PreoPeratIve evaluatIon History and PHysical Examination

Traditionally, osteochondritis dissecans (OCD) has been thought of as a rare disorder occurring in approximately 15 to 21 per 100,000 knees.1 However, OCD is becoming increasingly more common as a cause of knee pain in teenagers and young adults. This may be due to earlier and increasingly competitive athletic endeavors.2 In addition, the widespread use of magnetic resonance imaging (MRI) as a diagnostic tool for evaluating knee injuries has undoubtedly led to earlier recognition of OCD lesions. OCD is an acquired, potentially reversible lesion of the subchondral bone that may result in separation and instability of the overlying articular cartilage.1,3,4-11 The exact cause of OCD remains controversial.4-6,9 Multiple causes of OCD have been postulated, including endocrine imbalance, familial predisposition, vascular insufficiencies, epiphyseal abnormalities, and trauma.12-14 In contrast to adult OCD lesions, juvenile OCD lesions have the potential to heal with nonoperative treatment, such as activity modification (cessation of repetitive loading).15-19 Adult OCD lesions are more likely to be unstable, generally leading to worse outcomes through a progressive decline. OCD lesions may cause mechanical disruption of joint motion, loose body formation, mechanical wear in the involved compartment, and attrition of associated surfaces on the tibial plateau or the menisci. Thus, they are likely to lead to a progression of degenerative joint disease. The surgical treatment of OCD lesions once symptomatic is difficult and needs to be adjusted to the stage of the OCD lesion, the symptoms, and the associated damage at the time of treatment. PreoPeratIve evaluatIon