Patient-specific pelvic implants for acetabular reconstruction

• US 9,427,320 B2
• Filed: 11/27/2013
• Issued: 08/30/2016
• Est. Priority Date: 08/04/2011
• Status: Active Grant

• Current Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Inventors: Meridew, Jason
• Primary Examiner(s): Willse, David H
• Assistant Examiner(s): BLANCO, JAVIER G
• Application Number:
  US14/091,526
• Publication Number:
  US 20140088724A1
• Time in Patent Office: 1,007 Days
• Field of Search: 623/22.21, 623/22.38, 623/22.11, 623/22.15, 623/22.22, 623/22.32, 623/22.35, 623/22.36
• US Class Current: 1/1
• CPC Class Codes: A61F 2/30734 Modular inserts, sleeves or augments, e.g. placed on proximal part of stem for fixation purposes or wedges for bridging a bone defect
• 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 2/34 Acetabular cups
• CPC Class Codes: A61F 2002/30131 horseshoe- or crescent- or C-shaped or U-shaped
• CPC Class Codes: A61F 2002/30156 triangular
• CPC Class Codes: A61F 2002/30176 V-shaped
• CPC Class Codes: A61F 2002/30281 wedge-shaped
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/30576 with extending fixation tabs
• CPC Class Codes: A61F 2002/30578 having apertures, e.g. for receiving fixation screws
• CPC Class Codes: A61F 2002/30736 Augments or augmentation pieces, e.g. wedges or blocks for bridging a bone defect
• CPC Class Codes: A61F 2002/30948 using computerized tomography, i.e. CT scans
• CPC Class Codes: A61F 2002/3401 with radial apertures, e.g. radial bores for receiving fixation screws
• CPC Class Codes: A61F 2002/3403 Polar aperture
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing

Abstract

A pelvic implant includes a first surface including a recess configured for receiving a portion of a flange of an acetabular cage and a patient-specific second surface opposite to the first surface. The patient-specific second surface is preoperatively configured from a three-dimensional digital image of a pelvis of a patient to mate and closely conform to a corresponding surface of the pelvis under the flange in only one position.

Claims

1. A pelvic implant system comprising:

an acetabular cage implantable into a pelvis of a patient, the acetabular cage including an acetabular cup and a plurality of flanges coupled to an upper portion of the acetabular cup; and

a plurality of patient-specific spacers, wherein each patient-specific spacer comprises first and second opposing surfaces, a peripheral surface located between and to space apart the first and second surfaces, wherein the first surface has a recess configured to receive a complementary-shaped portion of a corresponding flange of at least one flange of the plurality of flanges, wherein the second surface defines a patient-specific bone-engaging surface preoperatively configured from a three-dimensional digital image of the pelvis of the patient to complementary mate and closely conform to a surface of the pelvis under the flange in only one position,

wherein at least one flange of the plurality of flanges includes an iliac flange and at least one spacer of the plurality of spacers includes an iliac spacer couplable to said iliac flange, the iliac spacer having a thickness that is determined during a preoperative plan according to an anatomy of the pelvis of the patient and a selected location for the iliac flange, and wherein the thickness of the iliac spacer is selected to be greater than a thickness of the iliac flange and a surface area of the iliac spacer is selected to be greater than a surface area of the iliac flange so as to provide reinforcement to the iliac flange such that the iliac flange is configured not to intraoperatively bend, either by itself or by a surgeon, when engaged to the pelvis,

wherein the patient-specific bone-engaging surface of the iliac spacer is preoperatively configured to have a mirror surface that complementary mates and closely conforms to an iliac surface of the pelvis under the iliac flange in only one position,

wherein another flange of the plurality of flanges is an ischial flange and another of the plurality of spacers is an ischial spacer couplable to said ischial flange, wherein the recess of the ischial spacer has a shape different from the shape of the recess of the iliac spacer, and

wherein the thickness of each patient-specific spacer of the plurality of patient specific spacers differs from that of the other patient-specific spacers such that the plurality of patient-specific spacers has a variable thickness.

2. The pelvic implant system of claim 1, wherein the peripheral surface includes a ridge surrounding the recess that is elevated relative to the first surface.

3. The pelvic implant system of claim 1, wherein at least the iliac flange includes a substantially square shape or square-like.

4. The pelvic implant system of claim 3, wherein the recess of the iliac spacer has an elongated rectangular shape.

5. The pelvic implant system of claim 3, wherein the recess of the iliac spacer has a square shape.

6. The pelvic implant system of claim 3, wherein the recess of the ischial spacer has a triangular shape.

7. The pelvic implant system of claim 1, wherein at least one flange of the plurality of flanges is removably coupled to the acetabular cup.

8. The pelvic implant system of claim 7, wherein the at least one flange of the plurality of flanges that is removably coupled to the acetabular cup is an ischial blade modularly coupled to the acetabular cup.

9. The pelvic implant system of claim 1, further comprising:

an obturator foramen hook modularly coupled to the acetabular cup.

10. The pelvic implant system of claim 1, wherein the iliac spacer includes a plurality of iliac spacers each having a mirror surface, wherein the thickness between the first and second opposing surfaces of each iliac spacer of the plurality of iliac spacers differ from that of the other iliac spacers due to the mirror surfaces such that the plurality of iliac spacers has a variable thickness.

11. A pelvic implant system comprising:

an acetabular cage implantable into a pelvis of a patient, the acetabular cage including an acetabular cup and a plurality of flanges coupled to the acetabular cup; and

a plurality of patient-specific spacers, wherein each patient-specific spacer has an elevated ridge that at least partially surrounds a recess surface that is recessed relative to an upper edge of the elevated ridge for receiving a complementary-shaped portion of one corresponding flange of the plurality of flanges, wherein each patient specific spacer further has a patient-specific bone-engaging surface that is designed and preoperatively configured based on a three-dimensional digital image of at least a portion of the pelvis of the patient to complementary mate and closely conform to a corresponding surface of the pelvis under one flange of the plurality of flanges in only one position;

wherein at least one flange of the plurality of flanges includes an iliac flange and at least one spacer of the plurality of spacers includes an iliac spacer couplable to said iliac flange;

wherein at least one flange of the plurality of flanges, at least one spacer of the plurality of spacers, or a combination thereof is designed and preoperatively configured based on the three-dimensional digital image of at least the portion of the pelvis of the patient to mate and closely conform to the corresponding surface of the pelvis under the flange in only one position, the at least one spacer having a thickness that is determined during a preoperative plan according to an anatomy of the pelvis of the patient and a selected location for the at least one of the plurality of flanges,

wherein the thickness of the iliac spacer is selected to be greater than a thickness of the iliac flange and a surface area of the iliac spacer is selected to be greater than a surface area of the iliac flange so as to provide reinforcement to the iliac flange such that the iliac flange does not intraoperatively bend, either by itself or by a surgeon, when engaged to the pelvis,

wherein at least one flange of the plurality of flanges is a patient-specific flange modularly coupled to the acetabular cup and having a patient-specific surface preoperatively configured from a three-dimensional digital image of the pelvis of the patient to mate and closely conform as a negative to a corresponding surface of the pelvis under the flange in only one position,

wherein another flange of the plurality of flanges is an ischial flange and another of the plurality of spacers is an ischial spacer couplable to said ischial flange, wherein the recess of the ischial spacer has a shape different from the shape of the recess of the iliac spacer, and

wherein the thickness of each patient-specific spacer of the plurality of patient specific spacers differs from that of the other patient-specific spacers such that the plurality of patient-specific spacers has a variable thickness.

12. The pelvic implant system of claim 11, wherein at least one flange is removably coupled to the acetabular cup.

13. The pelvic implant system of claim 11, wherein each patient-specific spacer of the plurality of patient-specific spacers includes a differently shaped perimeter.