The medial compartment and patellofemoral joint degenerate more severely in early stage knee osteoarthritis: a cross-sectional study.

OBJECTIVE: The purpose of this study was to compare the differences of degenerative characteristics of medial, lateral regions, femoral, patellar, and tibia parts of the knee joint in the early-stage of knee osteoarthritis (OA). PATIENTS AND METHODS: A total of 66 patients with early stage knee OA and 22 healthy volunteers who have no knee-related clinical symptoms were enrolled in this cross-sectional study. T2 mapping and 3D dual-echo images were acquired with a 3.0T MR scanner. The degenerative changes of the articular cartilage were quantified by a T2 mapping and cartilage thicknesses analysis. Any structural changes were conducted using the Whole Organ Magnetic Resonance Imaging Score (WORMS). RESULTS: In patients with knee OA, the thicknesses of medial cartilages were significantly thinner than lateral ones (2.13 mm vs. 2.34 mm, p<0.0001), but with higher T2 values (40.38 ms vs. 38.4 ms, p<0.0001) and WORMS scores (12.12 vs. 0.47, p=0.004). No significant differences were observed between medial and lateral cartilage in the healthy volunteers. The T2 values of the femoral (p<0.001) and patellar (p=0.012) cartilages of OA patients were higher than that of the healthy controls. Within OA group, the T2 values of femoral (p<0.0001) and patellar (p<0.0001) cartilages were higher than tibial ones. Moreover, the WORMS scores of femoral (p=0.001) and patellar (p<0.0001) cartilages were higher than that of the tibial ones. CONCLUSIONS: This study demonstrates that the medial compartment and patellofemoral knee joint degenerate more severely in patients with early-stage knee OA. [ABSTRACT FROM AUTHOR]