253. Long term outcome following percutaneous image-guided treatment of spinal synovial cysts: a population-based cohort study

Abstract

BACKGROUND CONTEXT Spinal synovial cysts, also known as lumbar facet joint cysts, are fluid-filled sacs that develop at the facet joints along the spine, most commonly as a result of degeneration and destabilization. Their estimated prevalence is 1%, and they are most often found at the L4-L5 level. For symptomatic patients, there is little evidence on which treatment is most effective. Percutaneous options would be preferable to avoid destabilization of the spine. However, some claim that percutaneous treatment does not provide sustainable long-term effects and recommend immediate surgery instead. This debate is heavily limited by the fact there are no long-term studies for percutaneous treatment options. PURPOSE The aim of this study was to assess long-term outcome in patients with spinal synovial cysts who were treated with minimally invasive percutaneous intra-articular steroid treatment. STUDY DESIGN/SETTING Population-based retrospective cohort study PATIENT SAMPLE Thirty-nine patients treated with minimally invasive percutaneous intra-articular steroid treatment and followed for a median of 11 years (range 3 – 21). OUTCOME MEASURES Self-assessed long-term pain relief without the need for invasive surgery. METHODS A population-based cohort-study was conducted of all adult (≥15 years) patients with symptomatic lumbar synovial cysts who were treated with percutaneous intra-articular steroid treatment between 1995 and 2014. Medical records and imaging data from digital hospital charts were retrospectively reviewed and standardized telephone interviews were performed to assess long-term results. Paired testing was applied. RESULTS Thirty-nine patients were included. All patients suffered from variations of lower back and leg pain, with two patients reporting unilateral leg weakness as well. Twenty-seven (67%) patients were female, and the median age was 61 years. The majority of the cysts were located at the L4-L5 level (56%). Successful intra-articular steroid treatment was achieved in 87% of cases. Thirty patients (77%) showed initial pain relief at the follow-up evaluation with their referring physician. During a median long-term follow-up of 11 years, 31% of the original cohort had sustained long-term pain relief without the need for invasive surgery. CONCLUSIONS Percutaneous treatment of spinal synovial cysts has excellent short-term outcome but results appear to diminish over time. While surgical methods have higher rates of treatment success, they risk the need for delayed stabilization surgery. Percutaneous treatment obviates the need for surgery in a substantial number of patients and can be suggested as a first line treatment. FDA DEVICE/DRUG STATUS DepoMedrol with lidocaine; Pfizer, (Approved for this indication)