofclamp shaft18 until bearingsurface58 abutsshoulder46 onouter sleeve14. A series of retainingpins19,21 and a third pin (not shown) are placed in theopenings56,57 and a third opening in nut16 (not shown). The retaining pins extend into the space betweennut16 andouter sleeve14.Nut16 is thereby retained onshoulder46 by bearingsurface58 and a series of retaining pins.

In the preferred embodiment, T-handle20 having a central opening aligned withcannula84 is added for ease of manipulation ofclamp shaft18 withinouter sleeve14. In the preferred embodiment, T-handle20 is welded ontoclamp shaft18, although it is contemplated that other means such as brazing or threading may be used to attach T-handle20. It is contemplated that a separate handle is not required, instead, the surface ofclamp shaft18 may be roughened for easy gripping by the surgeon or the shaft may be machined to define an enlarged area for gripping. Finally, at the option of the user, lateral rod approximator lever slides about the outer surface ofouter sleeve14 to passkey way13 and correspondingkey way15 on the opposite side oflever12 over pivot pins24 and25, respectively. In the preferred embodiment,lateral approximator lever12 can be selectively interconnected with the outer sleeve, thus permitting the lever to be added or removed at the user's discretion.

As shown inFIG. 14, it is contemplated that alateral approximator lever90 havingrod engaging end91 withrod hook94 could be pivotally attached toouter sleeve14 in a non-removable fashion. In this embodiment,lever90 is pivotally attached toouter sleeve14 by apivot pin92 and a similar pivot pin (not shown) disposed on the opposite side ofouter sleeve14. Moreover, in this embodiment,lever90 is provided with a mechanical means to urge the rod and implant into lateral alignment. The mechanical mechanism extends throughoblong opening93 inlever90. A threadedshaft95 is pivotally connected toouter sleeve14 by apin96. Anenlarged finger nut97 is threaded onto threadedshaft95 to urgelever90 into the desired position.

Referring now toFIGS. 2 through 4, in operation, the rod introduction apparatus of the present invention may be utilized to both laterally approximate a spinal rod to an implant having an opening for receiving a rod and to vertically reduce the rod into the opening of the implant. As will be appreciated by those skilled in the art, clampshaft18 is free to slide withinouter sleeve14 whenthreads28 are not engaged withspeed nut16. In a first area of freedom of movement, clampshaft18 is free to move the length ofsmooth shank portion35 disposed betweenthreads28 and T-handle20. In this position, grippingnose22 may be extended a substantial distance beyond therod engagement end40 ofouter sleeve14 into the insertion position in preparation for securely clamping an implant. It will be understood that with T-handleengaging speed nut16,space76 between clampingbranches36 and38 will be at its maximum, thereby permitting the clamping branches to extend around an implant. Asclamp shaft18 is manually withdrawn intoouter sleeve14, ramp surfaces72 and73 of the clamp shaft bear againstsurfaces60 and61 of the outer sleeve, thereby urging clampingbranches36 and38 toward one another and into the clamping position. It is contemplated that the action of drawingclamp shaft18 withinouter sleeve14 is performed only after aligningprojections42 with the corresponding recesses44 in theimplant26. In this manner, the implant may be securely gripped by the rod introduction apparatus of the present invention. At this point,speed nut16 may be partially rotated to engage at least a portion ofthreads28 in order to securely holdclamp shaft18 in the clamping position.

Once the implant has been securely gripped, thespinal rod50 may then be aligned with the opening in the implant, both laterally and vertically. For lateral approximation, lateralrod approximator lever12 is positioned as previously described about theouter sleeve14 and pivotally connected with pivot pins24 and25. As shown inFIG. 2, theupper end31 oflever12 is displaced from the body ofouter sleeve14, thereby pivoting about the pivot pins and extending therod engaging portion30 of the lever a sufficient distance laterally from the outer sleeve to securely engagespinal rod50 withinhooks32 and34. Afterhooks32 and34 are securely engaged withrod50, theupper end31 oflever12 is urged back into alignment withouter sleeve14, thereby urgingspinal rod50 into alignment withrod engagement end40 of the outer sleeve. Once this position has been achieved, the vertical displacement betweenrod50 andimplant26 may then be reduced.Speed nut16 is rotated while engagement withthreads28 to urge grippingnose22 of clampingshaft18 to be drawn intoouter sleeve14. As the clamping shaft is drawn into the outer sleeve,rod engagement end40approaches gripping nose22 and therebyforces rod50 intoimplant opening27. Once in the final position (FIG. 4),implant26 may be secured torod50 by any number of means, which include a threaded plug or blocking sleeve. In the preferred embodiment, clampshaft18 includes acannula84 extending therethrough. Once the rod has been positioned within theopening27 ofimplant26, a threadedplug88 is passed throughcannula84 until it seats into the correspondingly threaded opening inimplant26. A driving member extending throughcannula84 is used to tighten the plug in the implant. Threadedplug88 securely holds the rod in the implant opening.

Once the rod has been secured to the implant,rod adjustability lever12 is rotated away from engagement withouter sleeve14, thereby releasing therod50. Further,speed nut16 is rotated to urge grippingnose22 out ofouter sleeve14 and thereby separaterod engagement end40 fromrod50.Speed nut16 is continued to be rotated until it no longer engagesthreads28, which thereby allowsclamp shaft18 to slide within outer sleeve untilhandle20 engagesspeed nut16. This movement permits clampingbranches36 and38 to assume the insertion position and thereby release the implant. Once released, the rod introduction apparatus of the present invention may then be withdrawn.

Referring now toFIGS. 15 through 19, an alternative embodiment of the rod introduction apparatus according to the present invention includesouter sleeve110, clampingshaft118, andlateral approximator lever112. Similar to the first described embodiment,rod reduction apparatus101 is capable of gripping an implant, engaging a laterally offset longitudinal member and aligning the implant and offset longitudinal member and reducing the vertical distance between the implant and longitudinal member.

In this embodiment, clampingshaft118 comprises two articulatingbranches142 and143 pivoting about a connecting pivot pin144 (FIG. 16). While the branches illustrated do not define an internal cannula, it is contemplated that for certain applications it may be desirable that each branch form a portion of a cannula adapted for insertion of a fastener. Distally ofpivot pin144, articulatingbranches142 and143 define clampingbranches138 and136, respectively. Clampingbranches136 and138 haveprojections146 and145, respectively, adapted to engage corresponding recesses (not shown) inscrew126. Articulating movement ofbranches142 and143moves clamping branches136 and138 between an insertion position with clamping branches spaced by a first larger distance and a clamping position with clamping branches spaced by a second smaller distance. The branches are held in the clamping position by retainingcap140 pivotally connected to branch143 and selectively engagingbranch142. Articulatingbranch142 further includes arack117 disposed on its outer surface.

Outer sleeve110 includes mountingbrackets113 and144. An opening (not shown) is formed in the sidewall ofouter sleeve110 between mountingbrackets113 and114.Pinion116 is pivotally mounted to mountingbrackets113 and144 with a portion of the pinion extending through the opening and into the interior channel ofouter sleeve110.

Lateralrod approximation lever112 is pivotally mounted toouter sleeve110 bypivot pins124 and125. Therod engaging end120 oflever112 includes a pair ofhooks121 and122 for engaging a rod. As shown inFIG. 18, each hook includes anupper projection151 for securely engaging the rod during vertical reduction.

In operation, articulatingbranches142 and143 are separated to position clampingbranches136 and138 in the insertion position. The clamping branches are positionedadjacent screw126 withprojections145 and146 aligned with corresponding recesses (not shown) inscrew126. Articulating branches are then brought together, thereby urging projections into the screw recesses to securely hold the implant. Retainingcap140 is then rotated aboutpin141 until the cap securely engages articulatingbranch142. In this manner, the branches remain in the clamping position.

After the implant has been securely clamped,outer sleeve110 withinterconnected lever112 andpinion116 is slid over clampingshaft118 withpinion116 aligned withrack117 and is urged downwardly untilpinion116 engagesrack117.Lever112 is then positioned to engagerod150.Lever112 is moved to bringrod150 into lateral alignment withscrew126.Pinion116 is then rotated to urgeouter sleeve110 towardsscrew126 thereby urging engagedrod150 into vertical alignment withscrew126. In the illustrated embodiment,screw126 is a variable angle screw engagable by an eyebolt mechanism previously place onrod150. Such an eyebolt attachment mechanism is offered by Sofamor Danek Group as the TSRH™ Variable Angle Eyebolt. Once in alignment, the eyebolt mechanism is utilized to securely interconnect the screw and rod.

Once screw and rod are interconnected,pinion116 must be reversed to moveouter sleeve110 away fromscrew126. Oncepinion116 is free ofrack117,outer sleeve110 may be removed. Retainingcap140 is then removed from articulatingbranch142, thereby permitting the branches to disengagescrew126.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.

Claims (46)

1. A multiple action insertion apparatus for engaging a longitudinal member and an implant, comprising:

an implant holder including a first clamping branch and a second clamping branch cooperable with said first clamping branch to hold to an implant;

a reduction mechanism interconnected with said implant holder, said reduction mechanism having a distal end for engaging the longitudinal member, wherein said reduction mechanism urges the longitudinal member into vertical alignment with the implant; and

a lateral approximator mechanism interconnected with said implant holder, said lateral approximator mechanism having a distal end disposed adjacent said first and second clamping branches, said distal end adapted to engage the longitudinal member, wherein said lateral approximator mechanism urges the longitudinal member into lateral alignment with the implant.

2. The insertion apparatus ofclaim 1, wherein said lateral approximator mechanism is a lever arm pivotally connected to said implant holder.

3. The insertion apparatus ofclaim 1, A multiple action insertion apparatus for engaging a longitudinal member and an implant, comprising:

an implant holder including a first clamping branch and a second clamping branch cooperable with, and movable relative to, said first clamping branch to hold to an implant;

a reduction mechanism interconnected with said implant holder, said reduction mechanism having a distal end for engaging the longitudinal member, wherein said reduction mechanism urges the longitudinal member into vertical alignment with the implant; and

a lateral approximator mechanism interconnected with said implant holder, said lateral approximator mechanism having a distal end disposed adjacent said first and second clamping branches, said distal end adapted to engage the longitudinal member, wherein said lateral approximator mechanism urges the longitudinal member into lateral alignment with the implant,

wherein said implant holder comprises a shaft having a gripping end with a portion, said gripping end defining a first clamping branch and a cooperable second clamping branch, said first and second clamping branches tending to assume an insertion position defining a first distance between said first and second clamping branches, and said first and second clamping branches compressible into a clamping position defining a second distance between said first and second clamping branches, said first distance greater than said second distance; and

a sleeve defining an interior channel, said shaft slidably received within said interior channel, said shaft moveable between a first position with said portion extending from said sleeve and a second position with said portion drawn into said sleeve;

wherein movement of said shaft within said tubular sleeve from said first position to said second position controls said first and second clamping branches from said insertion position to said clamping position.

4. The introduction apparatus ofclaim 3, wherein said reduction apparatus comprises a series of external threads disposed on said shaft and an internally threaded nut rotatably mounted on said sleeve, said internally threaded nut cooperable with said external threads, said sleeve further defining a bearing surface adjacent said gripping end for engaging the longitudinal member, wherein rotation of said nut moves said shaft with respect to said sleeve and urges said bearing surface against the longitudinal member thereby reducing the distance between the longitudinal member and the implant.

5. The introduction apparatus ofclaim 4, wherein the longitudinal member is a rod and said bearing surface is a recessed area on said sleeve.

6. A multiple action insertion apparatus for engaging a longitudinal member and an implant, comprising:

means for attaching to an implant;

means for lateral approximation of a longitudinal member laterally offset from the implant, said means for lateral approximation interconnected with said means for attaching; and

means for vertical reduction of the longitudinal member vertically offset from the implant, said means for vertical reduction interconnected with said means for attaching, wherein said means for lateral approximation laterally aligns the longitudinal member over the implant and said means for vertical reduction vertically aligns the longitudinal member with the implant.

7. An implant holder for holding an implant adapted to receive a fastener, comprising:

means for gripping the implant said means for gripping including a gripping end and a handle defining a longitudinal cannula having a distal end adjacent said gripping end, said cannula adapted to receive a fastener cooperable with said implant;

wherein said means for gripping includes a first clamping branch and a second clamping branch defining said gripping end, said first and second clamping branches aligned in a spaced relationship and cooperable to engage the implant, and wherein said handle defines a series of threads opposite said gripping end, and further including a sleeve defining an internal channel adapted to receive at least a portion of said gripping end and said handle, and a nut rotatably mounted on said sleeve, said nut cooperable with said threads on said handle.

8. The implant holder ofclaim 7, wherein said sleeve has a distal end adjacent said gripping end and said sleeve defines a bearing surface adapted to bear against a longitudinal member, wherein rotation of said nut draws said handle into said sleeve and thereby reduces the distance between the implant engaged by said first and second clamping branches and the longitudinal member bearing against said bearing surface of said sleeve.

9. The implant holder ofclaim 8, further including a lateral approximating lever pivotally attached to said sleeve.

10. An implant holder for gripping an implant, comprising:

a shaft having a gripping end with a portion, said gripping end defining a first clamping branch and a cooperable second clamping branch, said first and second clamping branches tending to assume an insertion position defining a first distance between said first and second clamping branches, and said first and second clamping branches compressible into a clamping position defining a second distance between said first and second clamping branches, said first distance greater than said second distance; and

a sleeve defining an interior channel, said shaft slidably received within said interior channel, said shaft moveable between a first position with said portion extending from said sleeve and a second position with said portion drawn into said sleeve; and

an actuating mechanism for moving said shaft within said tubular sleeve, said actuating mechanism provided about said tubular sleeve and an actuating force for operating said actuating mechanism applied about the tubular sleeve,

wherein movement of said shaft within said tubular sleeve from said first position to said second position controls said first and second clamping branches from said insertion position to said clamping position.

11. The implant holder ofclaim 10, wherein said sleeve defines an engagement surface for engaging a longitudinal member to be interconnected with said implant, whereby positioning said shaft in said second position clamps the implant and further movement of said inner shaft into said sleeve urges the implant into alignment with the longitudinal member.

12. The implant holder ofclaim 11, further including means for controlling the position of said shaft within said sleeve wherein said actuator mechanism comprises threads provided about the central opening of said tubular sleeve.

13. The implant holder ofclaim 12, wherein said means for controlling actuator mechanism includes an external thread disposed on said inner shaft and a nut rotatably mounted on said tubular sleeve, said nut having an internal thread corresponding to said external thread, whereby said inner shaft may be drawn into said outer sleeve by rotation of said nut.

14. The implant holder ofclaim 11, wherein said threads on said shaft includes are formed as a series of external threads and said shaft further including includes an internally threaded nut rotatably mounted on said sleeve, said internally threaded nut cooperable with said external threads, wherein rotation of said nut moves said shaft with respect to said sleeve.

15. The implant holder ofclaim 14, further including a lateral approximator lever pivotally engaging said sleeve, said lateral approximator lever having a rod engaging end adapted to engage a laterally offset rod, wherein upon engaging a laterally offset rod, said lateral approximator lever may be pivoted toward said sleeve, thereby positioning the rod adjacent the implant.

16. The implant holder ofclaim 15, wherein said first and second clamping branches each have a distal end and include at least one projection defined on each of said distal ends.

17. The implant holder ofclaim 10, wherein said shaft includes a handle disposed opposite said gripping, said handle utilized to position said shaft within said sleeve.

18. The implant holder ofclaim 10, wherein said shaft is cannulated to slidingly receive a fastening member adapted to be engaged with the implant.

19. The implant holder ofclaim 10, wherein said attachment to said implant is a non-pivotal attachment.

20. The implant holder ofclaim 10, further including a lateral approximator lever pivotally engaging said sleeve, said lateral approximator lever having a rod engaging end adapted to engage a laterally offset rod, wherein upon engaging a laterally offset rod, said lateral approximator lever may be pivoted toward said sleeve, the rod is positioned adjacent the implant.

21. The implant holder ofclaim 20, wherein said lateral approximator lever removably engages said sleeve, whereby said lever may be selectively removed.

22. The implant holder ofclaim 10, wherein said first and second clamping branches each have a distal end and include at least one projection defined on said distal end.

23. The implant holder ofclaim 10, wherein said shaft defines a cannula having a distal end adjacent said first and second clamping branches, said cannula adapted to slidingly receive a fastener, whereby said fastener is delivered through said cannula to said distal end for interengagement with the implant.

24. An implant holder having a rod reduction mechanism for vertically aligning a longitudinal member and an implant, comprising:

means for gripping the implant;

a sleeve having an axis and a distal end adapted to engage the longitudinal member, said sleeve having an axial bore sized to receive said means for gripping, said means for gripping slidably received within said axial bore; and

threaded means for axially displacing said sleeve with respect to said means for gripping, whereby a verticalvertically offset longitudinal member is urged into alignment with the implant.

25. The implant holder ofclaim 24, wherein said means for gripping are articulating forceps.

26. The implant holder ofclaim 24, wherein said means for axial displacement includes a series of threads disposed on said means for gripping and a nut rotatably mounted on said sleeve and threadedly engagable with said threads.

27. The implant holder ofclaim 24, wherein said means for axial displacement includes a rack disposed on said means for gripping and a pinion pivotally mounted on said sleeve and interengagable with said rack.

28. A method for interconnecting a longitudinal member and an implant adapted to engage the longitudinal member, comprising the steps of:

providing an introduction apparatus having an attachment mechanism with a cannula and a vertical reduction mechanism;

attaching the introduction apparatus to the implant;

operating the vertical reduction mechanism, by actuating a threaded engagement mechanism of the vertical reduction mechanism, to force the longitudinal member into alignment with the implant;

inserting a fastener through the cannula;

interconnecting the fastener and the implant, wherein the longitudinal member is securely attached to the implant; and

removing the introduction apparatus.

29. A method for interconnecting a longitudinal member and an implant adapted to engage the longitudinal member, comprising the steps of:

providing an introduction apparatus having an attachment mechanism, a lateral approximation lever, and a vertical reduction mechanism;

attaching the introduction apparatus to the implant;

engaging a laterally offset longitudinal member with one end of the lateral approximator lever;

rotating the lever to urge the longitudinal member into lateral alignment with the implant;

operating the vertical reduction mechanism to force the longitudinal member into vertical alignment with the implant; and

interconnecting the longitudinal member and the implant.

30. The method ofclaim 29, A method for interconnecting a longitudinal member and an implant adapted to engage the longitudinal member, comprising the steps of:

providing an introduction apparatus having an attachment mechanism, a lateral approximation lever, and a vertical reduction mechanism;

attaching the introduction apparatus to the implant;

engaging a laterally offset longitudinal member with one end of the lateral approximator lever;

rotating the lever to urge the longitudinal member into lateral alignment with the implant;

operating the vertical reduction mechanism to force the longitudinal member into vertical alignment with the implant; and

interconnecting the longitudinal member and the implant,

wherein the providing step includes providing attachment mechanism having a cannula and further including the step of delivering a fastener through the cannula and to the implant prior to interconnecting the longitudinal member and the implant.

31. A method for interconnecting a longitudinal member and an implant adapted to engage the longitudinal member, comprising the steps of:

providing an introduction apparatus having an attachment mechanism with attachment prongs for attaching to the implant, a cannula and a vertical reduction mechanism;

attaching the introduction apparatus to the implant;

operating the vertical reduction mechanism to force the longitudinal member into alignment with the implant;

inserting a threaded fastener through the cannula;

interconnecting the fastener and the implant, wherein the longitudinal member is securely attached to the implant; and

removing the introduction apparatus,

wherein the introduction apparatus further comprises an elongated member that extends through the cannula, the elongated member engaging the fastener in said interconnecting step to cause the fastener to interconnect with the implant.

32. The method of claim 31, wherein the attachment prongs are formed on the proximal end of the cannula.

33. The method of claim 32, wherein the implant is a bone screw.

34. The method of claim 33, wherein the longitudinal member is an implantable rod.

35. The method of claim 32, wherein the elongated member is separate from the vertical reduction mechanism.

36. The method of claim 32, wherein the introduction apparatus further comprises an actuator for operating the vertical reduction mechanism in said operating step, and the actuator connects to the distal end of the cannula about a circumference of the distal end.

37. The method of claim 36, wherein the implant contains a threaded opening that receives the threaded fastener in said interconnecting step.

38. The method of claim 31, wherein the operating and inserting steps take place separately.

39. An implant holder for gripping an implant, comprising:

a shaft having a gripping end with a portion, said gripping end defining a first clamping branch and a cooperable second clamping branch, said first and second clamping branches tending to assume an insertion position defining a first distance between said first and second clamping branches, and said first and second clamping branches compressible into a clamping position defining a second distance between said first and second clamping branches, said first distance greater than said second distance; and

a sleeve defining an interior channel, said shaft slidably received within said interior channel, said shaft moveable between a first position with said portion extending from said sleeve and a second position with said portion drawn into said sleeve;

wherein movement of said shaft within said tubular sleeve from said first position to said second position controls said first and second clamping branches from said insertion position to said clamping position, and

wherein said implant holder further comprises an actuator for moving said shaft relative to said tubular sleeve, said actuator comprising a first portion engaging a first side of said sleeve and a second portion engaging a second side of said sleeve opposite said first side, said first and second portions moving relative to said shaft to actuate movement of said sleeve.

40. A system for spinal, surgery comprising:

said implant holder of claim 39;

a series of implants; and

a longitudinal member,

wherein said implant holder grips each of said series of implants, and

wherein the relative movement of said shaft and said tubular sleeve of said implant holder operate to reduce said longitudinal member to connect to an implant of said series of implants.

41. The system of claim 40, wherein said series of bone implants are bone screws and said longitudinal member is a rod.

42. The system of claim 41, wherein said shaft defines a passage through which a fastener for fastening said rod to a bone screw is insertable, while said first and second clamping branches grip said bone screw in the clamping position.

43. The system of claim 42, wherein a distal opening of said sleeve has an arcuate engaging edge for engaging said rod when said shaft and said sleeve are actuated relative to each other, said engaging edge operating to reduce said rod.

44. The system of claim 43, wherein said actuator is symmetrical with respect to opposing sides of said shaft.

45. A system for spinal surgery comprising:

the insertion apparatus of claim 40;

a series of implants; and

a longitudinal member,

wherein said implant holder grips each of said series of implants, and

wherein the relative movement of said shaft and said tubular sleeve of said implant holder operate to reduce said longitudinal member to connect to an implant of said series of implants.

46. A system for spinal surgery comprising:

said implant holder of claim 10;

a series of implants; and

a longitudinal member,

wherein said implant holder grips each of said series of implants, and

wherein the relative movement of said shaft and said tubular sleeve of said implant holder operate to reduce said longitudinal member to connect to an implant of said series of implants.

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