What is tennis elbow (lateral epicondylitis)?
Tennis elbow, better termed lateral epicondylitis, is an overuse syndrome that presents with lateral elbow pain. Etiologically, few patients who have symptoms of this disorder have acquired it through playing tennis, but it is generally seen in those performing activities that require repetitive wrist extension. The differential diagnosis of lateral elbow pain includes local conditions, elbow arthritis, loose body in the elbow joint, nerve compression of the radial nerve or posterior interosseous nerve, and cervical spondylosis with radiculitis. At present, most sports medicine physicians believe that lateral epicondylitis is primarily a degenerative process resulting from microtearing involving the origin of the extensor carpi radialis (ECR) muscles. The healing of the tendinous origin is impaired by chronic overuse and becomes symptomatic. On exam, pain is generally most pronounced with resisted wrist extension and specifically the extension of the middle finger as this tests the most commonly involved muscle, which inserts onto the dorsal aspect of the third metacarpal. Initial treatment is universally conservative and can include an elbow band over the proximal forearm, a wrist extension brace to off load the ECR brevis, NSAIDs, a home exercise program of stretching, or formal physical therapy. Corticosteroid delivered via injections or iontophoresis remains controversial but may be beneficial in the acute period for pain relief. Ultimately the condition is generally self-limited, with 90% of patients experiencing resolution of their symptoms in 12 to 18 months.