Acetabular cup prosthesis positioning instrument and method

Patent metadata

Field	Value
Publication number	US-9987148-B2
Application number	US-201414301877-A
Country	US
Kind code	B2
Filing date	Jun 11, 2014
Priority date	Jun 11, 2013
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

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.

First claim

The invention claimed is:

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, the pre-planned orientation data including calibration data programmed before said orienting using pre-operative imaging of the pelvis to set the initial reference orientation of the cup positioning instrument geometrically relative to the pelvis, the calibration data geometrically relating the cup positioning instrument in the initial reference orientation to the at least one landmark of the pelvis as pre-planned;
calibrating the inertial sensor unit in the initial reference orientation using the calibration data;
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 as tracked by the inertial sensor unit;
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 as tracked by the inertial sensor unit; 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 the 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 the 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 the 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 the 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 the 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 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, the orienting including
the cup forming a joint with the acetabulum,
an axis of the cup positioning instrument being in a planned initial orientation, and
a visual guide of the cup positioning instrument pointing toward at least one landmark,

the cup positioning instrument comprising an inertial sensor unit with pre-planned orientation data for a desired cup orientation based on the at least one landmark of the pelvis, the pre-planned orientation data including calibration data programmed to geometrically relate the cup positioning instrument when in the initial reference orientation to the at least one landmark of the pelvis, the pre-planned orientation data further including a desired abduction angle and a desired anteversion angle relative to the initial reference orientation;
calibrating the inertial sensor unit when in the initial reference orientation using the calibration data;
rotating the cup positioning instrument to the desired abduction angle as guided by an interface of the cup positioning instrument, based on movements relative to at least one landmark as tracked by the inertial sensor unit and relative to the initial reference orientation;
rotating the cup positioning instrument to the desired anteversion angle as guided by the interface of the cup positioning instrument, based on movements relative to the at least one landmark as tracked by the inertial sensor unit and relative to the initial reference orientation; and
upon reaching the desired cup orientation as indicated by the interface, impacting the cup into the acetabulum.

11. The method according to claim 10 , wherein orienting the cup positioning instrument in the initial reference orientation comprises orienting the cup positioning instrument to a predetermined position and orientation relative to the landmark of the pelvis.

12. The method according to claim 10 , wherein the steps of calibrating, and rotating the cup positioning instrument to the desired abduction angle and to the desired anteversion angle are performed with a single one of the inertial sensor unit, the inertial sensor unit being on the cup positioning instrument.

Assignees

• Orthosoft Inc
• Orthosoft Inc

Inventors

• Li Di
• Amiot Louis-Philippe
• Jansen Herbert
• Paradis Francois
• Robitaille Isabelle
• Falardeau Bruno
• Duval Karine
• Valin Myriam
• Leone Yvan
• Breton Yonik
• Pelletier Benoit
• Casaubon Jerome
• Chevrier Mathieu

Classifications

• A61F2/4603

  for insertion or extraction of endoprosthetic joints or of accessories thereof · CPC title

• A61B90/13

  guided by light, e.g. laser pointers · CPC title

• A61F2/4609 Primary

  of acetabular cups · CPC title

• A61B2034/2048

  using an accelerometer or inertia sensor · CPC title

• A61B2034/104

  Modelling the effect of the tool, e.g. the effect of an implanted prosthesis or for predicting the effect of ablation or burring · CPC title