PainSci notes on Grassi 2018:
A negative review of six trials of platelet-rich plasma injections for muscle strain, concluding that some hopeful early evidence is (predictably) “not confirmed by the recent high-level RCTs.” Although the quality of four of the trials reviewed was poor and they had positive results, two of them were better quality and had negative results.
The results of trials of PRP for other conditions is also generally disappointing, so this review’s conclusion is no surprise.
original abstract †Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
BACKGROUND: Muscle lesions account for one-third of sport-related injuries, thus representing a substantial problem for both players and their teams. The use of platelet-rich plasma (PRP) injections is rapidly growing in clinical practice, prompted by an unmet clinical need with a large commercial market. However, after early reports of positive preliminary experience, higher quality studies recently questioned the real benefit provided by PRP injections to promote muscle healing and return to sport.
OBJECTIVE: To evaluate the effect of platelet-rich plasma (PRP) injections on outcomes following acute muscle injuries.
DESIGN: Meta-analysis of randomized, controlled trials (RCTs), Level I.
DATA SOURCES: PubMed (MEDLINE), Cochrane (CENTRAL), Web of Science, clinicaltrials.gov, who.int, isrctn.com, greylit.org, opengrey.eu.
ELIGIBILITY CRITERIA: RCTs investigating the effect of PRP for the treatment of acute muscle injuries against at least one control group including patients treated with placebo injection or physical therapy. The outcomes evaluated were time to return to sport, re-injuries, complications, pain, muscle strength, range of motion (ROM)/flexibility, muscle function, and imaging.
RESULTS: Six studies, involving 374 patients, were included in the meta-analysis. The time to return to sport evaluated in all six studies was significantly shorter in patients treated with PRP (mean difference = - 7.17 days). However, if only the double-blind studies (n = 2) or studies including only hamstring injuries (n = 3) were considered, non-significant differences were found. Re-injuries (relative risk = - 0.03) and complications (relative risk = 0.01) were also similar between the two groups (p> 0.05), nor were any substantial differences found regarding pain, muscle strength, ROM/flexibility, muscle function, and imaging. The performance bias was high risk due to the lack of patient blinding in four studies. The quality of evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) was therefore low or very low.
CONCLUSIONS: The promising biological rationale, the positive preclinical findings, and the successful early clinical experience of PRP injections are not confirmed by the recent high-level RCTs. Therefore any benefit in terms of pain, function, return to sport, and recurrence using PRP injections for the treatment of acute muscle injuries is not supported. Due to the bias in the studies, the heterogeneity of the findings, and the limited sample size, the evidence should be considered to be of low or very low quality.
- “Strong evidence against platelet-rich plasma injections for chronic lateral epicondylar tendinopathy: a systematic review,” Robert-Jan de Vos, Johann Windt, and Adam Weir, British Journal of Sports Medicine, 2014.
- “Impact of autologous blood injections in treatment of mid-portion Achilles tendinopathy: double blind randomised controlled trial,” Kevin J Bell, Mark L Fulcher, David S Rowlands, and Ngaire Kerse, British Medical Journal, 2013.
- “Platelet-rich therapies for musculoskeletal soft tissue injuries,” Vinícius Y Moraes, Mário Lenza, Marcel Jun Tamaoki, Flávio Faloppa, and João Carlos Belloti, Cochrane Database of Systematic Reviews, 2014.
- “Autologous growth factor injections in chronic tendinopathy,” Michelle A Sandrey, Journal of Athletic Training, 2014.
- “Popular Blood Therapy May Not Work,” Gina Kolata, New York Times.
- “Meta-analysis Comparing Platelet-Rich Plasma vs Hyaluronic Acid Injection in Patients with Knee Osteoarthritis,” Yanhong Han, Hetao Huang, Jianke Pan, Jiongtong Lin, Lingfeng Zeng, Guihong Liang, Weiyi Yang, and Jun Liu, Pain Med, 2019.
- “The Efficacy of Platelet-Rich Plasma on Tendon and Ligament Healing: A Systematic Review and Meta-analysis With Bias Assessment,” Xiao Chen, Ian A Jones, Caron Park, and Jr Vangsness, American Journal of Sports Medicine, 2018.
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- Relationships Between Sleep Quality and Pain-Related Factors for People with Chronic Low Back Pain: Tests of Reciprocal and Time of Day Effects. Gerhart 2017 Ann Behav Med.
- Modulation in the elastic properties of gastrocnemius muscle heads in individuals with plantar fasciitis and its relationship with pain. Zhou 2020 Sci Rep.
- Association Between Plantar Fasciitis and Isolated Gastrocnemius Tightness. Nakale 2018 Foot Ankle Int.
- No Added Benefit of Combining Dry Needling With Guideline-Based Physical Therapy When Managing Chronic Neck Pain: A Randomized Controlled Trial. Stieven 2020 J Orthop Sports Phys Ther.
- Effectiveness of customised foot orthoses for Achilles tendinopathy: a randomised controlled trial. Munteanu 2015 Br J Sports Med.