Anatomy
Arthritis is a degenerative and age related condition. It causes the lining of the joint (cartilage) to wear away, leaving a roughened and worn joint surface that causes pain and loss of motion. In the shoulder, arthritis is likely to occur on the head of the upper arm bone (humerus) and on the glenoid, the ‘socket’ part of the scapula. It can also occur at the acromioclavicular joint (ACJ), where the collar bone (clavicle) meets the acromion, the bony tip of the shoulder blade (scapula).
Symptoms
Joint pain is the most common symptom of arthritis. This is often associated with a gradual reduction in the movement of the shoulder as the disease progresses. There may be a clicking noise in the joint when the arm is raised above the head. Pain is often felt in the shoulder at night, causing sleep disturbances.
Non-Operative Treatment
Conservative measures are usually the first step in treating the symptoms of shoulder arthritis. These include resting the shoulder and avoiding activities that cause pain to the shoulder. Non-steroidal anti-inflammatory drugs are also used to help reduce inflammation and control pain in the joint. Occasionally, the injection of cortisone and local anaesthetic drugs can be used to help control pain.
Operative Treatment - Copeland Hemiarthroplasty or Total Shoulder Replacement
When the pain and stiffness of arthritis become unbearable, it is time to consider shoulder replacement surgery. The part of the shoulder affected by arthritis determines the type of shoulder replacement. If only the head of the humerus is affected, I perform a Copeland Hemiarthroplasty. The humeral head only is resurfaced and replaced with a thin metal prosthesis. This is a very conservative operation. It is not associated with removal of a lot of bone stock, and does not require a stem down the humeral shaft. It is a simpler operation, with lower morbidity, faster recovery, and allows a total shoulder replacement to be performed if required at a later date.
The other option in shoulder joint replacement is a Total Shoulder Replacement. In this surgery, both the humeral head (ball) and socket (glenoid) will be replaced with prosthesis. A metal stem extends down the arm bone (humeral shaft), a metal ball replaces the humeral head, and the socket is replaced with polyethylene prosthesis. The prostheses may or may not be cemented in place.
An artificial shoulder usually has a life span of 10-15 years, so is often not recommended for a person under 50 years.
If the rotator cuff is torn or weakened prior to surgery, a cuff repair may also be performed during the shoulder replacement surgery.
Post-Operative Course
Hospitalisation following a hemiarthroplasty is usually 1-3 days. With a total shoulder replacement, it may be a day longer. A passive exercise program will be organised, and physiotherapy may be appropriate. A sling shoulder immobiliser will be worn for the first few weeks. It should be worn 24 hours a day, except for exercise and showering.
In the early stages following surgery, icing of the joint is appropriate. This should be applied to the shoulder joint region for 30-40 minutes two or three times a day for the first few days. Heat may also be helpful in a similar manner. Remember not to apply either ice or heat directly to the skin.
At six weeks, when the shoulder joint capsule is healed, an increased exercise program will occur. This will include active exercises, and final rehabilitation of the shoulder is best achieved in the swimming pool. If movement is sufficient, gentle freestyle swimming is ideal. Return to less arduous sports such as golf and bowls is fine, but sustained, particularly above-head activities are usually not possible after shoulder arthroplasty. Most people regain a reasonable range of movement, but few ever gain full range of movement after total replacement surgery of the shoulder.
Improvement following shoulder arthroplasty can go on for 6-12 months before the final stable result is achieved. Whilst regular appointments will be made during the post-operative period, it is important that you feel comfortable contacting the office or myself if you have any questions or any perceived problems with your shoulder replacement.
Practice Perspective
In my practice, I routinely perform a Copeland resurfacing hemiarthroplasty in the majority of arthritic shoulders. If a total shoulder arthroplasty is required, I use the French Aqualis prosthesis. The Copeland Hemiarthroplasty has excellent longevity, now out to 20 years.
Post-operatively, the arm requires immobilisation to allow healing of the surgical incision into the shoulder joint capsule, and this takes some six weeks to become secure. During that time, limited movement will be allowed, but movements that may damage the shoulder capsule repair must be restricted. These movements are rotation of the arm away from the body (external rotation), and elevation of the arm away from the body, (abduction). Forward flexion and pendulum activities are however allowed and may be started earlier without any risk.
Risks/Complications
Shoulder resurfacing surgery is a very successful procedure in most cases, however prolonged joint pain and stiffness may persist after surgery.
Other risks associated with this surgery include: