The shoulder is the most mobile of all joints. Unfortunately it can wear out, which is known as shoulder osteoarthritis
- Dr Duckworth
The shoulder joint is considered to be one of the most complex joints in the body.
It is made up of three main bones: the scapula, clavicle and humerus. The shoulder joint is unique in that the ball of the upper arm bone (the humeral head) is two times larger than the socket of the shoulder blade (the glenoid). This creates a very mobile joint, but demands an extensive array of tendons, ligaments and muscles to keep the joint together. These together allow the smooth movement found in the healthy shoulder.
The main shoulder joint (the glenohumeral joint) allows more movement than any other joint in the body. It is responsible for one to raise their arm, to put their arm up their back and to bring it out to the side.
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Unfortunately the shoulder joint can wear out like any other joint in the body and can therefore develop arthritis. This causes pain and joint destruction. The following three types of arthritis are the most common sources of joint damage seen in the shoulder:
Osteoarthritis is a disease which involves the breakdown of the tissue (cartilage) that normally allows the joint to move smoothly. When the gliding surface of the cartilage is gone, the bones grind against each other, creating popping sounds, pain and loss of normal shoulder movement. This condition occurs primarily in people over the age of 50. Osteoarthritis commonly affects the shoulder, hip and knee.
Rheumatoid arthritis is considered a systemic disease because it can affect any or all joints of the body. It affects women more often than men, and can strike both old and young. Rheumatoid arthritis causes the body’s immune system to produce a chemical that attacks and destroys the protective cartilage that covers the joint surface.
Trauma-related arthritis results when the joint is injured, either by fracture, dislocation or damage to the ligaments surrounding the joint causing instability or damage to the joint surfaces.
Osteoarthritis generally occurs in the 50 year old age group and older. It is usually of gradual onset and slowly progresses with time. Patients usually present with two main symptoms - loss of motion and pain. Pain varies and is usually aggravated by activity. Pain slowly increases over years and eventually keeps one awake at night. It is this symptom that normally brings the patient to see the specialist. The condition can generally be diagnosed by an examination and then by X-rays which show loss of the gap between the shoulder bones (the glenoid and the humeral head).
One also often does a CT scan to confirm the degree of damage to the joint. Once the condition has been diagnosed then treatment generally depends on the severity of the symptoms.
Most cases are initially treated with non-operative management. This usually includes modification of activities, anti-inflammatories and gentle physiotherapy and/or hydrotherapy. Occasionally patients are given a cortisone injection which can give temporary relief. If the patient has tried all these modalities and if the condition is severely limiting their lifestyle then surgery is generally recommended.
When conservative methods of treatment fail to provide adequate relief, total shoulder replacement is considered.