Diagnostic cervical zygapophyseal joint blocks for chronic cervical pain.

OBJECTIVES (1) To determine the prevalence of cervical zygapophyseal joint pain in a specialist clinical setting; (2) to review the number of diagnostic blocks needed to identify the segmental level of the symptomatic joints; and (3) to determine the distribution of segmental levels of cervical zygapophyseal joint pain in a clinical setting. DESIGN AND SETTING Retrospective audit of patients of three independent rehabilitation medicine specialists who had undergone cervical zygapophyseal joint blocks in hospital outpatient clinics and private rooms. PATIENTS 97 patients aged 18-82 years with chronic neck pain (with or without headache) of more than six months' duration refractory to conservative therapies. INTERVENTION Diagnostic fluoroscopic cervical third occipital and medial branch blocks of zygapophyseal joints. Diagnosis required confirmation by a repeat procedure. RESULTS 35 of 97 patients (36%) had a confirmed symptomatic cervical zygapophyseal joint (95% CI, 27%-45%). The symptomatic segmental level was found at the first attempt by reference to a standard pain diagram in 83% of cases (29 of 35). The most common symptomatic levels were C3-4 (11/35; 31%) and C5-6 (10/35; 29%). CONCLUSION The prevalence of cervical zygapophyseal joint pain estimated in this clinical study is lower than that found in previous research setting studies, but our requirement for confirmation by a repeat block (which many patients declined) makes our estimate conservative; it is likely that the true prevalence is higher. Zygapophyseal joints are clearly a common source of pain in patients presenting with chronic neck pain, with or without headache. Cervical zygapophyseal joint pain is readily diagnosable, enabling patients to seek further, targeted treatment.