Diagnostic workup for lumbar degenerative disc disease (DDD) includes imaging such as radiography, MRI, and/or CT myelography. If a patient has unsuccessful nonoperative treatment, the surgeon must then decide if obtaining updated images prior to surgery is warranted. The purpose of this study was to investigate whether the timing of preoperative neuroimaging altered clinical outcome, as reflected by the subsequent rate of revision surgery, in patients with degenerative lumbar spinal pathology.
From the Health Care Service Corporation administrative claims database, adult patients (minimum age 55 years old) with lumbar DDD who underwent surgery including posterior lumbar decompression with and without fusion (1–2 levels) and at least 5 years of continuous coverage after the index surgery were identified. The chi-square test 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).
Of 28,676 cases identified, 5128 (18%) had revision surgery within 5 years. The timing of preoperative MRI or plain radiography 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 = 0.017). This observation was strongest in patients undergoing decompression only (p = 0.002), but not significant in patients undergoing fusion (p = 0.845).
Routine reimaging prior to surgery, simply because the existing MRI is 6–12 months old, may not be beneficial, 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 data set.