RESUMO
An isolated avulsion fracture of the subscapularis from the lesser tuberosity of the proximal humerus is rare in the pediatric population and only a couple of cases have been described in literature. A 12-yearold right-handed boy, was admitted to the hospital with left shoulder pain after falling down the previ-ous day. Physical examination revealed tenderness on the lesser tuberosity and intertubercular groove of the humerus and a limited range of motion. Ultrasonography, computed tomography, and magnetic resonance imaging showed an isolated avulsion fracture of the subscapularis tendon from the lesser tuberosity of the humerus, accompanied by medial subluxation of the long head of the biceps tendon.In this case, a subscapularis avulsion fracture which is rare in this age group was detected at an early stage, and surgical treatment resulted in positive outcomes. Subscapularis avulsion fractures in children are difficult to diagnose in the early stages, and if not treated on time, the symptomatic improvement may be delayed. Timely and accurate diagnosis and treatment can help faster return to normal activi-ties. We would therefore like to report this case with a literature review.