Rotational osteotomy of the humerus for posterior instability of the shoulder.

We evaluated twelve shoulders (ten patients) that had recurrent, painful posterior instability and were treated by external rotational osteotomy of the humerus. The length of follow-up ranged from two to twelve years. The patients rated the result as excellent or good in ten of the twelve shoulders. Objectively, two shoulders were rated as excellent; eight, as good; and two, as fair. There was recurrent instability in one shoulder that had had multidirectional instability. One pseudarthrosis, which persisted for ten years, was revealed on the follow-up radiographs.