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Implant based planning, digitizing, and registration for total joint arthroplasty

a technology of total joint arthroplasty and implant based planning, applied in the direction of joint implants, bone drill guides, prosthesis, etc., can solve the problems of rtjr being a difficult and long procedure, requiring replacement, and limited life expectancy of replacement implants used in joint replacement surgeries

Active Publication Date: 2021-02-11
THINK SURGICAL
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The patent describes a method for removing a joint replacement implant that is attached to bone during revision surgery. This method involves collecting surface points on the implant using a digitizer and finding the best match between those points and a library of implant models to register the position of the implant. The method also includes computing the location of the material-implant interface based on the implant model and the registered position of the implant model, and then removing material at the interface to separate the implant from the bone. The patent also describes a computer-assisted surgical system that can help with the method. The technical effect of the patent is to provide a safe and effective way to remove joint replacement implants during revision surgery.

Problems solved by technology

The replacement implants used in joint replacement surgeries have a limited life expectancy and will sometimes need to be replaced.
RTJR is known to be a difficult and lengthy procedure because the surgeon typically has a limited amount of information about the location and amount of bone cement from the previous TJR.
However, these tools can be tedious to use, especially when trying to remove bone cement from deeper cavities or small holes.
Additionally, these tools present a risk of fracturing the bone when removing the implant or the bone cement.
To increase visibility of the bone cement and bone-implant interface, holes or windows may be cut or drilled into the bone; however, these procedures have the propensity to weaken the bone and increase the risk of later fracture.
Revision joint arthroplasty is a technically difficult procedure that often presents intraoperative challenges.
For example, difficulties in removing the previous implant or the bone cement may result in an excess removal of healthy bone.
Additionally, the bone structure may be damaged from the tools and the length of time required to adequately remove all of the bone cement, may put the patient's safety at risk.

Method used

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  • Implant based planning, digitizing, and registration for total joint arthroplasty
  • Implant based planning, digitizing, and registration for total joint arthroplasty
  • Implant based planning, digitizing, and registration for total joint arthroplasty

Examples

Experimental program
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Effect test

example 1

TKR Procedure (Restore Current Implant's Joint Line)

[0032]In an implementation of an embodiment of the inventive method for a revision TKR procedure to restore the joint line of the patient's current implant, the procedure is carried out in a three-step protocol which includes a pre-operative protocol, intraoperative protocol: registration, and intraoperative protocol: surgical procedure.

[0033]An embodiment of the pre-operative protocol of the inventive embodiment for the revision TKR includes the steps of: acquiring a CT scan of the operative bones with the installed implants; segmenting the installed implant from the volumetric data; segmenting the bone outside the implant region (this is for pre-operative planning only and is not required intraoperatively); determining the implant make / model / size, and registering the manufacturer's 3D model to the segmented implant in the patient, thus providing a transformation matrix between manufacturer's 3D model and the patient's DICOM data....

example 2

TKR Procedure (New Joint Line Perpendicular to Mechanical Axis)

[0036]In an implementation of an embodiment of the inventive method for a revision TKR to make a new joint line perpendicular to the mechanical axis, the procedure may be carried out in a three-step protocol that includes a pre-operative protocol, intraoperative protocol: registration, and intraoperative protocol: surgical procedure.

[0037]An embodiment of the pre-operative protocol of the inventive embodiment for the revision TKR includes: acquiring a CT scan of the bone with the installed implant; segmenting the installed implant; segmenting the bone outside the implant region: pre-operative planning only, and not required intraoperatively; determining the implant make / model / size, and registering the manufacturer's 3D model to the segmented implant in the patient, thus providing a transformation matrix between manufacturer's 3D model and the patient's DICOM data. The implant may be determined automatically by determinin...

example 3

THR Procedure

[0040]In an implementation of an embodiment of the inventive method for revision THR to restore a hip implant, the procedure may be carried out in protocol steps that include a pre-operative protocol, and an intraoperative protocol: with registration and surgical procedures.

[0041]An embodiment of the pre-operative protocol of the inventive embodiment for the revision THR includes the steps of: acquiring a CT scan of the bone with the installed implant; segmenting the installed implant; segmenting the bone outside the implant region: for pre-operative planning only, and not required intraoperatively; determining the implant make / model / size, and registering the manufacturer's 3D model to the segmented implant in the patient, thus providing a transformation matrix between manufacturer's 3D model and the patient's DICOM data. The implant may be determined automatically by determining which implant make, model, and size best matches the segmented implant, or the implant may ...

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PUM

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Abstract

A method for removing an implant attached to a bone during revision joint replacement surgery includes a library of implant models. A series of surface points are collected on the implant with a digitizer. A best match is computed between the collected surface points and an implant model in the library of implant models to register the position of the implant model to the implant. A location is computed of a material-implant interface based on the geometry of the implant model and the registered position of the implant model. Material is removed at the material-implant interface to separate the implant from the bone. A computer-assisted surgical system is provided for performing the method.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation-in-part of U.S. Nonprovisional application Ser. No. 16 / 215,055 filed 10 Dec. 2018, that in turn is a continuation of U.S. Nonprovisional application Ser. No. 15 / 532,284, filed 1 Jun. 2017, now US Patent Application No. 10,194,991, issued 5 Feb. 2019; that in turn is a US national phase filing of PCT / US2015 / 064258 filed 7 Dec. 2017; and in turn claims priority benefit of U.S. Provisional Application Ser. No. 62 / 088,896 filed 8 Dec. 2014; the contents of which are hereby incorporated by reference.FIELD OF THE INVENTION[0002]The present invention relates generally to the field of computer-aided surgical systems, and more specifically to a new and useful method for performing computer-aided total joint arthroplasty.BACKGROUND OF THE INVENTION[0003]Total joint replacement (TJR) (also called primary total joint arthroplasty) is a surgical procedure in which the articulating surfaces of a joint are replaced wit...

Claims

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Application Information

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IPC IPC(8): A61B34/10A61B34/20A61B34/30A61B17/15A61B17/16A61B17/17A61F2/38
CPCA61B34/10A61B34/20A61B34/30A61B17/154A61B17/1675A61F2002/3069A61B17/1764A61F2/389A61B17/15A61B2034/102A61B17/1703A61F2002/4632A61B2034/104A61B2034/2055A61B2034/2059A61B2090/064A61B2090/066A61F2002/4633A61F2002/4619A61F2002/4631A61F2/46A61F2/3662A61F2/3859A61B2034/105A61B2034/2068A61B2034/2051A61B2034/2063A61B34/32A61F2/32A61F2002/3895
Inventor BONNY, DANIEL PATRICKZUHARS, JOELHOPPE, MICHAEL E.
Owner THINK SURGICAL