Evaluation of a method to map tibiofemoral contact points in the normal knee using MRI.

A technique using magnetic resonance imaging (MRI) is proposed for analysis of knee motion that is practical in the clinical situation. T1 weighted fast spin echo (FSE) and spoiled gradient echo (GE) sequences were compared to image both knees at 15 degrees intervals from 0 degrees to 90 degrees flexion, while unloaded and loaded. The medial and lateral tibiofemoral contact points were mapped reliably using both FSE sequences and GE sequences with intra-class correlation((2,1)) of 0.96 (CI 99%=0.94-0.97) and 0.94 (CI 99%=0.91-0.97), respectively. Results were consistent with the current literature on knee motion: the medial and lateral tibiofemoral contact pathways were different (F(1,80) = 253.9, p < 0.0001) reflecting the longitudinal rotation of the knee, the loaded and unloaded knees were not different in the healthy knee (F(1,80) = 0.007, p = 0.935), and the left and right knee were consistent for each individual (F(1,80) = 0.005, p = 0.943). Therefore, right to left differences may be attributed to pathology. MRI analysis of knee kinematics as described by this technique of tibiofemoral contact point mapping provides a robust and reliable method of recording the tibiofemoral contact pattern of the knee.