Arthritis of the Shoulder
Damage to the normally smooth cartilage of the shoulder joint causes arthritis. This is an irreversible process and usually takes many years to develop and cause symptoms.
The most common cause is age related wear of the joint known as osteoarthritis. Other causes include trauma to the shoulder including dislocations and chronic inflammatory conditions such as rheumatoid arthritis. These can lead to relatively rapid destruction of the joint. The main symptoms of shoulder arthritis are pain, stiffness and loss of function.
Adhesive capsulitis is characterized by painful, gradual loss of active and passive shoulder motion often with no causal event.
The condition normally progresses through three phases. The first phase is characterized by pain and stiffness and usually lasts for three to four months. In the second phase the pain resolves and stiffness is the predominant feature. The final phase is the gradual resolution of the stiffness.
Impingement and Bursitis
Shoulder Impingement and bursitis are common causes of pain and loss of shoulder function. The tendon of the supraspinatus muscle runs from the shoulder blade onto the head of the humerus passing under a bony part of the shoulder blade known as the acromion. Shoulder Impingement occurs when there is narrowing of the space that the tendon passes through. This can result in disruption of the normal movement of the tendon and lead to pain in the shoulder when using the arm overhead as well as pain at night with discomfort sleeping on the affected shoulder.
The shoulder is the most commonly dislocated joint in the body. When shoulder dislocation occurs in adolescents and children the risk of re-dislocation is up to 95%.
Although not a life threatening problem, repeated dislocation is clearly lifestyle threatening and can effectively disable an otherwise active person.
Rotator Cuff Tears
The rotator cuff consists of 4 muscles with their tendons attaching to the humeral head. They are the supraspinatus, infraspinatus, subscapularis and teres minor.
These tendons centralise the relatively large ball in a small socket and assist in providing stability to the shoulder joint. When one or more of these tendons is damaged the shoulder can become painful and weak. In many cases the affected shoulder also becomes stiff.