{'fraction_non_alphanumeric': 0.0212428662016487, 'fraction_numerical': 0.012682308180088777, 'mean_word_length': 4.853432282003711, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Positive Effect of Platelet-Rich Plasma on Pain in Plantar Fasciitis: Response

Dear Editor: We read with great interest the paper published by Peerbooms et al, which intended to determine the effectiveness of platelet-rich plasma (PRP) compared with corticosteroid injection for chronic plantar fasciitis. In this multicenter randomized controlled trial, the authors enrolled 115 patients—63 in the PRP group and 52 in the steroid group. They found that there were more patients with 25% improvement in the Foot Function Index (FFI) pain score at the end of the 12 months of follow-up in the PRP group compared with the steroid group. However, there was no difference in quality of life at the end of 1 year between the 2 groups, as scored with the short version of the World Health Organization Quality of Life (WHOQOL-BREF). It was an interesting and clinically relevant study to evaluate the effectiveness of a relatively newer nonoperative therapeutic modality for chronic plantar fasciitis. However, we have certain concerns regarding the methodology of the study and the results, which, if addressed, will clarify the doubts of readers. First, were patients with chronic bilateral plantar fasciitis also included in the study, or were only unilateral cases enrolled? This information is not clear from the manuscript. Second, it was mentioned that 5 to 6 mL of 40 mg/mL triamcinolone acetate was used in the steroid group, amounting to 200 to 240 mg of drug per injection. The usual amount that is injected in clinical practice, as has also been mentioned in the literature, is 40 to 80 mg per injection. With such a large amount of steroid injection, the chances of serious local adverse effects like plantar fat pad atrophy and plantar fascia rupture could be worrisome. Also, most clinical studies have reported injecting steroid mixed with a local anesthetic for plantar fasciitis. In the current study, although it was mentioned that 0.05 mL of bupivacaine was injected at the point of maximum tenderness in both groups prior to drug injection, the actual amount of local anesthetic use was not mentioned. Moreover, it was mentioned that 0.05 mL of platelet concentrate was obtained for each patient from the disposable cylinders of the Gravitational Platelet Separation (GPS) system (Zimmer Biomet). This appears to be a typographical error as the manual of the aforementioned instrument mentions the output to be 6 mL. Furthermore, the sample size remaining in the steroid group for analysis at the end of the 1-year follow-up was 36, which was less than the calculated sample size of 42. This should be mentioned in the Discussion as the results need to be interpreted with caution owing to a smaller sample size for analysis of the results. Also, the stretching protocol followed in the 2 groups, although similar, was not mentioned in the article. It could have been included for better understanding of the readers and to improve reproducibility of the said results. We hope that the authors consider these factors and provide a reasonable explanation on the aforementioned points to make the article more understandable to the readers.