The indications, surgical techniques, results and complications of shoulder fusion are described. The indications are bacterial infection, paralytic disorders in infancy, combined deltoid and rotator cuff paralysis, post-traumatic brachial plexus lesions, inflammatory arthritis with severe rotator cuff involvement, failed arthroplasty, recurrent dislocation, after resection of tumours, irreparable rotator cuff tear, painful arthritis in a patient whose activities require power but not movement, the immunocompromised patient, and tuberculosis. Satisfactory results are achieved in children with isolated shoulder paralysis, but in adults loss of glenohumeral movement is associated with about 50% loss of function. The best results are obtained in cases of isolated shoulder paralysis with a normal arm and hand distally. The most frequent complications are nonunion (5-20%), fracture of the ipsilateral humerus (10-15%) and infection (3-5%). Other causes of failure are functional limitation, fusion in malposition, functional involvement of the distal joints, acromioclavicular dislocation, suprascapular traction neuritis, failure or migration of an internal fixation device, epiphyseal problems, and the complications of using an allograft. Shoulder replacement is most likely to be chosen for most destructive shoulder disorders, but fusion is useful in certain cases. [ABSTRACT FROM AUTHOR]