[Posterior shoulder dislocation]

Posterior dislocations of the shoulder can be caused by various mechanisms, the most common one, being epileptic seizures. Therefore many patients or their relatives hesitate to admit, how the injury has actually occurred. Spängler et al. published in 1975 several reasons why the diagnosis of "posterior subluxation of the humeral head" is often missed. Usually very typical errors in the evaluation of the clinical findings lead to misinterpretation of the radiograms. In spite of the fact that long-term results of untreated posterior subluxations can be surprisingly good, reduction must be achieved as soon as possible. Deep impression-fracture of the humeral head are the cause of recurrent dislocations. Various methods have been described to treat this condition by filling the defect with subscapularis tendon or cancellous bone. Avulsion-fractures of the posterior rim of the glenoid can successfully be refixed with small screws. In case of dislocation fractures through the anatomical neck, prosthetic replacement of the head leeds to satisfying results. So-called habitually dislocations are more common in boys and do usually not require surgery, as the inclination to dislocate becomes less frequent in later years. Only in adults operation may be indicated. Posterior apposition of a bone graft can be recommended.