RESUMO
BACKGROUND: Although MRI prognostic features for juvenile osteochondritis dissecans (JOCD) have been determined, the natural history of JOCD on serial MRI has not been fully documented. OBJECTIVES: To document the natural history of JOCD on serial MRI and to correlate this with arthroscopy and clinical outcome over a 5-year follow-up. MATERIALS AND METHODS: Twenty-one knees in 19 patients (15 boys, 4 girls; age range 5-15 years) with JOCD underwent MRI and clinical follow-up over 5 years. Lesions were classified as stable or unstable on MRI and compared with clinical and arthroscopic data. RESULTS: On 5-year follow-up, 17 of 19 patients were asymptomatic and 2 of 19 had minimal pain. Fourteen arthroscopies were performed on 11/21 knees. One of twenty-one had fragment fixation. On initial MRI, eight knees had marked fragmentation, high signal at the fragment/bone interface and incomplete defects in the hyaline cartilage (MRI stage III-stable), but no tear. Of these, five had arthroscopy, all confirming intact cartilage. One of twenty-one knees was unstable (MRI stage IVb) with a detached osteochondral fragment, requiring surgery. CONCLUSIONS: Despite extensive subchondral bone changes on MRI, all cases with intact cartilage (95%) improved with conservative treatment. Early MRI allows prompt diagnosis and institution of conservative treatment. This results in healing and avoidance of surgery in most patients.