Lateral Epicondylitis

Background

The most common overuse syndrome is related to excessive wrist extension and commonly referred to as “tennis elbow,” but it is actually more common in non-tennis players. It is also commonly referred to as lateral epicondylitis, but this is usually a misnomer because, in general, microscopic evaluation of the tendons does not show signs of inflammation, but rather angiofibroblastic degeneration and collagen disarray. Light microscopy reveals both an excess of fibroblasts and blood vessels that are consistent with neovessels or angiogenesis.[1]

The tendons are relatively hypovascular proximal to the tendon insertion. This hypovascularity may predispose the tendon to hypoxic tendon degeneration and has been implicated in the etiology of tendinopathies.[2] Most typically, the primary pathology is tendinosis of the extensor carpi radialis brevis (ECRB) tendon 1-2 cm distal to its attachment on the lateral epicondyle.[2, 3]

For patient education resources, see the Hand, Wrist, Elbow, and Shoulder Center, as well as Tennis Elbow.

NextEpidemiologyFrequencyUnited States

The annual incidence is 1-3% of the U.S. population. Men and women are equally affected. Typically, lateral epicondylitis affects individuals greater than age 40 years. There is usually a history of repetitive activity aggravating the extensor tendons of the forearm.

PreviousNextFunctional Anatomy

The area of maximal tenderness is usually an area just distal to the origin of the extensor muscles of the forearm at the lateral epicondyle. Most typically the ECRB is involved, but others may include the extensor carpi radialis longus (ECRL), extensor digitorum, and extensor carpi ulnaris.

The radial nerve splits into the superficial radial and posterior interosseus nerve (PIN) at the radiocapitellar joint. The PIN may become entrapped by pericapsular structures, causing radial tunnel syndrome.

PreviousNextSport-Specific Biomechanics

Tennis is the most common sport to cause lateral epicondylitis, but the condition can also be seen in those who play squash and badminton. Symptoms can occur after an improper backhand hitting technique, which can occur when the athlete attempts to increase power by increasing forearm force rather than relying on core, rotator cuff, and scapular power. This results in snapping the wrist with supination and irritation of the extensor tendons. Symptoms can also occur when an athlete does not get his or her feet into position and hits the ball late or with a bent elbow. The power of the hit is again generated from the forearm instead of the core.

Other causes of extensor tendinopathy in tennis are using new racquet, using a racquet that is strung too tightly, or using a racquet that is too heavy, as well as hitting wet or heavy balls or hitting into the wind. Another common racquet abnormality that causes lateral elbow extensor tendinosis is having a grip that is too large. Lateral epicondylitis is also seen more commonly in athletes who hit with a 1-handed backhand versus a 2-handed backhand.

Industrial athletes have certain occupational and leisure activities that lead to overuse injuries of the forearm wrist extensors, causing pain at the lateral epicondyle. These include carpenters, bricklayers, seamstresses and tailors, politicians (excessive handshaking), and musicians (eg, pianists, drummers). Such injuries can also be seen in individuals who perform a lot of computer work, a lot of typing, and a lot of mouse work for their occupations.

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