Study Design. A retrospective cohort study. Objective. The aim of this study was to determine the difference in 30-day readmission, reoperation, and morbidity for patients undergoing either posterior or anterior lumbar interbody fusion. Summary of Background Data. Despite increasing utilization of lumbar interbody fusion to treat spinal pathology, few studies compare outcomes by surgical approach, particularly using large nationally represented cohorts. Methods. Patients who underwent lumbar interbody fusion were identified using the NSQIP database. Rates of readmission, reoperation, morbidity, and associated predictors were compared between posterior/transforaminal (PLIF/TLIF) and anterior/lateral (ALIF/LLIF) lumbar interbody fusion using multivariate regression. Bonferroni-adjusted alpha-levels were utilized whereby variables were significant if their P values were less than the alpha-level or trending if their P values were between 0.05 and the alpha-level. Results. We identified 26,336 patients. PLIF/TLIF had greater operative time (P = 0.015), transfusion (P < 0.001), UTI (P = 0.008), and stroke/CVA (P = 0.026), but lower prolonged ventilation (P < 0.001) and DVT (P = 0.002) rates than ALIF/LLIF. PLIF/TLIF independently predicted greater morbidity on multivariate analysis (odds ratio: 1.155, P = 0.0019). In both groups, experiencing a complication and, in PLIF/TLIF, ASA-class ≥3 predicted readmission (P < 0.001). Increased age trended toward readmission in ALIF/LLIF (P = 0.003); increased white cell count (P = 0.003), dyspnea (P = 0.030), and COPD (P = 0.005) trended in PLIF/TLIF. In both groups, increased hospital stay and wound/site-related complication predicted reoperation (P < 0.001). Adjunctive posterolateral fusion predicted reduced reoperation in ALIF/LLIF (P = 0.0018). ASA-class ≥3 (P = 0.016) and age (P = 0.021) trended toward reoperation in PLIF/TLIF and ALIF/LLIF, respectively. In both groups, age, hospital stay, reduced hematocrit, dyspnea, ASA-class ≥3, posterolateral fusion, and revision surgery and, in PLIF/TLIF, bleeding disorder predicted morbidity (P < 0.001). Female sex (P = 0.010), diabetes (P = 0.042), COPD (P = 0.011), and disseminated cancer (P = 0.032) trended toward morbidity in PLIF/TLIF; obesity trended in PLIF/TLIF (P = 0.0022) and ALIF/LLIF (P = 0.020). Conclusion. PLIF/TLIF was associated with a 15.5% increased odds of morbidity; readmission and reoperation were similar between approaches. Older age, higher ASA-class, and specific comorbidities predicted poorer 30-day outcomes, while procedural-related factors predicted only morbidity. These findings can guide surgical approach given specific factors. Level of Evidence: 3

Study Design. Retrospective cohort study. Objective. The aim of this study was to determine the differences in 30-day readmission, reoperation, and morbidity for patients undergoing multilevel anterior cervical discectomy and fusion (ACDF) or single and multilevel anterior cervical corpectomy and fusion (ACCF). Summary of Background Data. Despite increasing rates of surgical treatment of cervical spine disease, few studies have compared outcomes by surgical technique. To the best of our knowledge, this is the only large-scale administrative database study that directly evaluates early outcomes between multilevel ACDF and single and multilevel ACCF. Methods. Patients who underwent ACDF and ACCF were identified using the NSQIP database. Multivariate regression was utilized to compare rates of readmission, reoperation, morbidity, and specific complications between surgical techniques, and to evaluate for predictors of primary outcomes. Results. We identified 15,600 patients. ACCF independently predicted (P < 0.001) greater reoperation (odds ratio [OR] = 1.876) and morbidity (OR = 1.700), but not readmission, on multivariate analysis. ACCF was also associated with greater rates of transfusion (OR = 3.273, P < 0.001) and DVT/thrombophlebitis (OR = 2.852, P = 0.001). ACCF had significantly (P < 0.001) greater operative time and length of stay. In the cohort, increasing age (P < 0.001), diabetes (P = 0.025), chronic obstructive pulmonary disease (P = 0.027), disseminated cancer (P = 0.009), and American Society of Anesthesiologists (ASA) class ≥3 (P < 0.001) predicted readmission. Age (P = 0.011), female sex (P = 0.001), heart failure (P = 0.002), ASA class ≥3 (P < 0.001), and increased creatinine (P = 0.044), white cell count (P = 0.033), and length of stay (P < 0.001) predicted reoperation. Age (P < 0.001), female sex (P = 0.002), disseminated cancer (P = 0.010), ASA class ≥3 (P < 0.001), increased white cell count (P = 0.036) and length of stay (P < 0.001), and decreased hematocrit (P < 0.001) predicted morbidity. Within ACDF, three or more levels treated compared to two levels did not predict poorer 30-day outcomes. Conclusion. Compared to multilevel ACDF, ACCF was associated with an 88% increased odds of reoperation and 70% increased odds of morbidity; readmission was similar between techniques. Older age, higher ASA class, and specific comorbidities predicted poorer 30-day outcomes. These findings can guide surgical solution given specific factors. Level of Evidence: 3

NA.