Efficacy of Combined Ultrasound-Guided Steroid Injection and Splinting in Patients With Carpal Tunnel Syndrome: A Randomized Controlled Trial.

OBJECTIVE: To compare the effectiveness of local steroid injection plus splinting with that of local steroid injection alone using clinical and electrophysiological parameters in patients with carpal tunnel syndrome (CTS).

DESIGN: Randomized controlled study with 12 weeks of follow-up.

SETTING: Tertiary care center.

PARTICIPANTS: Volunteer sample of patients (N=52) diagnosed with CTS.

INTERVENTIONS: Participants were randomly assigned to the steroid injection group (n=26) or the steroid injection-plus-splinting group (n=26). Patients of both groups received ultrasound-guided steroid injection with 1mL of 10mg (10mg/mL) triamcinolone acetonide (Shincort) and 1mL of 2% lidocaine hydrochloride (Xylocaine). Participants in the second group also wore a volar splint in the neutral position while sleeping and also during daytime whenever possible for the 12-week intervention period.

MAIN OUTCOME MEASURES: Participants were evaluated before the treatment and at 6 and 12 weeks after the onset of treatment. The primary outcome measure was Boston Carpal Tunnel Questionnaire scores. The secondary outcome measures were as follows: scores on the visual analog scale for pain; electrophysiological parameters, including median nerve distal motor latency, sensory nerve conduction velocity (SNCV), and compound muscle action potential and sensory nerve action potential (SNAP) amplitudes; and patient's subjective impression of improvement.

RESULTS: At 12-week follow-up, improvements in symptom severity and functional status scores on the Boston Carpal Tunnel Questionnaire as well as SNCV and SNAP amplitudes were greater in the group that received steroid injection combined with splinting than in the group that received steroid injection alone. The between-group difference was .48 points (95% confidence interval [CI], .09-.88 points; P=.032) in the Symptom Severity Scale score, .37 points (95% CI, .06-.67 points; P=.019) in the Functional Status Scale score, 3.38m/s (95% CI, 0.54-6.22m/s; P=.015) in the SNCV amplitude, and 3.21μV (95% CI, 0.00-6.46μV; P=.025) in the SNAP amplitude.

CONCLUSIONS: In people with CTS, steroid injection combined with splinting resulted in modestly greater reduction of symptoms, superior functional recovery, and greater improvement in nerve function at 12-week follow-up as compared with steroid injection alone. However, these small differences are of unclear clinical significance.