Effectiveness of Phonophoresis Treatment in Carpal Tunnel Syndrome: A Randomized Double‐blind, Controlled Trial
Authors: Boonhong Jariya , Thienkul Worakan 
Published: April 2019

Objective

To determine the effects of phonophoresis of piroxicam (PH‐P) and phonophoresis of dexamethasone sodium phosphate (PH‐Dex) on mild to moderate carpal tunnel syndrome (CTS), and to compare each of them with the control group of nondrug ultrasound (US) therapy.

Design

A randomized, double‐blind controlled trial.

Setting

Department of rehabilitation medicine, university hospital.

Participants

Patients with clinical signs and symptoms of CTS underwent an electrophysiological study to confirm the diagnosis of CTS and severity grading. Thirty‐three patients, 50 hands (52% of the patients had bilateral CTS, n = 17) with mild to moderate CTS were randomly allocated into three study groups: PH‐P, PH‐Dex, or US.

Intervention

All three groups received 10 sessions of 1‐MHz frequency, 1.0 w/cm2 intensity ultrasound wave with stroking technique, continuous mode, at the palm side of the hand over the carpal tunnel area—10 minutes per session, two to three times per week for 4 weeks, for a total of 10 sessions. During each session, the patients received 15 cm3 of study gel according to the study groups. The PH‐P group received 0.5% piroxicam gel mixture (equivalence of 20 mg of piroxicam). The PH‐Dex group received 0.4% dexamethasone sodium phosphate gel mixture (equivalence 60 mg of dexamethasone). The US group received nondrug gel.

Main Outcome Measurements

Boston Carpal Tunnel Questionnaire for symptom severity (BCTQ SYMPT), Boston Carpal Tunnel Questionnaire for functional status (BCTQ FUNCT) and electrophysiological parameters of the median nerve including distal sensory latency (DSL) and distal motor latency (DML) were evaluated before the first treatment and after the last treatment.

Results

After treatment, all treatment groups (PH‐P, PH‐Dex, and US) showed significant improvements of the BCTQ SYMPT (P < .001, −0.74 ± 0.73 [−1.12, −0.37], −0.91 ± 0.96 [−1.41, −0.42], and − 0.68 ± 0.71 [−1.05, −0.30], respectively) and the BCTQ FUNCT (P < .001, −0.68 ± 0.89 [−1.14, −0.22], −0.74 ± 0.84 [−1.17, ‐0.30], and − 0.80 ± 0.80 [−1.22, −0.37], respectively). For the BCTQ SYMPT, only the PH‐Dex showed an improvement score above MCID at 0.8 level [−0.91 ± 0.96]. The improvement of BCTQ FUNCT score of all groups was above Minimal Clincally Important Difference (MCID) at 0.5 level (−0.68 ± 0.89, −0.74 ± 0.84 and − 0.80 ± 0.80, respectively).The DSL was decreased in all groups but the changes were not statistically significant (P = .70, −0.11 ± 0.34 [−0.28, 0.06], −0.09 ± 0.32 [−0.26, 0.07], and − 0.14 ± 0.29 [−0.29, 0.02], respectively). The DML showed decrease only in PH‐DEX and the US group but it was not statistically significant (P = .68, 0.05 ± 0.44 [−0.17, 0.27], −0.09 ± 0.51[−0.34, 0.17], and − 0.27 ± 0.49 [−0.53, 0.01], respectively). All measured outcomes were not statistically different in between‐group‐comparison of BCTQ SYMPT, BCTQ FUNCT, DSL, and DML (P = .58, P = .79, P = .20 and P = .39, respectively). However, there was a clinically significant difference of the improvement of BCTQ SYMPT in between‐group comparison; only the PH‐DEX was above the MCID level, while the PH‐P and US were not.

Conclusions

Neither nondrug US nor phonophoresis treatments (PH‐P and PH‐Dex) were effective to improve the DSL and DML in mild to moderate CTS. All three groups showed significant improvements in clinical symptoms (BCTQ SYMPT) and functional status (BCTQ FUNCT). At 1 MHz frequency and 1.0 w/cm2 intensity of ultrasound wave, there is no statistically significant difference between phonophoresis and the nondrug US.

Level of Evidence

I