Customized acetabular cup positioning guide and method of generating and employing such a guide

Patent metadata

Field	Value
Publication number	US-9968456-B2
Application number	US-201615178065-A
Country	US
Kind code	B2
Filing date	Jun 9, 2016
Priority date	Mar 15, 2013
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

Implementations described and claimed herein provide an arthroplasty system and methods for positioning an acetabular cup implant. In one implementation, the system includes a shape-match hip guide having a patient specific mating region that is a negative of the surface contour of the inside surface of the patient's acetabular cup, and a directional rod that extends generally along the axis of the patient's femoral head and femoral neck. They system can additionally include an outrigger or silo device to aid in the alignment of surgical tools for preparing and implanting of the prosthetic acetabular cup in the patient's acetabular cup. Related methods are also disclosed herein for generating a shape-match guide and implanting an acetabular cup with the guide.

First claim

What is claimed is:

1. A method of manufacturing a custom acetabular cup positioning guide for use in an arthroplasty procedure on a portion of a hip region of a patient's body, wherein the portion of the hip region includes a patient's acetabular cup, the method of manufacturing comprising:
generating a plurality of two dimensional medical images of the portion of the hip region of the patient's body to undergo the arthroplasty procedure;
identifying landmarks on bone boundaries in the two dimensional medical images;
identifying a hip axis line by triangulating a plurality of the landmarks in the two dimensional medical images;
using a computer processor to generate a three dimensional bone model of the portion of the hip region of the patient's body to undergo the arthroplasty procedure from the plurality of two dimensional medical images, wherein the three dimensional bone model includes a three dimensional model of the patient's acetabular cup;
shape-matching an inside surface of the three dimensional model of the patient's acetabular cup relative to the hip axis line;
generating the custom acetabular positioning guide based upon the identification of the hip axis line and a negative contour of the inside surface of the three dimensional model of the patient's acetabular cup.

2. The method of claim 1 , wherein the custom positioning guide comprises a directional rod that extends generally along the hip axis line when the custom positioning guide matingly interdigitates with an inside surface of the patient's acetabular cup.

3. The method of claim 1 , further comprising generating a three dimensional acetabular cup positioning guide model from the three dimensional bone model.

4. The method of claim 1 , wherein the plurality of medical images are generated from MRI slices or CT slices.

5. The method of claim 1 , wherein identifying landmarks on bone boundaries include a user at a user interface employing at least one of a mouse, keyboard, pen-and-tablet system, touch screen system, or spatial input device to place landmark points.

6. The method of claim 1 , wherein the landmarks identified on the bone boundaries in the two dimensional images comprise a left teardrop and a right teardrop of a pelvis, a right anterior-superior ilium symphysis (“ASIS-R”), a left anterior-superior ilium symphysis (“ASIS-L”), and a pubic symphysis.

7. The method of claim 6 , wherein the landmarks are identified in a coronal image slice.

8. The method of claim 6 , wherein the plurality of landmarks used in triangulation in the two dimensional images include the ASIS-R, the ASIS-L, and the pubic symphysis.

9. The method of claim 8 , wherein identifying the hip axis line further comprises identifying a pelvic axis line in the two dimensional images that extends through the left teardrop and the right teardrop of the pelvis.

10. The method of claim 9 , further comprising determining an acute first angle between the pelvic axis line and a first line that extends through the pubic symphysis and either the ASIS-R or ASIS-L, wherein the first line will extend through the ASIS-R if a right hip region is to undergo the arthroplasty procedure and the first line will extend through the ASIS-L if a left hip region is to undergo the arthroplasty procedure.

11. The method of claim 10 , further comprising identifying a second angle by increasing the first angle by a surgically prescribed degree, rotated downward from the first line, wherein the second angle is coextensive with a hip axis angle, whereby the hip axis angle is defined between the first line and the hip axis line.

12. The method of claim 11 , wherein the surgically prescribed degree is about forty-five degrees.

13. A method of manufacturing a custom acetabular cup positioning guide for use in an arthroplasty procedure involving a hip region of a patient's body, wherein the hip region includes the patient's femoral head, femoral neck and acetabular cup, the guide including a mating region configured to matingly receive a portion of the patient's acetabular cup, the mating region including a surface contour that is generally a negative of a surface contour of the patient's acetabular cup, the surface contour of the mating region being configured to mate with the surface contour of the patient's acetabular cup in a generally matching or interdigitating manner when the patient's acetabular cup is matingly received by the mating region, the method of manufacture comprising:
a) generating medical imaging slices of the portion of the patient bone;
b) identifying landmarks on bone boundaries in the medical imaging slices;
c) identifying a hip axis line, the hip axis line being generally collinear with an axis of the patient's femoral head and femoral neck in a preoperative state, wherein the identifying the hip axis line comprises triangulating landmarks on the bone boundaries in the medical imaging slices;
d) using a computer processor to generate a three dimensional bone model of the patient's acetabular cup;
e) shape-matching an inner surface of the three dimensional bone model of the patient's acetabular cup relative to the bone axis line;
f) using data associated with the inner surface of the three dimensional model of the patient's acetabular cup to manufacture the custom acetabular cup positioning guide.

14. The method of claim 13 , wherein the medical imaging slices are generated from MRI slices or CT slices.

15. The method of claim 14 , wherein the landmarks identified on the bone boundaries in the medical imaging slices include a left teardrop and a right teardrop of a pelvis, a right anterior-superior ilium symphysis (“ASIS-R”), a left anterior-superior ilium symphysis (“ASIS-L”), and a pubic symphysis.

16. The method of claim 15 , wherein the landmarks are identified in a coronal image slice.

17. The method of claim 15 , wherein the landmarks used in triangulation in the two dimensional images include the ASIS-R, the ASIS-L, and the pubic symphysis.

18. The method of claim 16 , wherein identifying the hip axis line further comprises identifying a pelvic axis line in the two dimensional images that extends through the left teardrop and the right teardrop of the pelvis.

19. The method of claim 18 , further comprising determining an acute first angle between the pelvic axis line and a first line that extends through the pubic symphysis and either the ASIS-R or ASIS-L, wherein the first line will extend through the ASIS-R if a right hip region is to undergo the arthroplasty procedure and the first line will extend through the ASIS-L if a left hip region is to undergo the arthroplasty procedure.

20. The method of claim 19 , further comprising identifying a second angle by increasing the first angle by a surgically prescribed degree, rotated downward from the first line, wherein the second angle is coextensive with a hip axis angle, whereby the hip axis angle is defined between the first line and the hip axis line.

21. The method of claim 20 , wherein the surgically prescribed degree is about forty-five degrees.

Assignees

• Howmedica Osteonics Corp

Inventors

• Song keun

Classifications

• Y10T29/49002

  Electrical device making · CPC title

• A61F2002/4687

  Mechanical guides for implantation instruments · CPC title

• A61F2002/30952

  using CAD-CAM techniques or NC-techniques · CPC title

• A61F2002/30948

  using computerized tomography, i.e. CT scans · CPC title

• A61F2/4609 Primary

  of acetabular cups · CPC title