Author(s): Schwarzer AC, Aprill CN, Derby R, Fortin J, Kine G
STUDY DESIGN: This study is a prospective cross-sectional analytic study. OBJECTIVES: The authors determined the prevalence and clinical features of patients with pain stemming from the lumbar zygapophysial joints. SUMMARY OF BACKGROUND DATA: Previous studies have demonstrated a wide range of prevalence for zygapophysial joint pain and conflicting results with regard to clinical signs. METHODS: One hundred and seventy-six consecutive patients with chronic low back pain were investigated with a series of screening zygapophysial joint blocks using lignocaine and confirmatory blocks using bupivacaine. RESULTS: Forty-seven percent of patients had a definite or greater response to the screening injection at one or more levels but only 15% had a 50% or greater response to a confirmatory block. Response to zygapophysial joint injection was not associated with any single clinical feature or set of clinical features. CONCLUSIONS: The zygapophysial joint is an important source of pain but the existence of a "facet syndrome" must be questioned.