Scapulohumeral Periarthritis/ Adhesive Capsulitis

Frozen shoulder or scapulohumeral periarthritis, medically referred to as adhesive capsulitis, is a disorder in which the shoulder capsule, the connective tissue surrounding the glenohumeral joint of the shoulder, becomes inflamed and stiff. Movement of the shoulder is severely restricted. The condition is sometimes caused by injury that leads to lack of use due to pain but also often arises spontaneously with no obvious preceding trigger factor. These seemingly spontaneous cases are usually referred to as Idiopathic Frozen Shoulder. Rheumatic disease progression and recent shoulder surgery can also cause a pattern of pain similar to frozen shoulder. Intermittent periods of use may cause inflammation.

Abnormal bands of tissue (adhesions) grow between the joint surfaces, restricting motion. There is also a lack of synovial fluid, which normally helps the shoulder joint move by lubricating the gap between the humerus (upper arm bone) and the socket in the scapula (shoulder blade). It is this restricted space between the capsule and ball of the humerus that distinguishes adhesive capsulitis from a less complicated, painful, stiff shoulder. People with diabetes, stroke, lung disease, rheumatoid arthritis, and heart disease, or who have been in an accident, are at a higher risk for frozen shoulder. Adhesive capsulitis has been indicated as a possible adverse effect of some forms of highly active antiretroviral therapy (HAART). The condition rarely appears in people under 40 years old and (at least in its idiopathic form) is much more common in women than in men. Frozen shoulder in diabetic patients is generally thought to be a more troublesome condition than in the non-diabetic population. If a diabetic patient develops frozen shoulder then the time to full recovery is often prolonged.

With a frozen shoulder, one sign is that the joint becomes so tight and stiff that it is nearly impossible to carry out simple movements, such as raising the arm. People complain that the stiffness and pain worsen at night. Pain due to frozen shoulder is usually dull or aching. It can be worsened with attempted motion. A doctor, or therapist (occupational, massage or physical), may suspect the patient has a frozen shoulder if a physical examination reveals limited shoulder movement. Frozen shoulder can also be diagnosed if limits to the active range of motion (range of motion from active use of muscles) are the same or almost the same as the limits to the passive range of motion (range of motion from a person manipulating the arm and shoulder). An arthrogram or an MRI scan may confirm the diagnosis - although in practice this is rarely required. Most orthopaedic specialists make the diagnosis of frozen shoulder by recognising the typical pattern of signs and symptoms.

Physicians have described the normal course of a frozen shoulder as having three stages: