Post-traumatic avascular necrosis of the humeral head in displaced proximal humeral fractures.

Nineteen patients with displaced four-part fracture or fracture-dislocation of the proximal humerus were retrospectively studied to investigate the incidence of avascular necrosis and its clinical importance. The average followup duration was 23.6 months. No incidence of avascular necrosis of the humeral head with subchondral collapse was found. Four patients were found to have coarse trabeculae suggesting a revascularized humeral head which probably had become necrotic after the trauma. The treatment of choice for displaced four-part fracture or fracture-dislocation of the proximal humeral is early adequate open reduction and internal fixation rather than primary prosthetic replacement. The authors believe that a majority of the humeral heads in this injury develop avascular necrosis, but most of the humeral heads are quickly revascularized with creeping substitution.