Lateral epicondylitis or tennis elbow is a tendinopathy of the common extensor origin of the lateral elbow, and is estimated to have an annual incidence of 1-3%. It is characterized by tenderness over the lateral epicondyle of the humerus, normal range of motion, and pain on resisted extension of the wrist or fingers. Symptoms can persist for between 6 months and 2 years but usually resolve within 12 months. Although tennis elbow is often self-limited, around 20% of cases are refractory to conservative care. Tennis elbow is now thought to be non-inflammatory, and the pathologies are characterized by collagen degeneration, fibroblast proliferation, mucoid degeneration, and neovascularization.