Osteochondritis dissecans (OCD)
OCD is the end result of the aseptic separation of an osteochondral fragment with the gradual fragmentation of the articular surface. It is often associated with intraarticular loose bodies. The most common joints affected by osteochondritis dissecans are the knee, ankle and elbow, although it can also occur in other joints.
There are several classification systems for OCD lesions that are based upon plain radiograph, magnetic resonance imaging (MRI), or arthroscopic findings. On plain radiograph, the severity of the OCD lesion is defined according to the
Berndt and Harty Classification:
● Stage I – Small compressed, nondisplaced fragment
● Stage II – Partially detached fragment
● Stage III – Completely detached, nondisplaced foreign body
● Stage IV – Completely detached and displaced foreign body