Carpal Tunnel Syndrome Treatment Using Ultrasound-Guided Versus Landmark-Guided Corticosteroid Injection: A Randomized Prospective Trial

Carpal tunnel syndrome (CTS) is the most prevalent entrapment neuropathy occurring due to increased pressure in the carpal tunnel. The study aimed to evaluate the degree of symptom improvement, safety, and the change in electrophysiological findings after ultrasound (US)-guided versus Landmark (LM)-guided local steroid injection for the treatment of CTS. This randomized clinical trial recruited 52 patients with moderate or moderate-to-severe CTS. The subjects were randomly assigned to US-guided or LM-guided corticosteroid injection groups and received 40 mg methylprednisolone. After four weeks and 12 weeks of treatment, the patients were evaluated using the Boston questionnaire and electrophysiological parameters were determined. All variables, including symptom/functional scores and electrophysiological findings, improved significantly in both groups after four weeks (all P < 0.05), except for compound muscle action potential (CMAP) amplitude in the LM-guided group. The LM-guided group showed a regress in all variables in the 12th week compared to the 4th week; however, these improvements persisted at week 12 post-treatment in the US-guided group (P < 0.05), except for the functional status scale (FSS) and sensory nerve action potential (SNAP). The improvement in the CMAP amplitude at week 12 was more in the US-guided group than in the LM-guided group (P < 0.05); however, the SNAP amplitude and SNAP nerve conduction velocity (NCV) improved more significantly in the LM-guided group. Significant differences were not observed between the groups with respect to the symptom severity score (SSS), FSS, SNAP latency, and CMAP latency at weeks 4 or 12 after treatment (P > 0.05). The symptom severity, functional status, and all electrophysiological parameters improved significantly in both US-guided and LM-guided corticosteroid injection groups and generally, no statistically significant difference was observed between both methods.