Tennis elbow, also known as lateral epicondylitis or enthesopathy of the extensor carpi radialis origin, is a condition in which the outer part of the elbow becomes painful and tender. The pain may also extend into the back of the forearm. Onset of symptoms is generally gradual although they can seem sudden and be misinterpreted as an injury. Golfers elbow is a similar condition that affects the inside of the elbow.Enthesopathies are idiopathic, meaning science has not yet determined the cause. Enthesopathies are most common in middle age (ages 35 to 60).It is often stated that the condition is caused by excessive use of the muscles of the back of the forearm, but this is not supported by experimental evidence and is a common misinterpretation or unhelpful thought about symptoms. It may be associated with work or sports, classically racquet sports, but most people with the condition are not exposed to these activities. The diagnosis is based on the symptoms and examination. Medical imaging is not particularly useful. Signs consistent with the diagnosis include pain when a subject tries to bend back the wrist when the wrist is against resistance.Treatment involves decreasing activities that bring on the symptoms together with physical therapy or other treatment gradually increasing loads. Pain medications such as NSAIDS or acetaminophen (paracetamol) may be used. A brace over the upper forearm may also be helpful. The role of corticosteroid injections is debated.
Early experiments suggested that tennis elbow was primarily caused by overexertion. However, studies show that trauma such as direct blows to the epicondyle, a sudden forceful pull, or forceful extension cause more than half of these injuries. Repeatedly mis-hitting a tennis ball in the early stages of learning the sport causes shock to the elbow joint and may contribute to contracting the condition. Pathophysiology
Histological findings include granulation tissue, micro-rupture, degenerative changes, and there is no traditional inflammation. Therefore, the disorder is more appropriately referred to as tendinosis or tendinopathy—more accurately an enthesopathy—rather than tendinitis. There is no evidence of inflammation or repair.The extensor digiti minimi also has a small origin site medial to the elbow that this condition can affect. The muscle involves the extension of the little finger and some extension of the wrist allowing for adaption to "snap" or flick the wrist—usually associated with a racquet swing. Most often, the extensor muscles become painful due to tendon breakdown from over-extension. Improper form or movement allows for power in a swing to rotate through and around the wrist—creating a moment on that joint instead of the elbow joint or rotator cuff. This moment causes pressure to build impact forces to act on the tendon causing irritation and inflammation.Other speculative risk factors for lateral epicondylitis include taking up tennis later in life, unaccustomed strenuous activity, decreased mental chronometry and speed and repetitive eccentric contraction of muscle (controlled lengthening of a muscle group). Diagnosis
Physical examination
Diagnosis is based on symptoms and clinical signs that are discrete and characteristic.