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.
For example, extension of the elbow and flexion of the wrist cause outer elbow pain. There is point tenderness at the origin of the extensor carpi radialis brevis muscle from the lateral epicondyle (extensor carpi radialis brevis origin), 1 cm distal and slightly anterior to the lateral epicondyle. There is also pain with resisted wrist extension (Cozens test). Medical imaging
Medical imaging is not necessary or helpful.X-rays can confirm and distinguish possibilities of existing causes of pain that are unrelated to tennis elbow, such as fracture or arthritis. Rarely, calcification can be found where the extensor muscles attach to the lateral epicondyle. Medical ultrasonography and magnetic resonance imaging (MRI) are other valuable tools for diagnosis but are frequently avoided due to the high cost.Longitudinal sonogram of the lateral elbow displays thickening and heterogeneity of the common extensor tendon that is consistent with tendinosis, as the ultrasound reveals calcifications, intrasubstance tears, and marked irregularity of the lateral epicondyle. Although the term “epicondylitis” is frequently used to describe this disorder, most histopathologic findings of studies have displayed no evidence of an acute, or a chronic inflammatory process. Histologic studies have demonstrated that this condition is the result of tendon degeneration, which replaces normal tissue with a disorganized arrangement of collagen. Treatment
In some cases, severity of tennis elbow symptoms mend without any treatment, within six to 24 months. Tennis elbow left untreated can lead to chronic pain that degrades quality of daily living.