Later stages are characterized by dense collagenous tissue in the joint capsule.Under the microscope, the appearance of the affected shoulder joint capsule tissue is similar to the appearance of the tissue that restricts finger movement in Dupuytrens contracture. Diagnosis
Adhesive capsulitis can be diagnosed by history and physical exam. It is often a diagnosis of exclusion, as other causes of shoulder pain and stiffness must first be ruled out. On physical exam, adhesive capsulitis can be diagnosed if limits of the active range of motion are the same or similar to the limits to the passive range of motion. The movement that is most severely inhibited is external rotation of the shoulder.Imaging studies are not required for diagnosis, but may be used to rule out other causes of pain. Radiographs will often be normal, but imaging features of adhesive capsulitis can be seen on ultrasound or non-contrast MRI. Ultrasound and MRI can help in diagnosis by assessing the coracohumeral ligament, with a width of greater than 3 mm being  60% sensitive and 95% specific for the diagnosis. Shoulders with adhesive capsulitis also characteristically fibrose and thicken at the axillary pouch and "rotator interval", best seen as a dark signal on T1 sequences with edema and inflammation on T2 sequences. A finding on ultrasound associated with adhesive capsulitis is hypoechoic material surrounding the long head of the biceps tendon at the rotator interval, reflecting fibrosis.
Surgery to cut the adhesions (capsular release) may be indicated in prolonged and severe cases; the procedure is usually performed by arthroscopy. Surgical evaluation of other problems with the shoulder, e.g., subacromial bursitis or rotator cuff tear, may be needed. Resistant adhesive capsulitis may respond to open release surgery. This technique allows the surgeon to find and correct the underlying cause of restricted glenohumeral movement such as contracture of coracohumeral ligament and rotator interval. Physical therapy may achieve improved results after surgical procedure and postoperative rehabilitation.Physical therapy is an effective procedure that provides essential exercises to improve range of motion. Patients who receive the proper training from an authorized physiotherapist can perform these exercises independently at home. The physiotherapy treatment for frozen shoulder will include manual therapy to mobilize the affected joints and release their muscles. "Pendulum stretch", "finger walk", "towel stretch", "armpit stretch" and "crossbody reach" are some essential mobility exercises specifically designed to improve the shoulder mobility of patients with frozen shoulders. There are also limited case reports of therapy utilizing vibration platforms obtaining fast results, not as a post-operative aid, but instead of surgery.Acupuncture has been found to decrease pain levels and improve shoulder function and range of motion, particularly in shoulder flexion. Acupuncture combined with shoulder exercises was found to be more effective than shoulder exercise alone. However, further studies with longer follow-up times are needed to assess mid- and long term benefits. Prognosis
Most cases of adhesive capsulitis are self limiting, but may take 1 to 3 years to fully resolve.