Elsevier

Physical Therapy in Sport

Volume 17, January 2016, Pages 87-94
Physical Therapy in Sport

Literature review
The clinical impact of platelet-rich plasma on tendinopathy compared to placebo or dry needling injections: A meta-analysis

https://doi.org/10.1016/j.ptsp.2015.06.003Get rights and content

Highlights

  • PRP was not significantly superior to placebo or dry needling on tendinopathy.

  • PRP was marginally more effective than controls on rotator cuff tendinopathy.

  • The effects of potential sources of clinical diversity should be investigated.

Abstract

Objective

The purpose of this meta-analysis was to compare the impact of platelet-rich plasma with that of placebo or dry needling injections on tendinopathy.

Methods

The databases of PubMed, CENTRAL, Scopus, Web of Science, and trial registries, reference lists, and conference abstract books were searched up to December 2014. Adults with tendinopathy in randomized controlled trials were enrolled. The trials compared effect of platelet-rich plasma with that of placebo or dry needling. We used subgroup analysis linked to the anatomical location of the tendinopathy. The primary outcome was pain intensity at two or three and six months after intervention. The secondary outcome was functional disability at three months after treatment.

Results

Five trials were included. There was a statistically significant difference in favor of the platelet-rich plasma intervention at the second primary outcome time point (SMD −0.48, 95%CIs −0.86 to −0.10, I2 = 0%, p = 0.01) and at the secondary outcome time point (SMD −0.47, 95%CIs −0.85 to −0.09, I2 = 0%, p=0.01).

Conclusions

Platelet-rich plasma did not provide significantly greater clinical benefit versus placebo or dry needling for the treatment of tendinopathy at a six-month follow-up. However, there was a marginal clinical difference in favor of platelet-rich plasma injections on rotator cuff tendinopathy.

Introduction

Tendinopathy is a common orthopaedic problem that includes tendinitis, paratenonitis and tendinosis (Khan, Cook, Bonar, Harcourt, & Astrom, 1999). It is characterized by chronic pain, functional deterioration and tendon thickening. Both intrinsic and extrinsic factors have been implicated in the etiology of tendinopathy (Riley, 2004). The histopathology of tendinopathy reveals the absence or minimal presence of inflammatory cells, which has been confirmed by gene array studies (Alfredson et al., 2003, Ireland et al., 2001). Tendinopathy is characterized by increased mucoid substance, intra-tendinous degeneration, and collagen disorganization (Khan et al., 1999). In some cases, a 10- to 20-fold increase in calcium concentration may be detected (Kannus, 2000).

There are a variety of approaches for treating tendinopathy, with traditional methods (i.e., non-steroidal anti-inflammatory drugs and activity modification) still advocated as first-line management (Andres & Murrell, 2008). In cases where conservative treatments fail, surgical consultation is suggested.

In addition to the well-established conservative therapies, many investigational injectable treatments have been developed. Ultrasound- (US) guided dry needling intervention, and US-guided platelet-rich plasma (PRP) injections are two injectable treatments. PRP is defined as the volume of autologous plasma that has a platelet concentration above baseline (Marx, 2001). The dry needling technique, also known as peppering, consists of multiple tendon perforations without injecting any substances.

PRP, placebo and dry needling injections cause bleeding in the tendon, which can increase inflammation and induce the release of beneficial growth factors. This stimulates tendon healing (Filardo et al., 2010, Mishra et al., 2012). Consequently, it is thought that the needling of a tendon, with or without injecting any substances, exerts a positive clinical impact on rehabilitation (Dommerholt, 2011, Krey et al., 2015, Nagraba et al., 2013). The use of high platelet concentrations in PRP, results in the release of significantly greater amounts of beneficial growth factors than that released by any type of needling. Moreover, the concentration of growth factors increases linearly with increasing platelet number (Eppley et al., 2004, Marx, 2001). Nevertheless, it is evident that PRP with significantly high platelet concentrations does not further increase tendon rehabilitation (Marx, 2001, Rughetti et al., 2008). Considering this, we hypothesized that the clinical effect of PRP on tendinopathy would be greater than that of placebo or dry needling.

The purpose of this meta-analysis was to compare the clinical impact of PRP with that of placebo or dry needling on adults with tendinopathy. The primary outcome measure was pain intensity at two or three and six months after the initial intervention. The secondary outcome was functional disability at three months after the initial treatment.

Section snippets

Methods

The review was registered with PROSPERO (CRD42014010003) and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed (Liberati et al., 2009).

Results

The literature search retrieved 1565 potentially relevant studies. Duplicates were removed and the remaining 1205 studies were screened according to the information provided in their title and abstract. After the exclusion of 1179 records, the remaining 26 articles were eligible for full-text assessment. One of the retrieved trials was not randomized (Mishra & Pavelko, 2006). Two trials presented the results of the same study with different follow-up measurements (de Vos, Weir, Tol, Verhaar,

Discussion

Five RCTs comparing the impact of PRP with that of placebo or dry needling on tendinopathy were identified. There was no significant statistical heterogeneity in the overall results of the present quantitative synthesis. Therefore, there was no significant variability in the intervention effects that were evaluated in the included RCTs (Higgins & Green, 2011). At the first primary outcome time point and at the secondary outcome time point, pooled analysis indicated statistically significant

Conclusions

In conclusion, PRP injections did not provide significantly greater clinical relief compared to placebo or dry needling for the treatment of tendinopathy at a six-month follow-up. However, there was a marginal clinical advantage in patients who suffered from rotator cuff tendinopathy. The latter marginal clinical superiority should be further investigated in large-scale RCTs. Future research should determine the impact of potential sources of clinical diversity on the rehabilitation of

Conflict of interests

None declared.

Funding

This study was supported by the project “IKY scholarships” (State Scholarships Foundation) from resources of Operational Programme “Education and lifelong learning” of the European Social Fund (USF) of (NSRF), 2007–2013.

References (43)

  • R.J. de Vos et al.

    No effects of PRP on ultrasonographic tendon structure and neovascularisation in chronic midportion Achilles tendinopathy

    British Journal of Sports Medicine

    (2011)
  • R.J. de Vos et al.

    Platelet-rich plasma injection for chronic Achilles tendinopathy: a randomized controlled trial

    JAMA

    (2010)
  • J. Dommerholt

    Dry needling - peripheral and central considerations

    Journal of Manual & Manipulative Therapy

    (2011)
  • J.L. Dragoo et al.

    Platelet-rich plasma as a treatment for patellar tendinopathy: a double-blind, randomized controlled trial

    American Journal of Sports Medicine

    (2014)
  • B.L. Eppley et al.

    Platelet quantification and growth factor analysis from platelet-rich plasma: implications for wound healing

    Plastic and Reconstructive Surgery

    (2004)
  • A. Ferretti

    Epidemiology of jumper's knee

    Sports Medicine

    (1986)
  • G. Filardo et al.

    Use of platelet-rich plasma for the treatment of refractory jumper's knee

    International Orthopaedics

    (2010)
  • U. Fredberg

    Tennis elbow stretching and training program

    (2011)
  • J.P.T. Higgins et al.

    Cochrane handbook for systematic reviews of interventions

    (2011)
  • J.P.T. Higgins et al.

    Quantifying heterogeneity in a meta-analysis

    Statistics in Medicine

    (2002)
  • J.P.T. Higgins et al.

    Measuring inconsistency in meta-analyses

    BMJ

    (2003)
  • Cited by (35)

    • Shoulder Rotator Cuff Disorders: A Systematic Review of Clinical Practice Guidelines and Semantic Analyses of Recommendations

      2020, Archives of Physical Medicine and Rehabilitation
      Citation Excerpt :

      The effect of platelet-rich plasma injections in the treatment of RC tendinopathy remained unclear. A meta-analysis reported that platelet-rich plasma injections significantly reduce pain and disability when compared to a placebo injection or to dry needling.40 However, this review only included 2 RCTs on RC tendinopathy and could not conclude if the effect was clinically important or not.

    • An injectable platelet lysate-hyaluronic acid hydrogel supports cellular activities and induces chondrogenesis of encapsulated mesenchymal stem cells

      2019, Acta Biomaterialia
      Citation Excerpt :

      Preliminary results indicated that PRP is safe and can reduce pain and improve joint function [43–46]. However, despite the promising findings, the efficacy of using PRP for treating cartilage defect has remained controversial [47–49]. Variation in the platelet concentration provided by different preparation protocols may have a large impact on the clinical outcomes.

    View all citing articles on Scopus
    View full text