Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P31. Clinical utility of supine MRIs, lateral standing and flexion–extension X-ray images in patients with grade 1 spondylolisthesis

Abstract

BACKGROUND CONTEXT Surgeons have used lateral flexion–extension X-ray images to identify patients with clinically substantial instability and listhesis that require fusion. PURPOSE The purpose of this study is to determine the clinical utility of flexion–extension X-ray images by evaluating associations with supine MRI and lateral standing X-ray images and patient reported outcomes (PROs) at baseline and one-year post-op. STUDY DESIGN/SETTING Longitudinal cohort from a multisurgeon, single spine specialty practice. PATIENT SAMPLE Patients enrolled in quality outcome database from a single site with grade 1 spondylolisthesis. OUTCOME MEASURES Back pain (BP), leg pain (LP), and Oswestry Disability Index (ODI). METHODS Patients enrolled in QOD from a single site with grade 1 spondylolisthesis and complete preop and one-year postop PROs, including BP, LP, and ODI, and preop lumbar supine MRIs, lateral standing and flex–ext X-ray images were identified. Slip distance and percentage on all images were measured. Slip difference between flexion and extension was calculated. RESULTS Twenty-seven patients, mean age of 60.5years, 74% female were included. Mean listhesis on flexion films was significantly greater (8.5 mm) than on supine MRI (4.8 mm, p CONCLUSIONS There were no associations between preop or postop PROs and slip severity on any of the imaging modalities. As listhesis on standing and extension films were similar and slip difference between flexion and extension was not associated with PROs, lateral extension films may have limited clinical utility. Further studies are needed to clarify radiographic indications for fusion in patients with spondylolisthesis.