Adverse events associated with fluoroscopically guided zygapophyseal joint injections.

BACKGROUND In spite of the widespread performance of intra-articular zygapophyseal joint (IAZJ) injections, we know of no systematic analysis to date that examines the risks and types of adverse events when IAZJ injections are performed. OBJECTIVE To describe the type, incidence, and factors contributing to adverse events associated with fluoroscopically guided IAZJ injections. STUDY DESIGN A retrospective, cohort study of English-speaking adults aged 18 - 90 years who underwent fluoroscopically guided IAZJ injections between March 8, 2004, and April 19, 2007. Following IAZJ injections, 3 senior researchers recorded the presence and type of adverse events. The relationship of adverse events with age, gender, fluoroscopy time, vital signs, and trainee presence was analyzed with Fisher's exact or Wilcoxon rank sum 2-sided tests. Frequency of immediate (during or immediately after the procedure) or delayed (within 24 - 72 hours following the procedure) adverse events. SETTING Tertiary, academic, outpatient physical medicine and rehabilitation interventional spine clinic. RESULTS One hundred ninety-one patients (111 men) underwent 239 procedures. The mean and standard deviation (SD) of subject age was 56.4 (16.6) years ranging from 20 to 89. The mean and SD of pre-procedure 11-point Visual Analog Pain Scale was 5.5 (2.2) ranging from 0 to 10, and for post-procedure was 2.6 (2.6) ranging from 0 to 10. Trainees were involved in 52.3% of procedures. Reported immediate adverse events were vasovagal reaction (3.8%, n = 9) and steroid clogged needle (0.4%, n = 1). Follow-up data were available for 185/239 procedures (77.4%). There were 35 adverse events reported at mean follow-up interval of 1.8 days, of which the most frequent were injection site soreness (6.0%, n = 11), pain exacerbation (4.3%, n = 8), sleeplessness (2.2%, n = 4), and transient headache (1.6%, n = 3). Patient gender, age, trainee involvement, pre-procedural pain score, systolic or diastolic blood pressure, pulse, hemoglobin saturation as measured by pulse oximetry, volume of corticosteroid injected, and duration of fluoroscopy were not found to have a significant effect on immediate or delayed adverse events. LIMITATIONS This study is limited by a 24- to 72-hour follow-up window, which may have also been too small to capture more delayed complications, and a sample size too small to accurately define the incidence of rare complications. CONCLUSION Fluoroscopically guided IAZJ injections have minimal adverse effects. The most common immediate adverse event was vasovagal reaction and most common delayed adverse event was injection site soreness.