[Undiagnosed posterior dislocations of the shoulder joint. A preliminary report].

Posterior dislocations are infrequent injuries of the proximal humerus, counting for 1-4% of all shoulder dislocations. Frequently, they are related to epileptic seisures or electric current injuries or accompany complete anatomical neck fractures of the proximal humerus. Very frequently, they remain undiagnosed and their late diagnosis results in poor functional outcomes. The authors assess the surgical procedure and its results in five cases of primarily undiagnosed posterior dislocations. In two cases, transposition of the m. subscapularis was performed, in one case hemiarthroplasty, and in two cases derotation osteotomy of the proximal humerus was used. Although the study group was small, the preliminary results of the procedures for chronic posterior dislocation of the shoulder joint favours preservative procedures compared to hemiarthroplasty of the shoulder joint.