Frozen shoulder, or adhesive capsulitis is a common condition affecting people generally between the ages of 40-65, especially in people with a history of diabetes, thyroid problems, Parkinson’s, or cardiac disease. Patients with frozen shoulder have progressive loss of range of motion and pain with any motion of the affected shoulder.
The shoulder is a ball and socket joint, but the anatomy of the shoulder allows for an amazing amount of flexibility. The humeral head, or ball, sits on the glenoid, a very shallow socket. It resembles a golf ball on a tee. Because the socket is so shallow, the shoulder relies on the soft tissue around the shoulder for stability. The labrum, a thickened cartilage layer around the glenoid, and the ligaments and capsule, provide a majority of the stability to the shoulder. The muscles of the rotator cuff and scapula also provide stability.
Patients with frozen shoulder usually have increasing pain as their shoulder loses motion. The pain is often exacerbated by quick motions of the shoulder. The shoulder becomes more painful as the stiffness worsens, and it is difficult even for other people to move the shoulder. Diagnosis is usually made by physical exam. Radiographs and MRI are often obtained to rule out other problems in the shoulder.
The cause of frozen shoulder is not understood. Patients with frozen shoulder have thickening of the capsule around the shoulder, which leads to pain and loss of motion. It is more common in diabetics, patients with thyroid disease, and patients who have had a previous shoulder injury and have been immobilized.
Stage 1: “Freezing” Stage:
Characterized by a slow increase in pain, sometimes brought on by an apparently minor trauma. As the pain worsens, the shoulder loses motion.
Stage 2: “Frozen” Stage:
The pain improves, but the stiffness remains.
Stage 3: “Thawing” Stage:
Shoulder motion slowly returns to normal.
Stage 1 can last from 1 month to 9 months; stage 2 from 4 to 9 months, and stage 3 from 5 months to 2 years.