The medial femoral condyle is the larger and more prominent of the two distal femoral condyles, projecting further distally than the lateral condyle to compensate for the valgus angle of the femoral shaft. Its medial surface gives attachment to the medial collateral ligament and the posteromedial capsule. The posterior surface of the medial condyle is a common site for osteochondral defects and osteochondritis dissecans, particularly the posterolateral aspect of the medial condyle, which is the most common OCD site in the knee.
The medial femoral condyle is the most common site of osteochondritis dissecans in the knee, with the classic location on the posterior lateral surface of the medial condyle corresponding to the zone that articulates with the intercondylar eminence in flexion. MRI characterises OCD lesion stability by assessing the overlying cartilage and the underlying bone-lesion interface. Condyle fractures after total knee arthroplasty (periprosthetic) require plate fixation. Avascular necrosis of the medial femoral condyle produces spontaneous osteonecrosis of the knee (SONK).
Subchondral bone necrosis at the posterior lateral aspect of the medial condyle in adolescents and young adults produces activity-related knee pain and possible loose body formation; managed conservatively in stable lesions or by arthroscopic drilling, fixation, or osteochondral grafting for unstable fragments.
Avascular necrosis of the medial femoral condyle subchondral bone in older patients produces sudden onset medial knee pain without preceding trauma; early MRI shows bone marrow oedema and later radiographs show condylar flattening; treated with protected weight-bearing or, when articular collapse occurs, unicompartmental or total knee replacement.
