*Result*: O-Arm Navigated MIS-TLIF Avoids Violation and Delays Degeneration of the Supradjacent Facet Joint.

*Objective: O-arm navigated MIS-TLIF is one of the novel surgical techniques for treating lumbar spondylolisthesis, but there still lacks enough evidence regarding intraoperative facet joint violation (FJV) and postoperative facet joint degeneration (FJD). This study aimed to compare clinical outcomes, accuracy of screw placement, and supradjacent FJV between the O-arm navigated MIS-TLIF group (NavMIS-TLIF group) and the open-TLIF group for the treatment of low-grade lumbar spondylolisthesis, and further, to investigate the risk factors influencing FJD.
Methods: We retrospectively reviewed a cohort of patients with low-grade lumbar spondylolisthesis who had received O-Arm navigated MIS-TLIF or open TLIF from May 2018 to May 2023. All the patients were followed up for at least 1 year. The demographic and perioperative data were recorded. The ODI and VAS scores were collected before surgery, 3 months postoperatively, and at the final follow-up. Slip parameters were measured before surgery and at the last follow-up. The screw convergence angle at the upper instrumented vertebra was evaluated based on postoperative CT images. Accuracy of screw placement and supradjacent FJV were assessed after surgery. The FJD was assessed at the final follow-up in comparison to that before surgery.
Results: Each group had 42 patients. VAS back pain of the NavMIS-TLIF group at the 3-month follow-up was lower than that of the open-TLIF group, yet there was no significant difference in ODI and VAS scores between the groups at the final follow-up. Both groups had similar slip reduction results. The clinically accurate rate of screw placement in the NavMIS-TLIF group was 99.4%, significantly higher than 94.0% in the open-TLIF group. At the upper instrumented vertebra, the screw convergence angle of the NavMIS-TLIF group was significantly larger than that of the open-TLIF group. The incidence of FJV in the NavMIS-TLIF group (23.8%) was significantly lower than that in the open-TLIF group (53.6%). There was no significant difference in preoperative FJD between the two groups, while at the last follow-up, the open-TLIF group had more cases of FJD. The screw convergence angle had a negative correlation with FJV and the aggravation of FJD, and FJV was positively associated with the aggravation of FJD. Multivariable logistic regression showed that FJV served as an independent risk factor for the aggravation of FJD.
Conclusions: O-arm navigated MIS-TLIF has similar clinical outcomes and higher accuracy of screw placement compared to open TLIF. O-arm navigated MIS-TLIF reduces the incidence of FJV significantly, which probably helps to delay FJD.
(© 2025 The Author(s). Orthopaedic Surgery published by Tianjin Hospital and John Wiley & Sons Australia, Ltd.)*