The value of the provocation response in lumbar zygapophyseal joint injections.
OBJECTIVE
To determine the relationship between pain provocation and the analgesic response in lumbar zygapophyseal joint blocks.


METHODS
Consecutive patients undergoing intraarticular zygapophyseal joint blocks for the investigation of low back pain were included in this prospective study.


METHODS
The referred sample was from the metropolitan areas of New Orleans and San Francisco.


METHODS
Ninety patients with low back pain of > 3 months' duration and no history of lumbar surgery.


METHODS
All patients underwent one or more intraarticular injections of radiographic contrast followed by lignocaine (lidocaine) 2% into zygapophyseal joints between L2-3 and L5-S1. Those with definite responses at one or more levels underwent confirmatory blocks using 0.5% bupivacaine.


METHODS
Provocation of familiar pain and relief of pain after the injection of local anesthetic. Patients were assessed by an independent observer.


RESULTS
A total of 203 joints were studied. Adopting liberal criteria, either exact or similar reproduction of pain on the one hand correlated with either definite or complete relief of pain after a single, analgesic block on the other (p < 0.0001). However, when more stringent criteria were adopted, such as response to a confirmatory block using bupivacaine, there was no significant association.


CONCLUSIONS
This study calls into question the validity of pain provocation alone as a criterion standard in patients undergoing diagnostic lumbar zygapophyseal joint blocks.
Faculty of Medicine, University of Newcastle, Callaghan, NSW, Australia.
A C
AC
Schwarzer
R
R
Derby
C N
CN
Aprill
J
J
Fortin
G
G
Kine
N
N
Bogduk
D000328:Adult; D002045:Bupivacaine / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007270:Injections, Intra-Articular; D007278:Injections, Spinal; D008012:Lidocaine / Q000008:administration & dosage*; D017116:Low Back Pain / Q000175:diagnosis* / Q000628:therapy; D008159:Lumbar Vertebrae; D008297:Male; D010147:Pain Measurement; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity
D008012:Lidocaine; D002045:Bupivacaine