Kim GU, Park J, Kim HJ, et al. - This study was sought to correlate risk factors for each unfavorable surgical outcome according to two different definitions of “unfavorable” surgical outcomes after surgery for lumbar spinal stenosis (LSS) as well as compare the clinical course from the preoperative period to 3 years postoperatively between cases with favorable and unfavorable outcomes according to the two different definitions. Researchers included a total of 295 patients who had undergone spine surgery for LSS and a follow-up evaluation at 3 years postoperatively and classified into favorable and unfavorable groups, based on two different definitions for unfavorable surgical outcomes, as assessed at 12 months postoperatively: the patient-reported outcome and minimal clinically important difference methods. The data suggested that for LSS, a higher preoperative Oswestry Disability Index (ODI) score may be a risk factor for postoperative ODI > 22 after surgery. It may also be correlated with higher odds for enhancements in the ODI score of > 12.8.