Ultrasound-Guided Percutaneous Electrolysis Versus Dry Needling In Chronic Low Back Pain

Key Takeaways

• Ultrasound-guided percutaneous electrolysis was associated with broader short-term statistical improvement across several reported outcomes than electrical dry needling, although not all between-group differences reached established clinical importance thresholds.
• Both groups received weekly treatment for 6 weeks, with outcome assessments at baseline, 3 weeks, 6 weeks, and 10 weeks.
• No clinically significant complications were reported, and transient local discomfort, pain, or heaviness resolved within 72 hours.

In a double-blind randomized trial, adults with non-specific chronic low back pain had more favorable short-term changes with ultrasound-guided percutaneous electrolysis than with electrical dry needling. Among 64 participants who completed treatment and follow-up, the clearest between-group differences were seen in disability, pain intensity, and fear of movement, with additional separation in selected functional and patient-reported measures. Disability differences were statistically significant but did not reach known minimum clinically important difference thresholds. These findings reflect short-term results from this trial rather than a universal ranking of needling-based interventions.

The trial used a randomized, double-blind, parallel-group design with intention-to-treat analysis, and both the evaluator and statistical researcher remained blinded to allocation. Eligible participants were 30 to 67 years old, had non-specific chronic low back pain, an RMDQ score of at least 4, and no concurrent physiotherapy. Of 70 recruited patients, 64 completed the trial; mean age was 46.45 ± 10.5 years, 65.6% were women, and baseline characteristics were similar between groups. Primary outcomes were pressure pain threshold and disability, with secondary measures spanning pain intensity, fear of movement, sleep, quality of life, mental health, trunk flexor endurance, and lumbar mobility. Outcomes were assessed at baseline, 3 weeks, 6 weeks, and 10 weeks.

Significant time-by-group interactions favored electrolysis for disability (F = 5.70, p = 0.005), pain intensity (F = 7.42, p = 0.001), and fear of movement (F = 4.24, p = 0.019). Interactions also appeared for finger-to-floor distance (F = 19.30, p < 0.001), daytime sleep dysfunction (F = 3.14, p = 0.050), bodily pain (F = 5.03, p = 0.010), and total anxiety (F = 3.71, p = 0.030). At post-treatment, between-group differences favored electrolysis on the RMDQ (t = -2.72, p = 0.004) and ODI (t = -3.23, p < 0.001). At one month, between-group differences favored electrolysis on VAS pain (t = -3.18, p = 0.001) and TSK fear of movement (t = -2.62, p = 0.006). The authors noted that pain and kinesiophobia changes at follow-up tended to be clinically relevant, whereas disability changes did not reach known MCID values despite statistical significance. Active trigger point counts and pressure pain threshold at select sites also favored electrolysis, with the clearest comparative advantages after treatment and at one month.

Treatment was delivered once weekly for 6 weeks by clinicians with more than 6 years of invasive physiotherapy experience. Ultrasound-guided percutaneous electrolysis consisted of three bilateral punctures lasting 3 seconds each at 3 mA near the proximal epineurium of the posterior branches of L3, L4, and L5. The comparator involved bilateral electrical dry needling of active and latent trigger points in the iliocostalis lumborum, lumbosacral multifidus, and quadratus lumborum for 30 minutes at 2 Hz with 250-microsecond pulses. No clinically significant complications or meaningful adverse events were reported, and transient local discomfort, pain, or heaviness resolved within 72 hours.

The authors cited one-month follow-up, modest sample size, therapist non-blinding, and possible resource demands from ultrasound guidance; the findings remain bounded to the studied adult population.