Synopsis

Keywords: Musculoskeletal: Joints

We defined early-onset osteochondritis dissecans (OCD) as occurring at age < 12 years, with skeletal maturity < 15 points, and onset within < 1 month. For five cases meeting these criteria, we aim to chronologically observe imaging changes in early-onset OCD and discuss its early pathologies based on MRI findings. Early-onset OCD is presumed to involve loading pressure on the chondral tissue, leading eventually to the influx of synovial fluid/cells into the subchondral bone marrow, deterioration of the subchondral trabeculae, and progression to subchondral bone cysts or sclerosis. The presence of intraarticular ossification complicates the interpretation of findings.