Transverse connector for surgical implant extension

Abstract

The present invention relates to a transverse connector for connecting multiple implant extensions, including at least a first sleeve and a second sleeve. The first sleeve defines a first hole, which is suitable for axially receiving a first implant extension through the first hole. The second sleeve defines a second hole, which is suitable for axially receiving a second implant extension through the second hole. The transverse connector also includes a center housing. A first shaft connects the first sleeve to the center housing, and the second shaft connects the second sleeve to the center housing. The center housing includes at least one joint for connecting the center housing to at least one of the first and second shafts to allow the shaft to move relative to the center housing through a movable arrangement with one or more degrees of freedom.

Description

Technical Field

[0001] The present invention relates generally to surgical instruments and, more particularly, to a transverse link connected between two surgical implant extensions. Background Art

[0002] Surgery sometimes needs to use bone implants, a part of which is attached to the bone in the incision, and a part extends to the outside of the patient's body through the incision. For example, the bone implant can be attached to the bone in the incision, and some types of implant extensions can extend outside the incision. The term "extension" used herein may refer to any elongated body protruding from the bone implant outside the patient's body, including but not limited to a long section in the implant designed to be disconnected from the implant after the operation is completed, or a separate attachment such as a tube detachably connected to the bone implant. One purpose of the extension is to provide a structure that can distribute force on the implant and the bone anchored by the implant. For example, a force applying instrument can be attached to the extension and manipulated in some way to apply force to the bone by the extension and the bone implant. Such force can be applied to the extension and the implant to correct the position or orientation of the bone relative to other bones.

[0003] Bone implants with extensions can be used in surgeries to correct abnormal curvature of the spine. In spinal surgery, a pair of bone anchors, known as "pedicle screws," are attached to each side of a vertebral body. Pedicle screws can be used to apply force to the vertebral body and connect the vertebral body to a fixation element, such as a fixation rod. It is often necessary to correct the abnormal curvature of the spine by applying force to multiple pedicle screws at the same time. For example, it may be necessary to apply corrective force to multiple pedicle screws attached to a single segment in the spine. At other times, it may be necessary to apply one or more corrective forces to multiple segments at the same time. In the latter case, it may be necessary to apply a force to a pair of pedicle screws at one segment, while applying another force to another pair of pedicle screws at a different segment.

[0004] Applying forces to multiple extensions in a coordinated manner can be very difficult. Each extension extends from the patient at a unique angle and orientation. Therefore, each extension may require adjustment forces to be applied in a specific direction that is different from that of adjacent extensions. The spacing between extensions may also be very limited, making it difficult to attach separate instruments to each extension. In addition, procedures to adjust multiple segments simultaneously can be very difficult because it may require applying different forces to four or more extensions at the same time, in which case two or more surgeons may need to work together in a carefully coordinated manner. Summary of the invention

[0005] The inventors have developed an instrument that allows a surgeon to apply forces to multiple bone implants in a coordinated but simplified manner. This is achieved by a transverse connector or bridge that interconnects multiple extensions together. The transverse connector can be removably connected to multiple extensions and allows the application of adjustment forces to multiple bone implants in a coordinated manner. This allows the surgeon to apply a single adjustment force to multiple bone implants simultaneously through the transverse connector.

[0006] In a beneficial aspect of the present disclosure, a transverse connector is configured to connect a first implant extension to a second implant extension. The transverse connector includes a first sleeve, a second sleeve, and a center housing. The first sleeve defines a first hole, and the first hole is suitable for axially receiving the first implant extension through the first hole. The second sleeve defines a second hole, and the second hole is suitable for axially receiving the second implant extension through the second hole. A first shaft connects the first sleeve to the center housing, and a second shaft connects the second sleeve to the center housing.

[0007] In another advantageous aspect of the present disclosure, the center housing includes a first joint and a second joint. In this arrangement, the first shaft connects the first sleeve to the first joint of the center housing, and the second shaft connects the second sleeve to the second joint of the center housing.

[0008] In another advantageous aspect of the present disclosure, the first joint comprises a universal ball joint that is pivotable relative to the center housing.

[0009] In another beneficial aspect of the present disclosure, a universal ball joint includes a longitudinal channel and a plurality of spring segments extending around the longitudinal channel.

[0010] In another beneficial aspect of the present disclosure, the first shaft is axially displaceable through the longitudinal passage of the first joint.

[0011] In another advantageous aspect of the present disclosure, the first shaft includes a first sleeve end attached to the first sleeve, and a first free end opposite the first sleeve end, the first free end including a first stop to limit axial displacement of the first shaft through the longitudinal passage.

[0012] In another beneficial aspect of the present disclosure, the first shaft is rotatable in the longitudinal passage of the first joint.

[0013] In another advantageous aspect of the present disclosure, the first shaft comprises a first shaft cross section having a first abutment surface, and the longitudinal channel comprises a channel cross section having a first abutment edge. The first abutment edge is configured to abut the first abutment surface during rotation of the first shaft relative to the longitudinal channel and limit the rotation range of the first shaft.

[0014] In another beneficial aspect of the present disclosure, the second joint includes a cylindrical through hole passing through the center housing.

[0015] In another beneficial aspect of the present disclosure, the second shaft is axially displaceable through the through hole of the second joint.

[0016] In another advantageous aspect of the present disclosure, the second shaft includes a second sleeve end attached to the second sleeve, and a second free end opposite the second sleeve end, the second free end including a second stop to limit axial displacement of the second shaft through the through hole of the second joint.

[0017] In another advantageous aspect of the present disclosure, the second shaft is rotatable in the through hole of the second joint.

[0018] In another beneficial aspect of the present disclosure, the second shaft includes a second shaft cross-section having a second abutting surface, and the through hole includes a through hole cross-section having a second abutting edge, and the second abutting edge is configured to abut the second abutting surface and limit the rotation range of the second shaft during rotation of the second shaft relative to the longitudinal channel.

[0019] In another beneficial aspect of the present disclosure, the center housing includes an upper portion, a lower portion separated from the upper portion, and an adjustment screw extending through the upper portion and the lower portion.

[0020] In another beneficial aspect of the present disclosure, the upper and lower portions of the center housing form an adjustable clamp that releasably secures the first shaft in the first joint and releasably secures the second shaft in the second joint.

[0021] In another beneficial aspect of the present disclosure, the clamp can be adjusted to a locked state in response to rotation of the adjusting screw, wherein the upper and lower portions of the center housing are pulled together to the locked state to compress the first joint and the second joint and lock the position of the first shaft and the second shaft relative to the center housing.

[0022] In another beneficial aspect of the present disclosure, the clamp is adjustable to an unlocked state in response to rotation of the adjustment screw, wherein the upper and lower portions of the center housing are spread apart in the unlocked state to allow the first and second shafts to move relative to the center housing.

[0023] In another beneficial aspect of the present disclosure, the adjustment screw includes external threads, and the lower portion of the center housing defines a hole having internal threads, the external threads mating with the internal threads.

[0024] In another beneficial aspect of the present disclosure, at least one of the first sleeve and the second sleeve defines a sleeve axis and a cavity.

[0025] In another advantageous aspect of the present disclosure, at least one of the first sleeve and the second sleeve includes a locking ring defining a locking ring axis, the locking ring being translatable in the chamber in a direction transverse to the sleeve axis.

[0026] In another beneficial aspect of the present disclosure, the locking ring can be translated relative to at least one of the first sleeve and the second sleeve between a locked position and a released position, in which the locking ring axis is offset from the sleeve axis by a first distance, and in the released position, the locking ring axis is offset from the sleeve axis by a second distance, and the first distance is greater than the second distance.

[0027] In another advantageous aspect of the present disclosure, at least one of the first sleeve and the second sleeve includes a spring element in the chamber, the spring element applying a biasing force to the locking ring to urge the locking ring toward the locked position.

[0028] In another beneficial aspect of the present disclosure, the locking ring includes a protrusion extending radially inwardly into the bore, the protrusion being positioned in the bore to releasably engage one of the first and second implant extensions when the locking ring is in the locked position.

[0029] In another beneficial aspect of the present disclosure, the locking ring includes a release lug extending radially outward and away from the locking ring axis, and at least one of the first sleeve and the second sleeve defines a through slot into which the release lug extends.

[0030] In another advantageous aspect of the present disclosure, the release lug protrudes through the through slot in the exposed position, in which the release lug can be depressed against the biasing force of the spring element to shift the locking ring toward the released position.

[0031] In another beneficial aspect of the present disclosure, a transverse connector is configured to connect a first implant extension to a second implant extension. The transverse connector includes a first sleeve, a second sleeve, and a center housing. The first sleeve defines a first hole, which is suitable for axially receiving the first implant extension through the first hole. The second sleeve defines a second hole, which is suitable for axially receiving the second implant extension through the second hole. A first shaft connects the first sleeve to the center housing, and a second shaft connects the second sleeve to the center housing. At least one of the first shaft and the second shaft is connected to the center housing through a movable joint on the center housing.

[0032] In another beneficial aspect of the present disclosure, the transverse coupling includes a third sleeve defining a third bore adapted to axially receive a third implant extension therethrough. The transverse coupling also includes a third shaft connecting the third sleeve to the central housing.

[0033] In another beneficial aspect of the present disclosure, the transverse link comprises a fourth sleeve defining a fourth aperture adapted to axially receive a fourth implant extension therethrough. The transverse link further comprises a fourth shaft connecting the fourth sleeve to the central housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The Summary and Detailed Description sections will be better understood when viewed in conjunction with the accompanying drawings, which illustrate exemplary and non-limiting embodiments of the invention and depict elements that may be combined and arranged as shown or in any other combination and / or arrangement contemplated by one of ordinary skill in the art.

[0035] Figure 1 is a front view of a transverse connector according to an example of the present disclosure, the transverse connector being attached to two extensions, which are respectively attached to two bone implants anchored in bones;

[0036] Figure 2 yes Figure 1 A perspective view of a transverse coupling;

[0037] Figure 3 yes Figure 1 A top view of a transverse connecting member;

[0038] Figure 4 yes Figure 1 An exploded front view of an assembly of a transverse coupling;

[0039] Figure 5 yes Figure 4 A perspective view of a subassembly of an assembly of a transverse coupling;

[0040] Figure 6 is shown in a first adjustment position Figure 1 A cross-sectional view of an assembly of a transverse coupling;

[0041] Figure 7 is shown in a second adjustment position Figure 6 A cross-sectional view of an assembly of a transverse coupling;

[0042] Figure 8 is shown in a first operating state Figure 1 A top view of a sleeve of a transverse connecting member;

[0043] Fig. 9 yes Figure 8 A side cross-sectional view of a sleeve;

[0044] Fig.10 is shown in a second operating state Figure 8 A top view of a sleeve;

[0045] Fig.11 yes Figure 1 an enlarged perspective view of a cross-section of a transverse coupling showing a locking element in a first operative state;

[0046] Fig.12 yes Figure 1Another enlarged perspective view of a cross-section of the transverse coupling of , showing the locking element in a second operative state;

[0047] Fig.13 is a perspective view of a transverse coupling according to another example of the present disclosure;

[0048] Fig.14 is based on Fig.13 A top view of a transverse connecting member;

[0049] Fig.15 is a perspective view of a transverse connector according to another example of the present disclosure; and

[0050] Fig.16 is based on Fig.15 An exploded perspective view of a transverse connection member. DETAILED DESCRIPTION

[0051] As described above, a transverse connector according to the present disclosure can be attached to two or more extensions mounted on a pedicle screw. For example, a single transverse connector can be attached to a pair of extensions that are attached to a vertebral body to manipulate the vertebral body in a procedure known as "single-level torsion." Alternatively, a first transverse connector can be attached to a first pair of extensions that are attached to a first vertebral body, and a second transverse connector can be attached to a second pair of extensions that are attached to a second vertebral body. A first force can then be applied to the first pair of extensions via the first transverse connector, and a second force can be simultaneously applied to the second pair of extensions via the second transverse connector to adjust the first cone and the second vertebra relative to each other in a single-level torsion. In addition, the transverse connector can be attached to a block consisting of two or more vertebral bodies to adjust the vertebral block in a "monolithic" torsion.

[0052] Now refer to the drawings, and specifically refer to Figure 1 , a transverse connector 100 is shown according to one example. The transverse connector 100 is removably mountable to a variety of bone implants and extensions. As described above, the extension can be part of the implant itself, or a separate component attached to the implant, such as a surgical instrument. In this example, the transverse connector 100 will be described in conjunction with a first extension in the form of a first spinal rod fixator 20 and a second extension in the form of a second spinal rod fixator 20'. The first spinal rod fixator 20 is attached to the first pedicle screw 30, and the second spinal rod fixator 20' is attached to the second pedicle screw 30'.

[0053] The first pedicle screw 30 is anchored in the first pedicle P of the vertebral body B through the first incision I. Similarly, the second pedicle screw 30' is anchored in the second pedicle P' of the vertebral body B through the second incision I'. In this arrangement, the transverse connector 100 can receive the adjustment force F from the force-applying instrument 50 and transmit the adjustment force to the vertebral body B through the first and second spinal rod fixers 20, 20' and the first and second pedicle screws 30, 30'. The transverse connector 100, the rod fixer 20 and the rod fixer 20' together form a rigid structure. The adjustment force can be applied directly to this structure, or it can be applied by other instruments attached to this structure. For example, the transverse connector 100 can receive the adjustment force by applying force directly to one or two fixing rods of the rod fixers 20, 20'. Alternatively, the transverse connector 100 can receive the adjustment force by applying force to the adjustment screw 260 on the transverse connector. Force may be applied to the adjustment screw 260 by a force applicator attached to a center knob 261 on the adjustment screw.

[0054] The first and second pedicle screws 30, 30' are spaced apart and extend from their respective incisions I, I' at different trajectories. Therefore, the first and second spinal rod fixers 20, 20' are also spaced apart and extend from their respective incisions I, I' at different trajectories. The proximal ends of the first and second spinal rod fixers 20, 20' are separated by a unique spacing S, and the different trajectories of the first and second spinal rod fixers define an angular offset α between their respective longitudinal axes X, X'. The transverse connector 100 has a plurality of adjustable components to accommodate the spacing S and angular offset α between the first and second rod fixers 20, 20'. These adjustable components, which will be described in more detail, can be moved relative to each other through one or more degrees of freedom to accommodate an unlimited number of spacings and angular offsets between extensions.

[0055] refer to Figures 2 to 4 , the transverse coupling 100 includes a central housing 200, a first attachment assembly 300, and a second attachment assembly 400. The first attachment assembly 300 is removably mountable to the first spinal rod fixator 20, and the second attachment assembly 400 is removably mountable to the second spinal rod fixator 20'. The central housing 200 interconnects the first attachment assembly 300 and the second attachment assembly 400 in an adjustable configuration that allows the transverse coupling to accommodate different spacings and angular offsets between the extensions.

[0056] The first attachment assembly 300 includes a first sleeve 310 defining a first hole 312. The first hole 312 is adapted to axially receive the first rod holder 20 therethrough. The transverse connector 100 also includes a second sleeve 410 defining a second hole 412, the second hole 412 being adapted to axially receive the second rod holder 20' therethrough. The center housing 200 includes an upper housing portion 210 and a lower housing portion 220. The upper housing portion 210 and the lower housing portion 220 are interconnected together in a clamping arrangement. In the clamping arrangement, the upper housing portion 210 and the lower housing portion 220 define a first joint 230 and a second joint 240.

[0057] The first attachment assembly 300 includes a first shaft 320 extending outwardly and away from the first sleeve 310. The first joint 230 slidingly connects the first shaft 320 to the center housing 200. In a similar arrangement, the second attachment assembly 400 includes a second shaft 420 extending outwardly and away from the second sleeve 410. The second joint 240 slidingly couples the second shaft 420 to the center housing 200.

[0058] The first joint 230 includes a universal ball joint 232 that is pivotable relative to the center housing 200. The ball joint 232 defines a longitudinal passage 234 extending through the ball joint. The longitudinal passage 234 receives the first shaft 320 of the first attachment assembly 300 in a linear sliding relationship. This linear sliding relationship allows the first shaft 320 to move axially in a first degree of freedom relative to the center housing 200 through the longitudinal passage 234. The first shaft 320 can also rotate axially in a second degree of freedom relative to the longitudinal passage 234.

[0059] The ball joint 232 is sandwiched between the upper housing portion 210 and the lower housing portion 220 of the center housing 200. The upper housing portion 210 has a concave bearing surface 212 and the lower housing portion 220 has a concave bearing surface 222 opposite the concave bearing surface 212. The ball joint 232 slidingly engages the bearing surfaces 212, 222 to pivot in position between the upper housing portion 210 and the lower housing portion 220. In this arrangement, the ball joint 232 can pivot between the upper housing portion 210 and the lower housing portion 220. When the first shaft 320 is received in the longitudinal channel 234, the first shaft can pivot relative to the center housing 200 through a third degree of freedom that is independent of the first and second degrees of freedom.

[0060] The upper housing portion 210 and the lower housing portion 220 form two halves of a clamp to control the displacement of the first shaft 320 in the first joint 230. In particular, the upper housing portion 210 and the lower housing portion 220 can be clamped together to apply a compressive force on the ball joint 232. The longitudinal channel 234 has a first end 236 and a second end 238 opposite the first end. The first groove array 233 intersects the first end 236 of the longitudinal channel 234, and the second groove array 235 intersects the second end 238. The grooves 233, 235 form a flexible spring segment 237 surrounding the longitudinal channel 234. The spring segment 237 can be compressed under the stored energy in the locked state. In the locked state, the first shaft 320 cannot move axially or rotate through the longitudinal channel 234, and the ball joint 232 cannot pivot between the upper housing portion 210 and the lower housing portion 220. When some of the compressive force on the ball joint 234 is removed, the energy stored in the spring segments 237 is released, causing the spring segments to extend radially outward. As the spring segments 237 extend outward, they move toward a relaxed state in which at least some of the clamping force on the first shaft is removed. This removal of the clamping force allows the first shaft 320 to move axially through the longitudinal passage 234. Removing the compressive force on the ball joint 232 also allows the ball joint to pivot again between the upper housing portion 210 and the lower housing portion 220 of the center housing 200.

[0061] The first shaft 320 has a first sleeve end 322 attached to the first sleeve 310. The first shaft 320 also has a first free end 324 opposite the first sleeve end 322. The first free end 324 includes a first stop 326 to limit axial displacement of the first shaft 320 through the longitudinal passage 234.

[0062] The first shaft 320 defines a first shaft axis 321 that is parallel to the longitudinal axis of the longitudinal passage 234. When the first shaft 320 is not clamped in the ball joint 232, the first shaft can rotate about its longitudinal axis 321 in the longitudinal passage 234 in a second degree of freedom.

[0063] The second joint 240 includes a cylindrical through hole 244 defined between the upper housing portion 210 and the lower housing portion 220. The upper housing portion 210 forms a groove surface 214, and the lower housing portion 220 forms a groove surface 224. The groove surfaces 214, 224 form two halves of the through hole 244, and form the through hole when the upper housing portion 210 and the lower housing portion 220 are connected together. The second shaft 420 can move axially in a first degree of freedom through the through hole 244 of the second joint 240, similar to the first shaft 320 in the longitudinal channel 234. In addition, the second shaft 420 defines a second shaft axis 421 that is parallel to the longitudinal axis of the through hole 244. Therefore, the second shaft 420 can rotate in the through hole about the second shaft axis 421 in the second degree of freedom.

[0064] The second shaft 420 has a second sleeve end 422 attached to the second sleeve 410 and a second free end 424 opposite to the second sleeve end. The second free end 424 includes a second stopper 426 to limit axial displacement of the second shaft 420 through the through hole 244 of the second joint 240.

[0065] The shafts according to the present disclosure can be rotated 360 degrees about their longitudinal axis (if necessary) to first adjust the orientation of their corresponding sleeves. However, in many applications, a full 360 degree rotation is not necessary because the sleeves do not need to rotate a large range. Therefore, the accessory assembly according to the present disclosure can have a rotation limiter to limit the axial rotation range of the shaft.

[0066] Reference now Figures 5 to 7 , one example of a rotation limiter is shown between the second shaft 420 and the through hole 244. The second shaft 420 has a truncated cylindrical shape defining a first cylindrical surface 423 and a first abutment surface 425. The first cylindrical surface 423 and the first abutment surface 425 form a shaft cross section 427 that is a truncated circle or "D-shaped" shape. The through hole 244 has a similar D-shaped cross section 251, which has a first cylindrical edge 253 and a first abutment edge 255. The first abutment surface 425 is configured to abut the first abutment edge 255 during rotation of the second shaft 420 relative to the through hole 244. When the first abutment surface 425 abuts the first abutment edge 255, the first abutment edge prevents the second shaft 420 from rotating further in the rotational direction.

[0067] The first abutment surface 425 may be Figure 6 and Figure 7 The two opposite directions are shown adjoining the first abutment edge 255 . Figure 6 and Figure 7 The 40 degree positions in the figure represent the limits of axial rotation of the second shaft 420. Although not shown, it should be understood that the first shaft 320 and the longitudinal channel 234 can have the same or similar abutment surfaces and abutment edges, respectively, which limit the relative rotation of the first shaft to within 40 degrees. It should also be understood that the rotation limiter according to the present disclosure can also be configured to allow a smaller or larger axial rotation range, and does not need to limit the rotation to 40 degrees.

[0068] The sleeve and shaft according to the present disclosure can be interconnected with a fixed joint to fix the orientation of the sleeve relative to the shaft. Alternatively, the sleeve and shaft according to the present disclosure can be interconnected with one or a movable joint to allow the sleeve to be articulated in one or more degrees of freedom relative to the shaft. The movable joint allows the sleeve to tilt or pivot in one or more planes relative to its corresponding shaft to more easily adapt the locking ring hole to the position and angle of the extension. In this example, the first sleeve 310 is connected to the sleeve end 322 of the first shaft 320 by a pin connection 343. The second sleeve 410 is connected to the sleeve end 422 of the second shaft 420 by a tripod joint 441, which is in turn connected to the second sleeve by a pin connection 443. The sleeve end 322 of the first shaft 320 also has a bend 325, which provides a fixed angular offset between the free end 324 of the first shaft and the first sleeve 310.

[0069] The upper housing portion 210 and the lower housing portion 220 are interconnected by fasteners that hold the upper and lower housing portions together in a clamping arrangement. A transverse connector according to the present disclosure may utilize a variety of fasteners to interconnect the upper and lower housing portions in a clamping arrangement, including but not limited to threaded bolts, cam bolts, and other connectors suitable for pulling the upper and lower housing portions together and spreading them apart. In this example, as shown in FIG. Figure 4 As shown, the upper housing portion 210 and the lower housing portion 220 are connected to each other by an adjustment screw 260. The adjustable screw 260 extends through an upper hole 211, which extends through the upper housing 210. When the upper housing portion and the lower housing portion are assembled, the upper hole 211 is axially aligned with the lower hole 221 in the lower housing portion 220. The lower hole 221 has an internal thread 223, which cooperates with the external thread 263 on the adjustment screw 260. In this arrangement, the adjustment screw 260 can be freely inserted axially through the upper hole 211 into the lower hole 221 until the external thread 263 engages with the internal thread 223 in the lower hole. The adjustment screw 260 can then be rotated to engage the external thread 263 with the internal thread 223 and axially advance the adjustment screw into the lower hole.

[0070] refer to Figure 3As shown in the top view, the adjustment screw 260 can be rotated in a clockwise direction to draw the upper housing portion 210 and the lower housing portion 220 together and into a clamped state. In the clamped state, the first shaft 320 and the second shaft 420 are completely fixed to resist all movement relative to the center housing 200. That is, the upper housing portion 210 and the lower housing portion 220 are drawn together so that the first shaft 320 is frictionally locked in the ball joint 232 and cannot move axially or rotate in any direction relative to the ball joint. In addition, the ball joint 232 is compressed by the upper housing portions 210, 220 so that the ball joint is frictionally locked between the concave bearing surfaces 212, 222 and cannot pivot in any direction between the upper housing portion and the lower housing portion. In addition, the second shaft 420 is frictionally locked between the groove surface 214 and the groove surface 224 so that the second shaft 420 cannot move axially or rotate in any direction relative to the center housing 200.

[0071] The adjustment screw 260 can also be rotated counterclockwise to loosen the connection between the upper housing portion 210 and the lower housing portion 220, so that the upper housing portion and the lower housing portion are in a released state. In the released state, the upper housing portion 210 and the lower housing portion 220 have more freedom to expand, so that the friction on the ball joint 232, the first shaft 320 and the second shaft 420 is minimized and the friction is overcome by applying manual force on the shafts to move them relative to the center housing 200.

[0072] The transverse coupling according to the present disclosure preferably includes one or more components that prevent the upper housing portion from twisting or loosely moving relative to the lower housing portion and the adjustment screw when the upper housing and the lower housing are not in a clamped state. In this example, a wave spring 270 is inserted between the adjustment screw 260 and the upper housing portion 210. The wave spring 270 is compressed between the adjustment screw 260 and the upper housing portion 210 under stored energy. The energy stored in the wave spring 270 applies a constant pressure to the upper housing portion 210 in the direction of the lower housing portion 220 to maintain the upper housing portion in constant contact with the first shaft 320 and the second shaft 420. Even when the adjustment screw is loosened and the upper and lower housings are in a released state, the constant contact prevents the upper housing portion 210 from twisting, shaking, or otherwise moving in a loose manner around the adjustment screw 260.

[0073] The transverse coupling according to the present disclosure may also have various components for fixing and preventing assembly disassembly. In this example, a nut 280 is attached to the narrow end of the adjusting screw 260 to prevent the upper housing portion 210 and the lower housing portion 220 from being disassembled from other components. Figure 2 and Figure 4The nut 280 shown is attached to the narrow end of the adjusting screw 260 by welding. It will be appreciated that various types of fasteners may be used to prevent disassembly. These fasteners may be connected to the adjusting screw by welding, threading, locking pins, or various other types of connections.

[0074] Reference now Figures 8 to 12 , the first sleeve 310 and the second sleeve 410 will be described in more detail. The sleeves 310, 410 are designed to slide over a pair of extensions and lock to these extensions to interconnect the extensions as a unit. The sleeves according to the present disclosure may have one or more design features to accommodate different types of extensions, different types of locking mechanisms, or other design variables. In this example, the first and second sleeves 310, 410 are identical, and many of the same components are visible in the drawings in the two sleeves. Therefore, only the features of the sleeve 310 will be described, while understanding that the same features are present in the sleeve 410.

[0075] The first sleeve 310 includes a hollow housing 311 having an upper housing segment 313 and a lower housing segment 319. The upper housing segment 313 and the lower housing segment 319 are connected together to define a hollow chamber 314 between the housing segments. The hollow chamber 314 is substantially closed around the perimeter of the first sleeve 310, but is open to the first hole 312. The first hole 312 has a circumference consistent with a circle and defines a sleeve axis 316 passing through the center of the circle.

[0076] The first sleeve 310 has a floating locking ring 330 housed within the chamber 314. The locking ring 330 is translatable within the chamber 314 between a locked position that locks the first sleeve 310 to the extension and a released position that allows the first sleeve to slide up and down the extension. The locking ring 330 defines an opening 331 having a circumference consistent with a circle and a locking ring axis 332 passing through the center of the circle. The locking ring axis 332 is parallel to the sleeve axis 316.

[0077] The locking ring 330 can translate within the chamber 314 in a direction transverse to the sleeve axis 316. In the locked position, as shown in FIG. Figure 8 As shown, the locking ring axis 332 is offset from the sleeve axis 316 by a first distance D1. Fig.10As shown, the locking ring axis 332 is offset from the sleeve axis 316 by a second distance D2. When the locking ring 330 is moved to the locked position, the opening 331 is less aligned with the first hole 312. When the locking ring 330 is moved to the released position, the opening 331 is moved inwardly toward the center housing 200 so that the opening is more aligned with the first hole 312. In other words, the first distance D1 associated with the locked position is greater than the second distance D2 associated with the released position. If desired, the locking ring 330 can be arranged in the first sleeve 310 in such a manner that the locking ring axis 332 is coaxially aligned with the sleeve axis 316 when the locking ring is moved to the released position, in which case the second distance D2 will be zero. The locking ring 330 can also be arranged in the first sleeve 310 in such a manner that the locking ring axis 332 is moved past the sleeve axis 316 to be positioned closer to the center housing 200 than the sleeve axis, in which case D2 will be a negative value. Any of these arrangements are suitable so long as movement of the locking ring 310 toward the released position moves the protrusion away from the sleeve axis 316 and toward the center housing 200 .

[0078] The first sleeve 310 includes a spring element 318 in the chamber 311. The spring element 318 is held in a compressed state between the locking ring 330 and the inner wall 315 of the chamber 311. In this arrangement, the spring element 318 applies a biasing force radially inward to the sleeve axis 316 to push the locking ring to the locked position. The sleeve according to the present disclosure may include various spring elements that apply a biasing force on the locking ring, including but not limited to a coil spring, a disc spring, and a leaf spring. In this example, the spring element 318 is a wave spring. The locking ring 330 includes a protrusion 334 extending radially inward into the opening 331. The protrusion 334 is positioned to releasably engage a locking feature on the extension, such as a locking groove or a stop, when the protrusion is in the locked position. The protrusion 334 has a front edge 335, a rear edge 336, and a sliding edge 337 between the front edge and the rear edge. Each of the edges 334, 335, and 336 is used to lock and unlock the first sleeve 310 from the extension. The front edge 335 is designed to contact the top edge of the extension when the first sleeve 310 is initially placed on top of the extension. During initial placement, the locking ring 330 is urged by the spring element 318 to a locked position, wherein the protrusion 334 protrudes into the first hole 312. The front edge 335 has a chamfered surface 339 that abuts the upper edge of the extension when the first sleeve 310 is lowered onto the extension. As the first sleeve 310 is advanced downwardly along the extension, the orientation of the chamfered surface 339 and the floating arrangement of the locking ring 330 cause the locking ring to deflect against the biasing force of the spring element 318 and toward the center housing 200. This causes the protrusion 334 to temporarily move out of the locked position and into the unlocked position. The locking ring 330 deflects until the sliding edge 337 contacts the outer geometry of the extension. Fig.11 The first sleeve 310 and locking ring 330 are shown advanced down the extension E with the sliding edge 335 abutting the exterior of the extension.

[0079] The first sleeve 330 can be pushed downward around the outer geometry of the extension until the outer geometry of the extension prevents the first sleeve from being pushed further. For example, the outer geometry of the extension can have a widened section that cannot fit through the opening 331 in the locking ring 330. Thus, the widened section can stabilize the first sleeve 330 without moving any further downward extension. The extension can further include an opening or window positioned to engage the protrusion 334 to prevent the first sleeve 310 from inadvertently moving back or upward to the extension. In this design, the first sleeve 330 is pushed downward on the extension until the locking ring 330 engages the widened geometry, at which point the protrusion 334 is aligned with the cutout or window. The size of the cutout or window is the same as or slightly larger than the size of the protrusion 334, so that when the energy stored in the spring element 318 is released, the protrusion can snap into the cutout or window. Once the protrusion 334 enters the cutout or window, the rear edge 336 abuts the upper edge of the window, preventing the locking ring 330 and first sleeve 310 from moving back on the extension. Fig.12 Shown is the first sleeve 310 and locking ring 330 advanced further down on extension E with projection 334 snapping inwardly into window W and with rear edge 336 abutting the top edge of the window to prevent the first sleeve from reversing and moving the extension upward.

[0080] The sleeve according to the present disclosure may have one or more release mechanisms to move the locking ring out of the locked position and allow the sleeve to be removed from the extension. In this example, the locking ring 330 includes a release lug 338 that extends radially outward away from the locking ring axis 332. The sleeve housing 311 defines a through slot 317 into which the release lug 338 extends. The release lug 338 protrudes from the through slot 317 in an exposed position on the outside of the first sleeve 310. In this exposed position, the release lug 338 can be pressed down against the biasing force of the spring element 318 to shift the locking ring 330 toward the release position. This moves the protrusion 334 out of the window or the cutout in the extension so that the first sleeve 310 is no longer blocked from being lifted and removed from the extension. In order to remove the first sleeve 310 from the extension, the user can press and hold the release lug 338 inward toward the sleeve axis 316 and lift the first sleeve until the protrusion 334 is above the window or cutout. Once the protrusion 334 is over the window or cutout, the user can continue to depress the release lug 338 as the first sleeve 310 is lifted from the extension. Alternatively, the user can release the release lug 338, at which point the sliding edge 337 will abut the exterior of the extension and slide along the exterior geometry of the extension until the first sleeve 310 is removed.

[0081] For example, Figure 2 and Figure 3 As shown in the transverse connector 100 in FIG. 1 , a transverse connector according to the present disclosure may have a single pair of sleeves with associated shafts interconnected by a center housing. Alternatively, a transverse connector according to the present disclosure may have two or more pairs of sleeves with associated shafts interconnected by a center housing. Embodiments of two or more pairs of sleeves with associated shafts and a center housing may be presented as multiple transverse connectors 100 attached together in parallel. In a parallel arrangement, Figure 3 The illustrated transverse link 100 may be attached to a second transverse link located above it in the figure and to a third transverse link located below it in the figure. The three transverse links may be interconnected by connections interconnecting adjustment screws or other components of the transverse links.

[0082] The transverse connector according to the present disclosure may also have Figure 3 A single center housing is shown, but with three or more attachment assemblies connected to the center housing.

[0083] For example, Fig.13 and Fig.14 A transverse link 1000 is shown having a first attachment assembly 3000 (having a first sleeve 3100 and a first shaft 3200), a second attachment assembly 4000 (having a second sleeve 4100 and a second shaft 4200), and a third attachment assembly 5000 (having a third sleeve 5100 and a third shaft 5200), all connected to a central housing 2000. The first, second, and third attachment assemblies 3000, 4000, and 5000 are arranged around the central housing 2000 to connect the central housing to three different implants or extensions.

[0084] Fig.15 and Fig.16 Another transverse coupling 1000' is shown having a first attachment assembly 3000' (having a first sleeve 3100' and a first shaft 3200'), a second attachment assembly 4000' (having a second sleeve 4100' and a second shaft 4200'), a third attachment assembly 5000' (having a third sleeve 5100' and a third shaft 5200'), and a fourth attachment assembly 6000' (having a fourth sleeve 6100' and a fourth shaft 6200'), all connected to a central housing 2000'. The first, second, third, and fourth attachment assemblies 3000', 4000', 5000', and 6000' are arranged around the central housing 2000' to connect the central housing to four different implants or extensions.

[0085] It should be understood that embodiments according to the present disclosure may include five or more attachment assemblies attached to a single central housing. In addition, it will be understood that embodiments according to the present disclosure may have one or more attachment assemblies that are detachably connected to the central housing. The attachment assembly that can be detached from the central housing allows the transverse coupling to be modified and adapted to the number of implants or extensions that need to be connected to a single housing.

[0086] According to a first aspect, the invention relates to a transverse coupling 100; 1000; 1000' for connecting a first implant extension 20 to a second implant extension 20', the transverse coupling 100; 1000; 1000' comprising: a first sleeve 310; 3100; 3100' defining a first hole 312 adapted to axially receive the first implant extension 20 through the first hole 312; a second sleeve 410; 4100; 4100' defining a second hole 412 adapted to axially receive the first implant extension 20 through the second hole 412; 2 axially receives the second implant extension 20'; the central housing 200; 2000; 2000', which includes a first joint 230 and a second joint 240; a first shaft 320; 3200; 3200', which connects the first sleeve 310; 3100; 3100' to the first joint 230 of the central housing 200; 2000; 2000'; and a second shaft 420; 4200; 4200', which connects the second sleeve 410; 4100; 4100' to the second joint 240 of the central housing 200; 2000; 2000'.

[0087] According to a second aspect of the invention, the transverse coupling 100; 1000; 1000' is also characterized in that the first joint 230 comprises a universal spherical joint 232 which is pivotable relative to the central housing 200; 2000; 2000'.

[0088] According to the third aspect of the invention, the transverse coupling 100 ; 1000 ; 1000 ′ is also characterized in that the universal ball joint 232 comprises a longitudinal channel 234 and a plurality of spring segments 237 extending around the longitudinal channel 234 .

[0089] According to a fourth aspect of the invention, the transverse coupling 100 ; 1000 ; 1000 ′ according to the third aspect is further characterized in that the first shaft 320 ; 3200 ; 3200 ′ is axially displaceable through the longitudinal passage 234 of the first joint 230 .

[0090] According to the fifth aspect of the present invention, the transverse connecting member 100; 1000; 1000' according to the third or fourth aspect is also characterized in that the first shaft 320; 3200; 3200' includes a first sleeve end 324 attached to the first sleeve 310; 3100; 3100', and a first free end 324 opposite to the first sleeve end 322, and the first free end 324 includes a first stop 326 to limit the displacement of the first shaft 320; 3200; 3200' through the longitudinal channel 234.

[0091] According to a sixth aspect of the invention, the transverse coupling 100 ; 1000 ; 1000 ′ according to the third, fourth or fifth aspect is further characterized in that the first shaft 320 ; 3200 ; 3200 ′ is rotatable in the longitudinal channel 234 of the first joint 230 .

[0092] According to the seventh aspect of the present invention, the transverse connecting member 100; 1000; 1000' according to the third, fourth, fifth or sixth aspect is also characterized in that the first shaft 320; 3200; 3200' includes a first shaft cross-section having a first adjacent surface 425, and the longitudinal channel 234 includes a channel cross-section having a first adjacent edge 255, and the first adjacent edge 255 is configured to abut the first adjacent surface 425 during the rotation of the first shaft 320; 3200; 3200' relative to the longitudinal channel 234, and limit the rotation range of the first shaft 320; 3200; 3200'.

[0093] According to an eighth aspect of the invention, the transverse coupling 100; 1000; 1000' according to the previous aspects is also characterized in that the second joint 240 has a cylindrical through hole 244 which passes through the central housing 200; 2000; 2000'.

[0094] According to a ninth aspect of the present invention, the transverse coupling 100 ; 1000 ; 1000 ′ according to the eighth aspect is further characterized in that the second shaft 420 ; 4200 ; 4200 ′ is axially displaceable through the through hole 244 of the second joint 240 .

[0095] According to the tenth aspect of the present invention, the transverse connecting member 100; 1000; 1000' according to the eighth or ninth aspect is also characterized in that the second shaft 420; 4200; 4200' includes a second sleeve end 422 attached to the second sleeve 410; 4100; 4100', and a second free end 424 opposite to the second sleeve end 422, and the second free end 424 includes a second stop 426 to limit the axial displacement of the second shaft 420; 4200; 4200' through the through hole 244 of the second joint 240.

[0096] According to an eleventh aspect of the present invention, the transverse coupling 100 ; 1000 ; 1000 ′ according to the eighth, ninth or tenth aspect is further characterized in that the second shaft 420 ; 4200 ; 4200 ′ is rotatable in the through hole 244 of the second joint 240 .

[0097] According to the twelfth aspect of the present invention, the transverse connecting member 100; 1000; 1000' according to the eighth, ninth, tenth or eleventh aspect is also characterized in that the second shaft 420; 4200; 4200' includes a second shaft cross-section having a second adjacent surface, and the through hole 244 includes a through hole cross-section having a second adjacent edge, and the second adjacent edge is configured to abut the second adjacent surface during the rotation of the second shaft 420; 4200; 4200' relative to the longitudinal channel 234, and limit the rotation range of the second shaft 420; 4200; 4200'.

[0098] According to a thirteenth aspect of the invention, the transverse coupling 100; 1000; 1000' according to one of the previous aspects is further characterized in that the central housing 200; 2000; 2000' comprises an upper part 210, a lower part 220 separated from the upper part 210, and an adjustment screw 260 extending through the upper part 210 and the lower part 220.

[0099] According to the fourteenth aspect of the present invention, the transverse connecting member 100; 1000; 1000' according to the thirteenth aspect is also characterized in that the upper part 210 and the lower part 220 of the central shell 200; 2000; 2000' form an adjustable clamp, which can releasably fix the first axis 320; 3200; 3200' in the first joint 230 and releasably fix the second axis 420; 4200; 4200' in the second joint 240.

[0100] According to the fifteenth aspect of the present invention, the transverse connecting member 100; 1000; 1000' according to the fourteenth aspect is also characterized in that the clamp can be adjusted to a locked state in response to the rotation of the adjusting screw 260, wherein the upper part 210 and the lower part 220 of the central shell 200; 2000; 2000' are dragged together in the locked state to compress the first joint 230 and the second joint 240 and lock the position of the first axis 320; 3200; 3200' and the second axis 420; 4200; 4200' relative to the central shell 200; 2000; 2000'.

[0101] According to the sixteenth aspect of the present invention, the transverse connecting member 100; 1000; 1000' according to the fourteenth or fifteenth aspect is also characterized in that the clamp can be adjusted to an unlocked state in response to the rotation of the adjusting screw 260, wherein the upper part 210 and the lower part 220 of the central shell 200; 2000; 2000' are unfolded in the unlocked state to allow the first axis 320; 3200; 3200' and the second axis 420; 4200; 4200' to move relative to the central shell 200; 2000; 2000'.

[0102] According to the seventeenth aspect of the invention, the transverse connecting piece 100; 1000; 1000' according to the thirteenth, fourteenth, fifteenth or sixteenth aspect is also characterized in that the adjustment screw 260 includes an external thread 263, and the lower part 220 of the central housing 200; 2000; 2000' defines a hole 221 with an internal thread 223, and the external thread 263 cooperates with the internal thread 223.

[0103] According to an eighteenth aspect of the invention, the transverse coupling 100 ; 1000 ; 1000 ′ according to the previous aspects is further characterized in that at least one of the first sleeve 310 ; 3100 ; 3100 ′ and the second sleeve 410 ; 4100 ; 4100 ′ defines a sleeve axis 316 and a chamber 314 .

[0104] According to the nineteenth aspect of the present invention, the transverse connecting member 100; 1000; 1000' according to the eighteenth aspect is also characterized in that at least one of the first sleeve 310; 3100; 3100' and the second sleeve 410; 4100; 4100' includes a locking ring 330 that defines a locking ring axis 332, and the locking ring 330 can translate in the chamber 314 in a direction transverse to the sleeve axis 316.

[0105] According to the twentieth aspect of the present invention, the transverse connector 100; 1000; 1000' according to one of the previous aspects is also characterized in that the locking ring 330 can translate between a locked position and a released position relative to the first sleeve 310; 3100; 3100' and at least one of the second sleeves 410; 4100; 4100', in which the locking ring axis 332 is offset from the sleeve axis 316 by a first distance D1, and in the released position, the locking ring axis 332 is offset from the sleeve axis 316 by a second distance D2, and the first distance D1 is greater than the second distance D2.

[0106] According to the twenty-first aspect of the present invention, the transverse connector 100; 1000; 1000' according to the nineteenth or twentieth aspect is also characterized in that at least one of the first sleeve 310; 3100; 3100' and the second sleeve 410; 4100; 4100' includes a spring element 318 in the chamber 314, which applies a biasing force on the locking ring 330 to push the locking ring 330 to the locking position.

[0107] According to the twenty-second aspect of the present invention, the transverse connector 100; 1000; 1000' according to the nineteenth, twentieth or twenty-first aspect is also characterized in that the locking ring 330 includes a protrusion 334, which extends radially inward into the hole 312, and the protrusion 334 is positioned in the hole 312 to releasably engage one of the first implant extension 20 and the second implant extension 20' when the locking ring 330 is in the locked position.

[0108] According to the twenty-third aspect of the present invention, the transverse connector 100; 1000; 1000' according to the nineteenth, twentieth, twenty-first or twenty-second aspect is also characterized in that the locking ring 330 includes a release lug 338, which extends radially outward and away from the locking ring axis 332, and at least one of the first sleeve 310; 3100; 3100' and the second sleeve 410; 4100; 4100' defines a through groove 317 into which the release lug 338 extends.

[0109] According to the twenty-fourth aspect of the present invention, the transverse connecting piece 100; 1000; 1000' according to the twenty-third aspect is also characterized in that the release lug 338 protrudes through the through slot 317 in the exposed position, and in the exposed position, the release lug 338 can be pressed down against the biasing force of the spring element 318 to shift the locking ring 330 to the release position.

[0110] According to an alternative twenty-fifth aspect, the present invention relates to a transverse coupling 100; 1000; 1000' for connecting a first implant extension 20 to a second implant extension 20', the transverse coupling comprising: a first sleeve 310; 3100; 3100', which defines a first hole 312, the first hole 312 being adapted to axially receive the first implant extension 20 through the first hole 312; a second sleeve 410; 4100; 4100', which defines a second hole 412, the second hole 412 being adapted to axially receive the second implant extension 20' through the second hole 412; a central housing (200; 2000; 2000 '); a first shaft 320;3200;3200', which connects the first sleeve 310;3100;3100' to the central housing 200;2000;2000'; and a second shaft 420;4200;4200', which connects the second sleeve 410;4100;4100' to the central housing 200;2000;2000', at least one of the first shaft 320;3200;3200' and the second shaft 420;4200;4200' is connected to the central housing 200;2000;2000' via a movable joint 230 on the central housing 200;2000;2000'.

[0111] According to the twenty-sixth aspect, the features of the transverse connecting member 1000; 1000' according to the twenty-fifth aspect also include a third sleeve 5100; 5100', which defines a third hole, which is suitable for axially receiving a third implant extension through the third hole; and a third axis 5200; 5200', which connects the third sleeve to the central shell 2000; 2000'.

[0112] According to a twenty-seventh aspect, the transverse connector 1000' according to the twenty-sixth aspect also includes a fourth sleeve 6100' defining a fourth hole adapted to axially receive a fourth implant extension therethrough; and a fourth shaft 6200' connecting the fourth sleeve to the central housing 2000'.

Claims

1. A surgical instrument for spinal torsion, comprising a first implant extension (20), a second implant extension (20') and a transverse connector for connecting the first implant extension (20) to the second implant extension (20'), the first implant extension (20) being in the form of a first spinal rod fixator configured to be attached to a first pedicle screw (30), the second implant extension (20') being in the form of a second spinal rod fixator configured to be attached to a second pedicle screw (30'), and the transverse connector comprising: a first sleeve defining a first bore (312) adapted to axially receive the first implant extension (20) therethrough; a second sleeve defining a second bore (412) adapted to axially receive the second implant extension (20') therethrough; center housing; a first shaft connecting the first sleeve to the center housing; and a second shaft connecting the second sleeve to the center housing, At least one of the first shaft and the second shaft is connected to the center housing via a movable joint on the center housing, wherein The central housing includes a first joint (230) and a second joint (240); The first shaft connects the first sleeve to the first joint (230) of the center housing; The second shaft connects the second sleeve to the second joint (240) of the center housing; and The first joint (230) includes a universal ball joint (232) which is pivotable relative to the center housing. It is characterized in that The universal ball joint (232) includes a longitudinal channel (234) and a plurality of spring segments (237) extending around the longitudinal channel (234).

2. The surgical instrument of claim 1, wherein the first shaft is axially displaceable through the longitudinal passage (234) of the first joint (230).

3. The surgical instrument according to claim 1, wherein the first shaft includes a first sleeve end (322) attached to the first sleeve, and a first free end (324) opposite to the first sleeve end (322), the first free end (324) including a first stop (326) to limit axial displacement of the first shaft through the longitudinal channel (234), and / or wherein the first shaft is rotatable in the longitudinal channel (234) of the first joint (230), and / or wherein the first shaft includes a first shaft cross-section having a first abutting surface (425), and the longitudinal channel (234) includes a channel cross-section having a first abutting edge (255), the first abutting edge (255) being configured to abut the first abutting surface (425) during rotation of the first shaft relative to the longitudinal channel (234) and to limit the rotation range of the first shaft.

4. The surgical instrument of claim 1, wherein the second joint (240) includes a cylindrical through hole (244) passing through the center housing.

5. The surgical instrument according to claim 4, wherein the second shaft is axially displaceable through the through hole (244) of the second joint (240), and / or wherein the second shaft includes a second sleeve end (422) attached to the second sleeve, and a second free end (424) opposite to the second sleeve end (422), the second free end (424) including a second stop (426) to limit the axial displacement of the second shaft through the through hole (244) of the second joint (240), and / or wherein the second shaft is rotatable in the through hole (244) of the second joint (240), and / or wherein the second shaft includes a second shaft cross-section having a second abutting surface, and the through hole (244) includes a through hole cross-section having a second abutting edge, the second abutting edge being configured to abut the second abutting surface during rotation of the second shaft relative to the longitudinal channel (234) and limit the rotation range of the second shaft.

6. The surgical instrument according to claim 1, wherein the central housing includes an upper portion (210), a lower portion (220) separated from the upper portion (210), and an adjustment screw (260) extending through the upper portion (210) and the lower portion (220).

7. A surgical instrument according to claim 6, wherein the upper portion (210) and the lower portion (220) of the central housing form an adjustable clamp in which the first shaft is releasably fixed in the first joint (230) and the second shaft is releasably fixed in the second joint (240), and / or wherein the adjustment screw (260) includes an external thread (263) and the lower portion of the central housing defines a hole (221) having an internal thread (223), and the external thread (263) cooperates with the internal thread (223).

8. A surgical instrument according to claim 7, wherein the clamp is adjustable to a locked state in response to rotation of the adjustment screw (260), wherein the upper portion (210) and the lower portion (220) of the center housing are pulled together to the locked state to compress the first joint (230) and the second joint (240) and lock the position of the first axis and the second axis relative to the center housing, and / or wherein the clamp is adjustable to an unlocked state in response to rotation of the adjustment screw (260), wherein the upper portion (210) and the lower portion (220) of the center housing are expanded in the unlocked state to allow the first axis and the second axis to move relative to the center housing.

9. The surgical instrument of claim 1, wherein at least one of the first sleeve and the second sleeve defines a sleeve axis (316) and a chamber (314).

10. The surgical instrument according to claim 9, wherein at least one of the first sleeve and the second sleeve includes a locking ring (330) defining a locking ring axis (332), and the locking ring (330) can be translated in the chamber (314) along a direction transverse to the sleeve axis (316).

11. The surgical instrument according to claim 10, wherein the locking ring (330) is translatable relative to at least one of the first sleeve and the second sleeve between a locked position and a released position, wherein in the locked position, the locking ring axis (332) is offset from the sleeve axis (316) by a first distance (D1), and in the released position, the locking ring axis (332) is offset from the sleeve axis (316) by a second distance (D2), the first distance (D1) being greater than the second distance (D2), and / or wherein at least one of the first sleeve and the second sleeve includes a spring element (318) in the chamber (314), the spring element (318) applying a biasing force to the locking ring (330) to lock the locking ring. The ring (330) is pushed toward the locked position, and / or wherein the locking ring (330) includes a protrusion (334), which extends radially inwardly into the first hole (312), and the protrusion (334) is positioned in the first hole (312) to releasably engage one of the first implant extension (20) and the second implant extension (20') when the locking ring (330) is in the locked position, and / or wherein the locking ring (330) includes a release lug (338), which extends radially outward and away from the locking ring axis (332), and at least one of the first sleeve and the second sleeve defines a through slot (317) into which the release lug (338) extends.

12. The surgical instrument of claim 1, further comprising: a third sleeve defining a third bore adapted to axially receive a third implant extension therethrough; A third shaft connects the third sleeve to the center housing.

13. A surgical instrument according to claim 11, wherein the release lug (338) protrudes through the through slot (317) in an exposed position, and in the exposed position, the release lug (338) can be pressed down against the biasing force of the spring element (318) to shift the locking ring (330) toward the release position.

14. The surgical instrument of claim 12, further comprising: a fourth sleeve (6100') defining a fourth aperture adapted to axially receive a fourth implant extension therethrough; and a fourth shaft (6200') connecting the fourth sleeve to the center housing.

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