Inose H, Kato T, Onuma H, et al. - This study was sought to distinguish preoperative factors that predict poor postoperative outcomes and define clinically important abnormal instabilities in degenerative lumbar spondylolisthesis. Researchers designed a post-hoc analysis from a prospective randomized trial that compared the effectiveness of decompression, decompression with fusion, and decompression with stabilization for degenerative lumbar spondylolisthesis at the L4/5 level including a total of 70 patients with a 5-year follow-up period. The correlation between the postoperative recovery rate and preoperative radiographic parameters was tested. They further evaluated differences between the good recovery and poor recovery groups. The results exhibited that postoperative outcomes were correlated with the intervertebral angle and the presence of translation, while the degree of vertebral slippage and the presence of angulation was not associated with poor recovery after surgery for lumbar degenerative spondylolisthesis. The findings considered that careful preoperative measurement of these factors may help to prognosticate poor postoperative outcomes.