In shoulder replacement surgery, the damaged parts of the shoulder are removed and replaced with artificial implants. This may entail replacing just the head of the humerus bone (the ball) or replacing both the head and the glenoid (the socket).
There is a range of surgical options, depending on your individual circumstances. These include:
- Stemmed hemiarthroplasty: only the ball at the top of the humerus is replaced using a metal stem that sits inside the upper arm bone with a metal ball on the top. This type of surgery may be used if the humerus is severely fractured but the socket remains in good condition.
- Resurfacing hemiarthroplasty: This entails replacing just the joint surface at the head of the humerus with a cap-like prosthesis but no stem. This type of surgery may be recommended if you have intact cartilage in the shoulder socket (glenoid) or if there is no fracture of the humeral neck or head. It is ideal for younger or very active patients as it does not carry the same risk of components wearing and loosening that comes with total shoulder replacement.
- Total shoulder replacement: the arthritic joint is completely replaced with an artificial implant consisting of a polished metal ball and a plastic socket. If your bone is in good condition the surgeon may use a press-fit component. However, if the bone is soft, bone cement may be used to hold the components in place.
- Reverse shoulder replacement: Conventional shoulder replacement surgery is not suitable for patients with large tears in the rotator cuff who have developed a form of shoulder arthritis called cuff tear arthropathy. For these patients, reverse shoulder replacement provides the only surgical option. Whereas conventional shoulder replacement mimics the normal anatomy of the shoulder, with a plastic cup fitting into the shoulder socket and a metal ball at the top of the upper arm, in reverse shoulder replacement the metal ball is fitted into the socket and the plastic cup is attached to the upper end of the humerus. Rather than relying on the rotator cuff muscles to move the arm, a reverse total shoulder replacement uses the deltoid muscles. The result is a dramatic reduction in pain from arthritis with a better range of movement for people with cuff tear arthropathy.
- Balloon shoulder arthroplasty is another ground-breaking surgical procedure to treat the pain associated with major irreparable rotator cuff tears. It entails inserting a balloon-shaped device above the shoulder joint to create a physical barrier between the bones to reduce pain, improve shoulder function and delay more invasive surgery. The spacer dissolves naturally after around a year.
A range of conditions cause severe pain and disability in the shoulder joint, which may lead to the need for shoulder replacement surgery. These include:
- Osteoarthritis – a degenerative disease associated with wear and tear of the joint. It normally occurs in more elderly people although younger patients can also be affected. The condition causes cartilage in the shoulder joint to wear away, meaning the bones rub against one another resulting in pain and stiffness.
- Rheumatoid arthritis – a chronic autoimmune condition where inflammation and thickening of the capsule of the shoulder causes cartilage loss, pain and stiffness.
- Post-traumatic arthritis – arthritis that follows a serious shoulder injury, causing pain and loss of function in the shoulder.
- Rotator cuff injury – a large or long-standing rotator cuff tear may result in rotator cuff tear arthropathy, which can lead to arthritis.
- Severe fracture – if the head of the upper arm bone is shattered, fixing the fracture may lead to a very poor outcome with longstanding pain and poor function and a shoulder replacement may be recommended. This is particularly common in older patients with osteoporosis.
Surgery normally takes around two hours after which you will be moved to the recovery room and monitored while you recover from the anaesthetic. You should be able to get out of bed the day of or after surgery and go home after one to two days. You will be given antibiotics to prevent infection and pain relief medication. Physiotherapy will be important for your rehabilitation and you will be given exercises that will help to strengthen your shoulder and improve function. You will need to wear a sling for two to four weeks after surgery. Within two weeks you should be able to perform some basic everyday activities such as using your arm to eat and get dressed. Your surgeon will advise you when it is safe to drive. Six weeks after surgery you should regain much improved shoulder movement and will normally be able to return to work, depending on your career.
Joint replacement surgery is an effective way of reducing pain and improving movement and function in the affected shoulder. The majority of patients can return to their day-to-day activities, including low impact sports, without experiencing pain. Complications are rare but all surgery carries some risk, such as infection, shoulder instability or loosening of the implant, and your surgeon will discuss these with you. New advances means surgeons are continually developing less invasive techniques, which provide faster recovery times.