Frequency and severity of adverse events associated with dry needling: a systematic review and meta-analysis

IMPORTANCE: Dry needling (DN) is widely used in musculoskeletal practice. However, the incidence and severity of adverse events (AEs) associated to DN remain unclear. OBJECTIVE: The objective was to report the frequency and severity of AEs related to DN. DESIGN: This was a systematic review with meta-analysis. SETTING: Following the PRISMA checklist, PubMed, Web of Science, and Scopus databases were systematically searched from September 2024 to April 2025. STUDIES AND INTERVENTION: Case reports, case series, surveys, observational studies, and randomized clinical trials conducted on humans, applying DN and assessing associated AEs, were collected. MAIN OUTCOMES AND MEASURES: Methodological quality and risk of bias were assessed using the Joanna Briggs Institute tool, the AXIS tool, the PEDro scale and the Newcastle-Ottawa scale. Data were screened and extracted by 2 independent investigators, consulting a third researcher in case of doubts. The information was analyzed and classified in separate tables detailing the characteristics of the sample, the interventions, the AEs, and the methodological quality from the different types of studies. RESULTS: A total of 59 articles were included, comprising 25 patients in case reports and case series, 1947 patients in randomized clinical trials and prospective observational studies and 2380 professionals in surveys. DN was found to commonly produce minor AEs, ranging from 0% to 48.15% per treatment and from 2.56% to 72.73% throughout a clinician's career. Major AEs per treatment are uncommon (0%-0.43%) but are reported by 0.98% to 39.14% of professionals when assessing their complete clinical practice. CONCLUSIONS AND RELEVANCE: While DN is widely used and generally associated with minor AEs, this review highlights the potential for rare although serious complications.