The influence of varus and valgus deviation on patellar kinematics in healthy knees: An exploratory cadaver study

Patellofemoral instability may lead to osteoarthritis, anterior knee pain, and patellar luxation. The purpose of this study was to conduct an exploratory investigation into the difference of patellar kinematics of healthy knees during extension/flexion cycles in neutral, varus and valgus alignment.

The three-dimensional patellar kinematics of 10 lower extremities of whole body cadavers were examined during passive motion, in neutral position, and under valgus and varus stress. Kinematics was recorded by means of an optical computer navigation system.

The study samples did not significantly differ with regard to mediolateral patellar shift and epicondylar distance. Varus stress led to significantly higher external rotation than valgus stress (P=0.04) and to a significantly higher lateral patellar tilt than neutral position (P=0.016) and valgus stress (P=0.016). No difference was found between valgus stress and neutral position.

Analysis of tibiofemoral alignment alone is insufficient for predicting patellar kinematics.