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.