Background Tendinopathy is a difficult problem to manage and can result in significant patient morbidity. Currently, the clinical use of PRP in painful tendons is widespread but its efficacy remains controversial. Current experimental research postulates different efficiency among PRP formulations.Recent reviews showed that most clinical studies in tendinopathies have been performed with L-PRP. The investigators aim to examine the efficacy of pure-PRP in the management of epicondylitis.

The investigators hypothesized that pure PRP associated to needling intervention can enhance tendon healing in epicondylitis, improve function and reduce pain.

Methods and design Randomized double blind controlled trial, a total of 80 patients will be randomly allocated into one of two groups: PRP or control. Interventions: PRP group, ultrasound (US)guided needling associated to delivery of multiple PRP depots each alternate week for a total of two interventions. Control Group: US-guided needling with lidocaine each alternate week for a total of two interventions. Main outcome measure: Changes in pain and activity levels, as assessed by Disabilities of the Arm, Shoulder and Hand (DASH)outcome measure score, before and six months after intervention.The primary end-point is 25% reduction in DASH. The investigators will compare the percentage of patients, in each group, that achieve a successful treatment defined as a reduction of at least 25% in the DASH score.

Secondary outcome measures:Changes in pain and function as assessed by DASH and changes in pain as assessed by the visual analogue scale (VAS)at the 3, 6 and 12 month follow-up. Changes in sonographic features and neovascularity at 3, 6 and 12 months.

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.