Shoulder (Glenohumeral) Arthritis
Knowledge that empowers
What is it?
Arthritis is a degenerative condition affecting the smooth cartilage that lines the ball and socket joint of the shoulder.
As this cartilage wears out, there is increasing load placed on the underlying bone. This can eventually cause pain due to bone to bone friction and loss of range of movement due to bone deformity and abnormal bone formation. Osteoarthritis of the shoulder is less common in comparison to many other joints, principally the hips, knees, and hands. It is nonetheless a debilitating problem and can have a significant impact on the patient’s life.
Who is affected?
Traditionally thought of as a ‘wear and tear’ phenomenon. Some people are more susceptible to osteoarthritis than others.
Contributing factors are prior shoulder surgery, history of trauma, inflammatory conditions (mainly Rheumatoid arthritis), and shoulder overuse. People who have worked in occupations involving manual labour. Also particularly at risk are those who engage in high intensity overhead activities such as weightlifters or racquet sport players, collision athletes (rugby) or had those who had previous trauma to the shoulder.
It is also possible to develop significant arthritis in the shoulder years after suffering a significant tear of the rotator cuff tendons. This is known as a rotator cuff tear arthropathy. A large tear in the rotator cuff that isn’t treated can lead to a significant biomechanical imbalance in the shoulder. The shoulder joint progressively decentres. Once the shoulder joint decentres, the cartilage starts wearing during to abnormal forces and the patient develops significant pain, loss of motion and function.
Rheumatoid arthritis is a condition in which the patients own immune system mistakenly attacks the joints causing widespread inflammation and damage, being the glenohumeral joint one of the targets.
What are the symptoms?
Insidious onset, progressively worsening pain in the shoulder and the upper arm is often the most concerning symptom for those suffering from shoulder osteoarthritis. As the arthritis progresses, there is progressive loss of movement with “catching” and “clicking” heard during movements. It is often difficult to sleep on the affected shoulder.
What is the prognosis?
Osteoarthritis tends to progress over time, however there is no way to predict how quickly or how advanced the condition may become. Some patients function well for many years without treatment, and some patients require early treatment to help manage symptoms.
How is the diagnosis made?
A simple series of x-rays can help confirm the diagnosis of shoulder osteoarthritis. In some cases, an MRI scan may be useful to rule out other causes for shoulder pain, commonly concomitant rotator cuff tears. Similarly a CT scan of the shoulder may also be requested if it is decided that surgical management would be the most appropriate option.
Pathology tests may be required to check for other arthritic conditions.
Non surgical treatment
For younger patients, or for those with manageable symptoms, the aim is to delay shoulder replacement surgery as long as possible due to the wear that occurs on the surgical components once they are inserted.
If pain is not severe, no immediate treatment may be needed. Some activity and lifestyle modifications might be required to avoid unnecessary irritation of the shoulder.
Mild or moderate pain killers and anti-inflammatory medications may be taken to provide symptomatic relief. However, these drugs do not cure and will not alter the course of the disease
While physiotherapy cannot ‘cure’ arthritis, your physiotherapist can provide advice on pain management, how to modify your activity and ways that you can stay physically active despite your shoulder condition. Physiotherapy can also help to optimise the strength, mobility and function of your shoulder, and other areas around your shoulder to optimise your function.
An injection of corticosteroid into the glenohumeral (shoulder) joint can help control pain in people whose pain is not well controlled with medications. Corticosteroids are an anti-inflammatory that can help reduce pain associated with inflammation in shoulder arthritis. Should this be necessary, you will be referred to have this procedure under imaging guidance by a radiologist. If the injections provide good relief of pain, they can sometimes be repeated at periodic intervals. They do not usually increase movement of the shoulder, but can help with pain control.
There is now evidence that cortisone injections within the 4 months prior to surgery may increase the rate of infection. Therefore, it should be avoided if you are planning to have a surgery of your shoulder, especially a shoulder replacement.
Suprascapular nerve block
For some patients with high levels of pain who are not suitable for, or don’t want surgery, a nerve block performed under ultrasound guidance can provide effective pain relief for periods of time.
In advanced stages, surgery to replace the affected joint may be required. The ultimate aim of having joint replacement for shoulder arthritis is to reduce pain. Thanks to advances in technology, the prostheses used in joint replacement surgery can offer patients excellent levels of physical function.
A/Prof. Raniga will, in discussion with you, select the most appropriate joint replacement for you. A three-dimensional CT scan and surgical planning software are used prior to surgery for planning and to choose the correct sized components.
Anatomical Total Shoulder Arthroplasty (TSA)
If the rotator cuff tendons of the shoulder are intact, an anatomical total shoulder arthroplasty (joint replacement) can usually be performed. This replaces the ball and socket with components that perform the same function as a normal shoulder joint. A sling is worn for up to 4 weeks, followed by physiotherapy to help restore range of motion and function. Most patients achieve excellent pain relief and regain movement of the arm above shoulder height.
A hemi arthroplasty involves replacing the head of the humerus bone (the ball) with a prosthetic component. This technique is typically chosen in younger patients who do not have significant arthritis in the socket (glenoid). A suitable group would be those suffering from AVN (avascular necrosis) of the humeral head, because the glenoid (socket) is preserved in early stages.
Reverse shoulder arthroplasty (RSA)
If the rotator cuff tendons of the shoulder are torn, the classic anatomic total shoulder replacement does not work, because the ball is not kept in the socket effectively by the deficient rotator cuff. For this end, the ball and socket components are reversed (swapped), changing the joint biomechanics so that the shoulder moves with the deltoid muscle. This configuration changes the line of pull of the deltoid muscle to more easily elevate the arm in place of the normal tendons.
This procedure is ideal for patients who have arthritis with no rotator cuff tendons. Although the RSA does not give as good function as anatomic shoulder replacement, it improves preoperative range of motion and is very effective in taking away pain.
Following joint replacement surgery, a sling is typically required for a period of 4 weeks to protect the soft tissues that are affected during surgery. Following this period, it is critical to restore range of motion by completing a routine of exercises prescribed by your physiotherapist. Once sufficient healing of the soft tissues has occurred, it is then time to commence strengthening of the shoulder muscles.
The total time for rehabilitation depends on your choice of recreation and occupational tasks, however you can expect approximately the total time to be approximately 4-6 months.