From 1987 through 1991 thirty-five patients underwent surgical surgical repairs with Wolter's rook plates for acromioclavicular joint rupture. Sixteen of the patients had Post type IV lesions: another 19 patients had the same procedure for Tossy type III lesions. Ative shoulder motion up to 90 degrees of abduction and forward flexion was allowed 48 hours postoperatively. All but one patient regained full range of motion at 8 weeks. Precise bending of the plate before insertion and an accurate drill hole for the crook in the acromion were essential to prevent impingment and also precluded ventral or cranial subluxation in the joint. Using the shoulder evaluation method proposed by Constant and Murley, after 1 year 94.28% (33 of 35) of the patients had excelent results.