The underlying pathophysiology is incompletely understood, but is generally accepted to have both inflammatory and fibrotic components. The hardening of the<unk>  joint capsule is central to the disease process. This is the result of scar tissue (adhesions) around the joint capsule. There also may be a reduction in synovial fluid, which normally helps the<unk>  joint, a ball and socket joint, move by lubricating the gap between the humerus and the socket in the<unk>  blade. In the painful stage (stage I), there is evidence of inflammatory cytokines in the joint fluid. Later stages are characterized by dense collagenous tissue in the joint capsule. Under the microscope, the appearance of the affected<unk>  joint capsule tissue is very similar to the appearance of the tissue which stops the fingers from moving in Dupuytren’s contracture, a fairly common condition where the little finger curls into the palm.
Adhesive capsulitis of the shoulder
Biceps
Retrocalcaneal bursitis
Osteoarthritis
Shoulder impingement syndrome
Autoimmune disease
Milwaukee shoulder syndrome
Rotator cuff tear