Spontaneous osteonecrosis of the knee (SONK), an old term referring to an insufficiency fracture about the knee, is a cause of (usually) atraumatic acute knee pain in older patients. Women are affected three times more often than men. The most common location is at the medial femoral condyle, followed by the lateral femoral condyle, the medial tibial plateau (uncommon), and the lateral tibial plateau (rare).
The MR images here show a subchondral fracture of the medial femoral condyle with extensive adjacent marrow signal abnormality. The collapsed sclerotic bone is seen as an ovoid hypointense structure. The radiograph, obtained 4 months after the MRI, shows an area of depression and sclerosis along the medial femoral condyle.
Differential considerations include:
- Osteochondritis dissecans: Younger age group. The abnormality is usually on the non weight-bearing surface of the condyle, closer to the notch.
- Osteochondral fracture: History of trauma.
- Neuropathic (Charcot) arthropathy:
- Articular diseases: Conditions leading to chondral and/or meniscal pathology can have a similar appearance.
Who out there has been told they have this rare condition ? Feel free to contact me direct at jmo@google.com
ReplyDelete( I am 49 - 7 mo after first pain ,
Facing experimental procedure. I either want to see who has done it or share .