ABSTRACT
The most common presentation is in a child aged between 10 and 13 years. Boys are affected twice as commonly as girls. Bilateral lesions are present in 25%.
In osteochondritis dissecans there appears to be an underlying abnormality of the epiphysis. A history of injury is present in half the patients. Endogenous trauma from discoid menisci or tibial spines, ischaemia, abnormal ossification and hereditary influences have all been suggested as possible causes. The condition needs to be distinguished from osteochondral fracture and chondral flaps and separations which are traumatic in origin.
