Patient-Specific Spinal Fusion Cage and Methods of Making Same

• US 20150305878A1
• Filed: 04/24/2014
• Published: 10/29/2015
• Est. Priority Date: 04/24/2014
• Status: Active Grant

• Current Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Original Assignee: DePuy Synthes Products LLC (Johnson & Johnson)
• Inventors: O'Neil, Michael J, Lomeli, Roman
• Granted Patent: US 9,757,245 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/45 For evaluating or diagnosing the musculoskeletal system or teeth A61B5/1036, A61B5/1074, A61B7/006 take precedence
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61F 2/30942 for designing or making customized prostheses, e.g. using templates, CT or NMR scans, finite-element analysis or CAD-CAM techniques
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/4684 Trial or dummy prostheses
• CPC Class Codes: A61F 2002/30387 Dovetail connection
• CPC Class Codes: A61F 2002/30556 for adjusting thickness
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30581 having a pocket filled with fluid, e.g. liquid
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30971 Laminates, i.e. layered products
• CPC Class Codes: A61F 2002/30985 using three dimensional printing [3DP]
• CPC Class Codes: A61F 2002/4663 for measuring volumes or other three-dimensional shapes
• CPC Class Codes: A61F 2002/4689 acoustic
• CPC Class Codes: A61F 2002/469 electrical
• CPC Class Codes: A61F 2002/4696 optical

Abstract

A method of determining disc space geometry with the use of an expandable trial having endplate-mapping capabilities. An expandable trial is inserted into the disc space and its height is adjusted to obtain the desired decompression and spinal alignment (which is typically confirmed with the use of CT or Fluoroscopic imaging). The endplate dome/geometry dome is then determined by one of the following three methods:

• • a) direct imaging through the trial,
  • b) balloon moldings filled with flowable in-situ fluid (for example, silicon, polyurethane, or PMMA) from superior/inferior endplates or
  • c) light-based imaging through superior & inferior balloons.

Claims

1. An intervertebral trial having a distal end portion having upper and lower surfaces defining a height therebetween, wherein the height is adjustable and is adapted for insertion into a disc space between opposing vertebral endplates, and wherein the distal end portion has a functional feature adapted to map a contour of a vertebral endplate.

2. The trial of claim 1 wherein the functional feature is an imaging feature.

3. The trial of claim 2 wherein the imaging feature comprises at least one light emitter.

4. The trial of claim 2 wherein the imaging feature comprises an ultrasound emitter.

5. The trial of claim 3 wherein at least one of the upper and lower surfaces has a balloon attached thereto.

6. The trial of claim 4 wherein the balloon is filled with a fluid.

7. The trial of claim 6 wherein the fluid comprises a thermoset.

8. The trial of claim 6 wherein the fluid comprises a thermoplastic.

9. The trial of claim 6 wherein the fluid curable resin comprises is selected from the group consisting of a silicone, an acrylic polymer, and a polyurethane.

10. The trial of claim 1 further having a proximal end portion comprising a handle.

11. The trial of claim 7 further having an elongated intermediate portion.

12. The trial of claim 8 wherein the elongated intermediate portion comprises a rod.

13. The trial of claim 1 wherein the upper and lower surfaces are substantially planar.

14. A method of imaging an contour of a vertebral endplate, comprising the steps of;

a) selecting the trial of claim 1,

b) inserting the trial into the disc space,

c) expanding the height of the trial to create a first cavity between the upper surface of the trial and the upper vertebral endplate, and

d) producing an electronic 3D image of the first cavity.

15. The method of claim 14 wherein the 3D image is produced by ultrasound imaging.

16. The method of claim 14 wherein the 3D image is produced by light imaging.

17. The method of claim 14 wherein the 3D image is a molding.

18. The method of claim 14 wherein the expansion step creates a second cavity between the lower surface of the trial and the lower vertebral endplate.

19. The method of claim 18 further comprising the step of:

e) producing a 3D image of the second cavity.

20. A method of manufacturing a patient-specific intravetebral implant for a patient having a disc space defined by a pair of opposed vertebral endplates, comprising the steps of:

a) intraoperatively obtaining a 3D image of each of the vertebral endplates,

b) intraoperatively manufacturing, from the 3D images, the patient-specific intervertebral implant, and

c) inserting the patient-specific intervertebral implant into the disc space in the patient.

21. A method of building a patient specific intravertebral implant for a patient having a disc space defined by a pair of opposed vertebral endplates, comprising the steps of:

a) intraoperatively obtaining a 3D image of each of the endplates,

b) intraoperatively manufacturing, from the 3D images, a pair of prosthetic endplates,

c) intraoperatively attaching each prosthetic endplate to a core component to produce an assembled, patient specific intravertebral implant.

22. The method of claim 21 further comprising the step of:

d) inserting the assembled patient specific intravertebral implant into a disc space in the patient.

23. The method of claim 21 wherein step c) is accomplished within the disc space.

24. A patient-specific intervertebral fusion cage for insertion into a disc space defined by opposing upper and lower vertebral endplates in a patient, comprising:

a) an intermediate modular core component having an upper surface and a lower surface,

b) an upper endplate attached to the upper surface of the core component, and

c) a lower endplate attached to the lower surface of the core component,

wherein each of the upper and lower endplates are manufactured from 3D images of the opposing upper and lower vertebral endplates of the patient.