Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P25. Updated imaging does not affect revision rates in adults undergoing spine surgery for lumbar degenerative disease

Abstract

BACKGROUND CONTEXT Diagnostic workup for lumbar degenerative diseases (LDD) includes imaging such as radiographs, MRIs and/or CT-myelograms. If a patient fails conservative treatment, the surgeon must then decide if obtaining updated images prior to surgery is warranted. PURPOSE The purpose of this study is to determine if the timing of imaging impacts surgical decision-making as reflected by a difference in the rate of revision surgery in patients with lumbar degenerative disease. STUDY DESIGN/SETTING Analysis of private payor administrative claims database. PATIENT SAMPLE From the Health Care Service Corporation administrative claims database, adult patients (mean age 55) with LDD who had surgery including posterior lumbar decompression with and without fusion (1–2 levels) and at least five years of continuous coverage after the index surgery. OUTCOME MEASURES Revision surgery. METHODS From the Health Care Service Corporation administrative claims database, adult patients (mean age 55) with LDD who had surgery including posterior lumbar decompression with and without fusion (1–2 levels) and at least five years of continuous coverage after the index surgery were identified. Chi-square was used to determine differences in revision rates stratified by timing of each imaging procedure relative to the index procedure (≤6 months, 6–12 months, >12–24 months or >24 months). RESULTS Of 28,676 cases identified, 5,128 (18%) had revision surgery within 5years. The timing of preoperative MRI or plain radiographs was not associated with revision surgery. Among the entire cohort, there was a lower incidence of revision surgery in patients who had a CT-myelogram within 1 year prior to the index surgery (p=.017). This observation was strongest in patients undergoing decompression only (p=.002), but not significant in patients undergoing fusion (p=.845). CONCLUSIONS Routine re-imaging prior to surgery, simply because the existing MRI is 6-12 months old is probably unnecessary, at least as reflected in subsequent revision rates. The study also suggests that there may be a subset of patients for whom preoperative CT myelography reduces revision rates. This topic has important financial implications and deserves further study in a more granular dataset.