Patient specific instrumentation (PSI) for orthopedic surgery and systems and methods for using X-rays to produce same

• US 10,716,579 B2
• Filed: 03/08/2018
• Issued: 07/21/2020
• Est. Priority Date: 09/25/2013
• Status: Active Grant

• Current Assignee: Zimmer Incorporated (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Zimmer Incorporated (Zimmer Biomet Holdings, Inc.)
• Inventors: Couture, Pierre, Nguyen, Trong Tin, Neurohr, Anselm Jakob, Merette, Jean-Sebastien
• Primary Examiner(s): Gibson, Eric S
• Application Number:
  US15/915,619
• Publication Number:
  US 20180193035A1
• Time in Patent Office: 866 Days
• Field of Search: 606 86 R- 89
• CPC Class Codes: A61B 17/154 for preparing bone for knee prosthesis
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61B 17/157 Cutting tibia
• CPC Class Codes: A61B 17/1764 for the knee
• CPC Class Codes: A61B 2017/568 produced with shape and dimensions specific for an individual patient
• 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: G16H 50/50 for simulation or modelling of medical disorders

Abstract

A method of creating a patient specific instrument (PSI) for use in knee replacement surgery is described which includes performing at least two two-dimensional X-ray scans of a bone, each of the X-ray scans being taken from different angular positions, generating a digital bone model of the bone based on the X-ray scans, planning the PSI based on the digital bone model, including determining locations for one or more anchor points on the PSI which are adapted to abut a surface of the bone, the determined locations of the anchor points being disposed on the PSI at locations corresponding to areas of expected high accuracy on the digital bone model generated by the X-ray scans. The areas of expected high accuracy include at least a peripheral bone contour in at least one of the angular position of the X-ray scans. A suite of such PSI instruments is also described.

Claims

1. A patient specific system for knee replacement surgery, the patient specific system comprising:

a surgical guide adapted to be positioned on a bone;

a digital bone model of the bone generated using at least two two-dimensional X-ray scans of the bone taken from different angular positions; and

a patient specific instrument for positioning the surgical guide on the bone, the patient specific instrument formed based on the digital bone model, the patient specific instrument including;

a body having fastener guide holes, the fastener guide holes adapted to receive fasteners therein used to fasten the surgical guide to the bone; and

one or more anchor elements on the body adapted to abut one or more surfaces of the bone, the anchor elements being disposed in locations on the body of the patient specific instrument overlying a peripheral bone contour of the bone in at least one of the two-dimensional X-ray scans, said locations and the peripheral bone contour corresponding to areas of expected high accuracy on the digital bone model generated by the two-dimensional X-ray scans.

2. The patient specific system of claim 1, wherein the patient specific instrument includes a patient specific pin guide adapted for aligning bone pins on the bone, the bone pins being operable to mount the surgical guide thereto.

3. The patient specific system of claim 2, wherein the patient specific instrument has at least three of said anchor elements thereon.

4. The patient specific system of claim 3, wherein the at least three anchor elements include two bone spikes spaced apart in a medial-lateral direction.

5. The patient specific system of claim 4, wherein the patient specific instrument includes one of a tibial pin guide and a femoral pin guide, the bone spikes of the tibial pin guide being located on a proximal end of the tibial pin guide, and the bone spikes of the femoral pin guide being located on a distal end of the femoral pin guide.

6. The patient specific system of claim 5, wherein the tibial pin guide includes a distally located jack screw forming one of said anchor elements and adapted to abut an anterior surface of the tibia.

7. The patient specific system of claim 5, wherein the femoral pin guide includes an anteriorly extending blade on a proximal end thereof, the anteriorly extending blade forming one of said anchor elements and adapted to abut an anterior surface of the femur.

8. The patient specific system of claim 1, further comprising an extra-medullary guide mounted to the body, the extra-medullary guide including an elongated rigid alignment rod extending distally from the body and having a malleoli clamping element at a distal end thereof.

9. The patient specific system of claim 1, wherein the one or more anchor elements include a posterior abutting element disposed behind the body of the patient specific instrument, the posterior abutting element forming one of said anchor elements.

10. The patient specific system of claim 1, further comprising a hip-knee-ankle instrument including a tibia engaging portion and a femur engaging portion, each having a body having a pair of said fastener guide holes extending therethrough and one or more of said anchor elements thereon.

11. The patient specific system of claim 10, further comprising an extra-medullary guide mounted to the body of the tibia engaging portion, the extra-medullary guide including an elongated rigid alignment rod extending distally from the body and having a malleoli clamping element at a distal end thereof.

12. The patient specific system of claim 1, wherein the surgical guide is a resection cutting guide.

13. The patient specific system of claim 1, further comprising a pair of arms extending posteriorly from the body, each of the arms having one of the anchor elements disposed near a remote end thereof, said one of the anchor elements forming a posterior anchor of the patient specific instrument.

14. The patient specific system of claim 1, wherein the surgical guide and the body of the patient specific instrument are removably attached to each other.

15. The patient specific system of claim 1, wherein the surgical guide and the patient specific instrument are integrally formed.

16. The patient specific system of claim 1, further comprising an optical positioning element operable to position the patient specific instrument relative to the bone.

17. The patient specific system of claim 1, wherein the fastener guide holes comprise a pair of pin guide holes extending through the body.

18. The patient specific system of claim 1, wherein the two-dimensional X-ray scans are taken from substantially perpendicular positions, said locations on the body of the anchor elements corresponding to points on the peripheral bone contours in at least one of a frontal position and a medial or lateral position.

19. The patient specific system of claim 1, wherein the patient specific instrument is integrally formed of a material produced by additive manufacturing.

20. A patient specific instrument for knee replacement surgery, the patient specific instrument comprising:

a digital bone model of a bone generated using at least two two-dimensional X-ray scans of the bone taken from different angular positions, the digital bone model including a peripheral bone contour defined in at least one of the X-ray images;

an instrument body having fastener guide holes, the fastener guide holes adapted to receive fasteners therein used to fasten the surgical guide to a bone; and

one or more anchor elements on the instrument body adapted to abut the bone, the anchor elements being disposed in locations on the instrument body of the patient specific instrument overlying the peripheral bone contour of the digital bone model, said locations on the instrument body corresponding to areas of expected high accuracy on the digital bone model.