ACETABULAR CUP PROSTHESIS POSITIONING INSTRUMENT AND METHOD

• US 20140364858A1
• Filed: 06/11/2014
• Published: 12/11/2014
• Est. Priority Date: 06/11/2013
• Status: Active Grant

• Current Assignee: ORTHOsoft ULC. (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Orthosoft Inc. (Zimmer Biomet Holdings, Inc.)
• Inventors: Amiot, Louis-Philippe, Jansen, Herbert, Paradis, Francois, Falardeau, Bruno, Duval, Karine, Valin, Myriam, Leone, Yvan, Breton, Yonik, Pelletier, Benoit, Chevrier, Mathieu, Li, Di, Robitaille, Isabelle, Casaubon, Jerome
• Granted Patent: US 9,987,148 B2
• Time in Patent Office: Days
• US Class Current: 606/91
• CPC Class Codes: A61B 2034/104 Modelling the effect of the tool, e.g. the effect of an implanted prosthesis or for predicting the effect of ablation or burring
• CPC Class Codes: A61B 2034/2048 using an accelerometer or inertia sensor
• CPC Class Codes: A61B 90/13 guided by light, e.g. laser pointers
• CPC Class Codes: A61F 2/4603 for insertion or extraction of endoprosthetic joints or of accessories thereof
• CPC Class Codes: A61F 2/4609 of acetabular cups
• CPC Class Codes: A61F 2002/4687 Mechanical guides for implantation instruments

Abstract

A method for assisting in positioning the acetabular cup comprises orienting a cup positioning instrument with a cup thereon in an initial reference orientation relative to an acetabulum of a pelvis with the cup forming a joint with the acetabulum, the cup positioning instrument comprising an inertial sensor unit with pre-planned orientation data for a desired cup orientation based on at least one landmark of the pelvis, The cup positioning instrument is rotated to a desired abduction angle as guided by an interface of the cup positioning instrument, based on movements relative to at least one landmark. The cup positioning instrument is rotated to a desired anteversion angle as guided by the interface of the cup positioning instrument, based on movements relative to the at least one landmark. Upon reaching the desired cup orientation as indicated by the interface, the cup is impacted into the acetabulum.

Claims

1. A method for assisting in positioning the acetabular cup comprising:

orienting a cup positioning instrument with a cup thereon in an initial reference orientation relative to an acetabulum of a pelvis with the cup forming a joint with the acetabulum, the cup positioning instrument comprising an inertial sensor unit with pre-planned orientation data for a desired cup orientation based on at least one landmark of the pelvis;

rotating the cup positioning instrument to a desired abduction angle as guided by an interface of the cup positioning instrument, based on movements relative to at least one landmark;

rotating the cup positioning instrument to a desired anteversion angle as guided by the interface of the cup positioning instrument, based on movements relative to the at least one landmark; and

upon reaching the desired cup orientation as indicated by the interface, impacting the cup into the acetabulum.

2. The method according to claim 1, wherein orienting the cup positioning instrument in an initial reference orientation comprises orienting the cup positioning instrument to a vertical orientation with the patient in lateral decubitus.

3. The method according to claim 1, wherein orienting the cup positioning instrument in an initial reference orientation comprises pointing a visual guide toward the at least one landmark, and wherein rotating the cup positioning instrument comprises rotating the cup positioning instrument while the visual guide points toward the at least one landmark.

4. The method according to claim 1, wherein orienting the cup positioning instrument in an initial reference orientation comprises pointing another visual guide on a second landmark.

5. The method according to claim 4, wherein orienting the cup positioning instrument in an initial reference orientation further comprises orienting the cup positioning instrument to a vertical orientation with the patient in lateral decubitus, and wherein the at least one landmark is a frontal plane of the patient

6. The method according to claim 5, wherein orienting the cup positioning instrument in an initial reference orientation further comprises pointing the visual guide toward the ASIS as the second landmark.

7. The method according to claim 1, further comprising positioning a registration device supporting the inertial sensor unit in a planned manner in the acetabulum of the pelvis to record a pre-operative pelvic coordinate system on the inertial sensor unit, and transferring the inertial sensor unit to the cup positioning instrument prior to orienting the cup positioning instrument.

8. The method according to claim 7, wherein positioning the registration device in the planned manner comprises inserting a base of the registration device in the acetabulum, and abutting a patient-specific contour matching abutment surface of the registration device against the pelvis.

9. The method according to claim 1, comprising positioning a registration device in a planned manner in the acetabulum of the pelvis, securing a tracker device to the pelvis using the registration device to record a pre-operative pelvic coordinate system on an inertial sensor unit of the tracker device, and transferring pelvic coordinate system to the inertial sensor unit of the cup positioning instrument prior to orienting the cup positioning instrument.

10. A cup impactor assembly comprising:

a shaft;

a cup coupler at a cup end of the shaft adapted to releasably connect a cup in fixed relation for subsequent impacting;

a handle at an impacting end of the shaft;

a visual guide mounted to at least one of the shaft and the handle, the visual guide producing visual guidance toward at least one anatomical landmark of a pelvis;

an inertial sensor unit adapted to produce at least an orientation output related to an orientation of the cup impactor assembly and having a patient-specific file comprising;

calibration data based on a planned geometric relation between an initial reference orientation of the cup impactor assembly and the at least one anatomical landmark of the pelvis via the visual guidance of the visual guide, the calibration data for calibrating the inertial sensor unit relative to the pelvis for the inertial sensor unit to produce said orientation output; and

a desired acetabular cup orientation data based on preoperative planning.

11. The cup impactor assembly according to claim 10, wherein the visual guide is a light projector.

12. The cup impactor assembly according to claim 11, wherein the light projector projects two light beams angled relative to each other by a patient-specific angle based on a position of landmarks relative to one another, the planned geometric relation including the patient-specific angle.

13. The cup impactor assembly according to claim 11, wherein the initial reference orientation of the cup impactor assembly comprises a vertical orientation of the shaft with the patient in lateral decubitus with the visual guide pointing to two landmarks, the orientation output requiring that one of the two landmarks be pointed during movement to the desired acetabular cup orientation.

14. A kit comprising the cup impactor assembly according to claim 10, further comprising a registration device having a base adapted to be received in the acetabulum, a patient-specific contour matching abutment surface adapted to be abutted against the pelvis in accordance with a planned pelvic coordinate system, the registration device having a coupler adapted to be coupled to the inertial sensor unit to transfer the planned pelvic coordinate system prior to being used with the cup impactor assembly.