Leukocyte-rich PRP or Leukocyte-free PRP vs Placebo in the Treatment of Epicondylitis

Inclusion Criteria: Patients with epicondylitis of the elbow: 1. Patients with clinical picture of epicondylitis; 2. Duration of symptoms \> 3 months 3. Ultrasound picture of short or long radial extensor carpal tendinopathy; 4. Age \> 18 and \< 65 5. Both sexes; 6. Failure, defined as persistence of symptoms, of other conservative treatments for at least 3 months; 7. Hemoglobin \> 11 g/dl; 8. Platelet count \> 150,000 plt/mm3 (Recently performed CBC examination); 9. Negative serological tests for HBsAg, HCV Ab, HIV-1-2 Ab 10. No clinically significant electrocardiographic changes (Recently performed ECG); 11. Ability and consent of the patient to actively participate in clinical follow-up; 12. Signature of informed consent. Exclusion Criteria: 1. Patients undergoing previous surgical treatment on the epicondylar tendons; 2. Patients undergoing epicondylar infiltration in the previous 6 months; 3. Inability of patients to actively participate in clinical follow-up; 4. Incapacitated patients; 5. Patients with states of immunodepression; 6. Patients with fibromyalgia; 7. Ongoing systemic inflammatory diseases (stabilized outcomes of such diseases are not considered absolute contraindications); 8. Patients with uncontrolled thyroid metabolic disorders; 9. Patients abusing alcoholic beverages, drugs or medications; 10. Patients who have taken NSAIDs in the 3 days prior to blood collection; 11. Patients with coagulation problems or with ongoing antiplatelet therapy that cannot be suspended for at least 3 days prior to blood draw; 12. Patients with cardiovascular disease for whom a 300-mL blood draw would be contraindicated; 13. Positive serological tests for HBsAg, HCV Ab, HIV-1-2 Ab 14. Other current elbow diseases (osteoarthritis, prevalence of symptomatology due to epitrochleitis, stiff elbow, etc.)