Tennis elbow refers to pathology of the extensor tendon located on the outer side of the elbow causing significant pain. The medical term is 'lateral epicondylitis’. It is most frequent in tennis players, explaining the common name of this pathology.
Lateral epicondylitis, or tennis elbow, affects the muscles and tendons of the elbow that are used to extend the forearm. The forearm tendons, named extensors attach the muscles to the humerus and specifically to the lateral epicondyle. The main tendon involved in tennis elbow is called the extensor carpi radialis brevis. It functions by extending the wrist joint and grasping with the wrist extended (typical movements when using the tennis racquet in backhand). The exact pathophysiology of tennis elbow is unclear but it is thought to begin with small tears to the origin of the extensor carpi radialis brevis but can also involve the extensor carpi radialis longus as well as extensor carpi ulnaris. These tears cause local proliferation of cells named fibroblasts and formation of scar tissue in the tendon, which becomes inflamed, fibrotic and swollen. This pathophysiological mechanism is called tendinosis. These changes in the tendon are the result of overuse and repetitive movements.
According to Nirschl the pathology of tennis elbow can be divided in four stages:
Stage 1 - reversible inflammatory changes
Stage 2 - non-reversible pathologic changes to the insert of the extensor carpi radialis brevis muscle
Stage 3 - rupture of the extensor carpi radialis brevis muscle origin
Stage 4 - secondary changes such as fibrosis and calcification
Lateral epicondylitis can arise in combination with other tendon-related conditions such as De Quervain’s tenosynovitis, medial epicondylitis and carpal tunnel syndrome. Occasionally it is found concomitant with inflammation of the:
Radial nerve entrapment (radial tunnel syndrome in 5% patients)
Radial humeral bursa
Tennis elbow is mostly due to repetitive use of those movements that are commonly executed in playing tennis. It has an incidence of 50% in tennis players and occurs more frequently in individuals between 40-50 years of age. Lateral epicondylitis can also develop in other activities involving the frequent use of the elbows and wrists such as labourers (plumbers, painters, gardeners and carpenters) and computer users due to improper use of the keyboard.
A number of recreational sports and professions performing rigorous daily activities may increase the risk of acquiring tennis elbow such as:
Poor flexibility of the forearm
Occupations involving repetitive wrist extension (carpenters, bricklayers, tailors, pianists, drummers, computer users, typists)
The typical symptoms of tennis elbow include pain to the lateral side of the elbow, which may radiate to the forearm and wrist. Pain increases with wrist extension and supination and subsides with rest. Occasionally the pain can be felt to the arm, postero-laterally. As a consequence of lateral epicondylitis the patient may develop weakening of grip strength.
Lateral epicondylitis is primarily diagnosed by clinical examination. The patient’s history of sport or profession involving physical activities posing a risk for this pathology and past injuries will be discussed with the examiner. Clinical investigation focuses on the characteristics of pain at rest and during activity such as handshake and gripping. Palpation of the elbow anteriorly, medially, and posteriorly is performed to rule out any other disorder(s). Lateral palpation is used to detect for tenderness directly to the anterior inferior aspect of the epicondyle. The level of pain is assessed with resisted wrist extension. The possible involvement of the radial nerve is manifested by tenderness at touch. Chair raise test is often employed to determine the reduction in muscle strength and pain induced when raising the body keeping the arms extended and the wrists flexed. The examiner will also assess other pathologies including cervical radiculopathy, medial epicondylitis (Golfer’s elbow), radial nerve entrapment).
X-rays are only taken to exclude arthritis to the radio-capitellar joint or other bone-related conditions (osteophytes on the lateral epicondyle) and to visualise calcium deposits in the tendon.
Ultrasound is often sufficient to detect changes in the structure of the tendon including the presence of tears and swelling. MRI is performed seldom, when diagnosis is unclear and subtle changes of the bones and soft tissues may have not revealed with X-rays. Neural involvement is revealed by pain reduction following local injection of anaesthetics.
Conservative treatment for lateral epicondylitis is successful in 90-95% of patients following a standard regime including:
Administration of NSAID’s
Local injection of steroids
Autologous blood injections
Extracorporeal shock wave therapy
Botox injection (pain treatment)
If symptoms do not improve after 6 to 12 months of conservative treatment surgery is recommended. This involves the debridement or removal of the tendon segment with evident tendinosis. This is followed by the reattachment of the extensor tendon to the bone.
Surgery is achieved more frequently via open surgery through an incision over the elbow or arthroscopic surgery, which is a less invasive approach due to the reduced external access to the elbow.
Rehabilitation for a tennis elbow focuses on physical exercises to strengthen the muscles of the forearm and increase their flexibility through regular stretching. Additional rehabilitative therapy include:
Ultrasound, ice, massage or muscle stimulating techniques to improve muscle healing
Use of braces supports the muscle and relieves pain
After surgery the elbow is immobilised with a splint for about one week after which rehabilitation can commence. Physical therapy include initial stretching to restore muscle and tendon flexibility followed by more vigorous workout 2 months after surgery.
Sport activities can be resumed 4-6 months from the diagnosis. Physical exercise is critical for the treatment of tennis elbow, whether operated or not, and offers a variety of approaches:
Ice or heat
Taping or bracing during sport
Soft tissue massage
Progressive exercises to improve flexibility and strength
Introducing simple measures when practicing sport or other physical activities can help preventing a tennis elbow. Changing the characteristics of racquets with looser-strings, smaller, lighter and with smaller grips can reduce the stress on the forearm muscles and prevent recurrent tennis elbow.
Other recommendations include:
Use of taping, straps to minimise forearm muscle strain
Stretching exercises before and after practicing tennis/other sports
Warm up before sport
Patient education, activity modification
Avoid weight lifting
Ergonomic assessment of workplace
Maintain muscle strength with regular exercise