A brief procedure using saline could offer lasting relief for stubborn carpal tunnel symptoms without steroids, a small clinical trial suggests.
The numbness, tingling, weakness, and pain of carpal tunnel syndrome arise when the median nerve, a major nerve running from the forearm, is compressed inside a narrow passage in the wrist. Corticosteroid injections can reduce swelling and ease that pressure, but the relief may be temporary. Associated with repetitive hand and wrist movements, the condition affects roughly 5% to 10% of people over their lifetimes, and its incidence is rising.
A randomized trial of 63 patients now suggests that injecting saline around the nerve under ultrasound guidance can provide relief that lasts through six months of follow-up. Adding steroids to the procedure did not significantly improve its long-term benefits. The study was published in Radiology, a journal of the Radiological Society of North America (RSNA).
Using saline to free the nerve
The procedure, called nerve hydrodissection, uses carefully injected fluid to free the nerve from surrounding adhesions, tissue attachments that can restrict its movement. Ultrasound allows clinicians to guide the injection around the affected nerve. Hydrodissection is generally combined with steroid treatment, so its effectiveness without steroids has remained uncertain.
Study lead author Anindita Bose, M.D., assistant professor in the Department of Radiology at Mahatma Gandhi Medical College and Hospital in Jaipur, India, and colleagues studied patients with confirmed carpal tunnel syndrome who had not responded to conventional treatment.
“Most of our patients had been suffering from carpal tunnel syndrome for months to years and did not get much relief despite trying various treatments like pain medications, splints, lifestyle modification, and corticosteroids,” said study co-author Anupama Tandon, M.D., professor in the Department of Radiodiagnosis and Imaging at University College of Medical Sciences and Guru Teg Bahadur Hospital in Delhi, India. “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.”
To compare the treatments, the researchers randomly divided participants into three equal groups. One received hydrodissection with normal saline, a saltwater solution. Another received hydrodissection with saline and a corticosteroid, while the third received a corticosteroid injection alone. All three treatments were guided by ultrasound.
The team tracked symptoms, function, and pain using standardized clinical scores. Ultrasound measurements of the median nerve’s cross-sectional area allowed the researchers to assess changes in swelling. Follow-up assessments took place four, 12, and 24 weeks after treatment.
Less nerve swelling, longer-lasting relief
All three groups improved significantly by four weeks, but their outcomes diverged as follow-up continued.
“At 12 weeks and 6 months, both hydrodissection groups demonstrated further improvement in clinical symptoms and function, whereas patients who received corticosteroid injection alone experienced a recurrence of the symptoms, suggesting that the initial benefit was short-lived,” Dr. Tandon said.
The ultrasound measurements supported the symptom and function results. The median nerve’s cross-sectional area decreased by approximately 43% to 45% after hydrodissection, compared with approximately 15% after steroid injection alone, indicating a greater reduction in nerve swelling.
The lack of a significant additional long-term benefit from steroids in the hydrodissection groups matters because those drugs carry risks beyond the possibility that symptoms will return.
“Traditional steroid injection for carpal tunnel syndrome often provides only temporary relief, thus requiring repeats of the procedure,” Dr. Tandon said. “Further, steroids carry risk of localized skin changes, fat thinning and tendon weakening.”
A 15-minute procedure without hospitalization
Hydrodissection took an average of 15 minutes, and patients tolerated it well, with no significant immediate or delayed complications observed. Questionnaire responses indicated high satisfaction with the procedure. It was low-cost, required neither anesthesia nor hospitalization, and allowed patients to return to work within an hour.
“Overall, the study suggests that ultrasound-guided saline hydrodissection is a safe, minimally invasive treatment that can provide sustained clinical and morphological improvement in patients with refractory carpal tunnel syndrome,” Dr. Tandon said. “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.”
The researchers said larger studies across multiple centers, with longer follow-up, are needed. They have already launched a study comparing the long-term effectiveness of different fluids used for hydrodissection in carpal tunnel syndrome, including dextrose versus saline.
“This trial features an extended follow-up period to track long-term patient outcomes and establish the true durability of the treatment,” Dr. Tandon said.
Reference: “Efficacy of US-guided Hydrodissection for Carpal Tunnel Syndrome: A Prospective Randomized Controlled Trial” by Anindita Bose, Anupama Tandon, Gopesh Mehrotra, Siddharth Maheshwari and Ayush Khandelwal, 6 October 2026, Radiology.
DOI: 10.1148/radiol.260185
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