Summary

A single injection of PRP improves both pain and long term functional outcomes of the shoulder joint in primary adhesive capsulitis.

Abstract

Introduction

Corticosteroid injection provides short-term symptomatic relief in primary adhesive capsulitis however, the efficacy of the steroid injection via the route of administration is a subject of contention. Platelet-rich plasma contains growth factors that stimulate tissue repair and has the potential to the treatment of frozen shoulders. Aims and Objectives: To evaluate the efficacy of three injection methods in primary adhesive capsulitis. Methodology: A double-blinded randomized control study was conducted at the Government Institute of Medical Sciences, Greater Noida, Uttar Pradesh. All patients diagnosed with primary adhesive capsulitis with normal radiographs of their shoulders were included. A sample size of 30 patients was calculated to detect a 20% difference among the groups in the VAS score for pain based on the previous literature. Patients were randomized into 3 groups, using a computer-generated block randomization sequence by an independent researcher, which was disclosed to the investigator at the time of intended treatment.
The 3 groups were the Intra-articular Injection (IAI) Group- a mixture of 1 mL of triamcinolone (40 mg), 4 mL of 2% lidocaine, and 5 mL of normal saline was injected via anterior approach into the glenohumeral joint space; Subacromial Injection group (SAI) Group- the same cocktail was injected via posterior approach into the subacromial joint space and Platelet-rich Plasma (PRP) Group- 4 ml of autologous PRP harvested by centrifugation based buffy coat separation, was injected via posterior approach slowly under fluoroscopic guidance. All patients were administered an oral nonsteroidal anti-inflammatory drug and muscle relaxant for 4 weeks. Clinical symptoms were evaluated before treatment and at 1 month, 3 months, and 6 months after treatment. The clinical outcome was measured using the VAS score for pain, Simple Shoulder Test (SST), Constant score, and passive shoulder range of motion. Results: There was no significant difference in the primary outcomes between the groups of steroid injection, IAI and SAI groups, except for VAS at 2-3 weeks (P<0.02). PRP group showed statistical improvement in pain and constant score at follow-up. No major adverse effects were seen in both steroid and PRP injection groups. Conclusions: This study demonstrates that a single injection of PRP improves both pain and all range of motion of the shoulder joints. Whereas, when corticosteroid injection is used to treat adhesive capsulitis, both injection sites can be selected. However, more rigorous trials are needed to confirm the current findings.