Osteoarthritis is a type of degenerative joint disease. It involves the breakdown of the cartilage the covers bones. Without articular cartilage to prevent friction between two adjoining bones, swelling and inflammation occur. In severe cases, bone spurs can form.
WHAT IS SHOULDER ARTHRITIS?
Shoulder arthritis often involves this process of cartilage breakdown. The shoulder is not one joint but two; the acromioclavicular (AC) joint and the glenohumeral joint. The AC joint connects the clavicle (collarbone), and the tip of the shoulder blade (acromion). The glenohumeral joint connects the top of the arm bone to the scapula (shoulder blade).
WHAT ARE THE SYMPTOMS OF SHOULDER ARTHRITIS?
Shoulder arthritis is often characterized by pain during or after the movement of this joint. The condition may also cause pain to occur when a person is sleeping and the muscles around the joint relax. Another common sign of shoulder arthritis is stiffness or pain that limits the range of motion. When the arm moves to such an extent that engages the shoulder joint, the joint may produce a clicking sound.
WHAT CAUSES SHOULDER ARTHRITIS?
Arthritis is the result of gradual wear and tear that breaks down the cartilage between two or more bones. The degeneration of this living tissue, which is normally about as thick as one or two layers of cardboard, occurs in stages. First, the cartilage softens. When soft, cartilage can develop cracks. The degraded cartilage then starts to flake and deteriorate. In a latter stage, the cartilage wears down enough to expose bone surfaces. This exposure inhibits the ability of cartilage to move in a mothing, gliding motion.
Cartilage does not wear away spontaneously nor consistently. Certain parts of the cartilage over a bone may wear down, creating a spot that sticks and rubs. The covering over bone becomes irregular and eventually leads to additional damage to surrounding cartilage tissue, bit by bit. It can take years for this process to result in bone-on-bone traction.
WHAT CONDITIONS CAN LEAD TO SHOULDER ARTHRITIS?
There are several circumstances or conditions that can lead to shoulder arthritis, including:
- Trauma – A shoulder that has been injured in some way, whether dislocation or fracture, may develop what is called post-traumatic arthritis.
- Rotator cuff tear – is a common shoulder injury. When not treated promptly or if severe, the tear in the rotator cuff can degrade one or more of the tendons that support the shoulder joint to such an extent that the bones in the shoulder bump up against the humeral head.
- Rheumatoid arthritis – is a systemic autoimmune disorder in which the healthy cells in the body are being attacked by the immune system. Different than other types of shoulder arthritis, rheumatoid arthritis can affect both shoulders simultaneously.
- Avascular necrosis – For tissue like cartilage to live, they rely on good blood supply. Without it, they die. Avascular necrosis describes tissue death resultant from disrupted blood supply. In the shoulder, it is the humeral head that may not receive the necessary circulation. This could be due to injury, disease, or other factors. As a result, the humeral head will degrade, lose shape, and cause uneven wear of the cartilage that covers it.
HOW IS SHOULDER ARTHRITIS DIAGNOSED?
After taking a thorough medical history, a doctor performs a physical examination that evaluates range of motion, tenderness, pain, and other symptoms. This examination may reveal signs of weakness and atrophy caused by lack of use. The structures within the shoulder also need to be observed. To do this, a doctor will order one or more tests, such as:
- Blood tests to exclude diseases like rheumatoid arthritis
- Testing of synovial fluid taken from the shoulder joint
NON-SURGICAL TREATMENT OPTIONS FOR SHOULDER ARTHRITIS
Shoulder arthritis is usually treated non-surgically before intervention is considered. The process may include:
- Rest – Minor injuries or pain in the shoulder may improve by limiting the movement of this joint.
- Non-steroidal anti-inflammatory medication – This over-the-counter medication may be recommended to reduce irritation in the inflamed joint.
- Physical therapy – A noninvasive program, physical therapy involves certain exercises to improve the strength, flexibility, and stability of the joint.
- Moist heat and ice may be recommended to reduce
inflammation and pain.
- Prescription medication may be necessary in more severe cases.
SURGICAL TREATMENT OPTIONS FOR SHOULDER ARTHRITIS
Surgical intervention for shoulder arthritis may be necessary when more conservative modalities do not improve symptoms as desired. Shoulder surgery may involve:
- Resection arthroplasty. This procedure removes a small piece of the collarbone where it meets other bones at the AC joint.
- Hemiarthroplasty. This surgery remodels the head of the humerus, the bone of the upper arm, where it meets other structures at the glenohumeral joint.
- Total shoulder arthroplasty. More extensive shoulder arthritis may require the replacement of the entire shoulder joint with an artificial structure made of biocompatible materials.
HOW CAN SHOULDER ARTHRITIS BE PREVENTED?
The shoulder is one of the most used and most mobile joints of the body. Injury may not be completely avoidable, but steps can be taken to promote strength and integrity in the shoulder joint. Suggestions include:
Supporting joint cartilage by consuming foods rich in omega-3 fatty acids. These acids help control inflammation. Wild-caught sardines, mackerel, trout, and salmon are high in omega-3 fatty acids. Supplements with these acids are also available.
Exercise is good for all of our joints. Certain movements, such as plank pose or well-performed push-ups can strengthen the muscles that support the shoulder joint. The stabilization that stems from strong muscles can reduce wear and tear on the joint.
All movements and exercise, especially sports, must be engaged in with the proper form and equipment to reduce the risk of injury to the joint.
WHAT HAPPENS IF SHOULDER ARTHRITIS IS LEFT UNTREATED?
Shoulder arthritis must be treated. The earlier the better. Without adequate attention to the deterioration of the cartilage in the shoulder, patients run the risk of developing more extensive damage in the joint, such as:
- Bone spurs. Small growths may develop when the affected bone creates more surface area to support the weight and pressure within the joint.
- Tendon or ligament damage. When the joint is degraded by arthritis, tendon, and ligaments are forced to work harder and carry more weight and pressure than they are capable of. This causes stretching and can lead to injury.
- Septic arthritis, an infection in the joint, may occur in some cases. This condition can cause a deformity in the joint and exacerbate pain. Reconstructive surgery is needed to address this arthritic condition.
- Osteonecrosis. At a certain point, arthritis in a joint can impede blood flow to the bones and other structures.
Without adequate blood circulating through, the bone will weaken, degrade, and die.