Treatment of Epicondylitis by Ultrasound-guided Local Injections of PRP (Platelet Rich Plasma)

This was a prospective double-blind placebo-controlled randomized trial. Two ultrasound-guided injections of either PRP (ACP®, Arthrex) or saline solution were performed at 4 weeks interval.

Exclusion criterion was previous corticosteroid infiltration. All infiltrations were performed by Dr Bernard Montalvan. The selection of patients and the evaluation were conducted by Dr Patrick Le Goux who did not know which treatment had been allocated to which patient.

In the facility, no one apart from the investigators had access to full patient data.

An independent company represented by Mrs Amandine Ramseyer was hired to design, follow and carry the statistical analysis of the study. The data she got from the investigators were anonymous.

Patients were monitored by an independent evaluator blinded to treatment at baseline and 1, 3, 6 and 12 months follow-up.

Secondary criteria were the Roles-Maudsley score and the assessment of pain on isometric contraction of the extensor carpi radialis brevis and of the extensor digitorum communis.

The main evaluation criterion was the relative improvement from baseline to 6 months in pain score on visual analog scale (0-10).

Intragroup and intergroup intention-to-treat analyses were performed using Student's t-tests, applying the last-observation carried forward method. Differences of proportions were tested using chi-square. The sample size calculated was 22 patients per group so that this study had a power of 90% with typeI error rate α=0.05 to demonstrate a significant greater improvement of the global pain score of at least 10%, in the PRP over the placebo group with a standard deviation of 0.10. A "p" value of less than 0.05 was considered to be statistically significant. The SPSS software (version 19 for Windows) was used to perform statistics.

Inclusion criteria

• Patients suffering from tennis elbow for less than three months
• Patients having never received former medical or orthopedic treatment for tennis elbow

Exclusion criteria

• Patients having received any treatment for this specific pathology
• Evidence of ongoing tumoral affection (controlled by MRI)
• Tennis elbow history
• Elbow fracture history
• Associated elbow pathology
• Inflammatory rheumatic disorders
• Bleeding disorders
• Ongoing anticoagulation therapy
• Allergy to local anesthetic
• Ongoing or previous cancer affection
• Pregnancy
• Diabetes