The Effectiveness of Fu’s Subcutaneous Needling for Residual Pain After Percutaneous Vertebral Augmentation in Osteoporotic Vertebral Compression Fractures: A Randomized Clinical Trial Protocol [Letter]

We read with great interest the study protocol by Wang et al 1 This study has the potential to provide high-level evidence for the use of Fu's Subcutaneous Needling (FSN) in managing persistent pain after osteoporotic vertebral compression fractures (OVCFs), and may serve as a feasible non-pharmacological alternative for chronic postoperative pain management.However, several issues merit further clarification to enhance the rigor and impact of the study.First, there is an internal inconsistency in the definition of the primary outcome.The abstract identifies the Oswestry Disability Index (ODI) as the primary endpoint, whereas the main text designates the Visual Analog Scale (VAS) as the primary outcome, and the sample size calculation is based on ODI.This inconsistency undermines the coherence among the study hypothesis, sample size estimation, and statistical analysis.According to the SPIRIT-Outcomes extension, 2 primary outcomes should be pre-specified, clearly defined, and consistently reported to minimize selective reporting bias.We recommend that the authors define a single primary outcome and ensure consistency across the abstract, trial registration, methods, and statistical analysis sections.In addition, incorporating the minimal clinically important difference (MCID) into both sample size estimation and result interpretation would better align the study with contemporary high-quality RCT standards focusing on clinically meaningful patient benefit.Second, the follow-up duration of 30 days after treatment appears insufficient.In patients with residual pain following OVCF surgery, early pain relief does not necessarily correspond to sustained functional recovery.Important clinical events, such as adjacent vertebral fractures, symptom recurrence, and dependence on analgesics, typically require a longer observation period.Existing literature supports the use of 3 months as a key intermediate follow-up time point, with extension to 6 months or longer to adequately assess the durability of pain relief, functional recovery, and complications. 3,4We therefore suggest adding a 3-month follow-up time point and systematically recording clinical events such as rescue analgesic use during the study period.Third, the inclusion criteria involving the assessment of "tightness", "stiffness", "hardness", "sliding" and local tenderness are overly subjective, which may compromise the consistency of patient selection and the reproducibility of the study.Although these criteria are consistent with the FSN theory of "tense muscles", manual palpation has limited inter-rater reliability and may introduce variability in participant inclusion and outcome interpretation; 5 although local tenderness demonstrates relatively higher reliability, it is still insufficient to replace standardized assessment criteria.To improve methodological rigor, we recommend incorporating objective assessment tools, such as pressure pain threshold