BackgroundUltrasound-guided injections are an alternative to evaluate, it eliminates the risk of ionizing radiation for both the patient and the practitioner as fluoroscopic procedures require a radiology technician, increase the overall support time and cost, decrease accessibility.ObjectivesThe main objective of the study was to compare the short-term efficacy of posterior inter-apophyseal joint infiltrations under ultrasound versus scopic guidance.MethodsObservational, retrospective, single-centre study. Patients benefited from posterior zygapophysial joints injection(s) under fluoroscopy or ultrasound and a follow-up consultation at one month.ResultsData from 54 patients was collected. The evolution of VAS at 1 month was on average - 31.4cm (p <0.001) in the ultrasound group and - 31.3cm (p <0.001) in the fluoroscopy group with no statistically significant difference between the two groups (p =0.835). There were no injection-related complications in either group during the follow-up. The decrease in the consumption of NSAIDs was no statistically significant difference between both groups (p = 1.00). Statistically significant differences in procedure time were observed between groups with a longer time recorded for the ultrasound group (p = 0.007).ConclusionA corticosteroid injection of the posterior zygapophysial joints under ultrasound allows for a significant reduction in pain after one month with no difference found between the two techniques. Injection under ultrasound are a reliable, accessible and safe alternative.Disclosure of InterestsNone declared