Multilevel Standalone Anterior Plus Lateral Lumbar Interbody Fusion: A Propensity-Matched Comparison to Circumferential Lumbosacral Fusion.

Study DesignRetrospective Single-center propensity score-matched cohort study.ObjectiveAdjacent segment disease remains a major cause of revision surgery after multilevel lumbosacral fusion, and muscle-preserving approaches may help reduce this risk. This study compared clinical and radiographic outcomes between a muscle-preserving fusion combining standalone anterior plus lateral lumbar interbody fusion (A + LLIF) vs circumferential lateral plus posterior lumbar interbody fusion (L + PLIF).MethodsPatients who underwent multilevel lumbosacral fusion (2016-2023) with either A + LLIF or L + PLIF were included. L + PLIF patients with contraindications to standalone A + LLIF were excluded. Propensity score matching, based on age, BMI, PI-LL mismatch and stenosis severity, yielded 90 1:1-matched patients. The primary outcome was revision surgery. Secondary outcomes included spinopelvic alignment, cage subsidence, and perioperative metrics.ResultsBaseline characteristics were comparable between groups (mean age 57 ± 10 years; median fusion levels: 2 [range 2-4]). The 5-year cumulative incidence of revision surgery was significantly lower with A + LLIF (1/45 events; 2.2%) than with L + PLIF (14/45 events; 31.1%; P < .001), with superior perioperative outcomes and comparable radiographic alignment.Operative time, blood loss, and length of stay were significantly lower in the A + LLIF group (P < .001 for all). Spinopelvic parameters were largely equivalent, except for improved distal lordosis and LPA-PI mismatch in the A + LLIF group (P = .003 and P = .019, respectively). Cage subsidence rates were low and similar between groups.ConclusionsIn carefully selected patients, combined standalone anterior and lateral interbody fusion offers a paraspinal muscle-preserving alternative to circumferential fusion, with significantly lower revision rates, favorable perioperative outcomes, and comparable radiographic alignment.