Role of Lower Limb Muscle Strength in Knee Osteoarthritis Progression for Patients With Mild and Moderate Knee Osteoarthritis.

Objective: We aimed to elucidate the association of lower limb muscle strength with the volume loss of cartilages/menisci for patients with mild and moderate knee osteoarthritis.

Design: One hundred seventy individuals with mild and moderate knee osteoarthritis were included from the Osteoarthritis Initiative database. Five muscle strength variables were measured from isometric strength test. The measurement of volume on medial and lateral menisci and seven subregional cartilages from knee magnetic resonance scans were used for assessing 2-yr osteoarthritis progression.

Results: Along with the decreased lower limb muscle strength, the volume of patellar cartilage, medial meniscus, and lateral meniscus decreased more than cartilage on tibia and weight-bearing femoral condyle. However, the cartilage volume on the entire medial and lateral femoral condyle increased significantly. The maximum quadricep strength was the most sensitive muscle strength variable, and we found that it was more positively correlated with lateral meniscus volume than with other subregions at baseline and 24-mo follow-up.

Conclusions: This study shows the relationship between lower limb muscle strength and volumes of cartilage and meniscus for patients with mild and moderate knee osteoarthritis. In addition, our study indicates a biomechanical mechanism of quadricep strength and meniscus-related knee dynamic stability in progression of mild-to-moderate knee osteoarthritis.