Wolter's hook-plate provides active abduction and forward-flexion of up to 90 degrees two days postoperatively. Prebending of the plate and a precise drill hole for the hook in the acromion prevents later impingement of the hook on the humeral head or subluxation in the acromioclavicular joint, respectively. According to the shoulder evaluation form of C.R. Constant, 33 of 35 patients operated on between 1987 and 1991 at the trauma departments in Schwaz/Tirol and Bad Ischl showed excellent results one year postoperatively.