Manchikanti L, Manchikanti K, Cash K, Singh V, Giordano J,
In this study 424 patients with a history of 6 months of non-specific pain (either cervical or lumber spine)that was not attributed to disc-related pain with a redicular symptoms (as assessed by neurologic and redicular testing) were split into 6 groups according to age.
The patients were assessed by the use of facet nerve blocks using lidocaine and bupivacaine. The diagnostic criteria being that when lidocaine was applied to the joint in question 1) at least an 80% reduction in pain was seen, 2) the patient was able to perform previously pain limiting tasks (not specified) and finally 3) pain relief lasted for 2 hours and 3 hours when bupivacaine was applied. This was deemed to provide enough evidence to confirm a diagnosis of the facet joint being the structure at fault.
The study found that age there was no significant difference in the prevalence of facet joint dysfunction between the age groups in the patients reporting cervical pain. However in patients complaining of lumber pain the age group 51-60 years of age had a significantly larger proportion (44%) of positive results when compared to the <30 years groups. This difference was limited to this age group with none of the other >30 groups showing this difference.
False positives (classified as lidocaine having a analgesic effect which was not improved by bupivacaine)in all groups where found to be high (30-64%) leading us to question the reliability of this procedure. However as stated in this study with radiographical methods of diagnosis finding degenerative changes in symptomatic and non symptomatic patients to an equal degree, we have no gold standard method of assessing the prevalence of specific structures being at fault.
This study had a good total sample size but due to the groupings used the actual size of each was small with some groups with as little as 12 subjects. This calls us to question the results gained but may also be the reason that significant differences were not found in the other groups.
The idea of being able to diagnose specific structures as being at fault has great appeal to clinicians and researchers alike. For while treatments for non-specific back pain appear to have little effect the idea of a homogeneous sample for which a specific structure and therefore treatment can be devised has the hope of helping a section of this broad patient group.
Pain Physician 2008;11:67-75
Link to Abstract
Link to Article