Osteochondritis is a misleading term for this condition as it implies inflammation- evidence of which has yet to be proven. What really happens is that that a part of cartilage and bone separates from the rest of its bone to a varying degree. This most commonly affects the knee, but the elbow and ankle may also be affected. Depending on the maturity of the growth plate of the affected bone, osteochonditis dessicans may take the juvenile or adult form.
There is uncertainty over what exactly causes osteochondritis dessicans, but there appears to be a genetic factor, as well as links with trauma and ischaemia (poor blood supply to the area). Repetitive low grade trauma or overuse through activities like running is thought to contribute to the risk. Symptoms may include local swelling and pain, and possibly altered activities to avoid the pain. Osteochondritis dessicans of the knee often leads to changes in gait, particularly in the later stages.
The condition develops through four stages may require MRI to diagnose:
- Compression through the cartilage that affects the bone beneath
- A fragment partially detaches
- A fragment completely detaches but stays within the crater bed
- A fragment completely detaches, leaving the crater bed and becoming a loose body
Recommended treatment varies significantly through these stages and factors in the age of the patient, their skeletal maturity, and the location of the condition. The stage can be determined by imaging, and in less severe cases, particularly in juveniles where the growth plate has not fully matured, more conservative treatment is preferred. Surgery typically becomes an option further down the line, in later stage presentations and when conservative treatment has failed.