CT Fluoroscopy–Guided Interlaminar Epidural Steroid Injections in the Cervical Spine: Rate of Nontarget Injection Into the Retrodural Space of Okada

OBJECTIVE. The purpose of this study was to assess the rate of inadvertent injection into the retrodural space of Okada during CT fluoroscopy–guided interlaminar epidural steroid injection in the cervical spine. MATERIALS AND METHODS. Images from cases of cervical interlaminar epidural steroid injection under CT fluoroscopic guidance performed at a single institution between November 2009 and November 2015 were obtained and reviewed. For all cases, the following information was recorded: presence or absence of contrast material within the Okada space, cervical anatomic level at which the procedure was performed, laterality of approach, trainee presence, and years of proceduralist experience. Two-tailed chi-square tests were used to assess categoric variables, and t tests were performed to assess for continuous variables predictive of nontarget injection. RESULTS. A total of 974 CT fluoroscopy–guided cervical interlaminar epidural steroid injections were identified in 728 patients. The presence of contrast...