The Influence of Changes in Patellar and Femoral Prosthesis on Knee Extensor Mechanism after TKA

In order to study the influence of some position changes of prosthesis in patello-femoral joint on knee mechanism after total knee arthroplasty, a three-dimensional model of knee joint including patello-femoral joint has been developed. Changes in position parameters of patellar or femoral prosthesis were simulated. Patellar lateral transition, ratio of patellar tendon force to quadriceps force, and ratio of patello-femoral compressive force to quadriceps force are choosing to response performances of knee extensor mechanics. Results show that patellar thickening, patellar medial rotation, lateral rotation and forward rotation of femoral prosthesis will all increase the patello-femoral compressive force. And patellar thickening, patellar medial rotation, medial rotation and forward rotation of femoral prosthesis will also result in increase of ratio of patellar tendon force to quadriceps. And patellar medial rotation, medial rotation and forward rotation of femoral prosthesis will result in increase of patellar lateral translation