Customized arthroplasty cutting guides and surgical methods using the same

Patent metadata

Field	Value
Publication number	US-2016302806-A1
Application number	US-201615195639-A
Country	US
Kind code	A1
Filing date	Jun 28, 2016
Priority date	Oct 11, 2012
Publication date	Oct 20, 2016
Grant date	—

Abstract

Implementations described and claimed herein provide an arthroplasty system for making resections in a patient knee. In one implementation, the system includes a femoral cutting guide having a patient specific mating region, and a distal planar surface distally spaced from a distal resection surface based on thicknesses of femoral and tibial implants. The distal planar surface may be used to check ligament balance. The system further includes a tibial cutting guide having a patient specific mating region and a an anchor pin hole intersecting with a proximal resection slot near a medial or lateral edge of the proximal resection slot. The anchor pin hole being configured to receive an anchor pin that may serve as a sawing stop during a proximal resection.

First claim

1 . An arthroplasty system for making resections in a knee region of a patient tibia in preparing a patient knee for the implantation of a tibial implant, the knee region including surface topography including surface contours of a tibial plateau surface including a medial and lateral surface, the arthroplasty system comprising:
a) a unicompartmental cutting guide configured to facilitate resections in one of the medial or lateral surface of the tibial plateau and comprising:
i) a patient specific mating region custom configured to interdigitate with a portion of the surface topography of the knee region and comprising surface contours that are a general negative image of the surface contours of the one of the medial or lateral surface of the tibial plateau surface;
ii) a proximal resection slot comprising an exterior opening defined in an exterior anterior surface of the cutting guide, the proximal resection slot extending anterior-posterior and medial-lateral in the cutting guide and configured to guide a proximal resection in the knee region when the patient specific mating region interdigitates with the portion of the surface topography of the knee region such that the surface contours of the mating region make corresponding surface contact with the surface contours of the one of the medial or lateral surface of the tibial plateau surface; and
iii) an anchor pin hole comprising an exterior opening defined in the exterior anterior surface of the cutting guide, the anchor pin hole extending generally anterior-posterior through the cutting guide and intersecting the proximal resection slot near a medial or lateral edge of the proximal resection slot; and
b) an anchor pin comprising an elongated shaft configured to be received in the anchor pin hole in securing the cutting guide to the patient tibia.

2 . The arthroplasty system of claim 1 , wherein the anchor pin hole defines the medial or lateral edge of the proximal resection slot.

3 . The arthroplasty system of claim 1 , wherein the anchor pin hole is substantially coplanar with the proximal resection slot.

4 . The arthroplasty system of claim 1 , wherein the anchor pin hole includes a longitudinal center axis that is substantially centered distal-proximal relative to a distal-proximal thickness of the proximal resection slot.

5 . The arthroplasty system of claim 1 , wherein, when the anchor pin is received in the anchor pin hole, the anchor pin serves as a sawing stop.

6 . The arthroplasty system of claim 1 , wherein the anchor pin is harder and more saw resistant than a material of the cutting guide bordering the proximal resection slot.

7 . The arthroplasty system of claim 6 , wherein the anchor pin is formed of a metal or a ceramic.

8 . The arthroplasty system of claim 7 , wherein the material of the cutting guide bordering the proximal resection comprises a polymer.

9 . The arthroplasty system of claim 1 , further comprising a vertical resection slot comprising an exterior opening defined in an exterior proximal surface of the cutting guide, the vertical resection slot extending anterior-posterior and distal-proximal in the cutting guide and configured to guide a vertical resection in the knee region when the patient specific mating region interdigitates with the portion of the topography of the knee region such that the surface contours of the mating region make corresponding surface contact with the surface contours of the one of the medial or lateral surface of the tibial plateau surface.

10 . The arthroplasty system of claim 9 , wherein the anchor pin hole is substantially coplanar with the vertical resection slot but the anchor pin hole and vertical resection slot do not intersect.

11 . The arthroplasty system of claim 9 , wherein the anchor pin hole includes a longitudinal center axis that is substantially centered medial-lateral relative to a medial-lateral thickness of the vertical resection slot.

12 . The arthroplasty system of claim 1 , wherein the elongated shaft is configured to be received in the anchor pin hole in an interference fit.

13 . A method of performing a unicompartmental knee arthroplasty, the method comprising:
a) place a unicompartmental tibia cutting guide on a medial or lateral surface of a tibial plateau of a patient tibia, the unicompartmental tibia cutting guide comprising: i) a patient specific mating region custom configured to interdigitate with a portion of a surface topography of the medial or lateral surface of the tibial plateau and comprising surface contours that are a general negative image of surface contours of the medial or lateral surface of the tibial plateau; ii) a proximal resection slot comprising an exterior opening defined in an exterior anterior surface of the unicompartmental tibia cutting guide, the proximal resection slot extending anterior-posterior and medial-lateral in the unicompartmental tibia cutting guide; and iii) an anchor pin hole comprising an exterior opening defined in the exterior anterior surface of the unicompartmental tibia cutting guide, the anchor pin hole extending generally anterior-posterior through the unicompartmental tibia cutting guide and intersecting the proximal resection slot near a medial or lateral edge of the proximal resection slot; b) cause the patient specific mating region to interdigitate with the topography of the medial or lateral surface of the tibial plateau; c) insert an anchor pin into the patient tibia via the anchor pin hole such that the anchor pin is present within both the anchor pin hole and the patient tibia; and d) with the mating region interdigitated with the topography of the medial or lateral surface of the tibial plateau, make a proximal resection of the patient tibia via the proximal resection slot.

14 . The method of claim 13 , further comprising using the anchor pin present in both the anchor pin hole and the patient tibia as a sawing stop when making the proximal resection.

15 . The method of claim 13 , wherein the anchor pin hole defines the medial or lateral edge of the proximal resection slot.

16 . The method of claim 13 , wherein the anchor pin hole is substantially coplanar with the proximal resection slot.

17 . The method of claim 13 , wherein the anchor pin hole includes a longitudinal center axis that is substantially centered distal-proximal relative to a distal-proximal thickness of the proximal resection slot.

18 . The method of claim 13 , wherein the tibia cutting guide further comprises a vertical resection slot comprising an exterior opening defined in an exterior proximal surface of the cutting guide, the vertical resection slot extending anterior-posterior and distal-proximal in the cutting guide, the method further comprising at least beginning a vertical resection in the patient tibia via the vertical resection slot when the mating region is interdigitated with the topography of the medial or lateral surface of the tibial plateau.

19 . The method of claim 18 , wherein the anchor pin hole is substantially coplanar with the vertical resection slot but the anchor pin hole and vertical resection slot do not intersect.

20 . The method of claim 18 , wherein the anchor pin hole includes a longitudinal center axis that is substantially centered medial-lateral relative to a medial-lateral thickness of the vertical resection slot.

21 . The method of claim 18 , wherein at least beginning a vertical resection in the patient tibia via the vertical resection slot comprises scoring a vertical resection

Assignees

• Howmedica Osteonics Corp

Inventors

• Song keun

Classifications

• A61B2017/568

  produced with shape and dimensions specific for an individual patient · CPC title

• A61B17/157 Primary

  Cutting tibia · CPC title

• A61B17/1764 Primary

  for the knee · CPC title

• F04C2270/041

  Controlled or regulated · CPC title