Shoulder impingement is the condition of inflammation of the tendons of the shoulder joint. It is one of the most common causes of pain in the adult shoulder. The shoulder is a ‘ball-and-socket’ joint. A ‘ball’ at the top of the upper arm bone, humerus, fits neatly into a ‘socket’, called the glenoid, which is part of the shoulder blade, scapula. Shoulder impingement is also called swimmer’s shoulder or tennis shoulder.
Impingement results from pressure on the rotator cuff (tendons attached around the ball of the shoulder that rotate the shoulder) from part of the shoulder blade (scapula) as the arm is lifted (Subacromial impingement). It is more likely to occur in young and middle-aged people who engage in physical activities that require repeated overhead arm movements. The cause maybe due to the hook shape of the acromion process of the shoulder blade, due to bone growth from the under surface of the outer collar bone joint (AC Joint arthritis) or due to mobile portion of the acromion process of the shoulder blade by birth (Os Acromiale) The pain may be due inflammation of the fluid sac overlying the shoulder tendons (Subacromial bursitis) or an inflammation of the tendons itself (Rotator cuff tendinitis). In some circumstances, a partial tear of the rotator cuff may cause impingement pain. Rarely calcium deposits in the space between the arm bone and the shoulder blade (Calcific tendinitis) can predispose to bursitis and impingement.
Individuals with shoulder impingement may experience severe pain at rest and during activities, weakness of the arm and difficulty in raising the arm overhead.
Diagnosis involves physical examination by Dr Bala where he checks for the possible range of movements with the affected shoulder, strength of the tendons that rotate the shoulder and signs for this jamming. X-rays may assess the shape of a portion of the shoulder blade that predisposes to this. Ultrasound and MRI scans may be ordered to assess the injury and inflammation.
Conservative Treatment Options
Shoulder impingement can be treated with rest, ice packs, anti-inflammatory drugs, and avoiding the activities involving the shoulder. Dr Bala may advise physiotherapy to strengthen the muscles and steroid injections may be given if pain persists.
Arthroscopic or open surgery is recommended to remove the bony spurs and inflamed bursa (Subacromial decompression). The space is further improved by recessing one of the ligaments in the space between the arm bone and shoulder blade and shaving some bone off the under surface of the shoulder blade. If any of the tendons in this space are found torn, they may be repaired simultaneously.