Histological findings include granulation tissue, micro-rupture, degenerative changes, and there is no traditional inflammation. Longitudinal sonogram of the lateral<unk>  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. Therefore, the disorder is more appropriately referred to as tendinosis or tendinopathy rather than tendinitis. Colour Doppler ultrasound reveals structural tendon changes, with vascularity and hypo-echoic areas that correspond to the areas of pain in the extensor origin. The pathophysiology of lateral epicondylitis is degenerative. Non-inflammatory, chronic degenerative changes of the origin of the extensor carpi radialis brevis (ECRB) muscle are identified in surgical pathology specimens. It is unclear if the pathology is affected by prior injection of corticosteroid.<unk>  players generally believe<unk>  is caused by the repetitive nature of hitting thousands of<unk>  balls, which leads to tiny tears in the forearm tendon attachment at the<unk> . The extensor digiti minimi also has a small origin site medial to the<unk>  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<unk>  joint or rotator cuff. This moment causes pressure to build impact forces to act on the tendon causing irritation and inflammation. At least one author questions that lateral epicondylitis is caused by repetitive microtrauma/overuse, maintaining the theory is likely overstated and lacks scientific support. Other speculative risk factors for lateral epicondylitis include taking up<unk>  later in life, unaccustomed strenuous activity, decreased mental chronometry and speed and repetitive eccentric contraction of muscle (controlled lengthening of a muscle group).
Tennis elbow
Osteoarthritis
Runner's knee
Osteochondritis dissecans
Elbow fracture
Radiculopathy
Bunion
Ulna fracture