Patient case (clinical description): A 17-year-old male comes to the office due to several months of right elbow pain.  The pain is worse with activity and limits his workouts and activities.  He has tried over-the-counter medications with limited relief.  Medical history is notable for eczema, and current medications include a topical hydrocortisone ointment.  He is sexually active with his girlfriend and uses condoms. He does not smoke or drink alcohol. He plays tennis most of the days of the week. The comprehensive evaluation shows pain on the lateral side of the elbow, made worse by pressure applied on the lateral epicondyle of the humerus and when making a fist with the elbow joint straightened. The patient has this pain since last year and had several courses of physical therapy.

Patient's own account: I'm 17, and I had to go to the doctor because I've been suffering from my right elbow for several months. The pain is even worse when I do sports and it kind of limits me for my workouts and activities. I tried over-the-counter medications but it didn't work much. I had eczema before and my medication is ointments that contain cortisone. I am sexually active as a 17-year-old guy, and I have a girlfriend, and we use condoms. I don't smoke or drink. I play tennis most days of the week. I did an exam that showed pain on the side of my elbow and it was worse when they applied some pressure on it and when I was putting my hand as a fist. I have had this pain since last year, and I had several sessions of physical therapy already.

Clinical trial: Platelet Rich Plasma (PRP) in Chronic Epicondylitis

Eligibility criteria:
Inclusion criteria

          -  Tendinopathy present in either lateral or medial elbow

          -  Pain by palpation at the lateral or medial epicondyle of the elbow

          -  Baseline elbow pain >3/10 during resisted wrist extension

          -  History of at least two periods of elbow pain lasting more than 10 days

          -  Symptoms lasting at least 3 months or longer

          -  Body Mass Index between 20 and 35.

          -  Commitment to comply with all study procedures

          -  The patient must give written informed consent

        Exclusion Criteria:

          -  Presence of full tendon tear

          -  Body mass index> 35

          -  Systemic autoimmune rheumatologic disease (connective tissue diseases and systemic
             necrotizing vasculitis)

          -  Poorly controlled diabetes mellitus (glycosylated hemoglobin above 9%)

          -  Blood disorders (thrombopathy, thrombocytopenia, anemia with Hb <9)

          -  Patients receiving immunosuppressive treatments

          -  Received local steroid injection within 3 months of randomization received
             nonsteroidal antiinflammatory, opioids or oral corticosteroids within 15 days before
             inclusion in the study

          -  Severe heart diseasePatients unable to comply with scheduled visits, for work or spend
             long periods away from their habitual residence.

          -  Patients with active cancer or cancer diagnosed in the last five years.

          -  Analytical Diagnosis Hepatitis B, C or HIV infection.

          -  Pregnant or lactating.

          -  People who are taking a drug in clinical investigation or participated in any
             investigational study clinic (with an authorized or not) within 30 days prior to
             randomization.
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 35 Years old.
Subject must be at most 75 Years

Eligibility (NLI label): Contradiction