Relationships among bone mineral densities, static alignment and dynamic load in patients with medial compartment knee osteoarthritis.

OBJECTIVE To investigate the relationships among bone mineral density (BMD), static alignment and the adduction moment of the knee in patients with tibiofemoral osteoarthritis (OA). METHODS Sixty-nine patients with medial compartment knee OA underwent radiographic evaluation, gait analysis and BMD measurements at the proximal tibia and lumbar spine. RESULTS The bone mineral distribution of the medial to lateral part of the proximal tibia correlated significantly with the peak knee adduction moment and the mechanical axis. Furthermore, the adduction moment correlated significantly with the mechanical axis. However, the BMD of the lumbar spine and the bone mineral distribution of the posterior to anterior part of the proximal tibia did not correlate with any other measurement. CONCLUSIONS Our results suggest that the bone mineral distribution of the proximal tibia is directly affected but lumbar BMD is not influenced by the local mechanical stress around the knee with medial compartment OA.