ObjectiveTo identify effect of quantitative indicators of ilium height on approach of percutaneous endoscopic lumbar discectomy (PELD) treatment in patients with L5, S1 lumbar disc herniation.MethodsA retrospective study between May 2014 and March 2016 was conducted, including 100 patients with disc herniation at L5, S1, who were initially enrolled for the PELD treatment. Among them, 66 patients were successfully treated with PELD (group A), and the other 34 patients failed to perform puncture, catheterization, or microscopical operation due to the influence of iliac bone and other peripheral bone structures and treated with alternative surgical plans. By analyzing the X-ray films of lumbar vertebrae (including bilateral ilium) of the two groups before operation, the concept of ilium height rate and ilium angle rate was put forward innovatively. The ilium height rate and ilium angle rate of the two groups were measured and compared, and the diagnostic critical points of ilium height rate and ilium angle rate were determined by ROC curve analysis.ResultsThe ilium height rate was 0.61±0.09, 0.74±0.05 and the ilium angle rate was 0.66±0.08, 0.80±0.08 in groups A and B, respectively, showing significant differences between the two groups (F=69.729, P=0.000; F=65.165, P=0.000). ROC curve analysis showed that the critical point of ilium height rate was 0.71 (area under ROC curve was 0.927, P=0.000), and the critical point of ilium angle rate was 0.75 (area under ROC curve was 0.965, P=0.000).ConclusionPELD is not recommended for patients with L5, S1 intervertebral disc herniation, when the ilium height rate is greater than 0.71 and/or the ilium angle rate is greater than 0.75. Other surgical plans such as transpedicular approach, transpedicular approach, or open surgery, should be recommended to reduce the risk of surgery and the pain of patients.