Side view of the bones in the knee joint, showing a fragment of the femur breaking away secondary to osteochondritis dissecans.
The localised bit of bone may die off and leave a crater, but initially the compromised fragment may not be dead, and it may be possible to fix it back onto the main bone.
What is the cause of osteochondritis dissecans?
There is to date no proof of a single cause for osteochondritis dissecans, and it is likely that many different factors are involved.
Certainly it is associated with children, and small traumas to the knee are likely to be a factor, but the condition is also seen in adults.
....OCD remains an etiological, histological, and therapeutic mystery"....[There are] "4 different possible causes; traumatic, ischemic, hereditary, and idiopathic....Repetitive stress to immature knees and on the tibial spine on the lateral aspect of the medial femoral condyle during internal rotation of the tibia may contribute....Poor vascularity and induced ischemia have been described as a potential cause....[and]....cases of identical twins presenting with a similar disease process are highly suggestive of a genetic component"
....rare in patients who are <10 or ≥50 years old...Boys have more risk....Participation in high-level athletics is associated with the development of OCD...."
How is osteochondritis dissecans diagnosed?
Patients may complain of knee pain and swelling, with noises in the knee (crepitus or clicks) and there may be episodes of knee locking due to loose bodies in the knee. The quads muscles may be weak on that side, although this, too, is non-specific.
Diagnosis is usually confirmed by X-rays and MRI scan.
....This lesion is best observed in lateral and axial radiographic views, and it is located distally and preferentially in the medial facet(20). Computed tomography and magnetic resonance imaging are important for defining the location, extent and viability of the lesion....."
How is osteochondritis dissecans managed?
If the fragment dies (osteonecrosis), then the area is managed like a chondral defect. The area is cleaned out and a cartilage repair technique such as ACI or OATS may be employed to repair the area.
....The options vary according to whether the lesions are stable, unstable, viable or unviable....."
Other relevant links on KNEEguru
A-Z Keywords -
Forum discussions
- "OCD (Osteochondritis Dissecans) Spreading?" - Story of a patient with progressive OCD.