The research will be conducted in the General and Veteran Hospital "Croatian Pride" Knin.
The research will be a prospective, randomized, double-blinded, head-to-head comparative
study.
The goal of the research is to compare the efficacy of ultrasound-guided 5% dextrose
injection versus 5% dextrose with 40 mg methylprednisolone injection in patients with carpal
tunnel syndrome (CTS).
Randomization of patients will be performed before the intervention using computer software.
All participants will sign written informed consent and the study will be performed under the
ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments
or comparable ethical standards. The study is approved by the Ethical Committee at the
General and Veteran Hospital "Croatian Pride" Knin (approval number: 510.01/23-01/79).
Adult participants aged between 18 and 80 years with a clinical and electrophysiological
diagnosis of idiopathic CTS referred to the Physical Medicine and Rehabilitation clinic will
be randomly assigned into two groups using a random number generating software in a 1:1
manner.
Since patients can have CTS in one or both hands, randomization will be conducted according
to the patient, thus the same patient can receive the intervention only on one side which
will be considered worst.
The minimum sample size of a total of 70 participants (35 in each group) was estimated by
analyzing the power of the t-test for independent samples according to the following
characteristics: type one error (α=0.05), power (1-ß=0.80), and effect size (d=0.68).
The power analysis of the test was performed using the computer program G*Power for Windows,
version 3.1.3.
IBM SPSS Statistics version 29.0 software will be used for the data analysis.
Group one will receive an ultrasound-guided 4 ml single perineural injection of 5% dextrose
in the carpal tunnel and group two ultrasound-guided single perineural injection of 3 ml 5%
dextrose plus 1 ml 40 mg/ml methylprednisolone acetate in the carpal tunnel.
Participants, the physician who will perform the injection procedure and the assessor will be
blinded for the treatment allocation. The only person who will know which intervention drug
it is about will be the nurse who will prepare the medicine according to the randomization.
Clinical diagnosis of CTS will be made in the presence of at least one symptom (1. pain, 2.
pricking, 3. tingling, 4. burning, or 5. numbness in the innervation area of the median nerve
on the hand) and at least one sign (1. objective disturbance of the sense of touch, i.e.
hypoesthesia or dysesthesia in the innervation area of the median nerve on the hand, 2.
positive Tinel's sign, 3. positive Phalen's sign, or 4. positive compression test).
Inclusion criteria are age between 18 and 80 years and the diagnosis of idiopathic CTS based
on clinical and electrophysiological criteria.
Exclusion criteria are contraindications for local application of methylprednisolone or 5%
dextrose (hypersensitivity to the drug, infection, and skin damage at the application site),
previous wrist surgery, traumatic wrist injury within 2 years, previous wrist injection
within 6 months, previous physical therapy within 6 months, history of traumatic peripheral
nerve injury in the upper extremity, brachial plexopathy, severe cervical radiculopathy and
thoracic outlet syndrome, history of diabetes, history of thyroid disease, history of
inflammatory rheumatic disease, pregnancy and inability to cooperate with the study protocol.
Basic demographic data will be obtained: gender, age, Body Mass Index (BMI), level of
education, occupation, rating of hand activity and force level applied on the hand during the
day, cigarette smoking, hand dominance, affected hand, symptom duration, and history of
comorbid conditions.
Pain intensity (using a 10 cm Visual Analogue Scale; VAS pain, 0-10; 0=no pain, 10=the most
severe pain), symptoms severity and functional impairment (using the Boston Carpal Tunnel
Questionnaire; BCTQ), grip strength (using the Jamar hydraulic hand dynamometer in
kilograms), median nerve cross-sectional area (CSA) (using diagnostic ultrasound at the
carpal tunnel inlet), and quality of life (QoL) (using 36-Item Short Form Survey; SF-36) will
be measured immediately before injection, at 4, 12, and 24 weeks post-injection.
The primary outcome measure will be the change in pain intensity at 4 weeks post-injection.
Secondary outcome measures will be the change in pain intensity at 12 and 24 weeks
post-injection, and the changes in symptoms severity and functional impairment, grip
strength, median nerve CSA, and QoL at 4, 12, and 24 weeks post-injection.
During the study, acetaminophen and tramadol will be allowed for occasional pain relief
except for two days prior to the evaluation sessions due to possible interference with the
results.
Physical therapy, use of wrist splints, acupuncture, and invasive interventions for CTS other
than those included in the study protocol will not be allowed during the study.