The effectiveness of dry needling at myofascial trigger points for knee disorders: A quantitative synthesis of randomized controlled trials

Purpose: Dry needling (DN) targeting myofascial trigger points (MTrPs) has been proposed as a treatment for knee disorders, including knee osteoarthritis (KOA) and patellofemoral pain syndrome (PFPS). This meta-analysis evaluated the effectiveness of DN in improving pain and function in patients with knee disorders. Methods: This meta-analysis was conducted in accordance with PRISMA 2020 guidelines and was prospectively registered in PROSPERO (CRD420261294603). Systematic searches were performed in PubMed, Embase, Web of Science, Cochrane CENTRAL, CNKI, Wanfang, and VIP databases from inception to December 2025 for randomized controlled trials (RCTs) comparing DN targeting MTrPs with sham DN, no intervention, or other active treatments for knee disorders. Primary outcomes were pain intensity measured by the Visual Analog Scale (VAS) and Numeric Pain Rating Scale (NPRS). Secondary outcomes included functional status assessed by the WOMAC functional subscale and the Kujala Patellofemoral Score. Weighted mean differences (WMDs) were calculated using random-effects models. Risk of bias was assessed using the Cochrane Risk of Bias 2 (RoB 2) tool, and certainty of evidence was evaluated using the GRADE framework. Results: Twenty RCTs (n = 1,234; mean age range: 22–69 years) met the inclusion criteria. Compared with controls, DN significantly reduced knee pain across all pain measures: NPRS (WMD = –1.00, 95% CI: –1.25 to –0.76; I² = 0.0%), VAS (WMD = –1.19, 95% CI: –1.73 to –0.66; I² = 80.4%), and WOMAC Pain subscale (WMD = –1.76, 95% CI: –2.57 to –0.95; I² = 67.6%), with an overall pooled pain reduction of WMD = –1.25 (95% CI: –1.58 to –0.92; I² = 74.7%). DN also significantly improved knee function as measured by the WOMAC functional subscale (WMD = –6.59, 95% CI: –8.88 to –4.29; I² = 61.6%) and the Kujala Patellofemoral Score (WMD = 6.39, 95% CI: 4.64 to 8.14; I² = 30.1%). Pre-specified sensitivity analyses using standardized mean differences confirmed the robustness of these findings. The overall risk of bias was moderate, with concerns primarily related to inadequate blinding of participants and outcome assessors. The GRADE certainty of evidence was rated as moderate for all primary outcomes. Conclusion: DN targeting MTrPs provides significant short-term pain relief and functional improvement in KOA and PFPS, with pain reductions approaching clinically important thresholds. However, substantial heterogeneity, blinding limitations, and short follow-up necessitate cautious interpretation, and high-quality long-term RCTs are needed.