INTER-BODY SPACER

Abstract

The invention provides an inter-body spacer in the form of a vertebral body replacement. The spacer comprises a connector having, axially aligned, a socket and threaded socket. A threaded screw is receivable in the threaded socket of the connector at one side of the screw and an endplate receiving head is provided on the other end of the screw for receiving an endplate perpendicular to the axis. The spacer further comprises a cylindrical extension with one end rotatably receivable in the socket of the connector and an endplate receiving head on the other end of the extension for receiving an endplate perpendicular to the axis. A locating formation is provided on each endplate receiving head for locating the endplate at a specific angle about the axis. The spacer further comprises a selection of one or more end plates receivable on the endplate receiving head with the tissue engaging surface of the endplates being transverse to the axis of the spacer at differing angles. The invention also extends to a elongate thoracolumbar lateral plate.

Claims

1. An inter-body spacer in the form of a vertebral body replacement, which spacer comprises: a connector having, axially aligned, a socket and threaded socket; a threaded screw receivable in the threaded socket of the connector at one side of the screw and an endplate receiving head on the other end of the screw for receiving an endplate perpendicular to the axis; a cylindrical extension with one end rotatably receivable in the socket of the connector and an endplate receiving head on the other end of the extension for receiving an endplate perpendicular to the axis; a locating formation on each endplate receiving head for locating the endplate at a specific angle about the axis; a selection of one or more end plates receivable on the endplate receiving head with the tissue engaging surface of the endplates being transverse to the axis of the spacer at differing angles; and wherein the locating formation on each endplate receiving head for locating the endplate at a specific angle about the axis is a notch formed in the head or endplate with a complementary stub formation which fits snugly into the notch formed on either the endplate or head, as the case may be.

2. A spacer as claimed in claim 1, wherein the cylindrical extension is provided with one or more lateral threaded sockets extending into the connector transverse to the axis.

3. An inter-body spacer introducer or implantation tool, which introducer comprises: a thread tipped rod which engages, in use, one of the lateral threaded sockets of the connector; a sleeve over the rod, which rod and sleeve can be rotated relative to each other and which sleeve at the threaded end of the rod is provided with gears for engaging, in use, the gears of the pinion to rotate the pinion, in turn, to adjust the length of the inter-body spacer; an outer tube covering the rod and sleeve with a handle at the one end and locating means for locating the inter-body spacer at the other end with the thread tipped rod engaged as well as the gears of the sleeve engaged, with the locating means being in the form of U-shaped arms which fit snugly and complementally over the connector to locate the inter-body spacer and the introducer square to each other; and wherein the end of the sleeve opposite the gears extends past the handle of the outer tube and fitted with its own handle; and wherein a window is provided in the sleeve, between the handle of the outer tube and the handle of the sleeve to provide access to rod, which rod is provided with gripping means which can be gripped through the window to allow the rod to be rotated relative to the sleeve and outer tube.

4. An elongate thoracolumbar lateral plate, which can be used to complement the inter body spacer as claimed in claim 1, which lateral plate comprises: two parts of which one has a slot and the other a lockable screw, which screw is receivable in the slot and the two parts are slideably connected, and wherein the opposed end of each part is provided with a pair of first countersunk holes for receiving surgical screws there through, and wherein a second countersunk hole is provided adjacent each first countersunk hole, intersecting therewith.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0044] The invention is now described by way of example with reference to the accompanying drawings.

[0045] In the drawings:

[0046] FIG. 1 shows an exploded view of a typical vertebral body replacement by the applicant;

[0047] FIG. 2 shows a side and sectional side view B-B of a vertebral body replacement, in accordance with the invention;

[0048] FIG. 3 shows an exploded view of the vertebral body replacement;

[0049] FIG. 4 shows a selection of views of a square threaded screw;

[0050] FIG. 5 shows a selection of views of an endplate;

[0051] FIG. 6 shows a top view of an introducer with an engaged vertebral body replacement, in accordance with the invention;

[0052] FIG. 7 shows a sectional side view through B-B of the introducer with an engaged vertebral body replacement;

[0053] FIG. 8 shows a side view of the introducer with an engaged vertebral body replacement;

[0054] FIG. 9 shows a sectional side view through A-A of the introducer with an engaged vertebral body replacement;

[0055] FIG. 10 shows detail of the introducer engaged with a vertebral body replacement;

[0056] FIG. 11 shows an exploded view of the introducer engaged with a vertebral body replacement;

[0057] FIG. 12 shows a perspective view of and elongate thoracolumbar lateral plate, in accordance with the invention; and

[0058] FIG. 13 shows the elongate thoracolumbar lateral plate used with a mesh cage system.

[0059] Referring now to the drawings, FIG. 2 onwards, the inter-body spacer in the form of a vertebral body replacement, in accordance with the invention, is generally indicated by reference numeral 10.

[0060] The spacer 10 comprises a connector 12 having, axially aligned, a socket 14 and square threaded socket 16. The spacer 10 further comprises a square threaded screw 18 receivable in the threaded socket 16 of the connector 12 at one side of the screw and an endplate receiving head 20 on the other end of the screw for receiving an endplate 22 perpendicular to the axis. The spacer 10 further comprises a cylindrical extension 24 with one end rotatably receivable in the socket 14 of the connector 12 and an endplate receiving head 26 on the other end of the extension for receiving an endplate 22 perpendicular to the axis. A locating formation in the form of a pair of notches 70 are on each endplate receiving head 20 and 26 for locating the endplate with a complementary pair of stubs 72 at a specific angle about the axis. A selection of one or more end plates are receivable on the endplate receiving heads 20 and 26 with the tissue engaging surface 32 of the endplates being serrated and transverse to the axis of the spacer at differing angles. The endplate receiving heads 20 and 26 and the end plates 22 are provided with complementary Morse* taper formations 34 and 36 to attach the end plates to the heads. The cylindrical extension 24 is hollow and the treaded screw fits into the hollow with the screw 18 and cylinder 24 having complementary flat formations 38 and 40 to prevent rotation relative to each other. The cylindrical extension 24 is also provided with a circular slot 42 about the cylinder proximate the end receivable in the connector 12. A spring loaded lock ring 44 is provided to fit into the slot 42 and a slot 46 provided inside the connector 12. The connector 12 is further provided with a series of threaded holes 48 through the connector 12 arranged about the connector such that grub screws 50 can be screwed through the connector to engage the cylindrical extension 24 to fix the cylindrical extension and the connector and pinion 51 relative to each other. A sleeve or grub screw retaining ring 52 is provided to retain the grub screws 50. Slots 54 are provided in the retaining ring 54 may allow access for a tool to engage the grub screws. A slot 56 is provided in the threaded screw, a complementary hole 58 on the cylindrical extension 24 as well as the connector 12 to finally lock all the parts together with a sheer pin 60. The end plates 22 are provided with angled holes for receiving bone screws 62 there through.

[0061] The cylindrical extension 24 is also provided with a set of lateral threaded sockets 64 extending into the connector transverse or perpendicular to the axis for threadedly fixing and locating an introducer (FIG. 5 onwards).

[0062] A locating formation in the form of a pair of notches 70 is provided on each endplate receiving head 34 and 36 for locating the endplate at a specific angle about the axis with a complementary pair of stubs 72 formation which fits snugly into the notch is formed on the endplates 22.

[0063] Referring now to FIGS. 5 to 11, an inter-body spacer introducer or implantation tool 100 comprises a thread tipped rod 102 which engages, in use, one of the lateral threaded sockets 64 into the cylindrical extension 24 of the connector 12 and a sleeve 103 over the rod 102, which rod and sleeve can be rotated relative to each other and which sleeve at the threaded end of the rod is provided with gears 104 for engaging, in use, the gears of the pinion 51 to rotate the pinion, in turn, to adjust the length of the inter-body spacer 10. The introducer further comprises an outer tube 106 covering the rod 102 and sleeve 103 with a handle 108 at the one end and locating means 110 for locating the inter-body spacer at the other end with the thread tipped rod engaged as well as the gears of the sleeve engaged, with the locating means being in the form of U-shaped arms which fit snugly and complementally over the connector 12 to locate the inter-body spacer 10 and the introducer 100 securely and square to each other. The end of the sleeve 103 opposite the gears extends past the handle 108 of the outer tube 106 and is fitted with its own handle 112. A window 114 is provided in the sleeve 103, between the handle 108 of the outer tube 106 and the handle 112 of the sleeve 103 to provide access to the rod 102, which rod is provided with gripping means 114 which can be gripped through the window to allow the rod to be rotated relative to the sleeve and outer tube. All the components fit into each other and are held in place by means of a pin 116, which screws into the handle 112 to lock the components in place.

[0064] Referring now to FIGS. 12 and 13, which shows an elongate thoracolumbar lateral plate 120. The lateral plate 120 comprises two parts 120.1 and 120.2 of which one has a slot 122 and the other a lockable screw 124. The screw 122 is receivable in the slot and the two parts are slideably connected. Once the length of the lateral plate is determined, it can, in use, be set to that length by means of the lockable screw 124. Complementary retaining formations 126 and 128 provide support for lengthwise alignment, in use. The opposed end of each part 120.1 and 120.2 is provided with a pair of first countersunk holes 128 for receiving surgical screws 130 there through. A second countersunk hole 132 is provided adjacent each first countersunk hole 128, intersecting therewith. A notched screw 134 is provided in each second hole with the notch allowing the surgical screw to be turned in one position and preventing the surgical screw from coming out in another position. The inner, spinal side of the lateral plate 120 is provided with a pair of generally transverse shoulders (not shown) which extends towards the spine, in use, which provides support for the opposed top and bottom ends of the inner plate of a person's remaining vertebrae.

[0065] It shall be understood that the examples are provided for illustrating the invention further and to assist a person skilled in the art with understanding the invention and are not meant to be construed as unduly limiting the reasonable scope of the invention.