Systems and methods for measuring performance parameters related to orthopedic arthroplasty

Abstract

A knee balancing system for measuring performance parameters associated with an orthopedic articular joint comprises a force sensing module and one or more inertial measurement units. The force sensing module comprises a housing that includes an articular surface having a medial portion and a lateral portion, each of which is substantially mechanically isolated from the other. The force sensing module also includes first and second sets of sensors disposed within the housing. The first set of sensors is mechanically coupled to the medial portion of the articular surface and configured to detect information indicative of a first force incident upon the medial portion of the articular surface. The second set of sensors is mechanically coupled to the lateral portion of the articular surface and configured to detect information indicative of a second force incident upon a lateral portion of the articular surface. The inertial measurement unit is configured to detect information indicative of an orientation of at least one of a first bone and a second bone of a knee joint.

1 . A computer-implemented method for tracking performance parameters associated with an orthopedic joint, the method comprising:
 receiving, at a processor associated with a computer, first information indicative of a force detected at an articular interface between a first bone and a second bone of a patient;   receiving, at the processor, second information indicative of an orientation of at least one of the first bone and the second bone;   estimating, by the processor, a location of a center of the force relative to a surface of the articular interface, the estimated location based, at least in part, on the first information; and   estimating, by the processor, an orientation angle associated with at least one of the first bone and the second bone relative to a reference axis, the orientation angle based at least in part on the second information.   
     
     
         2 . The computer-implemented method of  claim 1 , further comprising:
 providing, by the processor, third information indicative of at least one of: the estimated location of the center of the force relative to the surface of the articular interface or the orientation angle associated with the at least one of the first bone and the second bone relative to the reference axis;   estimating, by the processor, a magnitude at the location of the center of the force detected at the articular interface, the magnitude based, at least in part, on the first information; and   wherein the third information is further indicative of a magnitude of the force detected at the articular interface.   
     
     
         3 . The computer-implemented method of  claim 2 , wherein receiving first information indicative of a force detected at the articular interface between the first and second bones of a patient includes:
 receiving information indicative of a first force applied to a medial portion of the surface of the articular interface;   receiving information indicative of a second force applied to a lateral portion of the surface of the articular interface;   wherein the third information is indicative of at least one of: a respective magnitude associated with each of the first force and the second force, a location of the first force relative to the medial portion of the surface of the articular interface, a location of the second force relative to the lateral portion of the surface of the articular interface, and an orientation angle associated with the at least one of the first bone and a second bone.   
     
     
         4 . The computer-implemented method of  claim 3 , wherein providing third information includes causing display of information indicative of a respective magnitude associated with each of the first force and the second force, a location of the first force relative to the medial portion of the surface of the articular interface, and a location of the second force relative to the lateral portion of the surface of the articular interface. 
     
     
         5 . The computer-implemented method of  claim 4 , wherein causing display of information indicative of a respective magnitude associated with each of the first force and the second force further includes causing display of information indicative of the respective magnitude associated with each of the first and second forces as a function of the orientation angle associated with the at least one of the first bone and the second bone. 
     
     
         6 . The computer-implemented method of  claim 1 , wherein providing third information includes causing display of at least one of: the estimated location of the force relative to the surface of the articular interface or the orientation angle associated with the at least one of the first bone and the second bone relative to the reference axis. 
     
     
         7 . The computer-implemented method of  claim 1 , wherein receiving second information indicative of the orientation of at least one of the first bone and the second bone includes receiving information indicative of the rate of angular rotation of the at least one of the first bone and the second bone and information indicative of linear acceleration of the at least one of the first bone and the second bone, wherein estimating the orientation angle associated with at least one of the first bone and the second bone relative to a reference axis is based, at least in part, on the information indicative of the rate of rotation and the information indicative of the acceleration.