One-Level versus Two-Level Anterior Lumbar Interbody Fusion (ALIF) from L4-S1: Comparison of Complications, Alignment, and Patient Outcomes.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Compare outcomes in patients undergoing one-level or two-level anterior lumbar interbody fusion (ALIF) at L4-S1. BACKGROUND: Although ALIF may deliver restoration of lumbar lordosis and improvement in clinical outcomes, it also carries risk of complications including major vascular injury. Whether one-level and two-level ALIF offers similar outcomes is not known. METHODS: Adults who underwent one-level L4-L5 or L5-S1 ALIF and two-level L4-S1 ALIF at a single academic institution were identified. Patient demographics, procedural characteristics, improvement in spinopelvic alignment, and one-year postoperative patient-reported outcome measures (PROMs) and complications were compared. Multivariate regression analyses, accounting for age, gender, and Charlson Comorbidity Index (CCI), were also performed. RESULTS: In total, 158 ALIF patients (111 one-level and 47 two-level) were included, with mean age of 51.4 years, 57.0% female, mean CCI of 1.2, and mean follow-up of 27.0 months. Surgical time (147.3 min vs. 124.6 min, P=0.002) and hospital length of stay (3.5 d vs. 2.9 d, P=0.036) were higher for two-level ALIF. One-year postoperatively, two-level ALIF patients had more caudal apex of lordosis (P=0.016) and 4.1 mm (P=0.002) and 2.0 mm (P=0.019) higher L4-L5 anterior and posterior disc heights, respectively. PROMs were not statistically different across groups (P>0.05). Finally, two-level ALIF patients were 10.9 times more likely to have in-hospital complications (P=0.040), such as intraoperative vascular injury (11.1% vs. 1.5%, P=0.040) or postoperative ileus (7.4% vs. 0.0%, P=0.027), than one-level ALIF patients. CONCLUSION: In this investigation with greater than one-year follow-up, two-level ALIF in the L4-S1 spine had higher procedural time, length of stay, and approach-related complications than one-level ALIF. Although there were minor improvements in alignment with two-level ALIF, PROMs were comparable with improvements from baseline to last follow-up. These findings may help surgeons carefully weigh the risks and benefits of one- versus two-level ALIF when determining surgical plans for patients. LEVEL OF EVIDENCE: IV.

Preoperative Resilience and Improvement in Patient-Reported Outcomes After Lumbar Spinal Fusion.

BACKGROUND: It is incompletely understood how preoperative resilience affects 1-year postoperative outcomes after lumbar spinal fusion. METHODS: Patients undergoing open lumbar spinal fusion at a single-center institution were identified between November 2019 and September 2022. Preoperative resilience was assessed using the Brief Resilience Scale. Demographic data at baseline including age, gender, comorbidities, and body mass index (BMI) were extracted. Patient-reported outcome measures including Oswestry Disability Index, PROMIS (Patient-Reported Outcomes Measurement Information System) Global Physical Health, PROMIS Global Mental Health (GMH), and EuroQol5 scores were collected before the surgery and at 3 months and 1 year postoperatively. Bivariate correlation was conducted between Brief Resilience Scale scores and outcome measures at 3 months and 1 year postoperatively. RESULTS: Ninety-three patients had baseline and 1 year outcome data. Compared with patients with high resilience, patients in the low-resilience group had a higher percentage of females (69.4% vs. 43.9%; P = 0.02), a higher BMI (32.7 vs. 30.1; P = 0.03), and lower preoperative Global Physical Health (35.8 vs. 38.9; P = 0.045), GMH (42.2 vs. 49.2; P < 0.001), and EuroQol scores (0.56 vs. 0.61; P = 0.01). At 3 months postoperatively, resilience was moderately correlated with GMH (r = 0.39) and EuroQol (r = 0.32). Similarly, at 1 year postoperatively, resilience was moderately correlated with GMH (r = 0.33) and EuroQol (r = 0.34). Comparable results were seen in multivariable regression analysis controlling for age, gender, number of levels fused, BMI, Charlson Comorbidity Index, procedure, anxiety/depression, and complications. CONCLUSIONS: Low preoperative resilience can negatively affect patient-reported outcomes 1 year after lumbar spinal fusion. Resiliency is a potentially modifiable risk factor, and surgeons should consider targeted interventions for at-risk patient groups.

Segmental Sagittal Alignment in Lumbar Spinal Fusion: A Review of Evidence-Based Evaluation of Preoperative Measurement, Surgical Planning, Intraoperative Execution, and Postoperative Evaluation.

BACKGROUND AND OBJECTIVES: Maintaining and restoring global and regional sagittal alignment is a well-established priority that improves patient outcomes in patients with adult spinal deformity. However, the benefit of restoring segmental (level-by-level) alignment in lumbar fusion for degenerative conditions is not widely agreed on. The purpose of this review was to summarize intraoperative techniques to achieve segmental fixation and the impact of segmental lordosis on patient-reported and surgical outcomes. METHODS: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, PubMed, Embase, Cochrane, and Web of Science databases were queried for the literature reporting lumbar alignment for degenerative lumbar spinal pathology. Reports were assessed for data regarding the impact of intraoperative surgical factors on postoperative segmental sagittal alignment and patient-reported outcome measures. Included studies were further categorized into groups related to patient positioning, fusion and fixation, and interbody device (technique, material, angle, and augmentation). RESULTS: A total of 885 studies were screened, of which 43 met inclusion criteria examining segmental rather than regional or global alignment. Of these, 3 examined patient positioning, 8 examined fusion and fixation, 3 examined case parameters, 26 examined or compared different interbody fusion techniques, 5 examined postoperative patient-reported outcomes, and 3 examined the occurrence of adjacent segment disease. The data support a link between segmental alignment and patient positioning, surgical technique, and adjacent segment disease but have insufficient evidence to support a relationship with patient-reported outcomes, cage subsidence, or pseudoarthrosis. CONCLUSION: This review explores segmental correction's impact on short-segment lumbar fusion outcomes, finding the extent of correction to depend on patient positioning and choice of interbody cage. Notably, inadequate restoration of lumbar lordosis is associated with adjacent segment degeneration. Nevertheless, conclusive evidence linking segmental alignment to patient-reported outcomes, cage subsidence, or pseudoarthrosis remains limited, underscoring the need for future research.