Shoulder Joint Replacement

Shoulder Replacement

Shoulder replacement is becoming more and more popular as a remedy for arthritis and fractures of the shoulder. Shoulder replacement surgery alleviates pain by replacing the damaged bone and cartilage with a metal and plastic implant. In a total or hemi shoulder replacement, the worn head of the upper arm bone or humerus is replaced with a metal ball mounted onto a stem. The socket or glenoid bone of the scapula may also be resurfaced with a polyethylene (plastic) component.

Arthritis of Shoulder

The shoulder is sometimes affected by arthritis. When arthritis of the shoulder is due to wear and tear, it is called osteoarthritis.

The Causes

Osteoarthritis is mainly due to age related degeneration. Secondary osteoarthritis may be due to damage to the shoulder caused by previous injury or surgery. Rheumatic problems like rheumatoid arthritis can also lead to shoulder arthritis.

A long-standing rotator cuff tear will lead to rotator cuff arthropathy. Because of the tear, the rotator cuff function becomes deficient and it is unable to stabilize the head of the humerus in the joint. As the head of the humerus abuts the acromion, it gets eroded and causes pain.

Symptoms

Pain behind the shoulder and also in the front is the main symptom. The pain is accompanied by progressive loss of ROM. Joint movements may be associated with clicks or crepitus. Muscle wasting is also observed.

Diagnosis

Clinical examination, X-rays, CT and MRI.

Treatment

Osteoarthritis

In the early stages, injection of Hyaluronate into the joint can give relief in some, with exercises and activity modification. Late stages require joint replacement. Recently we offer a new procedure called surface replacement, in which only the worn out surface is replaced with a cup. Previous procedures included cutting of the ball of the head of humerus to perform this procedure. In the recent technique, bone cutting is minimized and can be performed using smaller approach.

Rheumatoid Arthritis

Patients with rheumatoid arthritis can also benefit from surface replacement. This procedure makes the joint pain free with good range of movements.

Rotator Cuff Arthropathy

Arthritis resulting from the deficiency of rotator cuff is severe and the treatment is different from other forms of arthritis A good cuff is essential for shoulder replacement to be successful. Because the rotator cuff is totally useless in these patients, a novel procedure called reverse shoulder arthroplasty is used.

Shoulder Joint Replacement

Shoulder Joint replacement is not as frequently done as hip and knee replacement. Nevertheless, there are many indications and many types of shoulder prosthesis available. The types of shoulder joint replacement are

Shoulder Hemiarthroplasty - In this method, only half of the shoulder is replaced. The head of the humerus is replaced with prosthesis. This procedure is indicated in shoulder fractures which are beyond reconstruction and are associated with loss of blood supply.

Total Shoulder Replacement - In this procedure, both the ball and socket are replaced. Usually indicated in arthritis of the shoulder, this method has now been surpassed by the introduction of surface replacement of the shoulder. In this procedure, only the worn out surfaces of the joints are replaced. Hence sacrifice of excessive bone is avoided. And, this technique also allows for either the surface of the ball only or both the surfaces to be replaced.

Reverse Shoulder Replacement - This is a different type of shoulder replacement, where the ball and socket components are reversed. That is, the socket is on top of the arm bone and the ball where normally the socket will be in the shoulder blade. This type of joint is used in cuff tear arthropathy.

Reverse Shoulder Arthroplasty - Rotator cuff deficiency rules out the use of conventional replacement surgery in certain patients. Reverse shoulder involves the placement of a cup in the head of humerus (the erstwhile ball) and attaching a ball to the glenoid (the erstwhile cup). Because of this arrangement, the excessive superior migration of head of humerus is avoided. Because the cup becomes the ball and vice versa this procedure is called reversed shoulder arthroplasty.