Comparison of Platelet Rich Plasma and Alternative Therapies for the Treatment of Tennis Elbow (Lateral Epicondylitis)

\"Tennis elbow\" is the most common cause of lateral elbow pain, generally caused by either work or sports related repetitive strain. In this condition, a tendon along the outside of the elbow becomes inflamed leading to pain, especially with flexing and extending the elbow. Many treatments have been attempted, including physiotherapy and steroids, with little success. One treatment which has been very effective is the injection of the patients own blood (taken from their other non-affected arm) into their abnormal tendon. The blood recruits the patients own healing factors and heals the damaged tendon. As platelets are thought to be largely responsible, injection of concentrated platelets, extracted from the patient\'s blood (platelet rich plasma) is a newer, but expensive, technique. At this point, it is unclear whether whole blood, concentrated platelets, or simply passing a ultrasound-guided needle through the abnormal tendon as a means to stimulate tissue healing (tendon fenestration) is the better treatment. The objective of this trial is to compare platelet rich plasma, whole blood, dry needle tendon fenestration, and sham injection (with physical therapy) to identify the best and most cost-effective therapy for this debilitating condition.