Patient specific guide for acetabular reamer and impactor

Patent metadata

Field	Value
Publication number	US-2021059837-A1
Application number	US-201916559756-A
Country	US
Kind code	A1
Filing date	Sep 4, 2019
Priority date	Sep 4, 2019
Publication date	Mar 4, 2021
Grant date	—

Abstract

A customized patient-specific orthopaedic instrument for facilitating implantation of an acetabular cup prosthesis in a coxal bone of a patient and method of use is disclosed. The customized patient-specific orthopaedic instrument includes a customized patient-specific acetabular guide. The customized patient-specific acetabular guide includes a longitudinal passageway for an acetabular reamer and/or an impactor and a plurality of arms with attached mounting pads. Each pad of the guide is positioned relative to the body based on the contours of the coxal bone of the patient and a predetermined degree of anteversion and inclination angles of the acetabular cup prosthesis when implanted in the patient's coxal bone.

First claim

1 . An acetabular guide assembly comprising:
a generic guide member that includes a guide body and a passageway extending through the guide body along a central axis; at least one additively manufactured mounting pad defining a top surface and a bottom surface opposite the top surface, wherein the bottom surface has a patient-specific positive contour that matches a negative contour surface of a coxal bone proximate to an acetabulum; a plurality of arms that are configured to extend from the guide body to the at least one mounting pad, so as to support the guide member relative to the at least one mounting pad at a predetermined position and orientation, wherein the central axis has a predetermined relationship with respect to planes of anteversion and inclination, wherein the at least one mounting pad includes a plurality of coupling members that are each configured to couple to at least one of the plurality of arms, and an entirety of the mounting pad is seamless.

2 . The acetabular guide assembly of claim 1 , wherein the at least one mounting pad comprises a plurality of mounting pads whose bottom surface, respectively, is contoured so to fit onto a unique portion of the coxal bone.

3 . The acetabular guide assembly of claim 2 , wherein the coupling members have a predetermined spatial relationship with each other such that the central axis of the guide member supported by the mounting pads has the predetermined relationship with respect to the planes of anteversion and inclination.

4 . The acetabular guide assembly of claim 3 , wherein the upper surfaces of the mounting pads are substantially coplanar with each other when coupled to the arms, respectively, that in turn are coupled to the guide member.

5 . The acetabular guide assembly of claim 2 , wherein the mounting pads and arms define respective keyed surfaces, such that each of the mounting pads is configured to be coupled to a respective one of the arms and no other arm, wherein the keyed surfaces allow each of mounting pads to couple to the respective one of the arms in a predetermined orientation, and prevent each of the mounting pads from coupling to the respective one of the arms in any orientation other than the predetermined orientation.

6 . The acetabular guide assembly of claim 1 , wherein the at least one mounting pad comprises a single monolithic mounting pad that includes the plurality of coupling members and at least one patient-specific contour at its bottom surface.

7 . The acetabular guide assembly of claim 1 , wherein the at least one additively manufactured mounting pad comprises a plurality of mounting pads, and each of the mounting pads is uniquely keyed to a corresponding one of the arms so as to be located at a first predetermined location and oriented in a first predetermined orientation.

8 . The acetabular guide assembly of claim 1 , further comprising a tool shaft that is sized to be received in the passageway, and configured to rotate and translate in the passageway.

9 . An acetabular implantation system comprising:
the acetabular guide assembly of claim 8 ; and at least one of a reamer and an impactor that are configured to selectively couple to the tool shaft.

10 . The acetabular implantation system of claim 9 , wherein the tool shaft further comprises a stop member that is configured to abut the guide member so as to limit translation of the tool shaft in the passageway.

11 . First and second acetabular guide assemblies, each comprising:
a guide body that defines a longitudinal passageway, wherein the guide body of the first acetabular guide assembly is substantially identical to the guide body of the second acetabular guide assembly; a plurality of additively manufactured mounting pads each having respective patient-specific positive contours that match corresponding negative contoured surfaces at unique locations of a coxal bone proximate to an acetabulum, wherein the patient-specific positive contours of the mounting pads of the first acetabular guide assembly are all different than the patient-specific positive contours of the mounting pads of the second acetabular guide assembly; and a plurality of arms configured to extend from the guide body to the plurality of mounting pads, wherein the arms of the first acetabular guide assembly are configured to support the guide body of the first acetabular guide assembly at a first predetermined location and orientation with respect to the acetabulum of a first patient, and the arms of the second acetabular guide assembly are configured to support the guide body of the second acetabular guide assembly at a second predetermined location and orientation with respect to the acetabulum of a second patient.

12 . The first and second acetabular guide assemblies of claim 11 , wherein each of the mounting pads of the first acetabular guide assembly is uniquely keyed to a corresponding one of the arms of the first acetabular guide assembly so as to be located at a first predetermined location and oriented in a first predetermined orientation, and
wherein each of the mounting pads of the second acetabular guide assembly is uniquely keyed to a corresponding one of the arms of the second acetabular guide assembly so as to be located at a second predetermined location and oriented in a second predetermined orientation.

13 . The first and second acetabular guide assemblies of claim 12 , each further comprising a tool shaft configured to rotate and translate in a passageway of the guide body, the tool shaft further configured to selectively couple to a reamer and an impactor.

14 . The first and second acetabular guide assemblies of claim 13 , wherein the tool shaft comprises a stop member configured to abut the guide body so as to limit translation of the tool shaft in the passageway.

15 . A method for preparing an acetabulum for an implantation of an acetabular prosthesis, the method comprising:
fitting a bottom surface of at least one additively manufactured mounting pad onto a preplanned portion of a coxal bone proximate to the acetabulum, such that a guide member is supported relative to the at least one mounting pad at a predetermined location and orientation with respective to planes of anteversion and inclination; and inserting a tool shaft through the passageway, and rotating the tool shaft about the central axis so as to ream the acetabulum with a reamer attached to the tool shaft.

16 . The method of claim 15 , further comprising the step of guiding the tool shaft to rotate about the central axis during the rotating step.

17 . The method of claim 15 , further comprising the steps of:
removing the reamer from the tool shaft; and attaching an impactor to the tool shaft, wherein the impactor is translatable along the central axis so as to drive the acetabular prostheses into the acetabulum.

18 . The method of claim 15 , wherein the fitting step comprises fitting multiple contours onto respective unique predetermined locations of the coxal bone.

19 . The method of claim 18 , wherein the at least one additively manufactured mounting pad comprises a plurality of additively manufactured mounting pads, the method further comprising the step of coupling each of the plurality of additively manufactured mounting pads to the respective one of a plurality of arms in a predetermined orientation while preventing each of the plurality of additively manufactured mounting pads from being coupled to the respective one of the plurality of arms in any orientation other than the predetermined orientation

Assignees

• Depuy Synthes Products Inc

Inventors

• Rhodes James M

Classifications

• A61B2034/105

  Modelling of the patient, e.g. for ligaments or bones · CPC title

• A61B2034/108

  Computer aided selection or customisation of medical implants or cutting guides · CPC title

• A61B34/10

  Computer-aided planning, simulation or modelling of surgical operations · CPC title

• A61B17/1666

  for the acetabulum · CPC title

• A61B17/1746

  for the acetabulum · CPC title