Comparative study of modified midline lumbar interbody fusion and modified transforaminal lumbar interbody fusion for the treatment of single-level lumbar degenerative diseases.

Purpose: To evaluate the safety and efficacy of modified cortical bone trajectory (MCBT) screw combined with transarticular screw (TASS) fixation (MCBT-TASS) in modified midline lumbar interbody fusion (M-MIDLIF) for single-level lumbar degenerative disease (LDD).

Methods: We retrospectively included 104 patients with L4-5 or L5-S1 single-segment LDD who had indications for decompression, fusion, and internal fixation surgery from 2019 to 2022. They were subsequently divided into M-MIDLIF and modified transforaminal lumbar interbody fusion (M-TLIF) groups according to the surgical approach. Basic demographic, surgical, and radiological data, as well as clinical outcomes (Oswestry Disability Index (ODI) and visual analog scale (VAS) scores), were collected.

Results: Basic demographic data, fusion rates, postoperative hospital stays, and follow-up times did not significantly differ between the two groups. Compared with those in the M-TLIF group, the intraoperative blood loss (68.57 ± 14.84 mL) and postoperative drainage volume (33.93 ± 9.17 mL) in the M-MIDLIF group were lower (intraoperative blood loss: 171.79 ± 12.78 mL, p < 0.05; postoperative drainage volume: 65.36 ± 10.36, p < 0.05). In the M-MIDLIF group, there was no significant difference in the radiographic recognizable rate (91.07%) or intraoperative visual recognizable rate (87.50%) of internal inverted chevron-shaped (V-shaped) crests. The optimal position screw rates for the MCBT, TASS, and traditional pedicle screw (TPS) methods were 94.64%, 94.64%, and 87.5%, respectively, and the differences were not significant. MCBT technology preserved the integrity of the posterior ligamentous complex (PLC) in 92.85% of patients in the M-MIDLIF group. The facet joint violation (FJV) rate of MCBT screws (3.57%) was lower than that of TPS screws (14.29%). Compared with the M-TLIF group, the M-MIDLIF group presented greater reductions in the ODI and VAS scores for both low back and leg pain at 1 week postoperatively (P < 0.05). However, no statistically significant differences in these scores were observed between the two groups at later time points (p > 0.05).

Conclusion: M-MIDLIF can achieve decompression, fixation, and fusion via a median incision while preserving the integrity of the posterior ligamentous complex. In the treatment of single-level lumbar degenerative disease, M-MIDLIF has comparatively enhanced minimally invasive advantages over M-TLIF during the perioperative period while maintaining non-inferior clinical safety and efficacy relative to M-TLIF.