“Fractures of the proximal portion of the fifth metatarsal may be classified as avulsions of the tuberosity or fractures of the shaft within 1.5 cm of the tuberosity. Tuberosity avulsion fractures cause pain and tenderness at the base of the fifth metatarsal and follow forced inversion during plantar flexion of the foot and ankle. Local bruising, swelling and other injuries may be present. Nondisplaced tuberosity fractures are usually treated conservatively, but orthopedic referral is indicated for fractures that are comminuted or displaced…. “(1)“The development of a secondary center of ossification (apophysis) at the proximal end of the fifth metatarsal can be mistaken radiographically as a fracture site. In girls nine to 11 years of age and boys 11-14 years of age, the apophysis becomes visible on plain radiographs as fleck of calcification adjacent to the fifth metatarsal shaft. The apophysis has an oblique orientation, with the radiolucency aligned parallel to the fifth metatarsal diaphysis. No treatment is necessary.Apophysitis of the fifth metatarsal (Iselins disease) is a self limiting disorder of active children that spontaneously resolves with completion of growth. The child complains of localized pain on activity that resolves with rest. Physical examination reveals tenderness at the fifth metatarsal base. Rarely, the clinician finds associated ecchymosis and edema. Radiographic findings include irregular apophyseal density and shape. Treatment is primarily limitation of activity.Accessory Ossicles may also be confused with avulsion fractures. The os Vesalianum is quite rare and may be found next to the peroneus brevis insertion. The more common os perineum can be located at the lateral border of the cuboid within the substance of the peroneus brevis tendon. Each ossicle can be radiographically differentiated by its smooth appearance; in contrast avulsion fractures appear to have “scalloped” edges. Symptomatic accessory ossicles may be definitively treated with surgical excision.”(1) |