System and Method for Prosthetic Fitting and Balancing in Joints

Abstract

A device for intraoperative use in balancing joint forces and verifying the placement of the tibial component in total knee arthroplasty includes a spacer defining an enclosure; the spacer is sized to engage a top portion of the tibial component. A sensor array is embedded in the spacer, the sensor array measures forces on the spacer. A wireless transceiver is embedded in the spacer and forwards the output to a processor. The processor is analyzes the output and creates a pressure distribution graph indicative of the forces on the spacer, thereby assisting a surgeon in performing selective soft tissue release or component positioning in connection with surgical implantation of an orthopedic knee prosthesis.

1 . A device for intraoperative use in balancing joint forces and verifying the placement of the tibial component in total knee arthroplasty comprising:
 a spacer defining an enclosure, the spacer sized to engage a top portion of the tibial component;   a sensor array embedded in the spacer, the sensor array arranged to create an output indicative of the forces on the spacer;   a wireless transceiver embedded in the spacer and arranged to forward the output to a processor;   the processor arranged to analyze the output and create a pressure distribution graph indicative of the forces on the spacer;   thereby assisting a surgeon in performing selective soft tissue release or component positioning in connection with surgical implantation of an orthopedic knee prosthesis.   
     
     
         2 . The device of  claim 1 , including a signal conditioning and signal transmitting circuit capable of sending the output through wireless communication to a receiver operatively connected to the processor. 
     
     
         3 . The device of  claim 1 , wherein the spacer includes a power supply disposed inside a tibial post of tibial component, and wherein the power supply is insulated to thereby prevent patient injury from leakage or microshock. 
     
     
         4 . The device of  claim 1 , further comprising a joint angle sensor communicatively coupled to the processor, the joint angle sensor measuring an angle of a knee joint. 
     
     
         5 . The device of  claim 1 , further comprising a ligament tension sensor communicatively coupled to the processor, the ligament tensions sensor measuring tension of a knee ligament. 
     
     
         6 . The device of  claim 5 , wherein the ligament tension sensor is attached to an outer knee ligament. 
     
     
         7 . The device of  claim 5 , wherein the outer knee ligament is a medal cruciate ligament. 
     
     
         8 . The device of  claim 5 , further comprising a plurality of ligament sensors, each ligament sensor being attached to an outer knee ligament. 
     
     
         9 . The device of  claim 1 , further comprising a femoral component for attachment to an end of a femur. 
     
     
         10 . The device of  claim 9 , wherein the spacer includes a pair of opposed faces, a first face including a pair of condyle recesses and an extension for slidably engaging a groove in a femoral component, the extension preventing lateral movement between the spacer and the femoral component while allowing the spacer to rotate relative to the femoral component. 
     
     
         11 . The device of  claim 10 , wherein the spacer includes an elevated face opposite of the first face. 
     
     
         12 . The device of  claim 11 , further comprising a tibial tray for attachment to a tibia. 
     
     
         13 . The device of  claim 12 , wherein the elevated face cooperates with the tibial tray to form a snap-fit connection. 
     
     
         14 . The device of  claim 11 , wherein the elevated face includes a plurality of recesses for receiving sensors in the sensor array. 
     
     
         15 . The device of  claim 1 , wherein at least one sensor in the sensor array is a strain gage. 
     
     
         16 . The device of  claim 1 , wherein the pressure distribution graph is a three dimensional pressure distribution graph. 
     
     
         17 . The device of  claim 1 , wherein the spacer is bioengineered to remain in a human knee after total knee arthroplasty. 
     
     
         18 . The device of  claim 1 , wherein the processor compares the output to pre-determined pressure criteria. 
     
     
         19 . The device of  claim 1 , wherein the pressure distribution graph displays pressure distribution as a function of joint angle. 
     
     
         20 . The device of  claim 1 , wherein the pressure distribution graph displays pressure distribution as a function of ligament tension.