Whether Anterolateral Single Rod Can Maintain the Surgical Outcomes Following Oblique Lumbar Interbody Fusion for Double-Segment Disc Disease.

OBJECTIVE: To evaluate the outcomes of oblique lumbar interbody fusion (OLIF) combined with anterolateral single-rod screw fixation (AF) in treating two-segment lumbar degenerative disc disease (LDDD) and to determine whether AF can maintain the surgical results. METHODS: A retrospective analysis was performed on patients who underwent OLIF combined with AF (OLIF-AF) for LDDD at the L3-5 levels between October 2017 and May 2018. A total of 84 patients, including 44 males and 40 females, with a mean age of 62.8 ± 6.8 years, who completed the 12-month follow-up were eventually enrolled. Clinical outcomes, including the Oswestry Disability Index (ODI), visual analog scale (VAS) score for the low back and leg, and radiographic parameters, including the cross-sectional area (CSA) of the spinal canal, disc height (DH), foraminal height (FH), degree of upper vertebral slippage (DUVS), segmental lumbar lordosis (SL), fusion rate, and lumbar lordosis (LL), were recorded before surgery and 1 and 12 months after surgery. Surgical-related complications, including cage subsidence (CS), were also evaluated. The local radiographic parameters were compared between L3-4 and L4-5. The clinical results and all radiographic parameters were compared between patients with and without CS. RESULTS: Significant improvements were observed in radiographic parameters 1 day postoperatively (p < 0.05). Local radiological parameters in L4-5 had a significant decrease at 12 months postoperatively (p < 0.05), while they were well-maintained at L3-4 throughout the follow-up period (p > 0.05). CS was observed in 26 segments (15.5%). Endplate injury was observed in four segments (2.4%). There was no significant difference in the fusion rate between the segments with and without CS (p = 0.355). The clinical results improved significantly after surgery (p < 0.05), and no significant difference was observed between the groups with and without CS (p > 0.05). CONCLUSIONS: Anterolateral fixation combined with OLIF provides sufficient stability to sustain most radiological improvements in treating double-segment LDDD. Subsidence was the most common complication, which was prone to occur in L4-5 compared to L3-4, but did not impede the fusion process or diminish the surgical results.