抄録
We have treated an old unreduced posterior dislocation of the left shoulder joint associated with large impression fracture of the humeral head. A 52-year-old man fell down and injured his left shoulder. He was diagnosed as having a 3 part fracture of the humeral head. At that time, however, a posterior dislocation was overlooked. Although bone union was completed, motion pain and restriction of both external rotation and abduction persisted for 10 months. A posterior dislocation of humeral head was revealed by an axial x-ray film. His left shoulder was posteriorly dislocated and associated with about a 45 % bone defect of the anteromedial aspect of the humeral head. The posterior edge of glenoid rim was locked in the bone defect of the humeral head. Open reduction was performed, but redislocation occured easily with 20 degrees of internal rotation of the humeral shaft during the operation. Iliac cortical bone grafting was performed on the posterior rim of the glenoid to prevent redislocation. At present, active ROM of the affected shoulder is as follows: flexion,110degrees, extention,40 degrees, abduction,80 degrees, external rotation,55 degrees and internal rotation,20 degrees. According to Neer, in a case of posterior dislocation of humeral head associated with a 20 % ?40 % bone defect of the humeral head, the modified Mclaughlin procedure is the recommended method to prevent redislocation. However, in such a case as ours, in which subscapular muscle and anterior capsule of the shoulder joint is damaged extensively, posterior bone block operation might be the alternative procedure for prevention of shoulder dislocation.
