CT-guided ozone mixture injection in treatment of symptomatic lumbar facet synovial cysts

Background and aim: To evaluate the clinical and radiological outcomes, in terms of safety and efficacy, of a new treatment method for symptomatic lumbar facet synovial cysts (LFSC), based on ozone injection inside the cyst. Methods: We retrospectively reviewed clinical records and imaging studies of 77 patients who underwent CT-guided ozone treatment of symptomatic facet joint synovial cysts in our department over a 5-year span. Clinical outcome was assessed with Numerical Rating Scale (NRS) and Oswestry Disability Index (ODI) evaluations, obtained prior to the intervention and at 1-, 3-, 6- and 12-months follow-up. Follow-up MRI imaging at 6 and 12 months were obtained and confronted with the pre-procedural MRI to analyse cyst modification after the intervention. Results: Ozone administration was technically successful in 100% of procedures; no immediate complications occurred. At 1 month evaluation, 92% of the patients referred partial or complete symptomatic response; 86% of patients at 3 months and 84% at 6 months confirmed symptoms improvement; final assessment, at 12 months after intervention, outlined overall significant clinical improvement in 81% of patients. During the 12 months of follow-up only 3 patients had a relapse of the cyst (at 6 months) that were retreated with a 100% success. Conclusions: CT-guided ozone therapy for symptomatic LFSC is a safe and innovative treatment option, with good clinical results at 12 months follow-up in a significative percentage of patients, thus reducing the need for invasive surgical interventions.