Contracture of the shoulder.

A retrospective study involving 2027 patients with a limited range of motion of the shoulder in the period from 1970 to 1987 is described. Of these, 1219 patients (60%) were diagnosed as having frozen shoulder, with the highest incidence occurring in patients aged 50-60 years. The mechanism involved in the contracture is complicated. At first, the movement of the greater tuberosity at the subacromial level (also called the subacromial secondary joint) is limited due to bursitis. The external rotation of the upper arm then decreases, and the long rotator muscles contract. The relationship between the cause of contracture and the direction of the decreased mobility was analyzed. A ratio of the degree of external rotation with the arm beside the body to that achieved with the arm elevated to the horizontal plane showed values of almost one to one. Conservative treatment including physiotherapy, local anesthetic block, and joint distension must be attempted in all patients. If the conservative treatment remains ineffective, the surgical procedure should be considered. Satisfactory clinical results of arthroplasty of the subacromial joint were obtained in patients with frozen shoulder.