Your shoulder is the most mobile joint in your body. It is made up of a ball and socket joint called the glenohumeral joint which is surrounded by a fibrous sleeve called the capsule.
Osteoarthritis of the shoulder is a degenerative disease caused by the deterioration of cartilage and other tissues in the shoulder joint. It is less common than osteoarthritis of the hip and knee but nevertheless around three million people are believed to be affected.
Types of shoulder arthritis
In Why Have I Developed Shoulder Arthritis? we outlined the different types of shoulder arthritis and their causes. These include:
- Primary osteoarthritis of the main ball and socket joint (glenohumeral joint). In most people this is caused by a longstanding biomechanical imbalance of the muscles contracting around the joint increasing pressure on the cartilage surface. Breakdown of the cartilage in the joint occurs and eventually the bones begin rubbing together.
The same process of cartilage breakdown can also occur for other reasons, but with the same end result of arthritis:
- Rheumatoid arthritis is a type of inflammatory arthritis and an autoimmune disorder where your body attacks its own joint linings. The are many other forms of inflammatory arthritis too, many go undetected for years.
- Rotator cuff tear arthropathy is a form of arthritis that can develop if the rotator cuff – a group of four tendons and muscles that keep the shoulder stable within its socket – are severely torn and not repaired.
- Post-traumatic shoulder arthritis is another type of arthritis that can develop after serious injury, such as a shoulder fracture or repeated dislocation or even previous damage from surgery.
- Avascular necrosis occurs when the bone at the top of the humeral head dies and this may result in arthritis. It most commonly occurs after a fracture, but there are many other causes.
- AC joint arthritis is caused by damage to the cartilage in another smaller joint on top of the shoulder where the collarbone and shoulder blade meet.
All forms of arthritis produce pain, which worsens over time, as well as shoulder stiffness and loss of function.
Diagnosis of shoulder arthritis
A diagnosis of shoulder arthritis will be given following a detailed examination and discussion of your symptoms. Your doctor will check for pain when you move your shoulder, loss of muscle strength and movement, tenderness, a grating sensation inside the joint or swelling. You will normally be given an X-ray to check for changes in the bone, the formation of bony spurs or narrowing in the joint space. A CT scan is often useful to assess the pattern of arthritis, and an MRI scan may be needed to assess the soft tissues around the joint. A blood test may be required to check for rheumatoid arthritis if scans are suggestive of this.
Treatment for shoulder arthritis
In the early stages of the disease, lifestyle changes can help you to manage the symptoms of shoulder arthritis. These include:
- Exercises recommended by a physiotherapist to increase flexibility and range of motion.
- Taking painkilling medication and anti-inflammatories to help to control the symptoms.
- Making lifestyle changes recommended by a therapist, such as wearing clothing that does up at the front rather than pulling on over the head or avoiding using a hairdryer that requires the arms to be held above the head for long periods of time.
- Avoiding or easing back on work or sports that require overhead activity or heavy lifting
- Taking dietary supplements such as glucosamine and chondroitin which can help in some circumstances.
Non-surgical treatment for shoulder arthritis
Injections of corticosteroids
If painkilling medication proves insufficient, an orthopaedic surgeon may recommend an injection of corticosteroids into the shoulder joint. This can provide short-term relief from pain and inflammation and may help to delay the need for more invasive surgery. It can be repeated up to a few times per year. An alternative type of non-steroid medication called hyaluronic acid is available too, but it has not been shown to be more effective.
Surgery for shoulder arthritis
As arthritis becomes more advanced, you may be offered surgery to provide more long-term pain relief and help to restore function to the shoulder. Your orthopaedic surgeon will discuss the most suitable form of surgery for you, depending on the type and severity of your arthritis. Possible surgical treatments include:
- AC joint excision: This is commonly used to treat AC joint arthritis.It involves removing a small piece of the end of the collarbone to create more space in the arthritic joint and prevent the ends of the bones from rubbing together. The procedure can be performed by a keyhole technique, but very often the results are better using a traditional min-open surgery technique, especially for patients of larger stature or with advanced arthritis.
- Arthroscopic microfracture: This is a keyhole technique used to treat small and localised areas of damaged cartilage. Using a camera called an arthroscope to guide the procedure, it involves creating small holes in the bone to encourage new cartilage growth. It is not suitable for patients with more advanced arthritis.
- Partial joint replacement: This involves replacing the head of the humerus only and is also called a hemiarthroplasty. It is less popular now than it used to be and is usually reserved for younger patients for whom implanting a socket might cause problems in the future due to it wearing out.
- Total anatomic arthroplasty: Also called shoulder joint replacement, this is offered for the most severe types of arthritis. It involves replacing the whole shoulder with an artificial joint made from highly refined metal ball and a plastic socket. On average this surgery will result in about 10-15% better function than a partial replacement. However, it is only suitable for patients with strong and balanced rotator cuff tendons. Most plastic sockets last 10-15 years on average, maybe 20 years at best, and would need to revised after this time period
- Reverse shoulder arthroplasty: This surgery involves switching the position of the ball and socket within your joint using a specially designed prosthesis which maximises the strength of the large muscles around the shoulder. It is now the most commonly used type of shoulder replacement in the UK because the results are very good and most patients have who require a shoulder replacement also have a problem with their rotator cuff or a have very misshapen shoulder socket. This type of replacement has been in use for over 30 years but the design has been refined and improved a lot over that time, resulting in longer lasting and better performing implants with lower rates of complication.
If you are experiencing symptoms of shoulder arthritis, it is important to get an accurate diagnosis so you know what is causing the problem. Your orthopaedic surgeon can then discuss the most suitable treatment options with you.