Arthritis

Understanding the causes of arthritis is easiest if you understand the structure of the joints themselves.

The shoulder is made up of the shoulder blade (scapula), collarbone (clavicle) and upper arm (humerus). It is surrounded by the rotator cuff muscles and tendons, which help with the movements of the shoulder and help to keep the ball in the middle of the socket. There are two main joints in the shoulder: the acromioclavicular joint where the collarbone meets the shoulder blade; and the glenohumeral ball and socket joint where the head of the humerus moves on the socket (glenoid) of the scapula.

The elbow has two main joints within it. The main joint is the hinge between the upper arm (humerus) and the lower arm (ulna). This hinge allows the arm to bend and straighten. There is also a small ball and socket type joint at the elbow between the humerus and the radius bone of the lower arm which allows the forearm to rotate.

There are five main types of arthritis that can affect the shoulder and elbow:

• Osteoarthritis – wear and tear arthritis which causes the cartilage in the joint to wear away and can result in the bones rubbing against one another causing pain. It is more common in the acromioclavicular joint than the glenohumeral joint of the shoulder. It is common in the elbow after prolonged repetitive load in manual jobs or sport, leading to extra bone formation (osteophytes) that catch with pain when the arm bends or straightens.
• Posttraumatic arthritis – this is a form of osteoarthritis that develops after an injury.
• Inflammatory arthritis – this is an autoimmune disease that results in the immune system attacking the body’s own tissues, including the joints. Rheumatoid arthritis is the most well known inflammatory arthritis, causing the lining of the joints (the synovium) to swell, and leading to the joint surfaces eroding away. It can affect multiple joints at the same time.
• Avascular necrosis – this occurs when the blood supply to the joint is interrupted, causing the death of bone cells. In the shoulder it is most common in the head of the humerus after injury or certain drug treatments, but gradually it can damage the entire joint.
• Rotator cuff tear arthropathy – this arthritis of the shoulder can develop after a severe or long-standing rotator cuff tendon tear. Because the muscles no longer hold the shoulder in position, the shoulder pushes upwards and can wear away.

The symptoms of arthritis include:

• Pain which gradually worsens as the joint deteriorates and can become particularly bad at night, making it difficult to sleep.
• Loss of mobility and increasing weakness in the joint.
• A grinding, cracking or snapping sound when you move the affected joint.
• Stiffness in the joint.
• Locking of the joint due to loose pieces of cartilage or bone becoming trapped between the moving surfaces of the joint.
• Catching (impingement) when extra bone formation at the edges of the joint (osteophytes or spurs) bang together during movement.
• In the later stages of elbow osteoarthritis, numbness may occur in the ring finger or little finger due to pressure on the ulnar nerve.

A number of different approaches may be used to diagnose arthritis, including:

• A physical examination to assess for pain and weakness in the joint, loss of mobility and crepitus.
• X-ray to assess the extent of the arthritis. It can also check for the formation of painful bony spurs and narrowing of the joint space.
• CT or MRI scans can give detailed pictures of the damage to the bones themselves or the cartilage surface.

There are a number of possible treatments that will be determined by the type and extent of the arthritis. Initially, non-surgical treatments will normally be recommended including:

• An exercise program to improve the range of motion in the joint, build strength and learn how to perform everyday actions without exacerbating the pain.
• Anti-inflammatories and painkillers.
• Injections of corticosteroids into the joint to reduce pain and inflammation.
• Injections of hyaluronic acid into the joint to increase lubrication and reduce pain.
• Drugs to treat rheumatoid arthritis – following a review with a Rheumatologist.

Surgery
When the pain of arthritis becomes severe, you may be offered surgery. There are a number of surgical treatments for the common types of arthritis in the shoulder and elbow depending on the type of arthritis and the severity. Ultimately joints can be fully replaced, which is often called arthroplasty.

Acromioclavicular joint arthritis:
Arthroscopic resection – this is a minimally invasive (keyhole) surgical procedure to remove the worn out rubbing bone surface. It involves making a small incision in the skin and inserting an arthroscope, which is a tiny tube with a camera at one end that allows the surgeon to see inside the joint. Tiny surgical tools are inserted through further incisions in the skin to remove the end of the collarbone in the joint and prevent painful catching.

Open removal of the distal clavicle – this may be used if there are large spurs at the end of the collar bone requiring a bigger cut to remove them fully.

Shoulder ball and socket (glenohumeral joint) arthritis:

• Arthroscopic debridement – this is a minimally invasive (keyhole) surgical procedure to remove rough bone surfaces and loose debris and release tight tissue creating stiffness. Sometimes early arthritis or cartilage damage can be treated with keyhole surgery techniques to try and fill holes and prevent further cartilage damage
• Open debridement – this isn’t commonly used for shoulder arthritis but may allow removal of abnormal bone or tissue causing pain and stiffness.
• Anatomic total shoulder replacement – this involves replacing both the head of the humerus and the shoulder socket with a metal and plastic joint of a similar shape and size.
• Reverse total shoulder replacement – this involves replacing the ball and socket joint by swapping the socket for a ball attached to the shoulder blade and placing a cup at the top of the arm bone. This complicated replacement allows the arm to lift using the outside shoulder muscles (deltoid) when there may be damage or failure of the rotator cuff muscles.
• Hemiarthroplasty – involves replacing just the head (ball) of the humerus.

Elbow Joint

• Arthroscopy – this is a minimally invasive (keyhole) surgical procedure to remove some of the bone spurs and loose fragments whilst releasing tight linings around the joint. Small patches of damaged cartilage can sometimes be treated with keyhole techniques to prevent further damage and fill any holes.
• Open debridement – if there are large bone spurs then an open operation through a larger cut may allow the surgeon to remove bone and scar tissue to relieve painful catching and improve movement. This type of operation is sometimes called an ‘OK’ procedure.
• Elbow joint replacement – for severe arthritis an elbow joint replacement can replace part or all of the hinge of the elbow. This complex procedure should be performed by an expert in a major orthopaedic centre such as Nottingham. It is excellent for relieving pain and improving movement but there are limits to the weight that can be lifted after the procedure to protect the joint in the long term.