Minimally invasive procedure may offer lasting carpal tunnel relief

Clinical takeaway: For patients with carpal tunnel syndrome (CTS) that persists despite conservative treatment, ultrasound-guided hydrodissection with normal saline may provide a minimally invasive, steroid-free option with more durable symptom relief than corticosteroid injection alone.

Corticosteroid injections can ease CTS symptoms, but the benefit is often temporary. Hydrodissection uses fluid injected under ultrasound guidance to separate the median nerve from surrounding tissues and potentially restore nerve mobility, but whether the mechanical procedure itself provides benefit independent of the injectate has been unclear.

In a prospective, single-center randomized trial, investigators studied 63 wrists in 39 adults with nerve conduction study-confirmed CTS persisting for more than 3 months despite conservative treatment. Wrists were assigned to ultrasound-guided hydrodissection with normal saline, corticosteroid injection alone, or hydrodissection with saline plus corticosteroid, with follow-up through 24 weeks.

All 3 treatments improved symptoms initially, but their trajectories subsequently diverged. At 24 weeks, 85.7% of wrists treated with saline hydrodissection and 90.5% treated with hydrodissection plus corticosteroid achieved a clinically meaningful improvement in symptom severity, compared with none receiving corticosteroid injection alone. Pain scores fell from a mean 4.62 to 0.52 with saline hydrodissection and from 4.95 to 0.57 with hydrodissection plus steroid; with steroid injection alone, pain initially improved but returned to its baseline mean of 4.52 by 24 weeks.

Ultrasound findings paralleled the clinical results. At 12 weeks, median nerve cross-sectional area had decreased by about 44% with saline hydrodissection and 46% with hydrodissection plus corticosteroid, versus 11% with corticosteroid alone. Adding corticosteroid to hydrodissection provided no significant additional long-term benefit.

No major immediate or delayed complications occurred; 8% of participants experienced minor pain and swelling that resolved within 3 to 4 days. The study was limited by its small, single-center population and 24-week follow-up, and researchers called for larger multicenter studies with longer follow-up and evaluation of additional injectates.

“It came as a pleasant surprise to find that a simple procedure of dissecting the median nerve under ultrasound guidance with normal saline provided them long-term relief,” study co-author Anupama Tandon, MD, said in the press release. “Thus, hydrodissection merits to be a minimally invasive option for mild to moderate carpal tunnel syndrome and can defer and even alleviate the need for surgery.”

Source: Bose A, et al. (2026 Oct) Radiology. Efficacy of US-guided Hydrodissection for Carpal Tunnel Syndrome: A Prospective Randomized Controlled Trial