[Shoulder arthrodesis. Possible causes of functionally poor results].

Due to severe articular destruction of the glenohumeral joint with corresponding soft tissue changes arthrodesis has been performed in 24 patients since 1973. After an average period of 5.4 years (2-15) years, 22 patients were reviewed. Primary bone consolidation was achieved in all cases. During the observation period in 7 cases one of the following additional operations had to be performed on the involved shoulder: subcapital osteotomy due to excessive abduction (2 cases), resection of the acromio-clavicular joint due to painful osteoarthritis (2 cases), partial resection of an ugly acromion projecting laterally (1 case), removal of the fixation plate protruding proximally (4 cases). 18 patients experienced a marked improvement after arthrodesis. No improvement in 2 cases and a deterioration in 2 cases were the result of a not optimal positioning of the arthrodesis. A position of 20 of abduction, 20 to 30 of flexion and 45 of internal rotation proved to be functionally the most beneficial. Patients will be only painless if the optimal position of the arthrodesis was achieved. Excessive abduction and flexion was generally experienced as unpleasant. Deviation in the rotational position leads to functional restriction. The remaining function after arthrodesis is often overrated.