KINETIC ASSESSMENT AND ALIGNMENT OF THE MUSCULAR-SKELETAL SYSTEM AND METHOD THEREFOR

• US 20140277526A1
• Filed: 09/13/2013
• Published: 09/18/2014
• Est. Priority Date: 03/18/2013
• Status: Active Grant

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: OrthoSensor, Inc (Stryker Corporation)
• Inventors: Stein, Marc, Roche, Martin
• Granted Patent: US 9,820,678 B2
• Time in Patent Office: Days
• US Class Current: 623/20.14
• CPC Class Codes: A61B 17/154 for preparing bone for knee prosthesis
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61B 17/157 Cutting tibia
• CPC Class Codes: A61B 17/1764 for the knee
• CPC Class Codes: A61B 2034/102 Modelling of surgical devices, implants or prosthesis
• 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 2034/105 Modelling of the patient, e.g. for ligaments or bones
• 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 34/25 User interfaces for surgical systems
• CPC Class Codes: A61B 5/103 Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes A61B5/08 takes precedence; measuring aids for tailors A41H1/00; measuring instruments specially adapted for dentistry A61C19/04
• CPC Class Codes: A61B 5/1036 Measuring load distribution, e.g. podologic studies
• CPC Class Codes: A61B 5/1072 measuring distances on the body, e.g. measuring length, height or thickness A61B5/1076 takes precedence
• CPC Class Codes: A61B 5/1121 Determining geometric values, e.g. centre of rotation or angular range of movement
• CPC Class Codes: A61B 5/45 For evaluating or diagnosing the musculoskeletal system or teeth A61B5/1036, A61B5/1074, A61B7/006 take precedence
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 5/4571 Evaluating the hip
• CPC Class Codes: A61B 5/4585 Evaluating the knee
• CPC Class Codes: A61B 5/4851 Prosthesis assessment or monitoring
• CPC Class Codes: A61B 5/4887 Locating particular structures in or on the body
• CPC Class Codes: A61B 5/686 : Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 90/37 : Surgical systems with images on a monitor during operation
• CPC Class Codes: A61F 2/38 : for elbows or knees
• CPC Class Codes: A61F 2/3836 : Special connection between upper and lower leg, e.g. constrained
• CPC Class Codes: A61F 2/461 : of knees
• 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 2002/4658 : for measuring dimensions, e.g. length
• CPC Class Codes: A61F 2002/4668 : for measuring angles
• CPC Class Codes: G06F 3/0481 : based on specific properties of the displayed interaction object or a metaphor-based environment, e.g. interaction with desktop elements like windows or icons, or assisted by a cursor's changing behaviour or appearance

Abstract

A system is disclosed herein for providing a kinetic assessment and preparation of a prosthetic joint comprising one or more prosthetic components. The system comprises a prosthetic component including sensors and circuitry configured to measure load, position of load, and joint alignment. The system further includes a remote system for receiving, processing, and displaying quantitative measurements from the sensors. The kinetic assessment measures joint alignment under loading that will be similar to that of a final joint installation. The kinetic assessment can use trial or permanent prosthetic components. Furthermore, adjustments can be made to the applied load magnitude, position of load, and joint alignment by various means to fine-tune an installation. The kinetic assessment increases both performance and reliability of the installed joint by reducing error that is introduced by elements that load or modify the joint dynamics not taken into account by prior assessment methods.

Claims

1. A system to support kinetic assessment, joint modification, and installation of a final prosthetic joint comprising:

a prosthetic component configured to measure load, position of load, and joint alignment;

a remote system coupled to the sensing insert configured to receive measurement data from the prosthetic component where a joint assessment and subsequent changes to affect load, position of load, and joint alignment are performed under muscular-skeletal loading whereby a final joint installation has similar loading, position of load, and alignment.

2. The system of claim 1 where the prosthetic component comprises:

at least one articular surface;

a plurality of load sensors underlying each articular surface configured to measure load and position of load; and

at least one three axis accelerometer configured to measure an arc maximum that relates to alignment.

3. The system of claim 2 where the remote system is configured to monitor position of load on a display and where a correction comprising one of rotating a prosthetic component or soft tissue tensioning can be performed under muscular-skeletal loading to move position of load on the at least one articular surface within a predetermined area range.

4. The system of claim 3 where the at least one three axis accelerometer is configured to support measurement of an offset of a first bone of the joint relative to a mechanical axis.

5. The system of claim 4 where the at least one three axis accelerometer is configured to support measurement an offset of a second bone relative to a mechanical axis.

6. The system of claim 5 where the system is configured to determine a total offset relative to a mechanical axis and the system is configured to indicate if the total offset is within a predetermined offset range.

7. The system of claim 1 where the prosthetic component is configured to be referenced to a first plane, where the prosthetic component is configured to be referenced to a second plane that is perpendicular to the first plane, where the first plane corresponds to zero gravity and where the three axis accelerometer is configured to measure tilt and location.

8. A method of kinetic assessment, joint modification, and installation of a final prosthetic joint comprising:

inserting a prosthetic component configured to measure load, position of load, and joint alignment into a joint;

transmitting measurement data from the sensing to a remote system;

measuring load on an articular surface of the prosthetic component; and

adjusting the loading applied by the muscular-skeletal system to the prosthetic component until the loading is within a predetermined load range; and

measuring joint alignment under load.

9. The system of claim 8 further including the steps of:

referencing the prosthetic component to a first reference plane where the prosthetic component includes a three-axis accelerometer referenced to gravity;

referencing the prosthetic component to a second reference plane that is perpendicular to the first plane; and

zeroing the sensored insert such that the first reference plane corresponds to zero gravity.

10. The system of claim 8 further including the steps of:

adjusting the loading applied by the muscular-skeletal system with a shim coupled to the prosthetic component;

measuring position of load with a plurality of load sensors underlying the articular surface; and

adjusting the position of load within a predetermined area range.

11. The system of claim 10 further including the steps of:

rotating the prosthetic component to change a position of load;

monitoring the position of load on the remote system; and

fixing the position of the prosthetic component when the position of load is within the predetermined area range on the articular surface.

12. The system of claim 10 further including a step of performing a step of soft tissue tensioning to change the load applied to the articular surface or to change a position of load applied to the articular surface.

13. The system of claim 8 further including a step of measuring bone slope of a prepared bone surface.

14. The system of claim 13 further including a step of modifying the prepared bone surface to be within a predetermined slope range.

15. The system of claim 14 further including the steps of:

measuring anterior-posterior slope of the prepared bone surface; and

measuring the medial-lateral slope of the prepared bone surface.

16. The system of claim 8 further including the steps of:

measuring an offset of a first bone of the joint relative to the mechanical axis where the three-axis accelerometer is configured to provide measurement data to determine the offset of the first bone; and

measuring an offset of a second bone of the joint relative to a mechanical axis and where the three-axis accelerometer is configured to provide measurement data to determine the offset of the second bone.

17. The system of claim 16 further including adjusting joint alignment within a predetermined alignment range where a joint assessment and subsequent changes to affect load, position of load, and joint alignment are performed under muscular-skeletal loading whereby a final joint installation has similar loading, position of load, and alignment.

18. A method of kinetic knee assessment for installing a prosthetic knee joint comprising:

inserting a sensored insert configured to measure load, position of load, and joint alignment into a knee joint;

transmitting measurement data from the sensing to a remote system;

measuring load on at least one articular surface of the sensored insert; and

shimming the sensored insert until a load is within a predetermined load range;

measuring the position of load with a plurality of load sensors underlying at least one articular surface of the sensored insert;

measuring alignment of a femur and tibia relative to a mechanical axis of the leg under load with a three-axis accelerometer within the sensored insert; and

monitoring loading, position of load, and alignment on the remote system.

19. The method of claim 18 further including the steps of:

measuring an offset of a tibia relative to the mechanical axis under muscular-skeletal loading;

measuring an offset of a femur relative to the mechanical axis under muscular-skeletal loading; and

combining the offsets to determine an alignment relative to the mechanical axis of the leg.

20. The method of claim 18 further including a step of measuring the anterior-posterior slope of a proximal end of the tibia.