Ultrasound-Guided Injection of Carpal Tunnel Syndrome Using Hyaluronic Acid vs Corticosteroid vs Glucose 5%

Overview

Carpal tunnel syndrome (CTS) is a common peripheral nerve entrapment disorder caused by compression of the median nerve at the wrist. This study is a comparative study designed to evaluate the efficacy of three ultrasound-guided injection treatments for patients with mild to moderate CTS: hyaluronic acid (HA), corticosteroid, and 5% glucose (D5W). A total of 60 adult patients with clinically and electrophysiologically confirmed mild to moderate CTS will be enrolled and divided into three groups of 20 patients each. Participants will receive a single ultrasound-guided injection using one of the three study interventions. Clinical assessment will include Phalen's test and Tinel's sign. Electrophysiological assessment will include median nerve sensory and motor nerve conduction parameters, while ultrasonographic assessment will include measurement of the median nerve cross-sectional area. Participants will be reassessed three months after the intervention using the same clinical, electrophysiological, and ultrasonographic measures. The study will compare changes in these outcomes among the three treatment groups to evaluate their relative efficacy in the management of mild to moderate CTS.

Detailed Description Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome and results from compression of the median nerve as it passes through the carpal tunnel at the wrist. The carpal tunnel is a relatively narrow osteofibrous canal containing the median nerve and nine flexor tendons. Any condition that decreases the available space within the tunnel or increases the volume of its contents may increase intracarpal pressure and compromise median nerve function. The clinical severity of CTS can range from mild to severe. Mild CTS is generally characterized by intermittent sensory symptoms and sensory conduction abnormalities, whereas moderate CTS may involve both sensory and motor nerve conduction abnormalities. Severe disease may be associated with persistent numbness, weakness, thenar muscle atrophy, and evidence of more advanced nerve damage. The present study will focus on patients with mild to moderate CTS, confirmed clinically and electrophysiologically. Conservative management of CTS includes wrist splinting, physiotherapy, and local injections. Corticosteroid injection is an established treatment option that can provide short-term symptomatic relief. More recently, other injectates have been investigated. Hyaluronic acid (HA) has been proposed as a treatment that may reduce perineural adhesions and improve median nerve gliding. In addition, perineural injection and hydrodissection using 5% glucose (D5W) have shown promising results in patients with neuropathic pain conditions, including CTS. Ultrasound guidance will be used for all injections. Ultrasound guidance allows visualization of the median nerve and surrounding anatomical structures during the procedure and facilitates accurate placement of the injectate while avoiding direct injury to the median nerve. Ultrasonography will also be used to measure the median nerve cross-sectional area (CSA), providing an objective structural parameter for assessment and follow-up. Study Objective The primary objective of this comparative study is to evaluate and compare the efficacy of ultrasound-guided injections of hyaluronic acid, corticosteroid, and 5% glucose in patients with mild to moderate CTS. Treatment response will be evaluated using clinical, electrophysiological, and ultrasonographic findings. Study Population and Design The study will be conducted in the Department of Rheumatology, Rehabilitation, and Physical Medicine at Tanta University Hospitals. A total of 60 adult patients with mild to moderate CTS will be included. Participants will be divided into three treatment groups, with 20 patients in each group. Eligible participants will be adults aged 18-70 years with clinical symptoms of CTS lasting at least 6 weeks and electrophysiological confirmation of mild to moderate CTS. All participants must be able to provide informed consent. Patients will be excluded if they have received an injection into the same wrist within the previous 6 months, have undergone previous carpal tunnel surgery, have severe CTS characterized by absent sensory potentials or electromyographic evidence of denervation, or have local infection or coagulopathy. Baseline Assessment Before treatment, all participants will undergo a baseline assessment. This will include a full medical history and comprehensive neurological and musculoskeletal examination of the wrist. Clinical assessment will include: Phalen's test. Tinel's sign. Electrophysiological assessment will be performed using nerve conduction studies (NCS), including: Median sensory distal amplitude and conduction velocity. Median motor distal latency and amplitude. Maintenance of limb temperature at or above 32°C during the examination. Ultrasound examination will be performed to determine the cross-sectional area of the median nerve using tracing of the inner hyperechoic rim of the epineurium. Intervention Procedures All injections will be performed under sterile conditions with ultrasound guidance. The participant will be positioned either supine or seated with the forearm supinated. The ultrasound probe will be positioned transversely over the inlet of the carpal tunnel, and an in-plane ulnar approach will be used. Particular care will be taken to avoid piercing the median nerve. Participants will receive one of the following ultrasound-guided injection interventions: Group 1 - Hyaluronic Acid Participants in the HA group will receive 2-3 mL of high-molecular-weight hyaluronic acid. The HA will be injected perineurally with the intention of creating a gliding plane around the median nerve and reducing perineural adhesions. Group 2 - Corticosteroid Participants in the corticosteroid group will receive triamcinolone acetonide 40 mg mixed with 1 mL of lidocaine. The injection will be administered into the carpal tunnel under ultrasound guidance. Group 3 - 5% Glucose Participants in the 5% glucose group will receive 5 mL of 5% glucose (D5W) by ultrasound-guided hydrodissection around the median nerve. The procedure will aim to separate the median nerve from the flexor retinaculum and surrounding tissues. Follow-Up and Outcome Assessment Participants will be reassessed 3 months after the injection. Follow-up assessment will include repetition of the clinical, electrophysiological, and ultrasonographic evaluations. Clinical outcomes will be assessed using Phalen's test and Tinel's sign. Electrophysiological outcomes will be evaluated using nerve conduction studies, including the relevant median sensory and motor nerve conduction parameters. Ultrasonographic follow-up will include reassessment of the median nerve cross-sectional area. The study will compare the findings obtained after treatment among the three intervention groups to assess differences in treatment response. Study Duration The study is planned to continue for at least 12 months, from January 2026 to December 2026. Potential Benefits The study is intended to provide comparative information regarding three non-surgical injection approaches for the management of mild to moderate CTS. The findings may help in evaluating the relative clinical, electrophysiological, and ultrasonographic responses associated with hyaluronic acid, corticosteroid, and 5% glucose injections. Potential Risks The protocol identifies infection as a potential risk associated with injection procedures. Sterile equipment and sterile technique will be used to minimize this risk. Any unexpected risk that becomes apparent during the study will be communicated promptly to the participant and the relevant ethical committee. Ethical Considerations Informed consent will be obtained from all participants before their inclusion in the study. Participant privacy and confidentiality will be maintained. Patient names will be removed from electrophysiological and ultrasound reports to protect participant identity. Any unexpected risks arising during the course of the research will be promptly communicated to the participant and the ethical committee. The results of the study will be tabulated and statistically analyzed, and the findings will subsequently be discussed in relation to available published data.