Do surgical patellar interventions restore patellar kinematics in fixed-bearing, cruciate-retaining total knee arthroplasty?: An in vitro study.

Despite different surgical patellar interventions, the decision how to treat the patella during TKA remains controversial. The purpose of this study was to quantify the effect of different reconstructive patellar interventions on patellar kinematics during TKA using optical computer navigation. We implanted ten navigated TKAs in full body specimens. During passive motion, the effect of different surgical patellar interventions on patellar kinematics was analysed. A contrarily tilt behaviour was observed in the TKA group without patellar intervention compared to the natural knee. Lateral release led to similar tilt values (P < 0.05). All surgical interventions led to a 3 to 5mm medial shift of the patella (P < 0.05). None of the analysed surgical patellar interventions could restore natural patellar kinematics after TKA.