Case: Bilateral OCD of the Knee
Reported by Myles Clough, Orthopaedic Surgeon, Kamloops, BC, Canada
14 year old boy with two year history of bilateral knee pain (Right > Left). The pain was intermittent with a recent increase and the sensation of something moving in the right knee. The pain was increased by activity and by keeping the knee flexed for any length of time. It is felt primarily under the kneecaps. He has been aware of a large amount of fluid in the knees. He was referred on suspicion (by his GP) of osteochondritis dissecans.
Examination showed bilateral synovial effusions and retropatellar crepitus and pain. His knees were stable.
Xrays showed normal-looking femoral condyles but abnormality of the patellae was suspected. CT scans of the knees showed bilateral osteochondritis of the patellae. He was booked for arthroscopy of his right knee.
At arthroscopy the undersurface of the patella was noted to be elevated and irregular. Probing showed that the area separated away readily (view from superolateral portal).
The loose area was "craterized."
Several loose bodies were found in the posteromedial compartment of the knee.
At follow-up three weeks post operation the patient's pre-operative symptoms have been relieved with only minimal fluid on the knee. He will be reviewed at 2 months and a decision will be made about the left knee which is minimally symptomatic at present.
a) Is bilateral OCD of the patella as rare as I think it is?
b) Given the state of the joint surface would there have been any point in attempting fixation of the loose fragment?
c) I prepared the patient and family for a mosaicplasty if this procedure doesn't give relief of symptoms. Would anyone do that as a primary procedure? Has the apparant success of osteochondral grafting modified the way we should treat OCD?
d) How aggressive should I be with the left side?
e) What sports limitations should be applied?
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