Objective To investigate the feasibility, safety, and clinical efficacy of oblique lateral interbody fusion (OLIF) combined with posterior percutaneous pedicle screw fixation in the treatment of isthmic spondylolisthesis at L5/S1.

Methods A retrospective analysis was conducted on the clinical data of 41 patients with isthmic spondylolisthesis at L5/S1. All patients received OLIF combined with posterior percutaneous pedicle screw fixation. Perioperative indicators (operative time, intraoperative blood loss, and postoperative hospital stay) were observed. Clinical efficacy was evaluated using the Visual Analogue Scale (VAS) scores for low back pain/leg pain and the Oswestry Disability Index (ODI) before surgery, at 1 week and 3 months after surgery, and at the last follow-up. Imaging parameters intervertebral disc height (IDH), segmental lumbar lordosis angle (SLLA) of the L5/S1 segment, sagittal diameter of the spinal canal (SD-SC), and spondylolisthesis rate were measured before surgery, at 1 week after surgery, and at the last follow-up. The incidence of complications and the intervertebral fusion rate at 6 months after surgery were also recorded.

Results All 41 patients successfully completed the surgery. At 1 week and 3 months after surgery and at the last follow-up, the VAS scores for low back pain and leg pain, as well as the ODI, were lower than those before surgery, with statistically significant differences (P < 0.05). At 1 week after surgery and at the last follow-up, the IDH, L5/S1 SLLA, and SD-SC were increased compared with those before surgery, while the spondylolisthesis rate was decreased, with statistically significant differences (P < 0.05). At 6 months after surgery, the intervertebral fusion rate was 95.1%(39/41), and the complication rate was 17.1%(7/41). Most complications were transient symptoms, and no serious complications such as screw breakage, intraspinal hematoma, or injury to important blood vessels and nerves occurred.

Conclusion OLIF combined with posterior percutaneous pedicle screw fixation is a safe and effective treatment for isthmic spondylolisthesis at L5/S1. It can achieve minimally invasive reconstruction of the spinal sequence through innovative anatomical approaches.