Synopsis

• Osteochondritis dissecans (OCD) is defined as an area of osteonecrosis in subchondral bone that supports overlying cartilage.
• If the patient's growth plates are still open, the lesion is considered juvenile OCD (JOCD) and has a better prognosis for healing than adult OCD, where the growth plates are closed.
• Separation of cartilage from the underlying necrotic subchondral bone may result in a stable or unstable fragment of bone with attached overlying cartilage in the knee.
• OCD is caused by many factors including genetics, ischemia, altered local growth, inflammation, ossification, and repetitive microtrauma of the joint. It may also be idiopathic.

• Prevalence is 15-29 cases of OCD per 100 000 people.
• Most frequently seen in patients aged 10-19 years.
• Males are at 4 times increased risk compared to females.
• 69% of cases involve the lateral aspect of medial femoral condyle.
• 15% of cases involve the weight-bearing portion of the lateral femoral condyle.

• Male
• Active in sports
• Black race or Hispanic or Asian descent
• Obese

• Grade 1 – normal articular cartilage
• Grade 2 – fragmentation in situ
• Grade 3 – partial detachment
• Grade 4 – complete detachment, loose body present