Expandable intervertebral cage and surgical method

Claim 2

A bio-compatible intervertebral prosthesis for implantation between adjacent vertebrae comprising: a) a cage body that includes a plurality of components including at least first and second separable cage sections configured and sized to be inserted between adjacent vertebrae; b) said cage sections being separable along the longitudinal axis of said cage body; c) the cage body having an anterior section with an internally threaded bore; d) the cage body having an internal recess defined by a recess surface; e) the cage body having anterior and posterior end portions; f) An expansion screw with proximal and distal end portions, the proximal end having means thereon for forming a connection with a rotary driver for rotating the screw, the distal end portion being sized and shaped to force the first and second cage sections apart as the screw advances longitudinally within the cage body to engage the recess surface along the length of the distal end of said expansion screw and in a direction from the anterior to the posterior end portions thereof; g) wherein said expansion screw has a length less than the length of the cage body and wherein said expansion screw does not extend beyond the end of said cage body; and h) wherein the first and second cage sections move apart incrementally as the screw advances into the internally threaded bore and recess surface.

Claim 3

The apparatus of claim 1, wherein the cage body has an outer surface with a generally cylindrical shape.

Claim 4

The apparatus of claim 1 wherein the cage body sections each have corresponding flat abutting surfaces.

Claim 5

The apparatus of claim 1 wherein the cage body recesses are generally conically shaped.

Claim 6

The apparatus of claim 1 wherein each of the cage sections has a recess portion that engages the expansion screw.

Claim 7

The apparatus of claim 1 wherein the distal end of the expansion screw is conically shaped.

Claim 8

The apparatus of claim 1 wherein the anterior section includes an anterior fitting that carries the internally threaded bore.

Claim 9

The apparatus of claim 1 wherein the expansion screw has a cylindrically shaped threaded section and a conically shaped unthreaded section.

Claim 10

The apparatus of claim 1 wherein the cage body sections are slideably attached at the posterior end portion thereof.

Claim 11

A bio-compatible intervertebral prosthesis for implantation between adjacent vertebrae comprising: a) a cylindrically shaped cage body that includes at least first and second separable sections configured and sized to be inserted between adjacent vertebrae, each section having a flat inner surface portion that engages the flat inner surface of the other component; b) said separable sections being separable along the longitudinal axis of said cage body; c) the cage body having an anterior fitting integral thereto with an internally threaded bore; d) the cage body having anterior and posterior end portions; e) each of the cage body sections having a conically shaped internal recess with a bearing surface; f) an externally threaded expansion screw that engages the internal threads of the fitting, the screw having proximal and distal end portions, the proximal end having a tool receptive socket thereon for forming a connection with a rotary driver tool that can rotate the screw, the distal end portion being sized and shaped to force the first and second components apart as the screw advances longitudinally within the cage body to engage the recess surface along the length of the distal end of said expansion screw and in a direction from the anterior to the posterior end portions thereof; g) wherein said expansion screw has a length less than the length of the cage body and wherein said expansion screw does not extend beyond the end of said cage body; and h) wherein the first and second sections move apart incrementally as the screw advances into the internally threaded bore and recess surface.

Claim 12

A bio-compatible intervertebral prosthesis for implantation between adjacent vertebrae comprising: a) a cylindrically shaped cage body that includes at least first and second separable sections configured and sized to be inserted between adjacent vertebrae, each section having a flat inner surface portion that engages the flat inner surface of the other component; b) said separable sections being separable along the longitudinal axis of said cage body; c) the cage body having an anterior fitting integral thereto with an internally threaded bore; d) the cage body having anterior and posterior end portions; e) each of the cage body sections having a conically shaped internal recess with a bearing surface; f) an externally threaded expansion screw that engages the internal threads of the fitting, the screw having proximal and distal end portions, the proximal end having a tool receptive socket thereon for forming a connection with a rotary driver tool that can rotate the screw, the distal end portion being sized and shaped to force the first and second components apart as the screw advances longitudinally within the cage body to engage the recess surface along the length of the distal end of said expansion screw and in a direction from the anterior to the posterior end portions thereof; g) wherein said expansion screw has a length less than the length of the cage body and wherein said expansion screw does not extend beyond the end of said cage body; and h) wherein the first and second sections move apart incrementally as the screw advances into the internally threaded bore and recess surface.

Claim 13

The apparatus of claim 10 further comprising means for receiving bone graft material.

Claim 14

The apparatus of claim 10 further comprising bore means for receiving bone fusion augmenting material.

Claim 15

The apparatus of claim 10 further comprising roughened surface means on the outer bone engaging surface of at least one of the components for enhancing fixation of the cage body to the patents vertebral bodies.

Claim 16

The apparatus of claim 10 wherein at least one of the components has a roughened surface for engaging the end plates of the patient's vertebral bodies.

Claim 17

The apparatus of claim 10 wherein the tool receptive portion is a socket.

Claim 18

A bio-compatible intervertebral prothesis for implantation between adjacent vertebrae comprising: a) a cylindrically shaped cage body that includes at least first and second separable cage sections configured and sized to be inserted between adjacent vertebrae, each having b) a flat inner surface portion that engages the flat inner surface of the other component; c) said separable sections being separable along the longitudinal axis of said cage body; d) the cage body having an anterior fitting integral thereto with an internal bore; e) the cage body having anterior and posterior end portions; f) each of the cage body sections having a conically shaped internal recess surface with a bearing surface; g) An expansion pin that engages the bore of the anterior fitting, the pin having proximal and distal end portions, the proximal end having a tool receptive portion thereon for forming a connection with a driver tool that can manipulate the pin, the distal end portion being sized and shaped to force the first and second sections apart as the pin advances longitudinally within the cage body to engage the recess surface along the length of the distal end of said expansion screw in a direction from the anterior to the posterior end portions thereof; h) wherein said expansion screw has a length less than the length of the cage body and wherein said expansion screw does not extend beyond the end of said cage body; and i) wherein the first and second sections move apart incrementally as the pin advances into the bore and recess surface.

Claim 19

A bio-compatible intervertebral prothesis for implantation between adjacent vertebrae comprising: a) a cylindrically shaped cage body that includes at least first and second separable cage sections configured and sized to be inserted between adjacent vertebrae, each having b) a flat inner surface portion that engages the flat inner surface of the other component; c) said separable sections being separable along the longitudinal axis of said cage body; d) the cage body having an anterior fitting integral thereto with an internal bore; e) the cage body having anterior and posterior end portions; f) each of the cage body sections having a conically shaped internal recess surface with a bearing surface; g) An expansion pin that engages the bore of the anterior fitting, the pin having proximal and distal end portions, the proximal end having a tool receptive portion thereon for forming a connection with a driver tool that can manipulate the pin, the distal end portion being sized and shaped to force the first and second sections apart as the pin advances longitudinally within the cage body to engage the recess surface along the length of the distal end of said expansion screw in a direction from the anterior to the posterior end portions thereof; h) wherein said expansion screw has a length less than the length of the cage body and wherein said expansion screw does not extend beyond the end of said cage body; and i) wherein the first and second sections move apart incrementally as the pin advances into the bore and recess surface.

Claim 20

The apparatus of claim 16 wherein the expansion pin is a threaded expansion screw.

Claim 21

The apparatus of claim 16 wherein the cage body bore is threaded.