Efficacy of Steroid Injection in Patients With Bifid Median Nerve Diagnosed Carpal Tunnel Syndrome

Overview

Various median nerve anatomical variations have been reported in the literature.One of these is the bifid median nerve.Due to its relatively higher cross-sectional area, it can facilitate compression of the median nerve in the carpal tunnel.Therefore, bifid median nerve is relatively common in patients with CTS.Some studies have shown that the bifid median nerve has an effect on surgical failure in the treatment of carpal tunnel syndrome.Apart from surgical treatment, perineural injection with corticosteroids is a treatment method that has been used for a long time in the treatment of mild and moderate carpal tunnel syndrome.It is controversial whether bifid median nerve has a negative effect on treatment effectiveness.When looking at the literature, there is no previous study on this subject.With the introduction of ultrasound into our daily practice, the frequency of ultrasound-guided perineural injections has increased.Ultrasound allowed us to see variations in the median nerve before injection.The aim of the study is to compare the effectiveness of steroid injection in patients with CTS with bifid median nerve and patients with CTS with non-variant median nerve.It is also to investigate whether this anatomical variation has a negative effect on the treatment.

Our study was designed as a prospective, double-blind randomized controlled study.Patients with an electrophysiological diagnosis of moderate CTS who applied to Etlik City Hospital Physical Therapy outpatient clinic will be included in the study.There are no sensitive groups.The research period was determined as 1 year.Sample size was calculated using the statistical power analysis programme G Power 3.1.9.4 for windows.Based on the study by Walker FO,the minimum number of patients required to achieve a significant change of 20 mm in VAS assesment before and after treatment(with a 5% Type 1 and Type 2 margin of error, 80% working power and 95% confidence interval) was found to be 17(total 34 patients) for each group.Considering the possibility of 20% loss during the study,ıt was decided to include at least 20(total 40) patients for each group.Demographic and clinical characteristics of Patients who met the inclusion criteria and completed the 'Informed Volunteer Consent Forum' will be recorded.The general pain of the patients will be evaluated with Visual Analog Scala,The symptom severity and functional status of the patients will be evaluated with the Boston Carpal Tunnel Questionnaire,The patients' hand grip strength measurement will be evaluated with a dynamometer.The patient hand diagram will be marked according to the patient's sensory symptoms.Median nerve cross-sectional area will be measured at the pisiform level with ultrasound, Distal motor latency and sensory nerve conduction velocity will be recorded with EMG.Pre-injection baseline assessments of participants will be made by a blinded investigator. In all patients, the median nerve will be visualized with ultrasound with a 12 MHz linear probe at the scaphoid-pisiform level.Afterwards, perineural injection(2cc:1cc 2% lidocaine hidroclorid+1cc betamethasone) will be performed using an in-plane approach around the median nerve.