<unk> , is the result of vascular arterial insufficiency to the medial femoral condyle of the<unk>  resulting in necrosis and destruction of bone. It is often unilateral and can be associated with a meniscal tear.
Spontaneous osteonecrosis of the knee
Facet joint arthrosis
Osteoradionecrosis
Post-traumatic arthritis
Calcific bursitis
Retrocalcaneal bursitis
Osteochondritis
Transient synovitis