Comparative outcome of lidocaine versus bupivacaine for cervical medial branch block (CMBB) in chronic cervical facet arthropathy: a randomized double-blind study.

OBJECTIVE: This study evaluated the effect of prolonged concordant response and functional clinical improvement between lidocaine and bupivacaine for cervical medial branch block (CMBB) in chronic cervical facet syndrome.

METHODS: Sixty-two patients diagnosed with chronic cervical facet syndrome were randomized into either lidocaine or bupivacaine groups. The therapeutic CMBB was performed under ultrasound guidance. Either 2% lidocaine or 0.5% bupivacaine with a volume of 0.5-1 ml per level, according to the patient's pain symptoms. The patients, pain assessor, and pain specialist were blinded. The primary outcome was the duration of pain reduction by at least 50%. The numerical rating scale (NRS) of 0-10 and the Neck Disability Index (NDI) questionnaire were recorded.

RESULTS: There was no significant difference in the duration of 50% and 75% pain reduction and NDI between the lidocaine and bupivacaine groups. Lidocaine provided significant pain reduction up to 16 weeks (P<0.05) and significant improvement in neck functional outcomes up to 8 weeks (P<0.01) compared to the baseline. Whist bupivacaine yielded significant pain alleviation for up to 8 weeks for pain upon neck mobilization (P<0.05) and demonstrated notable improvement in neck function up to 4 weeks (P<0.01) compared to the baseline.

CONCLUSION: CMBB using lidocaine or bupivacaine provided clinical benefits in prolonged analgesic effect and improving neck functions for chronic cervical facet syndrome. Lidocaine illustrated better performance and could be considered a local anesthetic of choice regarding the prolonged concordance response.