Frozen shoulder

Anatomy of shoulder joint

The shoulder joint is a ball and socket joint. The ball is the top of the arm bone (the humeral head), and the socket is part of the shoulder blade (the glenoid). Together these bones form the glenohumeral joint. The shoulder joint allow flexion/ extension, abduction/adduction and internal/external rotation.

Frozen shoulder is also called adhesive (scarred) capsulitis (inflamed joint capsule). This is a problem that occurs in the shoulder resulting in stiffness, loss of motion and substantial pain. The motion loss in this disorder is due to tightening and thickening of the ligaments and other supporting structures of the shoulder. This tightening and thickening (fibrosis) results in restriction of movement that can severely limit function.

Causes

A frozen shoulder may arise after a fracture or other arm injury. It may also be related to a rototor cuff tear, degenerative arthritis or previous shoulder surgery. Many cases of frozen shoulder, however, do not have a known cause. These cases are called idiopathic or primary adhesive capsulitis. Despite not having a known cause, primary adhsive capsulitis can be associated with systemic disorders such as diabetes and cardiovasular disease.

Pathology of frozen shoulder

The causes of a frozen shoulder are unknown. The problem of a frozen shoulder occurs in 3 phases. Each phase is approximately 4 months in length.

• Initially, a "freezing phase" occurs.
• Followed by a "frozen phase"
• Completed by a "thawing phase"

Frozen shoulder may last as long as a year. Fortunately, it is very rare for the disorder to recur. This disorder usually occurs between the ages of 40 and 60. It is twice as common in women as men with about 70% of the cases occur in women. There may be some association with thyroid disease, diabetes and other diseases.

Most cases of frozen shoulder follow a specific pattern. Initially, there is an acute phase that is characterized by significant pain, difficulty sleeping and significant functional impairment. This is followed by a progressive stiffening phase when the shoulder motion worsens. The final phase is the resolution or thawing phase identified by the gradual return of both motion and function. The overall course is variable but can last 12-24 months.

Signs and symptoms

Frozen shoulder typically develops slowly, and in three stages:

• Painful stage. During the painful stage, which can last anywhere from two to nine months, pain occurs with any movement of your shoulder.
• Frozen stage. Pain may begin to diminish during this stage, which may last from four to 12 months. However, your shoulder becomes stiffer and your range of motion decreases notably. It's perhaps as much as 50 percent less than in the other arm. Avoid extreme movements that cause pain during this stage. But, you can and should continue normal use of your shoulder.
• Thawing stage. During the thawing stage, which can last up to 12 months, the condition may begin to improve. Although this healing process sometimes occurs on its own, you may need the help of a doctor.
• The pain associated with frozen shoulder may be aching or burning. For some people, the pain worsens at night, sometimes disrupting normal sleep patterns.
• The patient usually cannot lift their arm up past shoulder height, cannot do up their bra or tuck in their shirt
• Has difficulty reaching across under the other arm (i.e. washing the opposite arm pit). The exact degree of shoulder stiffness present may be variable but in order for a shoulder to be classified as truly frozen there must be significant movement loss (i.e. less than 100 degrees of abduction or sideways movement).

Diagnosis

If there is loss of both active (movement without assistance) and passive (movement with assistance) on physical examination, the diagnosis of a frozen shoulder can be made. The patient will also describe a pattern of pain that is a times severe and at other times mild. The overall function of the shoulder in the acute phase of a frozen shoulder is poor.

Treatment

Frozen shoulder treatment primarily consists of pain relief and physiotherapy Exercises and stretching for frozen shoulder serves two functions:

First, to increase the motion in the joint

Second, to minimize the loss of muscle on the affected arm (muscle atrophy)

Diligent physiotherapy is often key and can include ultrasound, electric stimulation, range of motion exercise maneuvers, ice packs, and eventually strengthening exercises. Physical therapy can take weeks to months for recovery, depending on the severity of the scarring of the tissues around the shoulder.