Po-Cheng Chen, Lin-Yi Wang, Ya-Ping Pong, Yi-Jung Hsin, Mei-Yun Liaw, Chia-Wei Chiang
Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital-Kaohsiung Medical Center, 83305 Kaohsiung, Taiwan ROC
DOI: 10.2340/16501977-2308

Objective: To compare the outcomes of ultrasound-guided vs direct approach corticosteroid injection in patients with idiopathic carpal tunnel syndrome.
Methods: A double-blind randomized controlled study. Wrists affected by carpal tunnel syndrome were randomized to the ultrasound-guided (n = 22 wrists) or direct approach injection group (n = 17 wrists) before receiving 1 ml Betamethasone. Outcome measures were physical findings and electrodiagnostic parameters assessed at 1, 3 and 6 months after injection. Complications were also recorded.
Results: Both groups showed improvement through-out the follow-up period after injections, in physical findings and in most electrodiagnostic parameters (all p<0. 05). The ultrasound-guided injection group showed greater improvements in the Semmes-Weinstein Monofilament test result (p = 0. 004), sensory nerve conduction velocity (p = 0. 038), and digit-4 comparison study result (p = 0. 046). Three wrists with weakness were found in the direct approach injection group, yet none were noted in the ultrasound-guided injection group (p=0. 040).
Conclusion: Both ultrasound-guided and direct approach corticosteroid injection protocols improved clinical symptoms and signs, physical function, and most electrodiagnostic parameters of patients with carpal tunnel syndrome throughout the follow-up period. However, the ultrasound-guided injection group showed greater improvements in the Semmes-Weinstein Monofilament test, sensory nerve conduction velocity, and digit-4 comparison study.

Local corticosteroid injections can be considered for treatment of mild to moderate carpal tunnel syndrome. Because ultrasound-guided injections could provide greater improvement of symptoms and avoid adverse events in most musculoskeletal disorders, we studied the effectiveness and safety of ultrasound-guided corticosteroid injections for carpal tunnel syndrome. Better improvement of sensory examination and nerve conduction study were observed in ultrasound-guided injections than blind injections. Besides, the discomforts experienced by patients within the first week after local injections were fewer in ultrasound-guided injections. Therefore, we recommend ultrasound-guided corticosteroid injections for carpal tunnel syndrome.

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