A Practice Audit of CT‐Guided Injections of Pars Interarticularis Defects in Patients with Axial Low Back Pain: A Primer for Further Investigation

Objective To assess whether computed tomography(CT)‐guided injections of local anesthetic and corticosteroid into chronic lumbar pars interarticularis defects may identify and provide benefit to a cohort of patients where the pars defects act as a primary axial pain generator. Design Retrospective practice audit. Setting Single academic radiology pain management practice. Patients 59 consecutive patients undergoing CT‐guided injections of lumbar pars defects. Methods Patients were assessed with a pain numerical rating scale (NRS, 0–10) and Roland–Morris disability questionnaire (R–M) prior to injection and at 2 weeks and 2 months follow‐up. For categorical outcomes, successful pain relief response was defined as either ≥50% reduction in NRS or pain 0/10; functional response was defined as ≥40% reduction in R–M score. Continuous outcomes (mean NRS, R–M scores) were assessed for significant change following injection. Results For categorical outcomes, 37.9% of patients were responders at 2 months' follow‐up; 20.7 % had complete relief of index pain. For functional recovery, 34.5% were responders at 2 months. Using continuous outcomes, mean NRS was 5.4 ± 2.1 prior to injection and 3.6 ± 2.6 at 2 months (P