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.

BACKGROUND

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.

PURPOSE: 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.

STUDY DESIGN/

SETTING

Double blinded randomized controlled clinical trial.

PATIENT SAMPLE: 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.

OUTCOME MEASUREMENT: 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.

METHOD: 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.

RESULTS

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.

CONCLUSIONS

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.