Abstract
Metaphyseal burst sign, which is soft tissue edema in the metaepiphyseal region, is defined as a novel initial sign of subchondral insufficiency fracture of the knee (SIFK). We reported the first Iranian case of the SIFK in femoral medial condyle characterized by a metaphyseal burst sign which could be an early sign of the SIFK. Early diagnosis and treatment could dramatically relieve the sign and symptoms of patients with significant improvement of the MRI scan.