Acupuncture and dry needling for physical therapy of scar: a systematic review

This systematic review investigated the efficacy of acupuncture and dry needling in the treatment of scars, a topic of growing interest in physical therapy. Scars can cause pain, functional limitation, and significant aesthetic changes, especially when they do not heal properly, developing into hypertrophic scars or keloids. Dry needling, defined by Western medicine as a type of acupuncture, uses filiform needles to stimulate soft tissues, including scar tissue. The authors conducted a comprehensive search of multiple databases (MEDLINE, EMBASE, Web of Science) from inception through October 2023, following PRISMA guidelines.

Studies investigating the efficacy of acupuncture or dry needling applied locally on scars were included. The search yielded 11 eligible studies: two randomized controlled trials, eight case reports, and one case series, totaling 161 participants. The studies addressed different types of scars, including postsurgical, keloid, hypertrophic, and burn scars. Methodologic quality was assessed using appropriate scales (PEDro for clinical trials, JBI for case reports).

Most case reports were of low to moderate quality, with only one study reaching the maximum score. The clinical trials were classified as good to fair quality. The interventions varied significantly in treatment frequency, duration, number of sessions, needle insertion sites, and manipulation techniques. Needles were inserted around the scars using techniques such as 'surrounding the dragon,' with diameters ranging from 0.15 to 0.30 mm and lengths from 5 to 60 mm.

Needle retention time ranged from 2 minutes to 24 hours. Nine of the ten studies reported a reduction in scar-related pain, measured by different scales (VAS, NRS, Likert). Scar characteristics were assessed using the Vancouver Scar Scale (VSS) and the Patient and Observer Scar Assessment Scale (POSAS). However, many studies combined acupuncture with other therapeutic modalities, such as ultrasound, massage, or medications, limiting the interpretation of the specific effects of acupuncture.

The significant heterogeneity across studies precluded meta-analysis. Limitations include the scarcity of randomized controlled trials, variable methodologic quality of case reports, non-standardized treatment protocols, and frequent combination with other therapies. In addition, scar age varied widely (from 5 weeks to 8 years), hindering conclusions about the optimal timing for intervention. The authors conclude that, although most studies suggest benefits of acupuncture and dry needling for pain and scar-related symptoms, current evidence does not allow definitive conclusions about efficacy.

Multicenter, randomized, controlled clinical trials with standardized protocols, larger samples, and uniform outcome measures are needed to establish the actual efficacy of these interventions in scar treatment.