Correlation between knee kinematics and patellofemoral contact pressure in total knee arthroplasty.

The aim of this study is to evaluate the relationship between patellofemoral contact stress and intraoperative knee kinematic patterns after mobile bearing total knee arthroplasty (TKA). Medial osteoarthritic knees of forty-six posterior-stabilized total knee prostheses were evaluated using a computed tomography-guided navigation system. Subjects were divided into two groups based on intraoperative knee kinematic patterns: the medial pivot group (n=19) and the non-medial pivot group (n=27). Mean intraoperative patello-femoral contact stress was significantly lower in the medial pivot group than in the non-medial pivot group (1.7MPa vs. 3.2MPa, P<0.05). An intraoperative medial pivot pattern results in reduced patello-femoral contact stress.