Comparison of Pedicle Screw Fixation With or Without Cement Augmentation Combined With Single-segment Isthmic Spondylolisthesis in Osteoporotic Spine

Purpose: This study aims to investigate the necessity of cement-augmented pedicle screw fixation in single-segment isthmic spondylolisthesis with osteoporosis.Method: Fifty-nine cases were reviewed retrospectively. Thirty-three cases were in the polymethylmethacrylate-augmented pedicle screw (PMMA-PS) group, and the other 26 cases were in the conventional pedicle screw (CPS) group. Evaluation data included operation time, intraoperative blood loss, hospitalization cost, hospitalization days, rates of fusion, screw loosening, bone cement leakage, visual analog scores (VAS), Oswestry disability index (ODI), lumbar lordosis (LL), pelvic tilt (PT) and sacral slope (SS).Results: The operation time and blood loss in the CPS group decreased significantly compared to those in the PMMA-PS group (P < 0.05). The average hospitalization cost of the PMMA group was significantly higher than that of the CPS group (P < 0.05). There was no significant difference in the average hospital stay between the 2 groups (P > 0.05). The initial and last follow-up postoperative VAS and ODI improved significantly in the two groups (P < 0.05). There were no significant differences in VAS and ODI at each time point between the 2 groups (P > 0.05). The last postoperative spine-pelvic parameters were significantly improved compared with those preoperatively (P < 0.05). In the PMMA-PS group, the fusion rate was 100%. The fusion rate was 96.15% in the CPS group. No significant difference was found between the two groups for the fusion rate (P > 0.05). Nine patients in the PMMA-PS group had bone cement leakage (27.27%). There was no screw loosening in the PMMA-PS group. There were 2 cases of screw loosening in the CPS group. There were no significant differences in screw loosening, postoperative adjacent segment fractures, postoperative infection or postoperative revision between the 2 groups (P > 0.05).Conclusions: The use of PMMA-PS on a regular basis is not recommended for posterior lumbar interbody fusion for the treatment of single-segment isthmic spondylolisthesis with osteoporosis.