Allograft reconstruction of segmental defects of the humeral head associated with posterior dislocations of the shoulder.

Six men underwent operative management of defects of the humeral head involving at least 40% of the articular surface, following posterior dislocation of the humeral head. The cause of dislocation was a grand mal seizure in three and a fall in three cases. In five cases the dislocation was reduced under general anaesthesia, and in all the posterior dislocation recurred early. Time between dislocation and surgery ranged from 7 to 8 weeks. The defect in the head, revealed by CT, was filled with an allogeneic segment of humeral head contoured to restore the spherical shape. All the patients returned to their occupation 4 months later. The mean duration of follow-up was 62.6 (60-68) months. At discharge, four of the men had no complaints of pain, instability, clicking or catching; two had pain, clicking, catching and stiffness. Radiographs and CT revealed no failures of fixation or of incorporation of the allograft. In four cases the contour and volume of the graft were maintained, but in the two with a bad clinical result, flattening and collapse of the graft and osteoarthrosis were observed. If the procedure fails, prosthetic reconstruction should be simple because the skeletal anatomy has not been distorted.