Patients and methods: This double-blind randomized controlled trial was performed on 42 patients (9 males, 33 females; mean age: 46.7±2.1 years; range, 18 to 70 years) with mild to moderate CTS between May 2021 and June 2021. The corticosteroid group (n=21) was injected with 40 mg triamcinolone, and in the O3 group B (n=21), 4 mL of a 10 mcg/mL oxygen (O2)-O3 mixture was injected. Symptom severity and functional impairments were assessed using a Visual Analog Scale and Boston Carpal Tunnel Questionnaire. Electrodiagnostic and ultrasonographic parameters were obtained at baseline and eight weeks after the procedure.

Results: The O2-O3 solution improved pain and Boston Carpal Tunnel Questionnaire score after eight weeks (p<0.001); however, the change was nonsignificant compared to the corticosteroid group (p>0.05). Sensory nerve and compound muscle action potential latencies were not significantly changed eight weeks after O2-O3 injection (p>0.05), while both were significantly decreased in the steroid injection group (p<0.001). Volar bulging and median nerve cross-section surface area were not improved after O2-O3 injection, while the improvement was significant in the corticosteroid arm (p=0.02).

Conclusion: Symptoms in patients with mild to moderate CTS may be alleviated by local O2-O3 injection; however, electrodiagnostic and ultrasonographic indices may be unchanged. Corticosteroid local injection may alleviate patient symptoms along with electrodiagnostic and ultrasonographic parameters. Keywords : Carpal tunnel syndrome, corticosteroid, ozone