Translational Medicine
Open Access

Platelet-Rich Plasma Injections for Frozen Shoulder: Efficacy in Pain Reduction and Shoulder Function Improvement

Sabih Ahmed^{* *}Correspondence: Dr. Sabih Ahmed, Department of Orthopedics, Orthopedic Surgeon and General Practitioner, Aftab Clinic PVT, Ethiopia, Email:

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Description

Adhesive capsulitis, colloquially known as frozen shoulder, is a frequently encountered musculoskeletal disorder characterized by chronic pain and reduced range of motion in the shoulder joint [1]. Despite its high prevalence, especially among individuals aged between 40 and 65 years, the pathophysiology remains elusive, leading to varied approaches in management [2].

Historically, treatment modalities for frozen shoulder have ranged from physiotherapy, Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), to more invasive techniques such as manipulation under anesthesia and arthroscopic capsular release [3]. However, none of these have consistently demonstrated long-term efficacy and some possess associated risks, prompting the search for alternative treatments [4].

Platelet-Rich Plasma (PRP), concentrated plasma fraction rich in platelets, has garnered attention in recent years for its potential in treating various orthopedic conditions [5]. PRP releases growth factors that can modulate inflammation, potentially facilitating tissue repair and regeneration [6]. While its application has been researched in conditions like osteoarthritis and tendinopathies with promising results, its role in the treatment of frozen shoulder remains an emerging domain of inquiry [7].

Recent pilot studies have suggested potential benefits of PRP in reducing pain and improving function among frozen shoulder patients [8]. Yet, the literature lacks large-scale randomized trials that can confirm these findings and establish PRP as a standard conservative intervention for adhesive capsulitis. This study, therefore, aims to bridge this gap, offering a comprehensive analysis of PRP's therapeutic potential for frozen shoulder, compared against conventional saline injections [9].

Study design

We implemented a single-center, double-blind, randomized controlled trial to assess the efficacy of PRP injections versus saline injections in addressing frozen shoulder [10].

Participants

Two hundred participants were selected, each diagnosed with frozen shoulder in line with the American Academy of Orthopedic Surgeons (AAOS) criteria. Exclusion parameters included those with prior shoulder surgeries, systemic inflammatory diseases or patients who had received corticosteroid injections in the past three months [11,12].

Intervention

In the PRP cohort, blood was drawn and PRP was isolated via a dual-spin centrifugation method as detailed by Kapoor et al., [13]. The control group was administered isotonic saline injections. Utilizing ultrasound guidance, we ensured the precise delivery of injections into the joint capsule for both groups [14].

Outcome measures

We designated the primary outcome as the reduction in pain intensity, evaluated through the Visual Analog Scale (VAS). As a secondary outcome, shoulder mobility was assessed via the Range of Motion (ROM) protocol [15]. Evaluations were scheduled at baseline and then at intervals: 1, 3 and 6 months’ post-intervention.

Statistical analysis

Data was processed using the Statistical Package for Social Sciences (SPSS) version 25 [16]. Descriptive statistics summarized the demographic information. Between-group differences were discerned employing the t-test for continuous variables and chi-square test for categorical ones, with statistical significance set at a p-value <0.05. Out of the 200 participants who were enrolled, 198 successfully completed the study. The initial characteristics across both groups did not show significant differences [17]. When evaluating pain reduction, participants in the PRP group demonstrated a mean VAS score decrease of 2.5 ± 0.8 at the 1-month mark, contrasting with the saline group's reduction of 1.2 ± 0.7 [18]. By the end of 6 months, the PRP cohort experienced a reduction of 4.8 ± 1.1, while the saline cohort had a reduction of 2.3 ± 0.9. In terms of Range of Motion (ROM), there was a noticeable enhancement in the PRP group. After 6 months, forward flexion in this group increased on average by 40°, with external rotation improving by 25°. In contrast, the saline group saw increases of just 20° and 10° in forward flexion and external rotation, respectively [19]. Our study distinctly emphasizes the therapeutic promise of PRP injections in the treatment of frozen shoulder. A significant reduction in VAS scores in the PRP group over the saline group indicates its potential efficacy in pain management [20]. The marked ROM improvements observed among PRP recipients further accentuate its therapeutic potential. These effects are postulated to arise from the presence of growth factors in PRP that possibly modulate inflammation and promote tissue regeneration [21]. However, it's paramount to acknowledge our study's limitations. The relatively short observation period does not allow for a comprehensive assessment of long-term outcomes. Additionally, the saline group might have experienced a placebo effect, which is often linked with injection-based treatments [22,23].

Conclusion

The study findings robustly support the potential of Platelet- Rich Plasma (PRP) as a viable alternative or adjunctive therapy for frozen shoulder, showcasing substantial enhancements in pain alleviation and Range of Motion (ROM). The observed positive outcomes underscore the importance of further exploration. To thoroughly validate and understand the longterm efficacy of PRP, we advocate for extensive studies with larger participant cohorts. Expanding the scope of research will not only strengthen the evidence supporting PRP's effectiveness in frozen shoulder treatment but also provide insights into the durability of its therapeutic effects. This comprehensive approach is imperative for informing clinical practice and advancing patient care. The call for extended investigations aligns with the commitment to evidence-based medicine, ensuring that the potential benefits of PRP in managing frozen shoulder are thoroughly examined and established for broader clinical application.

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