PATIENT-SPECIFIC TOOLS AND IMPLANTS

• US 20110160867A1
• Filed: 03/07/2011
• Published: 06/30/2011
• Est. Priority Date: 02/27/2006
• Status: Active Grant

• Current Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Inventors: WHITE, JOHN R., MERIDEW, JASON D., METZGER, ROBERT
• Granted Patent: US 8,535,387 B2
• Time in Patent Office: Days
• US Class Current: 623/20.36
• CPC Class Codes: A61B 17/1624 Drive mechanisms therefor
• CPC Class Codes: A61B 17/164 intramedullary
• CPC Class Codes: A61B 17/1659 Surgical rasps, files, planes, or scrapers
• CPC Class Codes: A61B 17/1668 for the upper femur A61B17/164 takes precedence
• CPC Class Codes: A61B 17/809 with bone-penetrating elements, e.g. blades or prongs bone staples A61B17/0642; intramedullary nails with a plate at an end A61B17/7233
• CPC Class Codes: A61B 2034/105 Modelling of the patient, e.g. for ligaments or bones
• CPC Class Codes: A61B 2034/108 Computer aided selection or customisation of medical implants or cutting guides
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• 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 2/3601 for replacing only the epiphyseal or metaphyseal parts of the femur, e.g. endoprosthetic femoral heads or necks directly fixed to the natural femur by internal fixation devices non-prosthetic internal fixation devices for the femoral head or neck A61B17/74
• CPC Class Codes: A61F 2/3609 Femoral heads or necks; Connections of endoprosthetic heads or necks to endoprosthetic femoral shafts A61F2/3601 takes precedence
• CPC Class Codes: A61F 2002/30574 with an integral complete or partial collar or flange
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30617 Visible markings for adjusting, locating or measuring
• CPC Class Codes: A61F 2250/0097 Visible markings, e.g. indicia
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A method for preparing a femoral neck for receiving a neck implant includes obtaining image data of a proximal femoral bone and femoral neck of a patient by a medical imaging method and constructing a three-dimensional image model of the proximal femoral bone and neck of the patient using the image data. The method further includes identifying a three-dimensional cortical boundary surface at an interface between cortical and cancellous bone of the patient using the image model. A patient-specific broach having a three-dimensional cutting surface closely matching and complementary to the cortical boundary surface of the patient using the image model is designed and manufactured.

Claims

1. A femoral neck implant comprising:

a body for implantation into a femoral neck of a patient, the body having a patient-specific cross-section of variable size and shape along a longitudinal axis of the body and a patient-specific three-dimensional outer surface that closely nests and conforms complementarily to a cortical boundary surface corresponding to a cortical/cancellous bone interface surface of the femoral neck of the specific patient after removing only the cancellous bone from the femoral neck; and

a neck portion extending from the body and configured for coupling with a femoral head implant.

2. The femoral neck implant of claim 1, wherein the neck portion is configured to be aligned along a patient-specific articulation axis.

3. The femoral neck implant of claim 1, further comprising a flange coupled to the body and configured for abutting a resected surface of the femoral neck of the patient.

4. The femoral neck implant of claim 1, wherein the body is sized to extend only into the femoral neck of the patient and has a patient-specific length.

5. The femoral neck implant of claim 1, in combination with a femoral head.

6. The femoral neck implant of claim 5, wherein the femoral head is patient-specific.

7. The femoral neck implant of claim 5, in combination with an acetabular cup.

8. A femoral neck cutting tool comprising:

a body having a patient-specific cross-section of variable size and shape along a longitudinal axis and a patient-specific three-dimensional outer cutting surface that closely nests and conforms complementarily to a cortical boundary surface corresponding to a cortical/cancellous bone interface surface of a femoral neck of the specific patient and configured for removing only the cancellous bone from the femoral neck of the patient; and

a non patient-specific coupling component for engaging a non patent-specific driver tool.

9. The cutting tool of claim 8, wherein the coupling component includes a protrusion extending from a proximal surface of the cutting tool and a bore defined through the proximal surface of the cutting tool.

10. The cutting tool of claim 9, in combination with a driver tool having a distal surface with a driver tool bore for receiving the protrusion and a retractable rod having a distal portion insertable into the bore of the cutting tool for holding the cutting tool.

11. A method for preparing a femoral neck for receiving a neck implant comprising:

obtaining image data of a proximal femoral bone and femoral neck of a patient by a medical imaging method;

constructing a three-dimensional image model of the proximal femoral bone and neck of the patient using the image data;

identifying a three-dimensional cortical boundary surface at an interface between cortical and cancellous bone of the patient using the image model;

designing a patient-specific broach having a three-dimensional cutting surface closely matching and complementary to the cortical boundary surface of the patient using the image model; and

manufacturing the patient-specific broach.

12. The method of claim 11, wherein image data includes data obtained from any of MRI, CT, X-ray, ultrasound imaging methods.

13. The method of claim 11, further comprising:

designing a patient-specific neck implant having a body with a three-dimensional outer surface closely matching and complementary to the cortical boundary surface of the patient using the image model; and

manufacturing the patient-specific neck implant.

14. The method of claim 13, wherein the neck implant includes a flange coupled to the body, the flange configured for engaging a resected surface of the femoral neck of the patient.

15. The method of claim 14, wherein the neck implant includes a neck portion extending from the body for coupling to a femoral head component at a patient-specific axis.

16. The method of claim 13, further comprising sizing the neck implant to extend only into the femoral neck of the patient and have a patient-specific length.

17. A method of preparing a femoral neck for receiving a femoral neck implant comprising:

resecting a femoral head from a femoral neck of a patient according to a pre-operative patient-specific plan; and

removing only cancellous bone from the femoral neck and proximal femoral bone of the patient using a patient-specific broach having a three-dimensional cutting surface closely matching and complementary to a cortical/cancellous bone interface surface of the femoral neck of the patient.

18. The method of claim 17, further comprising:

coupling a driver tool to the patient-specific broach; and

inserting the broach into the femoral neck of the patient.

19. The method of claim 18, further comprising:

inserting a protrusion extending from a proximal surface of the broach into a bore of a distal surface of the driver tool; and

inserting a distal portion of a retractable rod of the driver tool into a bore defined through the proximal surface of the broach to secure the broach to the drivel tool.

20. The method of claim 17, further comprising:

implanting a patient-specific neck implant having a three-dimensional outer surface closely matching and complementary to the cortical/cancellous bone interface surface of the femoral neck of the patient after the cancellous bone is removed.

21. The method of claim 20, further comprising engaging a proximal flange of the neck implant with a resected surface of the femoral neck.

22. The method of claim 20, further comprising coupling a femoral head implant to a neck portion of the neck implant.

23. A method of preparing a femoral neck for receiving a femoral neck implant comprising:

coupling a driver tool to a patient-specific broach having a three-dimensional cutting surface closely matching and complementary to a three-dimensional cortical/cancellous bone interface surface of the femoral neck of the patient;

inserting the broach into a resected femoral neck of the patient using the driver tool.

removing only cancellous bone from the femoral neck and proximal femoral bone of the patient using the patient-specific broach; and

exposing the three-dimensional cortical/cancellous bone interface surface after removing the cancellous bone.

24. The method of claim 23, further comprising:

implanting a patient-specific neck implant having a three-dimensional outer surface closely matching and complementary to the exposed cortical/cancellous bone interface surface of the femoral neck of the patient after the cancellous bone is removed.

25. A patient-specific guide for preparing a femoral neck of a patient for receiving a femoral neck implant comprising:

a first wall having a first inner surface with a patient-specific inner bore therethrough, wherein the first inner surface is configured to mate with a resected surface of the femoral neck; and

a peripheral wall extending from the first wall, wherein the peripheral wall includes a three-dimensional patient-specific peripheral inner surface configured to mate in only one position with an outer peripheral surface of the femoral neck after resection.

26. The patient-specific guide of claim 25, wherein the patient-specific inner bore is configured during a preoperative plan of the patient for guiding a cutting tool to remove only cancellous bone from the femoral neck to an interface boundary between the cortical and cancellous bone for receiving a neck implant.

27. The patient-specific guide of claim 26 in combination with a patient-specific neck implant.