Classification
OCD is classified by the progression of the disease in stages. There are two main staging classifications used; one is determined by MRI diagnostic imaging while the other is determined arthroscopically. However, both stagings represent the pathological conditions associated with OCD's natural progression.
While the arthroscopic classification of osteochondral lesions is considered standard, the Anderson MRI staging is the main form of staging used in this article. Stages I and II are stable lesions. Stages III and IV describe unstable lesions in which a lesion of the cartilage has allowed synovial fluid between the fragment and bone.
| Stage | Evaluation | Findings |
|---|---|---|
| I | Early | Subchondral bone flattening in the epiphyseal plate before growth plate closure |
| IIA | Stable | Subchondral cyst present |
| IIB | Unstable | Incomplete separation of the osteochondral fragment due to repetitive trauma |
| III | Unstable | Effusions (fluid around an undetached, undisplaced osteochondral fragment) |
| IV | Terminal | Complete separation (detachment) of osteochondral fragment(s); mechanical irregularities and formation of loose bodies |
| Grade | Findings |
|---|---|
| A | Articular cartilage is smooth and intact but may be soft or ballottable |
| B | Articular cartilage has a rough surface |
| C | Articular cartilage has fibrillations or fissures |
| D | Articular cartilage with a flap or exposed bone |
| E | Loose, nondisplaced osteochondral fragment |
| F | Displaced osteochondral fragment |
Read more about this topic: Osteochondritis Dissecans