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

This comprehensive meta-analysis examined the effectiveness of dry needling targeting myofascial trigger points in the treatment of knee disorders, specifically knee osteoarthritis and patellofemoral pain syndrome. The study analyzed data from 20 randomized controlled trials involving 1,234 participants, with ages ranging from 22 to 69 years. The research was conducted following rigorous PRISMA 2020 guidelines and was prospectively registered on PROSPERO. The researchers performed systematic searches across multiple databases from inception through December 2025, including PubMed, Embase, Web of Science, Cochrane CENTRAL, and Chinese databases.

Dry needling is a minimally invasive intervention that involves inserting solid filiform needles into myofascial trigger points for therapeutic purposes. Unlike traditional acupuncture, it is based on musculoskeletal anatomy and aims to elicit local twitch responses to inactivate trigger points. The results demonstrated significant reductions in pain intensity across all measures evaluated. On the Numeric Pain Rating Scale (NPRS), there was a mean reduction of 1.00 points, while on the Visual Analog Scale (VAS) the reduction was 1.19 points.

Both reductions approach or exceed the minimal clinically important difference thresholds of 1.0-2.0 points on a 0-10 scale. For knee function, dry needling also demonstrated significant improvements. On the WOMAC functional scale, there was a 6.59-point improvement on a 0-100 scale, falling at the lower end of established estimates of clinically important difference. The Kujala score for patellofemoral pain showed a 6.39-point improvement, although slightly below the clinical significance threshold of 8-10 points.

The proposed mechanisms of action include peripheral and central effects. Peripherally, needle insertion elicits local twitch responses that can interrupt sustained sarcomere contraction, restore local blood flow, and reduce nociceptive biochemical mediators. Centrally, it can modulate spinal segmental inhibition through activation of A-delta afferents, potentially attenuating central sensitization. However, the study identified important limitations that require cautious interpretation.

There was substantial heterogeneity among studies, with variations in needling protocols, target muscles, concomitant interventions, and participant characteristics. Most studies demonstrated concerns regarding blinding of participants and assessors, which can inflate perceived treatment effects, especially considering that all primary outcomes are subjective and self-reported. In addition, most trials evaluated short-term outcomes (≤12 weeks), preventing conclusions about the durability of treatment effects. Inconsistent documentation of adverse events also limited systematic assessment of the safety profile.

The study found no trials directly comparing dry needling with first-line treatments recommended by guidelines, making it difficult to position this intervention within the treatment hierarchy. The clinical implications suggest that dry needling can be considered as adjuvant therapy within a multimodal treatment approach, complementing therapeutic exercise, manual therapy, and pharmacological treatments. However, the authors do not recommend routine integration into clinical practice at this time, suggesting that its use be guided by individualized clinical judgment and the presence of identifiable trigger points.