We operated on 13 patients with birth palsy who had dysfunction of the shoulder. Five external rotation osteotomies of the humerus were performed, two of which were combined with muscle transfer of the latissimus dorsi for external rotator reconstruction. Four combined trannfers of the latissimus dorsi muscle and the pectoralis major muscle and four combined transfers of the trapezius muscle and the latissimus dorsi muscle were performed. The gain in external rotation by osteotomy immediately after the operation was equivalent to the angle rotated. In the three cases without the latissimus dorsi muscle transfer, however, the gain decreased year by year and the gain had been totally lost at the final follow-up. On he other hand, the gain was maintained in cases with simultaneous latissimus dorsi muscle transfers. When the latissimus dorsi and the pectoralis major muscles were transferred, external rotation improved from-21 degrees to 33 degrees and the gain has been maintained. In addition, improvement in abduction was found in three of the five osteotomy cases and one out of the four muscle transfer cases of the latissimus dorsi and the pectoralis major. After muscle transferes of the trapezius and the latissimus dorsi, abduction improved from 50 degrees to 100 degrees and external rotation improved from-8 degrees to 12 degrees.
