Evaluation of the difference in the effect of platelet-rich plasma (PRP) injection using the Peppering ands single injection techniques on pain and function in patients with elbow extensor tendinopathy: A randomized, double-blind clinical trial

Peppering vs. Single PRP Injection for Pain and Function in Lateral Epicondylitis"

A double-blind randomized clinical trial on 34 patients with wrist injury, comparing the effects of PRP injection using Peppering and Single techniques alongside standard treatments on symptom relief and wrist function

Study location: Sports Medicine Department, Sina Hospital 3–4 mL of PRP was prepared from brachial artery blood by single-spin centrifugation. Patients were seated, elbow at 90°, forearm in pronation. 2 mL of 2% lidocaine was injected subcutaneously. Peppering: PRP injected in multiple directions at the point of maximal tenderness. Single: PRP injected only at the point of maximal tenderness. Patients were observed for 30 min, advised 48-hour rest, acetaminophen as needed, and no anti-inflammatories for 2 weeks. Outcomes (NRS, PRTEE, pressure pain threshold, hand grip) were measured at baseline, 4 and 8 weeks.

Inclusion: Age 18–60, lateral elbow tendinopathy, pain ≥2/10 NRS. Exclusion: Upper limb/neck surgery/injury, recent whiplash/fibromyalgia/cervical stenosis, chronic inflammatory/neuro-psychiatric disease, recent physio/acupuncture/chiropractic, nerve compression, bleeding disorder/NSAID/steroid use, pregnancy

Group 1: PRP via Peppering + Counterforce brace + wrist extensor stretching Group 2: PRP via Single + Counterforce brace + wrist extensor stretching

Determining the effect of PRP injection by Peppering method versus single in the lateral epicondyle on pain symptoms and function in patients with acute elbow extensor tendinopathy./ Determining the effect of PRP injection by Peppering method versus single on wrist strength/NRS scale for lateral elbow pain/Function by Patient Related Tennis Elbow Evaluation or PRTEE/Pain pressure threshold

The distribution of volunteers will be done by random block design with variable blocks of two, four or six (one group with the symbol A and the other group with the symbol B) and using the random number table of the Random allocation software. The sample allocation ratio will be 1:1 and volunteers will be randomly assigned to one of the two injection groups, Single and Peppering.

This study was conducted as a randomized, double-blind clinical trial. Both participants and outcome assessors were blinded to the type of intervention. To maintain blinding, all injections were performed behind a sterile drape and out of the patient’s visual field, using identical syringes, equipment, and a uniform local anesthesia protocol in both groups. The duration of the procedure was also standardized to avoid any perceptible differences between the two injection techniques. All injections were performed by a single physician who, due to the inherent differences between the Peppering and Single techniques, was aware of the allocation but had no role in patient assessment or data collection. Outcome measures, including the Numerical Rating Scale (NRS), the Patient-Rated Tennis Elbow Evaluation (PRTEE), grip strength, and Pain Pressure Threshold (PTT), were recorded by an independent assessor blinded to group assignment. Participants were randomized into two groups in a 1:1 ratio using sequentially numbered, opaque, sealed envelopes to ensure allocation concealment. The success of blinding was evaluated during follow-up by directly asking both participants and assessors to guess the assigned group. Unblinding was allowed only in cases of medical necessity and was fully documented.