The shoulder joint is the most mobile joint in the body, allowing one a great deal of mobility. It is called to service in many sports like cricket, athletics involving throwing like Javelin throw, shot put, Base ball, Tennis, Volley ball, Badminton etc. Swimmers also suffer from shoulder pain and a faulty technique in free style may lead to a condition called instability. A variety of injuries and conditions affect the shoulder in professional sportsmen.  Sports medicine deals with injuries to the knees, shoulders, elbows and ankle. It is a relatively new branch of Orthopaedic surgery, very popular in the US where every practice has a sports medicine surgeon. In India too it is catching on. Minimally invasive orthopaedic surgery, either arthroscopically or through smaller incisions is effective in treatment of these sports injuries and return of the person to professional sport.

To understand the medical terms, knowledge of a bit of anatomy of the shoulder may be useful.

Anatomy

The shoulder joint is formed by the union of the ball at the upper end of the arm bone (humerus) with the socket at the outer end of the shoulder blade (scapula). A bag like capsule surrounds and protects it.  A group of tendons called the rotator cuff are attached to top of the arm bone.  They serve as dynamic restraints to movement. There is a discrepancy between the radius of curvature of the ball and its socket which renders the shoulder unstable. Imagine a golf ball (ball of the humerus) sitting on a tee (socket of shoulder blade), that?s how unstable it is. The rotator group of tendons, acting as restraints, the bony orientation and a negative suction force between the components are some of the stabilizing influences and dislocation is thus prevented. However dislocations frequently occur, as a price for the freedom of movement possible. In close proximity to the joint, are important nerves and blood vessels.

Common Injuries and conditions of the shoulder

1. Instability - is a frequent problem affecting the shoulder in sportsmen and normal individuals as well. It means that the joint dislocates or has a tendency to dislocate in varying degrees. An injury to the shoulder is the main cause of dislocation and most dislocations occur in a forward direction (anterior instability). Frequently the cause is a fall on the outstretched hand. A dislocation results when the ball of the joint is pushed out, tearing the tight capsule in its wake and denting the bone.

In other individuals there may not be any history of trauma and the shoulder may dislocate spontaneously. These individuals are loose jointed and have ligamentous laxity. In some cases, the initial event of dislocation may not be dramatic as the joint might have only dislocated partially. Later on the resultant instability causes pain rendering diagnosis difficult. The person says that his arm goes dead suddenly. A fielder who has to throw the ball from the boundary in an overhead manner avoids this maneuver and instead throws it in underarm, fearing a dead arm. These defects render the shoulder unstable and over 95 percent of young men with a acute dislocation will develop a tendency to recurrent dislocation. The acute dislocation and subsequent recurrences have to be put back under an anesthetic, until surgical stabilization is carried out. This can be done arthroscopically or by open surgery.  While open surgery remains the gold standard in chronic dislocators, arthroscopic stabilization does not cause restriction of movements for sportsmen where preservation of movement is important. Suture anchors are handy in this arthroscopic operation. Rehabilitation is quicker in the anatomical operations.

 2. Tendonitis refers to an inflammation of tendons surrounding the shoulder. The rotator cuff tendons can get inflamed due to over use and overload/fatigue, trauma and age related degenerative changes. Swelling and crowding of the tendons underneath the bony arch of the shoulder blade occurs leading to impingement. Pain results during overhead activities. Night pain is present in advanced cases by lying on the affected shoulder.

3. Impingement is a phenomenon in which the rotator cuff (group of tendons) rubs against the undersurface of the bony acromion (crow like) projection of the shoulder blade. Once again it can be due to weakness of the rotator cuff or be due to instability. Differentiation between instability and impingement can be difficult and clinical acumen is needed. Internal impingement occurs in baseball pitchers as in the picture where the arm is cocked back for throwing.

4. Rotator cuff tears ?Tears of the rotator cuff in young sportsmen are due to trauma like a fall on the outstretched hand.  In the older person, tears are due to age related degeneration.  Large rotator cuff tears result in weakness during overhead activities. These tears have a poor capacity to heal spontaneously and need to be repaired, particularly in the young sportsman.  In the older patient a trial of conservative treatment with analgesics and one or two cortico-steroid injections may be useful before embarking on surgery.

5. Labral tears- The labrum is a band of cartilage attached to the glenoid cavity (socket). It can be torn in many sports and also in non sports related domestic and road accidents. Diagnosis is usually by MR arthrography (where a radio opaque dye is injected into the joint and an MR scan taken). Arthroscopic surgery is the only surgical option in patients with symptoms like pain, clicking or locking. There may be associated instability.

6. Muscle ruptures-These occur due to sudden contraction of muscles against an unexpected resistance.

7. Acromio clavicular joint injuries- These result from a fall on the shoulder. It leads to a separation and upward prominence of the collar bone at the acromio-clavicular joint Pain and deformity with a upward prominence of the collar bone result. While the minor varieties can be treated conservatively, surgery is necessary for the major types.

 8. Nerve injuries- They may be associated with a shoulder dislocation, in which case there may be paralysis of the shoulder and blunting of sensation in the upper arm. More severe injuries are due to traction on the brachial plexus which is the circuitry of nerves supplying the entire upper limb. Complete or partial paralysis of the upper extremity can occur.  Brachial plexus injuries in most cases are temporary injuries, however may need investigation by an electromyogram.

Diagnosis of shoulder injuries in sportsmen is to differentiate mainly between impingement and instability. The orthopedic surgeon is an important member of the team which consists of a team physiotherapist, sports psychologist and rehabilitation expert.