From the SAYSO Trainer’s Notebook
Dissecans (OCD)
OCD is neither common nor rare. It occurs most frequently in knees, and in the knees of children, teenagers, and young adults. Basically, portions (called 'lesions') of the smooth parts of the knee surfaces that rub against each other become damaged. Parts of the cartilage may separate from the bone. The cause of OCD is difficult to determine, but trauma, inherent cartilage defects, and sudden losses of circulation to portions of the knee bone are all suspected.
Less like the more common Osgood Schlatter Disease, a limited range of motion can be a symptom of OCD. Confirmation of the diagnosis requires radiography, and even then, indications may be subtle.
Untreated, the severity of OCD will increase. Treatment of OCD requires resting the injured joint for a long period. Surgery is required in some cases.