Tennis Elbow

Introduction

Henry J. Morris first described “lawn tennis elbow,” now referred to as lateral epicondylitis, in 1882 (Figure 1). The annual incidence of lateral epicondylitis is approximately 1% to 3% of the general population, with the majority of patients being 35 to 40 years old or older. Men and women are affected equally. Lateral epicondylitis typically occurs in racquet and throwing sports but can result from work-related injury as well. The etiology is believed to be overuse and repetitive microtrauma from eccentric contractions of the extensor muscles. The injury occurs between the extensor carpi radialis brevis and the periosteum of the lateral epicondyle (Scuderi & McCann, 2004). A microscopic invasion of immature fibroblast and nonfunctional vascular buds leads to an “angiofibroblastic tendinosis,” first described by Nirschl in 1979. Scarring and calcifications develop within the degenerated tendon, with little to no inflammatory cells present; the term epicondylitis is a misnomer, as “itis” implies the major cause to be an inflammatory process, and anatomical studies do not support this. Studies have shown that this area is extremely hypovascular—that is, it does not receive a generous blood supply—thus limiting its potential to heal.

Discussion Analysis

Tennis elbow, or lateral epicondylitis, is characterized by pain at the lateral (outer) aspect of the elbow. The patient may also complain of tenderness on palpation of the area of concern, usually the dominant arm. This entity was first described in a scientific article in 1873, and since that time, the mechanism of injury, pathophysiology, and treatment of this condition have been much debated. The disorder is due to overuse of the extensor carpi radialis brevis (ECRB) muscle, which originates at the lateral epicondylar region of the distal humerus. Tennis elbow can also be classified as tendinitis, indicating inflammation of the tendon, or tendinosis, indicating tissue damage to the tendon (Ryan, Salvo: 337).

The most common cause of lateral epicondylitis is, as the common name suggests, tennis. It is estimated that tennis elbow occurs in 50% of tennis players. However, this condition is caused not only by tennis but also by any activity associated with repetitive extension (bending back) of the wrist. The activity initiates contraction of the muscles that cause the hand to extend (bend back). There is a significant increased risk of overuse injury if playing for more than 2 hours/week and more than two to four times per week. In players older than 40 years, the risk increases two- to threefold. Significant risk factors have been identified and include improper technique and the size and weight of the racquet.

Anatomy and Mechanism of Injury

To understand the mechanism of injury of this condition, knowledge of some basic anatomy of  the elbow is helpful. The elbow is a hinge joint—a junction between two bones primarily connected to each other by ligaments and tendons from the muscles near the humerus. The humerus is a long bone originating from the shoulder and extending to the elbow. It has two bumps called epicondyles—one on the medial (closest to the body) side and one on the ...