The rotator cuff muscles that surround the shoulder joint are required for normal shoulder movement as they hold the humeral head (ball) on to the glenoid (socket) as the arm is elevated. The rotator cuff can tear and get damaged, particularly as we get older. If too much damage occurs the rotator cuff is unable to keep the humeral head centred on the glenoid during shoulder movement. The deltoid muscle (the outer muscle) pulls the head upwards, out of the socket, when it contracts causing you to shrug your shoulder when you want to lift it. This, in turn, leads to wearing out of the joint cartilage and the development of arthritis, known as cuff tear arthropathy.
Factors to consider
You have been diagnosed with shoulder arthritis with a non-functioning rotator cuff. It is likely that you have already tried non-surgical treatments for your shoulder such as pain killers, lifestyle changes, physiotherapy and injections.
If these measures have not improved your symptoms then the next logical step is to consider a shoulder replacement.
This is a major procedure with potential risks and so you need to consider this carefully. When considering any operation it is important for you to weigh up how bad your symptoms are and what an operation can achieve. A reverse shoulder replacement is very effective at improving pain. It is also quite effective at improving mobility and function.
The main problem in your shoulder is the loss of the rotator cuff muscles. These can not be replaced which means a conventional shoulder replacement will fail in the same way that your own shoulder “failed” as the humeral head can not remain centred on the glenoid.
A reverse shoulder replacement compensates for the loss of the rotator cuff muscles by switching the humeral head to a socket and the glenoid to a ball. The “ball” is replaced with metal and the “socket” with plastic. So, when the deltoid muscle contracts and tries to pull the humeral head upwards the socket hitches on the ball and allows the arm to elevate.
A reverse total shoulder replacement removes the worn out joint and replaces it with an artificial joint. The combination of a metal ball and plastic socket provides low friction to allow your shoulder to move easily.
The operation is performed under a general anaesthetic and you will spend 3-4 hours in the operating department. The operation itself takes approximately 2 hours.
Once under general anaesthetic an incision is made at the front of your shoulder. The worn out shoulder is removed and the new reverse shoulder replacement is inserted. The wound is closed normally using an absorbable stitch. A dressing is applied and your arm is placed in a sling.
The operation is performed under a general anaesthetic and so you will be given instructions as to when you need to stop eating and drinking (normally the night before) before you come into hospital.
It is common for you to be offered a nerve block to help with the pain. The nerve block allows excellent pain relief immediately after the operation. It is considered a safe method of providing pain relief with few complications (less than 1%). You will wake up with a numb arm, similar to when you sleep on your arm awkwardly. The block wears off within 12-24 hours and so it is important to take pain killers the night after the surgery even if you don’t have pain when you go to sleep.
The anaesthetist will talk more about the nerve block when they see you. If you do not want a nerve block your pain can be well controlled with local anaesthetic given during the operation.
What are the risks?
All operations involve an element of risk. Joint replacement surgery is a major operation and so, as with any major operation, complications can occur.
The risk of infection is small and is thought to be about 1%. This is a serious complication but is thankfully quite rare. You are given antibiotics around the time of your surgery to reduce your risk.
If infection does occur you may need to have the shoulder replacement removed, treat the infection using antibiotics and then replace the shoulder at a later date.
Damage to nerves and blood vessels around the shoulder can occur but this is rare. Total shoulder replacement carries a risk of developing blood clots in the leg veins (DVTs) and your lungs (PEs) of approximately 0.5%. You will undergo an assessment to work out your risk for developing blood clots before your surgery and your doctor may prescribe blood thinning medication depending on this assessment.
All joint replacements can wear out, loosen or dislocate. Most shoulder replacements (>80%), however, continue to work well beyond 10 years.
The reverse shoulder replacement changes how your shoulder works by increasing the tension on the deltoid muscle. This means that extra tension is placed on the shoulder blade, which can sometimes fracture. This occurs in up to 5% of patients. The fracture does not normally require any specific treatment apart from rest. Occasionally, a further operation to fix this fracture might be required.
Local anaesthetic or a nerve block will be used during the operation and so you will feel comfortable when you first wake up. The nerve block can make your whole arm feel numb. This can last up to 12 hours but the shoulder may be sore after it wears off. You will be given a combination of pain killers to go home with. It is important that you take regular pain relief so that you can start moving your arm early.
You may also be given an icepack. The nurses will show you how to place the icepack on your shoulder. The icepack should be taken off after 15 minutes and can be used every 2 hours.
You will wake up with your arm in a sling. The arm should be comfortable but it is important to let the nurses know if you have pain so that further pain killers can be given. You will need to use this sling during the first 6 weeks and so it is important to understand how it works. The nurses and physiotherapists will help you with this.
The wound is closed using dissolvable stitches. There will be dressings applied to the wound following your operation. These can occasionally come off and will need to be replaced during the first 2 weeks after surgery to protect the wound.
The dressings are splash proof but not waterproof and so you should avoid getting them wet.
The stitches do not need to be removed but there may be loops at each end of the wound that can be trimmed. The nurses will arrange this to be done at your local GP practice before you are discharged.
Physiotherapy is important to ensure that your shoulder fully recovers. The physiotherapist should see you in hospital to explain some simple exercises you can do after the operation. They will also ensure a physiotherapy appointment is made for you within 3 weeks of the operation. Physiotherapy can be arranged local to you.
You can drive when you feel you are safe to drive. This means that you feel confident that you have full control of your car and are able to swerve out of the way of something in the road. This will vary between patients but normally takes a minimum of 6 weeks.
Return to work
This depends on what your job is. You should be able to return to a “desk job” by around 6 weeks after your surgery. If you have a more manual job it can take up to 12 weeks before you feel ready to return to work. Please discuss this further with your surgeon or physiotherapist if you feel unsure. A sick note can be given to you at the time of your surgery if required. Please ask the nurses on the ward if you need one.
What to expect
Recovery following surgery can be quite variable. Most people will feel good pain relief at an early stage. An improvement in movement, however, will take considerably longer as your muscles need time to regain their strength and adapt to the changes in your shoulder. Your symptoms should be improved/improving by 3 months with the majority fully recovered by 6 months. It can, however, take up to a year for some patients to fully improve.