Shoulder Arthritis

Arthritis or osteoarthritis is a condition where the articular cartilage of a joint is damaged and is progressively lost. 

The shoulder is a joint commonly affected by arthritis. Because it is a major joint with a pivotal role in many activities, arthritis can have a significant impact on your life. Arthritis is a progressive disease that comes on over years and decades. When the cartilage is completely lost, the person may reach the stage of having “bone on bone”.

Many conditions lead to cartilage damage and osteoarthritis. However, many cases are idiopathic, which means that there is no specific cause. There is probably a genetic component to this idiopathic variety, and joints other than the shoulder are commonly involved (knees, hips and hands). A long-standing, massive rotator cuff tear can lead to a particular type of arthritis, so-called “cuff tear arthropathy”. Injuries, such as dislocations and fractures, can cause cartilage damage.  Diseases that cause inflammation of a joint such as Rheumatoid Arthritis can lead to cartilage damage. Arthritis is more common as we age, but it is not an inevitable consequence of ageing. 

Symptoms of shoulder arthritis

The predominant symptom of arthritis is pain. However, a person can have significant arthritis but only mild symptoms. Often the pain from osteoarthritis is intermittent. Factors such as increased activity (e.g. going for a much longer walk than usual) or a minor injury may trigger an acute exacerbation. Typically these flares tend to resolve with time and appropriate nonsurgical treatment. As the arthritis progresses, the pain tends to worsen both in intensity and duration. In the later stages of the disease, the pain can be disabling. Night pain is commonplace and tends to cause sleep disturbance as the arthritis deteriorates. Many people seek definitive treatment when the night pain becomes severe.

Arthritis can cause other symptoms in the shoulder. Arthritis leads to loss of movement, especially the ability to raise the arm and place the hand behind the back. Other symptoms include swelling and weakness. Problems with day-to-day activities such as dressing and personal hygiene can also occur.

Shoulder arthritis diagnosis

The diagnosis of osteoarthritis of the shoulder can be made based on your age, symptoms and the findings when a doctor examines your shoulder. However, imaging of the joint is required to confirm the diagnosis. X-Rays show characteristic changes of a reduced gap between the two bones (indicative of the extent of cartilage damage) and the presence of bone spurs (osteophytes) that project out from the bones.

As yet, there is no specific treatment to restore the cartilage damage. The cartilage loss is slowly progressive worsening over years to decades. However, as mentioned above, the pain from the arthritis is intermittent. 

Treatment

Non-surgical treatment

The initial treatment of arthritis is nonsurgical.

Gentle strengthening

Loss of muscle mass starts in our thirties and worsens as we age. Arthritis will compound the problem. An appropriate exercise program may help strengthen your shoulder and arm, and improve its function. A physiotherapist can facilitate a strengthening program 

Once lost, shoulder movement is hard to restore. However, maintaining the existing range of motion is important.

Medication

Medications may be required to help with the arthritic pain. Paracetamol is the recommended first-line analgesic. Paracetamol is useful for an acute flare of pain, or more regularly, as the arthritis worsens. Nonsteroidal anti-inflammatory drugs (NSAIDs) can be helpful for short term use. Because of potential side effects, use caution for people with heart, kidney and gastrointestinal conditions. Therefore please discuss with your family doctor before using. COX-2 inhibitors such as Celebrex can be tried and are often better tolerated.

More potent analgesics such as opioid-containing drugs should be used cautiously and only for a short duration. Surprisingly they are often not that helpful for the pain of arthritis.

Cortisone injections into the joint can be helpful for some people, mainly if there is an inflammatory component to the arthritis. The duration of benefit of a cortisone injection is variable. They also tend to be less effective with repeated injections.

There are also many treatments purported to help or “cure” arthritis, but there is little evidence for their use. Glucosamine and chondroitin are two of the building blocks of cartilage. Although widely used, their benefit remains unproven. There is no scientific substantiation for many other heavily advertised supplements. Stem cell therapy is a costly and heavily promoted procedure with little evidence of its clinical benefit.

Surgical treatment

Shoulder replacement

Shoulder replacement (or shoulder arthroplasty) has become the treatment of choice for people with end-stage shoulder arthritis. It is a significant procedure. It involves removing the worn-out articular cartilage and then resurfacing the shoulder with metal and plastic components. Before your shoulder replacement, further imaging is required to determine the best option. A CT scan assesses bone loss and the shape of the glenoid socket. An MRI or ultrasound looks at the presence of rotator cuff damage.

There are two main types of shoulder replacement, “anatomic” and “reverse”. With an anatomic replacement, a plastic socket resurfaces the arthritic socket. A metallic ball attached to a stem that secures it into the humerus bone replaces the head of the humerus. As its name implies, a reverse shoulder replacement replaces the socket with a ball and top of the humerus with a socket. Reverse shoulder replacements are now the most standard variety performed in Australia.

Most people stay in the hospital for two to three days after the operation. Rehabilitation to get the shoulder moving and to build up strength is critical to a good outcome. The rehab program should continue for a minimum of three months to get the most benefit after a shoulder replacement. The vast majority of people obtain good pain relief and improved function.