What is shoulder replacement surgery?
Shoulder replacement is a procedure which replaces a worn-out shoulder joint, which is a ball and socket joint. It restores function and most importantly relieves pain.
Shoulder joint replacement surgery is less common than knee or hip replacement surgery, but it is a safe and effective procedure for relieving severe shoulder pain associated with conditions such as shoulder osteoarthritis and severe rotator cuff injuries.
It is normally only offered when other, less invasive procedures, such as medication and pain-relieving injections, are no longer effective or if you have a severe shoulder fracture.
If you have pain and stiffness in your shoulder joint, your consultant will assess you and may request X-rays, MRI scans and a CT scan. The decision-making process will review the condition of your ball and socket shoulder joint and also the state of your rotator cuff.
Why might I need shoulder replacement surgery?
The shoulder is a ball and a socket joint with a large ball and a shallow socket to allow a larger range of movement than any other joint in the body. It can be compared to a golf ball and tee. The shoulder’s stability relies on the surrounding soft tissues including the muscles and tendons which form the rotator cuff and the shoulder capsule, which is the ligament surrounding the shoulder joint.
The joint surfaces are covered with articular cartilage, which allows for frictionless movements of the joint. The rotator cuff muscles keep the shoulder centred.
Two types of arthritis develop in the shoulder joint, one with an intact rotator cuff known as osteoarthritis of the shoulder joint and the other where the rotator cuff is deficient (rotator cuff arthropathy), which develops with irreparable degenerative rotator cuff tears. This decompensates the humeral head and leads to superior migration of humeral head causing impingement, pain and stiffness (pseudo paralysis).
The type of joint replacement required varies according to the type of arthritis involved. An arthritic shoulder with intact rotator cuff would need a total shoulder replacement that mimics the normal anatomy of the shoulder joint. Rotator cuff arthropathy requires a reverse shoulder replacement, where the ball and socket are switched to improve shoulder function. This type of shoulder replacement relies on the outer deltoid muscle to power the shoulder. Some shoulder fractures especially in elderly population are also treated with this kind of shoulder replacement to improve function.
In addition to this, trauma is also a causative factor in the development of shoulder arthritis. 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.
Shoulder replacement surgery
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).
Our consultants use the latest technology to perform shoulder replacements and work with a range of the latest implants to ensure that patients benefit from the most suitable option for their condition and anatomy.
There are a range of surgical options for shoulder replacement, depending on whether you have an intact rotator cuff or not. After careful examination and reviewing your MRI and CT scans, your consultant will make a decision about which implant would be appropriate for you.
Typically, if your rotator cuff is intact, you will get an anatomic or total shoulder replacement. If the rotator cuff is torn, your consultant will perform a reverse shoulder replacement.
There are different types of humeral implants which are long stem, short stem and stemless. These all depend on your bony anatomy and your consultant will discuss these options with you and plan your operation depending on these criteria. The implants are most commonly made of metal including titanium, cobalt chrome alloys, polyethylene. Ceramic shoulder replacements can be used; however, these are relatively new and there are currently no studies comparing the outcomes with other materials.
The new generation of short stems or stem less implants provide better restoration of normal anatomy in young patients where bone preservation is vital. These need a less invasive technique to insert and work to conserve bone stock, allowing for easy revision in the future if this is required.
Options for shoulder replacement surgery 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 is the only definitive surgical treatment. 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.
After having your pre assessment, you will be admitted on the day of operation. The surgical procedure normally takes 1 to 2 hours but extra recovery and anaesthetic time should be allowed for. Your consultant makes an incision in the front of the shoulder about 6 to 8 inches long and removes your humeral head, that is the ball and also your socket is smoothed. The appropriate socket device will have been decided in advance and discussed with you and the operation will be planned virtually using dedicated computer software.
Sometimes, they may also use patient specific implantation, which is a surgical guide used to prepare the socket for implantation. Once they have prepared the socket, they will fit the appropriate implant. Then the shoulder joint is reduced and examined to assess for any instability or any problems. Once the surgeon is satisfied that a stable implant has been fitted, they will wash the shoulder joint and close the incision.
After the surgery, you will remain in the recovery room until the anaesthetic has worn off. You can expect to stay in hospital for one to two days, but you will be encouraged to get out of bed and mobilise from the day of or after the surgery. On discharge, you will be given antibiotics and pain relief medication and you will need to wear a sling for two to four weeks after surgery.
You will have a visible scar in the front of the shoulder from the incision. however, the overall shape of the shoulder should not change.
Physiotherapy will be important for your rehabilitation and you will be given exercises that will help to strengthen your shoulder and improve function. Within two weeks you should be able to perform some basic everyday activities such as using your arm to eat and get dressed. Six weeks after surgery you should expect improved shoulder movement and most will be able to return to work, depending on your career. Your surgeon will advise you when it is safe to drive.
As with any major surgery, there are potential risks and complications with shoulder replacement surgery. These risks are related to the procedure itself and the generic anaesthetic risks. The risks relevant to the procedure are infection, damage to nerves or blood vessels, fracturing of the bone while doing the procedure, dislocation of the implant and wearing of the shoulder implants. There is also a risk of blood clots, postoperative pneumonia and the general anaesthetic risks. Your surgeon will discuss these risks with you at length during the consent process and would make a joint decision with you about proceeding with the surgery. If you have any further questions, you should discuss these with the consultant on the day of your operation.
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 mean surgeons are continually developing less invasive techniques, which provide faster recovery times.
Studies have shown that total shoulder replacement has excellent survivorship with up to 90% survival in the first 10 years and 81% in 20 years. This can be affected by factors including activity, age, weight, rotator cuff function and overall health. In the long term, implants do wear, and loosening can occur, and, in this case, you may require revision surgery.