HIP REPLACEMENT IN COMPUTER-ASSISTED SURGERY

• US 20090099570A1
• Filed: 10/10/2008
• Published: 04/16/2009
• Est. Priority Date: 10/10/2007
• Status: Active Grant

• Current Assignee: ORTHOsoft ULC. (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Orthosoft Inc. (Zimmer Biomet Holdings, Inc.)
• Inventors: Amiot, Louis-Philippe, PARADIS, Francois, Odermatt, Daniel
• Granted Patent: US 8,790,351 B2
• Time in Patent Office: Days
• US Class Current: 606/91
• CPC Class Codes: A61B 17/1666 for the acetabulum
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 34/73 Manipulators for magnetic surgery
• CPC Class Codes: A61F 2/4609 of acetabular cups

Abstract

A system for calculating a position and orientation of an acetabular cup in computer-assisted surgery comprises a first trackable reference secured to a pelvis, with a frame of reference being associated with the first trackable reference. A device is positionable between a femoral neck and the acetabulum of the pelvis in a known relation, the device having a second trackable reference. Sensors track the trackable references for position and orientation. A position/orientation calculator calculates a position and orientation of the frame of reference and of the device and for determining an orientation of the neck axis with respect to the frame of reference from the known relation at a desired position of the femur. An implant position/orientation calculator provides cup implanting information with respect to the orientation of said neck axis as a function of the tracking for position and orientation of at least the first trackable reference.

Claims

1. A device for digitizing a femoral neck axis of with respect to a pelvic frame of reference in computer-assisted surgery, comprising:

a trackable member trackable for position and orientation by a computer-assisted surgery system;

a body connected to the trackable member, the body having an interface portion adapted to be releasably coupled to a neck of one of an implanted femoral implant and a provisional in a known relation, and a bone interface portion adapted to be positioned against a pelvis such that the body of the device interrelates the implanted femoral implant or provisional to the pelvis, the neck axis of the femoral implant or provisional being calculable thereat with respect to the pelvic frame of reference as a function of the known relation and of the position and orientation of the trackable member.

8. The method according to claims 1, wherein doing surgical treatment is performed on a bone model or a cadaver.

2. A method of doing surgical treatment in computer-assisted surgery for guiding an operator in inserting a cup implant of a hip joint implant into an acetabulum, comprising:

positioning a trackable reference on a pelvis, the trackable reference being trackable in space for position and orientation so as to define a frame of reference;

inserting any one of a provisional and a femoral implant into a femur;

digitizing a neck axis of the provisional or femoral implant with respect to the frame of reference; and

inserting the cup implant into the acetabulum by obtaining cup implanting information with respect to the orientation of said neck axis as a function of the tracking for position and orientation of the trackable reference.

3. The method according to claim 2, wherein obtaining cup implanting information comprises tracking an orientation of reamer altering the acetabulum.

4. The method according to claim 2, wherein obtaining cup implanting information comprises tracking an orientation of the cup implant being implanted.

5. The method according to claim 2, further comprising reaming the acetabulum prior to digitizing the neck axis.

6. The method according to claim 2, wherein digitizing the neck axis comprises coupling the neck of the provisional or femoral implant and the acetabulum with a tracked device, and orienting the femur to a desired posture.

7. The method according to claim 2, wherein digitizing the neck axis comprises orienting the femur to a desired posture.

9. A system for calculating a position and orientation of an acetabular cup in computer-assisted surgery, comprising:

a first trackable reference secured to a pelvis, with a frame of reference being associated with the first trackable reference;

a device positionable between a femoral neck and the acetabulum of the pelvis in a known relation, the device having a second trackable reference;

sensors for tracking the trackable references for position and orientation;

a position/orientation calculator for calculating a position and orientation of the frame of reference and of the device and for determining an orientation of the neck axis with respect to the frame of reference from the known relation at a desired position of the femur; and

an implant position/orientation calculator for providing cup implanting information with respect to the orientation of said neck axis as a function of the tracking for position and orientation of at least the first trackable reference.

10. The system according to claim 9, further comprising a reamer for reaming the acetabulum of the pelvis, the reamer having another trackable reference such that the cup implanting information is calculated as a function of the orientation of the reamer.

11. The system according to claim 9, further comprising another trackable reference removably connected to the acetabular cup such that the cup implanting information is calculated as a function of the orientation of the acetabular cup.

12. The system according to claim 9, wherein the device comprises a body connected to the second trackable reference, the body having an interface portion adapted to be releasably coupled to a neck of an implanted femoral implant or provisional in the known relation, and a bone interface portion adapted to be positioned into the acetabulum such that the body of the device interrelates the implanted femoral implant to the pelvis.

13. The system according to claim 9, wherein the cup implanting information comprises anteversion angle, offset angle, limb length discrepancy, range of motion data, visal displays of an axis with respect to a pelvic image.

14. The system according to claim 9, wherein the desired posture comprises the patient in a regular lying posture.

15. The system according to claim 9, wherein the position/orientation calculator comprises a model of the device, and the known relation comprises the model of the device.

16. The system according to claim 9, wherein the femoral neck is the femoral neck of any one of a femoral implant and provisional.