Comparative Outcome Analysis of Leukocyte-Rich Platelet-rich Plasma, Leukocyte-Poor Platelet-rich Plasma, Injectable Platelet-rich Fibrin and Corticosteroid Injections in Periarthritis of the Shoulder: A Double-Blinded, Four-Arm Randomized Controlled Trial.

INTRODUCTION

Periarthritis of the shoulder (adhesive capsulitis) is a common, disabling condition. Autologous platelet concentrates have emerged as regenerative alternatives to corticosteroids. Still, the comparative efficacy of leukocyte-rich platelet-rich plasma (LR-PRP), leukocyte-poor platelet-rich plasma (LP-PRP), injectable platelet-rich fibrin (iPRF), and triamcinolone remains undefined.

OBJECTIVE

This study aimed to compare the efficacy, safety, and functional outcome of intra-articular LR-PRP, LP-PRP, iPRF, and triamcinolone in patients with periarthritis of the shoulder over 12 months.

MATERIALS AND

METHODS

In this single-center, double-blinded, four-arm randomized controlled trial, 64 patients were allocated 1:1:1:1 (n = 16 per arm) to receive a single intra-articular injection of 5-6 mL LR-PRP, 5-6 mL LP-PRP, 5-6 mL iPRF, or 1 mL (40 mg) triamcinolone. The primary outcomes were the Visual Analog Scale (VAS) for pain and the disabilities of the Arm, Shoulder and Hand (DASH) score, assessed at baseline and at 1, 3, 6, and 12 months. Data were analyzed using repeated-measures analysis of variance in Statistical Package for the Social Sciences v26.0, with P < 0.05 considered significant.

RESULTS

All groups improved significantly from baseline (P < 0.001). At 1 month, the triamcinolone group showed the greatest improvement (VAS 3.1; DASH 30.2). From 6 months onward, the platelet-concentrate arms were superior; at 12 months, iPRF achieved the best outcomes (VAS 1.6 ± 0.6; DASH 15.0 ± 4.6), followed by LP-PRP (VAS 1.8; DASH 16.8) and LR-PRP (VAS 2.1; DASH 19.2), whereas the triamcinolone group regressed (VAS 4.2; DASH 37.4) (between-group P < 0.001 at 12 months). Adverse events were transient; post-injection swelling and pain were more frequent with LR-PRP.

CONCLUSION

Corticosteroids offered the fastest early relief, but their effect was not durable. Platelet concentrates, particularly iPRF and LP-PRP, produced superior and sustained pain and functional benefit at 12 months with an excellent safety profile, supporting their use as durable regenerative options for periarthritis of the shoulder.