The Specificity of Cervical Facet Medial Branch Blocks

Overview

Cervical facet arthropathy is a common cause of chronic neck pain. The "gold standard" for diagnosis is either blocking the facet joints, or more commonly blocking the medial branch nerves that innervate the joints. However, many studies have found a high false-positive rate when the nerves are blocked using 0.5 ml of local anesthetic. We will randomize patients to receive either cervical facet medial branch blocks with 0.25 ml of local anesthetic and contrast, or 0.5 ml. We will then do a CT scan to determine the accuracy and specificity of each block. Our hypothesis is that using the higher volume (0.5 ml) might be responsible for the high false-positive rate.

Inclusion criteria: Dept. of Defense beneficiaries \> 18 years of age; neck pain \> 3 months duration; cervical paraspinal tenderness Exclusion criteria: Radicular signs or symptoms; use of anticoagulants or bleeding disorder. Outcome measures: The number of blocks whereby the contrast bathes the target nerve; the number of blocks whereby the contrast spreads to the medial branch nerve at the adjacent spinal level; the number of times the contrast diffuses into the intervertebral foramen or epidural space. We will also compare pain relief over 8 hours following the block between both volumes.

Conditions