Spontaneous osteonecrosis of the knee: tibial plateaus.

Spontaneous osteonecrosis of the medial tibial plateau is less recognized than osteonecrosis of the medial femoral condyle, but it presents in a similar manner. These patients have a sudden onset of pain on the medial side of the knee associated with a spectrum of MRI changes in the tibial subchondral bone. The small lesions can resolve with only minimal residual scar remaining in the subchondral zone. If the lesion is large, it can collapse or show MRI changes of osteonecrosis. Recognition of this problem may help avoid unnecessary intra-articular surgical intervention.