Osteochondritis dissecans (OCD) is a fragmentation and possible separation of a portion of the cartilage of the joint.
This usually presents during adolescence.
Symptoms are pain aggravated by motion, limited motion, clicking, and swelling.
It may be caused by injury, but not always. A history of significant trauma can be elicited in approximately 50% of patients. Males are more commonly affected with a ratio of 3:1.
The osteochondral fragment may 1) remain in situ, 2) be slightly displaced or 3) be loose within the joint cavity. If the fragment remains attached to the underlying bone, healing can occur. If completely detached, complete healing does not occur. The loose cartilage body may increase in size and cause locking and clicking of the joint. In some cases, the fragment may become absorbed. Treatment of this lesion depends on the status of the fragment.
The lesions are classified on MR Scans , as follows:
Grade 1: intact cartilage with signal changes in subchondral bone
Grade 2: a high signal breach of the cartilage; low signal posterior to the lesion
Grade 3: thin high signal rim extending behind the osteochondral fragment indicating synovial fluid around the fragment
Grade 4: mixed or low signal loose body in the center of the lesion or free within the joint
The type and extent of surgical treatment depends on the grade of the lesion.
Grade 1 lesions generally do not require surgical treatment.
Grade 2 lesions are usually drilled in an attempt to aid healing of the fragment.
Grade 3 lesions although attached by a rim of articular cartilage, require internal fixation.
Grade 4 lesions require removal and debridement of the bony bed.