Tonosu J, et al. - In this study, 285 candidates were researched to evaluate the association between spinopelvic parameters and postoperative sacroiliac joint-related pain (SIJP) after lumbar spine surgery. Authors determined postoperative SIJP (unilateral buttock pain) as per the following criteria: a sacroiliac joint (SIJ) score greater than 4/9 postoperatively; positive response to analgesic especially SIJ injection with fluoroscopy; no other complications associated to the surgery. They noted that the pelvic incidence (PI) in the SIJP group was significantly greater as compared to that in the non-SIJP group. They reported no significant discrepancies in lumbar lordosis (LL), pelvic tilt, sacral slope, and PI minus LL. They noticed a 3.0% incidence of postoperative SIJP after lumbar spine surgery.