Femoral Base Plate THA

• US 20180049807A1
• Filed: 07/31/2017
• Published: 02/22/2018
• Est. Priority Date: 12/15/2015
• Status: Active Grant

• Current Assignee: TechMah Medical LLC (Enovis Corp.)
• Original Assignee: TechMah Medical LLC (Enovis Corp.)
• Inventors: Mahfouz, Mohamed R.
• Granted Patent: US 10,441,362 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 17/746 the longitudinal elements coupled to a plate opposite the femoral head
• CPC Class Codes: A61B 17/80 Cortical plates , i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates
• CPC Class Codes: A61B 17/8061 specially adapted for particular bones A61B17/70 and A61B17/74 take precedence
• CPC Class Codes: A61B 17/808 Instruments for holding or positioning bone plates, or for adjusting screw-to-plate locking mechanisms
• CPC Class Codes: A61B 2034/104 Modelling the effect of the tool, e.g. the effect of an implanted prosthesis or for predicting the effect of ablation or burring
• 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 2034/2048 using an accelerometer or inertia sensor
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2/4607 of hip femoral endoprostheses
• CPC Class Codes: A61F 2002/30943 using mathematical models
• CPC Class Codes: A61F 2002/4633 for selection of endoprosthetic joints or for pre-operative planning
• CPC Class Codes: Y10S 623/908 Bone
• CPC Class Codes: Y10S 623/911 Bone

Abstract

A method of creating a mass-customized femoral bone base plate comprising: (i) establishing anatomical landmarks across a plurality of bone models of a statistical atlas; (ii) establishing instrument landmarks across the plurality of bone models of the statistical atlas; (iii) establishing definitions for a reference plane calculation across the plurality of bone models of the statistical atlas, where the reference plane represents a boundary of a prosthetic implant; (iv) establishing an attachment site for a mass-customized femoral bone base plate using the anatomical landmarks, the instrument landmarks, and the reference plane; and, (v) fabricating the mass-customized femoral bone base plate configured to be attached to a femur, where the attachment sites of the mass-customized femoral bone base plate are predetermined to avoid impingement with the prosthetic implant when implanted.

Claims

1. A method of creating a mass-customized femoral bone base plate comprising:

establishing anatomical landmarks across a plurality of bone models of a statistical atlas;

establishing instrument landmarks across the plurality of bone models of the statistical atlas;

establishing definitions for a reference plane calculation across the plurality of bone models of the statistical atlas, where the reference plane represents a boundary of a prosthetic implant;

establishing an attachment site for a mass-customized femoral bone base plate using the anatomical landmarks, the instrument landmarks, and the reference plane; and

,

fabricating the mass-customized femoral bone base plate configured to be attached to a femur, where the attachment sites of the mass-customized femoral bone base plate are predetermined to avoid impingement with the prosthetic implant when implanted.

2. The method of claim 1, wherein establishing the anatomical landmarks includes computing a tip of a femoral lesser trochanter point for each of the plurality of bone models of the statistical atlas.

3. The method of claim 1, wherein establishing the anatomical landmarks includes computing a plane marking an edge of a lesser trochanter, tangent to a femoral shaft for each of the plurality of bone models of the statistical atlas.

4. The method of claim 1, wherein establishing the anatomical landmarks includes computing a femoral overall anatomical axis for each of the plurality of bone models of the statistical atlas.

5. The method of claim 1, wherein establishing the anatomical landmarks includes computing a projection of a lesser trochanter point on a femoral overall anatomical axis for each of the plurality of bone models of the statistical atlas.

6. The method of claim 1, wherein establishing the anatomical landmarks includes computing a projection of a lesser trochanter point on a plane marking an edge of a lesser trochanter for each of the plurality of bone models of the statistical atlas.

7. The method of claim 1, wherein establishing the anatomical landmarks includes computing a medial-lateral direction as a vector between a projection of a lesser trochanter point on a femoral overall anatomical axis and the femoral lesser trochanter point for each of the plurality of bone models of the statistical atlas.

8. The method of claim 1, wherein establishing the anatomical landmarks includes computing an anterior-posterior direction as a cross product of a femoral overall anatomical axis and a medial-lateral direction for each of the plurality of bone models of the statistical atlas.

9. The method of claim 1, wherein establishing the anatomical landmarks includes computing a superior inferior direction as a femoral overall anatomical axis direction for each of the plurality of bone models of the statistical atlas.

10. The method of claim 1, wherein establishing the instrument landmarks includes computing a shifted lesser trochanter point as a projection of the lesser trochanter point on a plane marking an edge of the lesser trochanter is shifted 1 millimeter in a medial-lateral direction for each of the plurality of bone models of the statistical atlas.

11. The method of claim 10, wherein establishing the instrument landmarks includes computing a location of a fastener for the mass-customized femoral bone base plate as an intersection of a line pointing along an anterior-posterior direction and passing through the shifted lesser trochanter point for each of the plurality of bone models of the statistical atlas.

12. The method of claim 1, wherein establishing the instrument landmarks includes computing a midpoint between two fasteners for the mass-customized femoral bone base plate to establish a location of a third fastener shifted between zero and ten millimeters in a medial-lateral direction for each of the plurality of bone models of the statistical atlas.

13. The method of claim 1, wherein establishing the instrument landmarks includes computing a location for a fastener for the mass-customized femoral bone base plate that is a closest point on a femoral bone model to a shifted lesser trochanter point for each of the plurality of bone models of the statistical atlas.

14. The method of claim 1, wherein establishing the instrument landmarks includes computing a location of a fastener for the mass-customized femoral bone base plate that is shifted distally in a direction of an anatomical axis for each of the plurality of bone models of the statistical atlas.

15. The method of claim 1, wherein establishing the instrument landmarks includes computing a femoral plate plane as the plane containing at least one fastener location for the mass-customized femoral bone base plate for each of the plurality of bone models of the statistical atlas.

16. The method of claim 1, wherein establishing the instrument landmarks includes computing a direction of a fastener for the mass-customized femoral bone base plate for each of the plurality of bone models of the statistical atlas.

17. The method of claim 16, wherein the direction is taken normal to a femoral plate plane.

18. The method of claim 17, wherein the femoral plate plane is rotated between ten and thirty degrees medially around an axis connecting the location of multiple fasteners for the mass-customized femoral bone base plate.

19. The method of claim 1, wherein establishing the definitions includes defining a reference plane normal to a proximal anatomical axis and a neck axis and passing through an anatomical axis point for each of the plurality of bone models of the statistical atlas.

20-28. -28. (canceled)

29. A femoral base plate assembly comprising:

a plate having a bone contacting surface configured to approximate a topography of an exterior of a femur, the plate including a first plurality of orifices angled with respect to the bone contacting surface and configured to orient a respective fastener in a predetermined angular orientation, the plate including a second plurality of orifices with at least one of the second plurality of orifices being threaded, where each of the orifices extending through the bone contacting surface and through a top surface opposite the bone contacting surface.

30-47. -47. (canceled)