Prosthetic device, method of planning bone removal for implantation of prosthetic device, and robotic system

Abstract

A prosthetic device, method for planning bone removal, and a robotic system for implantation of a prosthetic device in bone are disclosed. The prosthetic device can include a body portion for attachment to a bone, wherein the body portion includes an implantation surface configured to face the bone upon implantation, and a constraint structure. The prosthetic device, method, and robotic system can be configured to cause the constraint structure and bone to interact so as to constrain the prosthetic device in the bone.

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS[0001]This application claims priority to U.S. Provisional Patent Application Ser. No. 61 / 208,451, filed on Feb. 24, 2009, which is hereby incorporated by reference in its entirety.BACKGROUND OF THE INVENTION[0002]1. Field of Invention[0003]The present invention relates to a prosthetic device for implantation in bone, methods of planning bone removal for implantation of a prosthetic device in bone, and robotic systems for preparing a bone to receive a prosthetic device.[0004]2. Description of Related Art[0005]Conventional prosthetic implantation techniques involve resecting a pocket of material from a bone to provide a void or pocket within the bone that receives a prosthetic device. After resection of bone material is complete, the prosthetic device is implanted within the pocket. The prosthetic device is typically secured in place with bone cement.[0006]Using the conventional techniques, undesired movement of the prosthetic device rela...

AI Technical Summary

Benefits of technology

[0008]An embodiment relates to prosthetic device for implantation in bone. The prosthetic device includes a body portion for attachment to a bone, wherein the body portion includes an implantation surface configured to face the bone upon implantation. The prosthetic device further includes constraint structure comprising at least one of: (i) at least one compressive projection projecting from the implantation surface in a lateral direction of the body portion and configured to provide a compressive force between the at least one compressive projection and the bone, (ii) at least one interlock projection projecting from the implantation surface and having an interlock-projection surface configured to receive bone in a space between the interlock-projection surface and a proximal portion of the implantation surface, and (iii) at least one recess in the implantation surface and configured to receive bone to constrain the body portion in at least two translational degrees of freedom. The constraint structure is configured to constrain the prosthetic device in the bone.

[0009]Another embodiment relates to a method for planning bone removal for implantation of a prosthetic device into bone. The method includes storing data representative of a prosthetic device in a computer readable medium, wherein the prosthetic device includes a body portion having an implantation surface configured to face the bone upon implantation and at least one feature that provides a constraint structure that will constrain the prosthetic device in the bone. The method further includes defining, based on the data, at least one bone-cutting pattern for (i) removing a first portion of bone in a first area sufficient to seat the body portion and (ii) at least one of removing and maintaining a second portion of bone in a second area configured to interact with the constraint structure.

[0010]Yet another embodiment relates to a robotic system for preparing a bone to receive a prosthetic device. The robotic system includes a controllable guide structure configured to guide cutting of the bone into a shape for receiving the prosthetic device. The robotic system further includes a computer readable medium for storing data representative of the prosthetic device, wherein the prosthetic device includes a body portion having an implantation surface configured to face the bone upon implantation and at least one feature that provides a constraint structure that will constrain the prosthetic device in the bone. The robotic system further includes a control system for controlling the guide structure, wherein the control system is configured to define at least one bone-cutting pattern for (i) removing a first portion of bone in a first area sufficient to seat the body portion and (ii) at least one of removing and maintaining a second portion of bone in a second area configured to interact with the constraint structure.

Problems solved by technology

Using the conventional techniques, undesired movement of the prosthetic device relative to the bone may occur.

This expansion gap may cause the prosthetic device to be less than fully constrained, which can permit unwanted movement of the prosthetic device.

For example, during trial articulation of a leg, contact forces from a femoral condyle can cause unwanted movement of a tibial inlay.

In addition, undesired movement can occur during final fixation as a surgeon presses against the prosthetic device to disperse the bone cement and squeeze out excess bone cement.

Using conventional techniques, it also may be undesirably difficult to properly position a prosthetic device in the pocket in the bone.

For example, there can be difficulty in positioning the cup of a hip acetabulum in a desired tilt / abduction and anteversion due to difficulty in knowing exactly where a pelvis is located during total hip arthroplasty.

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