LOW back pain is usually a self-limiting symptom, but it costs at least $16 billion each year1 , 2 and disables 5.4 million Americans.3 The fact that a benign physical condition has such an importa...

Back pain and sciatica.

A group of 109 patients with unilateral low back pain for over three months were randomised to receive one of three types of injection treatment: cortisone and local anaesthetic injected into two facet joints (28), the same mixture around two facet joints (39), or physiological saline into two facet joints (42). The effect of the treatment was evaluated in relation to work attendance, pain, disability and movements of the lumbar spine. Patients were examined one hour and two and six weeks after treatment and also completed a questionnaire after three months. A significant improvement was observed in work attendance, pain and disability scores, but this was independent of the treatment given and movements of the lumbar spine were not improved. Of the 70 patients with initial pain relief after injection, 36% reported persisting benefit at the three month follow-up, independent of the mode of treatment given. We conclude that facetjoint injection is a non-specific method of treatment and the good results depend on a tendency to spontaneous regression and to the psychosocial aspects of back pain.

A randomised clinical trial

Background Chronic low back pain is a common problem with many treatments, few of which have been rigorously evaluated. This randomized, placebo-controlled trial was designed to evaluate the efficacy of injections of corticosteroid into facet joints to treat chronic low back pain. Methods Patients with chronic low back pain who reported immediate relief of their pain after injections of local anesthetic into the facet joints between the fourth and fifth lumbar vertebrae and the fifth lumbar and first sacral vertebrae were randomly assigned to receive under fluoroscopic guidance injections of either methylprednisolone acetate (20 mg; n = 49) or isotonic saline (n = 48) in the same facet joints. Ninety-five patients were followed for six months and their condition assessed with scales of pain severity, back mobility, and limitation of function. Results After one month, none of the outcome measures evaluating pain, functional status, and back flexion differed clinically or statistically between the ...

https://www.nejm.org/doi/pdf/10.1056/NEJM199110033251405

A Controlled Trial of Corticosteroid Injections into Facet Joints for Chronic Low Back Pain

Lumbar zygapophysial joint arthropathy is a challenging condition affecting up to 15% of patients with chronic low back pain. The onset of lumbar facet joint pain is usually insidious, with predisposing factors including spondylolisthesis, degenerative disc pathology, and old age. Despite previous reports of a "facet syndrome," the existing literature does not support the use of historic or physical examination findings to diagnose lumbar zygapophysial joint pain. The most accepted method for diagnosing pain arising from the lumbar facet joints is with low-volume intraarticular or medial branch blocks, both of which are associated with high false-positive rates. Standard treatment modalities for lumbar zygapophysial joint pain include intraarticular steroid injections and radiofrequency denervation of the medial branches innervating the joints, but the evidence supporting both of these is conflicting. In this article, the authors provide a comprehensive review of the anatomy, biomechanics, and function of the lumbar zygapophysial joints, along with a systematic analysis of the diagnosis and treatment of facet joint pain.

/pdf/pathogenesis-diagnosis-and-treatment-of-lumbar-zygapophysial-knk3rctugh.pdf

Pathogenesis, Diagnosis, and Treatment of Lumbar Zygapophysial (Facet) Joint Pain

OBJECTIVES--To determine the prevalence of pain arising from the zygapophysial joint in patients with chronic low back pain and to determine whether any clinical features could distinguish patients with and without such pain. METHODS--Sixty three patients with chronic low back pain were studied prospectively. All patients underwent a detailed history and physical examination as well as a series of intra-articular zygapophysial joint injections of 0.5% bupivacaine starting at the symptomatic level to a maximum of three levels or until the pain was abolished. They also received injections of normal saline into paraspinal muscles to act as controls. RESULTS--All patients proceeded with the injections. Twenty (32%; 95% confidence interval (CI) 20 to 44%) obtained greater than 50% relief of their pain following the administration of saline. Fifty seven patients completed the study; 23 of them (40%; 95% CI 27 to 53%) failed to obtain relief following the injection of saline but obtained relief following one or more intra-articular injections of local anaesthetic. None of the historical features or clinical tests could discriminate those patients with and those without zygapophysial joint pain. CONCLUSION--Pain originating from the zygapophysial joint is not uncommon, but this study failed to find any clinical predictors in patients with such pain.

https://ard.bmj.com/content/annrheumdis/54/2/100.full.pdf

Prevalence and clinical features of lumbar zygapophysial joint pain: a study in an Australian population with chronic low back pain.

Patterns of pain referral, induced from the posterior elements, have been studied in normal volunteer subjects. A series of intracapsular and pericapsular injections were performed at the L1-2 and L4-5 levels. The areas of pain referral indicate overlap between the upper and lower lumbar spine. It is also shown that the pericapsular and intrafacetal pain referral areas are similar and that the upper lumbar spine is more sensitive than the lower.

I W McCall

Papers

Induced pain referral from posterior lumbar elements in normal subjects.