A Saline Injection Could Offer Longer Relief From Carpal Tunnel Pain
NEWS | 19 October 2026
Typing with numb fingers, struggling to hold a pen, or waking with an aching hand can make everyday life exhausting for people with carpal tunnel syndrome. The condition develops when a nerve supplying the hand becomes squeezed inside a narrow passage at the wrist. Pressure can disrupt the nerve's signals, causing pain, tingling, numbness, and weakness. Now, a small trial has found that injecting saline around the trapped nerve could ease symptoms for longer than a steroid injection. Relief persisted for six months after the saline procedure, by which time the initial benefits of steroid injection alone had largely faded. Ultrasound guides needle placement during hydrodissection for carpal tunnel syndrome. (Bose et al., Radiology, 2026/RSNA) The saline is used to open up space between tissues. In the procedure, called hydrodissection, a clinician uses ultrasound to guide a fine needle alongside the nerve. The sterile salt solution is injected around it, separating it from tissues that restrict its movement. This aims to help the nerve move more freely. A steroid injection eases symptoms by reducing inflammation and swelling. "This relieves the pressure on the nerve and improves patients' symptoms," radiologist Anupama Tandon, from University College of Medical Sciences and Guru Teg Bahadur Hospital in India, told ScienceAlert. The researchers wanted to establish how much benefit came from separating the tissues. Most earlier hydrodissection studies included medication in the injected fluid, so it was hard to tell whether the procedure or the drug deserved the credit. Led by radiologist Anindita Bose from Mahatma Gandhi Medical College and Hospital, the team studied 39 adults whose symptoms had persisted for more than three months, despite treatments such as medication or wrist splints. Some had the condition in both hands, so the trial included 63 wrists. Ultrasound images show fluid separating the wrist nerve from surrounding tissues. Red arrows mark the needle. (Bose et al., Radiology, 2026/RSNA) Each wrist was randomly assigned to one of three treatments. One group received hydrodissection with saline alone. Another received a steroid injection without the tissue-separating procedure. The third received hydrodissection with steroid added to the saline. All treatments were guided by ultrasound. The steroid-containing injections also included a local anesthetic. The researchers then followed changes in pain, numbness, and difficulty using the hand, with ultrasound scans checking nerve swelling during the first three months. All three treatments helped initially. The difference emerged over the following months: Pain returned in the steroid-only group, while relief continued in the saline-only hydrodissection group. Adding steroid to hydrodissection did not clearly improve the results. Ultrasound images supported the patients' reports. Nerve swelling decreased more in both hydrodissection groups than in the group given steroid injections alone. These findings support the researchers' explanation that separating the nerve from surrounding tissues contributes to relief. However, the trial had no group that received a dummy injection, so the contribution of patients' treatment expectations could not be assessed separately. Tandon described a young typist whose pain and numbness had become so disruptive that her job was at risk. Medication and a wrist splint had failed to help. "Post hydrodissection, she had improvement in her symptoms and was able to resume her work," Tandon said. Treatment took around 15 minutes and required no hospital stay. No major complications were observed. Some participants experienced mild pain and swelling that settled within a few days. One experienced tingling during needle placement, with no lasting neurological effects reported. Larger studies are needed to establish how reliably the procedure works and how long relief lasts. This trial involved a small number of people at one center, with follow-up ending at six months. It did not directly compare hydrodissection with surgery. "It is beneficial for mild to moderate CTS [carpal tunnel syndrome]," Tandon said, "while severe cases require surgery." The team has begun a longer study comparing saline with dextrose, a type of sugar, to investigate which fluid provides more lasting relief. The research has been published in Radiology.
Author: Esra Öz.
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