A randomised controlled trial on the efficacy of hydroelectrophoresis in acute recurrences in chronic low back pain patients.

AIM: Physical therapy efficacy in the treatment of low back pain (LBP) has been widely debated and is far from achieving high levels of evidence. Hydroelectrophoresis (Hydrofor) is a novel method of driving drugs through the dermal tissue, which has been proposed for muscle pain treatment. Aim of this randomised placebo-controlled study was to ascertain the efficacy of Hydrofor treatment on acute relapsing episodes of pain in chronic LBP subjects. METHODS: Eighteen under-50 adults (M/F: 7/11; age 35+/-8 years) suffering from chronic LBP were enrolled within 3 to 4 days of back pain relapse. After a complete clinical and functional assessment patients were randomly divided into 2 equal groups. Group A received 3 Hydrofor applications of a mixture containing both NSAIDs and muscle relaxants, whereas Group B received 3 Hydrofor applications of a drug-free solution. Afterwards, both groups performed the same rehabilitation treatment consisting of 7 group sessions of standard physiotherapy, including stretching, range of motion and extension exercises. The Oswestry disability index (ODI), the Million instrument scale and a visual analogue scale (VAS) were chosen as outcome measures and applied at baseline, after Hydrofor/placebo applications, after completion of rehabilitation sessions and, at last, 2 months later. The two-way Friedman test was used to analyse within-group (time effect) and between-group (time x group effect) differences. RESULTS: All subjects declared a significant pain reduction since the first Hydrofor application. Pain evolution overlapped in the 2 groups until the 3rd session, after which Group A significantly diverged from Group B, as they affirmed a greater symptom reduction than controls (time x group effect: VAS: F = 7.4, p <0.01). Such difference disappeared after the physiotherapy sessions as well as 2 months later (time x group effect: VAS: F = 2.1, p =0.08). Pain-related disability showed a greater reduction in Group A than B immediately after Hydrofor application (time x group effect: ODI: F=3.9 p <0.05; Million: F=4.1 p<0.05), but the mean scores almost overlapped at the 2 month follow-up (time x group effect: ODI: F=2.3 p =0.08; Million: F=1.3 p=0.26). CONCLUSIONS: Hydrofor treatment relieves relapsing LBP and could be recommended to active adults as a safe technique shortening the time needed to achieve functional restoration.