Introduction: This study aimed to compare accuracy of screw placement and supradjacent facet joint violation (FJV) between O-arm navigated MIS-TLIF group (NavMIS-TLIF group) and open-TLIF group for the treatment of low-grade lumbar spondylolisthesis, and further, to investigate the risk factors influencing facet joint degeneration (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 for at least one 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 NavMIS-TLIF group at 3-month follow-up was lower than open-TLIF group, yet there was no significant difference in ODI and VAS scores between groups at the final follow-up. Both groups had similar slip reduction results. The clinically accuracy rate of screw placement in NavMIS-TLIF group was 99.4%, significantly higher than 94.0% in open-TLIF group. At the upper instrumented vertebra, screw convergence angle of NavMIS-TLIF group was significantly larger than open-TLIF group. The incidence of FJV in NavMIS-TLIF group (23.8%) was significantly lower than open-TLIF group (53.6%). There was no significant difference in preoperative FJD between the two groups, while at the last follow-up, 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.
Discussion: O-arm navigated MIS-TLIF has similar clinical outcomes and higher accuracy of screw placement compared to open TLIF. Meanwhile, O-arm navigated MIS-TLIF achieves larger screw convergence angle and significantly reduces the incidence of FJV. Since FJV serves as an independent risk factor for the aggravation of FJD, O-arm navigated MIS-TLIF thus probably helps to delay FJD.