Do Moments and Strength Predict Cartilage Changes after Partial Meniscectomy?

Purpose: Higher knee load and quadriceps weakness are potential factors involved in the pathogenesis of knee osteoarthritis after arthroscopic partial meniscectomy (APM). In people following APM, this study evaluated the association between external knee joint moments and quadriceps strength and 2-yr change in indices of cartilage integrity in the medial tibiofemoral compartment and patella.

Methods: Seventy people with medial APM were assessed 3 months after APM (baseline) and reassessed 2 yr later (follow-up). At baseline, isokinetic quadriceps strength and the external knee adduction moment (peak and impulse) and knee flexion moment (peak) during walking were assessed. Magnetic resonance imaging was used to assess cartilage (cartilage volume and cartilage defects) in the medial tibial compartment and patella at baseline and follow-up.

Results: Increased peak knee adduction moment during fast-pace walking at baseline was associated with onset or deterioration of medial tibiofemoral cartilage defects (OR, 2.06; 95% CI, 1.03-4.12; P = 0.042) over 2 yr. Increased peak knee flexion moment during normal-pace walking at baseline was associated with loss of patellar cartilage volume over 2 yr (β = -0.24; 95% CI, -0.47 to -0.01; P = 0.04). No significant association was observed for quadriceps strength.

Conclusion: In middle-age adults, a higher peak knee adduction moment and peak knee flexion moment at 3 months after medial APM may be associated with adverse structural changes at the medial tibia and patella over the subsequent 2 yr. These preliminary findings warrant further investigation as interventions aimed at reducing these moments may be designed if appropriate.