- Eduardo Anitua
- Roberto Prado
Platelet-Rich Plasma for Chronic Plantar Fasciitis: as with any other treatment, a comprehensive protocol is necessary
We have read with great interest the recent article by Shetty et al. (1). In this appealing clinical trial, the authors compare the pain and functional outcomes of single injection of platelet-rich plasma (PRP), corticosteroids (CS), and placebo for the treatment of patients diagnosed with chronic plantar fasciitis. At the end of the follow-up period (18 months), both treatments showed superior statistically significant results compared with treatment with placebo. Nevertheless, the treatment with CS showed better recovery in the short term (<1 month), whereas the PRP treatment demonstrated better results in the long term (6 to 18 months). The authors conclude that the better long-term results and the lower reinjection and surgery rates of PRP make it a more attractive choice that CS injection. We believe that this study confirms the efficacy of PRP treatment in plantar fasciitis lesions; however, we would like to comment constructively on several aspects.
Our main concern is the poor reporting of the PRP obtaining protocol. In this regard, the authors only state that “The PRP was prepared using a standard double centrifugation protocol by the central laboratory of our institute.” They do not include any detail of the procedure (except for the double centrifugation), nor reference to any publication that explains it. They do not carry out a product characterization because they do not indicate the basic characteristics that it contains, such as platelet and leukocyte content, or activation mode.
The authors describe details of the rest of the products that they use, which allows both replication and comparison to the study, such as corticosteroid (methylprednisolone acetonide, 40 mg/mL), placebo (0.9% normal saline), and lidocaine (1%). In the same way that changes in concentration or components of these drugs can affect clinical efficacy, the composition of PRP can affect the clinical outcome (2,3). We believe that one way to overcome these limitations is to adequately report the methods of obtaining and performing an accurate characterization of the PRP that is given to the patient. A highly recommended option is to follow the guidelines proposed by Murray et al (4), in which the “Minimum Information for studies evaluating Biologics in Orthopaedics” (MIBO) is suggested.
On the other hand, we would like to know why this clinical trial has been classified with a level of evidence 2, when by its design it could be considered level 1 (control group, block randomization of patients, treatment blinded to the randomization process, patients blinded to the treatment, 100% follow up, no crossover). We encourage the authors to explore the option suggested in the discussion of their article, the combination of CS and PRP. There is in vitro evidence that can support this strategy (5). We also suggest the authors further detail the procedures for obtaining PRP in future studies to promote the advance of biological therapies with PRP.