Shoulder joint replacement surgery

Also known as shoulder arthroplasty, shoulder replacement surgery involves removing parts of the shoulder joint and replacing them with artificial ones. 

Your shoulder is a ball and socket joint, also known as the glenohumeral joint. The head of the bone in the upper arm (humerus) sits in the socket (glenoid cavity) of the shoulder blade (scapula). Ligaments and tendons keep the joint in place. In a healthy joint, the ball should move freely in its socket. If the shoulder is damaged by injury or the cartilage covering the end of the humeral head or glenoid is worn away due to an arthritic condition, it can become painful and stiff. If this happens and conservative treatments are not effective in reducing pain and stiffness in the joint, shoulder arthroplasty surgery may be recommended.

Why would I need shoulder replacement surgery?

You might be advised to have a shoulder replacement if you've suffered an injury that has resulted in significant damage. However, people who experience persistent shoulder pain tend to be suffering from arthritis. The two main types of arthritis that can affect the shoulder joint are:

• Osteoarthritis: This is a degenerative condition that causes joint cartilage to gradually wear away due to the ageing process. It usually affects the knee and hip joints. However, the condition can also affect the shoulder, especially in younger people who play a sport which results in increased pressure and inflammation within the joint. If this occurs after an injury, it's also referred to as post-traumatic arthritis. 
• Rheumatoid arthritis: This is an autoimmune condition where the immune system attacks the lining of the joints, leading to inflammation and damaged cartilage. This can also cause pain and stiffness in the shoulder joint. 

In both of these conditions, the articular cartilage that covers the ends of the bones in the joint wears away, resulting in friction between the bones during movement. This is what causes pain, stiffness and immobility.

• Massive rotator cuff failure: If the rotator cuff tendons have all torn your shoulder cannot move properly even though the cartilage is intact. A special type of shoulder replacement, called a ‘reverse’, can restore function in this situation. 

What happens during shoulder replacement surgery? 

Total shoulder arthroplasty involves replacing both the ball and socket via surgery. In some cases, a partial shoulder replacement is carried out. This procedure replaces just the ball if this is the only component that's damaged. 

A general anaesthetic is normally given for a total shoulder replacement surgery, which means you'll be asleep throughout the procedure. If you're given a regional anaesthetic, you'll remain awake with the shoulder completely numbed by a nerve block. Your surgeon will discuss which method of anaesthesia will be used with you. 

The damaged parts of the joint will be removed (usually both the ball and socket). This allows the surgeon to implant the new components. These normally comprise a titanium stem that is inserted into the humerus and connected to a metal ball. These materials enable the shoulder joint to move freely and without friction. The surface skin cut will be closed with stitches and the area covered with a dressing. 

What are the benefits of shoulder arthroplasty? 

The main benefit is a significant reduction in pain. You'll also experience greater mobility and movement of the joint, allowing you to carry out regular activities without restriction. If a painful shoulder joint prevents you from participating in sporting activities such as golf, tennis or cricket, you should find that you can engage in these hobbies pain-free after your recovery period. Surgery can be especially helpful if you have significant pain or difficulty when undertaking everyday tasks, such as driving or working, and non-invasive treatments or medication proved insufficient. 

Are there any risks to having shoulder replacement surgery? 

Complications during the procedure are rare but the following can sometimes occur: 

• Infection: This can occur locally at the site of the wound but is rare provided it is kept clean and dry 
• Nerve damage: Damage to the nerves or arteries is uncommon but there is a small risk with this type of surgery  
• Loose shoulder joint: There is a small risk that the glenoid can become loose following surgery. A shoulder replacement typically lasts 15 years before it wears out. You may want to have it re-replaced at that time.
• Unstable joint: The ball can move out of the socket (dislocation). 

Although the need for further surgery is uncommon, revision surgery might be carried out if the original artificial joint fails. This is usually due to a fracture, dislocation or wear and tear of the artificial joint. There are also some general risks relating to the anaesthetic that your surgeon will explain to you before undergoing your shoulder replacement operation.