SPONTANEOUS OSTEONECROSIS OF KNEE

A radiolucent lesion in the medial femoral condyle was observed in 40 knees in 39 patients over age 60. Most patients had had spontaneous onset of severe knee pain. Twelve knees were radiographically normal within 2 months following onset of pain. Seven knees proceeded to osteoarthritis whereas others became rather asymptomatic. Strontium‐85 scintimetry of symptomatic knees showed exceedingly high values. Biopsy showed evidence of repair of bone tissue. The condition was identified as osteonecrosis, the natural history and management of which were discussed. Only 2 patients had a history of systemic adrenocorticosteroid treatment; no other conditions commonly associated with osteonecrosis were identified. Copyright © 1968 American College of Rheumatology