Prolonged pain reducing effect of sodium hyaluronate-carboxymethyl cellulose solution in the selective nerve root block (SNRB) of lumbar radiculopathy: a prospective, double-blind, randomized controlled clinical trial

Abstract

The pattern of linear graph schematized by visual analogue scale (VAS) score displaying pain worsening between 2 days and 2 weeks after selective nerve root block (SNRB) is called rebound pain. The purpose of this study was to determine if sodium hyaluronate and carboxymethyl cellulose solution (HA-CMC sol) injection could reduce the occurrence of rebound pain at 3 days to 2 weeks after SNRB in patients with radiculopathy compared with injection with corticosteroids and local anesthetics alone. Double blinded randomized controlled clinical trial. A total of 44 patients (23 of 24 patients in the Guardix group and 21 of 24 patients in the control group) who finished the follow-up session were subjects of this study. Patients were asked to write down their average VAS pain scores daily for 12 weeks. Functional outcomes were assessed by Oswestry Disability Index, Roland Morris Disability Questionnaire , and Short Form-36. A cocktail of corticosteroids, 1% lidocaine, 0.5% Bupivacaine, and 1 mL of normal saline was used for the control group whereas a cocktail of corticosteroids, 1% lidocaine, 0.5% Bupivacaine, and 1 mL of HA-CMC solution was used for the G group. Study participants were randomized into one of two treatment regimens. They were followed up for 3 months. VAS score at 2 weeks after the procedure was 4.19±1.32 in the control group, which was significantly (p<.05) higher than that (2.43±1.24) in the G group. VAS score at 6 weeks after the procedure was 4.00±1.23 in the control group and 3.22±1.45 in the G group, showing no significant (p=.077) difference between the two groups. There were no significant differences in functional outcomes at 6 or 12 weeks after the procedure. Compared with conventional cocktail used for SNRB, addition of HA-CMC sol showed effective control of rebound pain at 3 days to 2 weeks after the procedure.