PATELLA TRACKING

• US 20090264737A1
• Filed: 04/05/2007
• Published: 10/22/2009
• Est. Priority Date: 04/07/2006
• Status: Active Grant

• Current Assignee: Depuy International Limited (Johnson & Johnson), DePuy Orthopädie GmbH (Johnson & Johnson)
• Original Assignee: Depuy International Limited (Johnson & Johnson), DePuy Orthopädie GmbH (Johnson & Johnson)
• Inventors: Naybour, John, Haechler, Joerg
• Granted Patent: US 8,361,160 B2
• Time in Patent Office: Days
• US Class Current: 600/424
• CPC Class Codes: A61B 17/158 Cutting patella
• CPC Class Codes: A61B 17/1767 for the patella
• CPC Class Codes: A61B 2017/564 Methods for bone or joint treatment
• CPC Class Codes: A61B 2034/105 Modelling of the patient, e.g. for ligaments or bones
• CPC Class Codes: A61B 2034/107 Visualisation of planned trajectories or target regions
• CPC Class Codes: A61B 2034/108 Computer aided selection or customisation of medical implants or cutting guides
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2090/3916 Bone tissue
• CPC Class Codes: A61B 2090/3925 ultrasonic
• CPC Class Codes: A61B 2090/3954 magnetic, e.g. NMR or MRI
• CPC Class Codes: A61B 2090/397 electromagnetic other than visible, e.g. microwave
• CPC Class Codes: A61B 2090/3983 Reference marker arrangements for use with image guided surgery
• 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 90/36 Image-producing devices or illumination devices not otherwise provided for
• CPC Class Codes: A61F 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2/4684 Trial or dummy prostheses
• CPC Class Codes: A61F 2002/3052 unrestrained in only one direction, e.g. moving unidirectionally
• CPC Class Codes: A61F 2002/30528 Means for limiting said movement
• CPC Class Codes: A61F 2002/3881 with moving parts

Abstract

A device and methods for use in determining the trajectory of a patella of a patient during a navigated knee replacement surgical procedure are described. The device includes a first component including a mounting for attachment to a posterior surface of the patient'"'"'s patella and a second component having an outer surface presenting a formation adapted to engage with a femoral part of the patient'"'"'s knee. A slider mechanism allows the second component to translate relative to the first component in a substantially medial-lateral direction of the patient when the first component is attached to the patient'"'"'s patella. The device can be used in a method to help determine the medial-lateral position for a patella implant.

Claims

1. A computer implemented method for assessing the position of a patella implant for a patient during a navigated knee replacement surgical procedure, wherein a trial patella implant is attached to the posterior of the patient'"'"'s patella by a first component of the trial patella implant and a second component of the trial patella implant can translate relative to the first component in the medial-lateral direction, the method comprising a computer assisted surgery system:

determining the trajectory of the patella as the knee joint is articulated while the second component is free to translate relative to the first component from tracking data for the patella; and

determining the medial-lateral displacement of the second component relative to the patella over at least a part of the trajectory.

5. A method as claimed in claim 1 or 2, wherein the trajectory is relative to a femoral or tibial part of the knee joint.

6. Computer program code including instructions which when executed by a data processor carries out the method of claim 1.

7. A computer readable medium bearing computer program code as claimed in claim 6.

9. A device as claimed in claim 1, and further comprising a lock mechanism which can be operated to prevent translation of the second component relative to the first component.

2. A method for assessing the positioning of a patella implant for a patient during a navigated knee replacement surgical procedure, the method comprising:

attaching a trial patella implant to the posterior of the patient'"'"'s patella by a first component of the trial patella implant, wherein a second component of the trial patella implant can translate relative to the first component in the medial-lateral direction; and

determining the trajectory of the patella as the knee joint is articulated while the second component is free to translate relative to the first component; and

determining the medial-lateral displacement of the second component relative to the patella over at least a part of the trajectory.

3. A method as claimed in claim 2 and further comprising:

determining the trajectory of the patella as the knee joint is articulated while the second component is fixed in the medial-lateral direction relative to the first component.

4. A method as claimed in claim 3, and further comprising comparing the trajectories.

8. A device for use in determining the trajectory of a patella of a patient during a navigated knee replacement surgical procedure, the device including:

a first component including a mounting by which the first component can be attached to a posterior surface of the patient'"'"'s patella;

a second component having an outer surface presenting a formation adapted to engage with a femoral part of the patient'"'"'s knee in use; and

a slider mechanism by which the second component can translate relative to the first component in a substantially medial-lateral direction of the patient when the first component is attached to the patient'"'"'s patella in use.

10. A device as claimed in claim 8 or 9, and further comprising a resilient biassing means which can act to resist translation of the second component relative to the first component.

11. A device as claimed in any of claims 8 to 10, wherein the first component is substantially planar and the sliding mechanism is configured so that the second component translates in a plane substantially parallel to the plane of the first component.

12. A device as claimed in any of claims 8 to 11, and further comprising a marker trackable by a tracking system and in which the maker is attached to the second component.

13. A device as claimed in any of claims 8 to 12, and further comprising a further marker trackable by a tracking system and in which the further maker is attached to the first component.

14. A device as claimed in claim 12 or 13, in which the maker is attached within the component.