Comparative analysis of the impacts of 30-day perioperative complications on patient-reported outcome measures following multilevel anterior versus posterior cervical fusion

OBJECTIVE Many studies have compared outcomes following anterior and posterior cervical fusion, yet the differences in the impacts of perioperative complications on outcomes have not been well studied. This study aimed to assess the differences in the effects of 30-day perioperative complications on patient-reported outcome measures (PROMs) after multilevel anterior versus posterior cervical fusion. METHODS Adult patients who underwent anterior or posterior cervical fusion at three or more levels between 2014 and 2020 were analyzed. Each group was subdivided based on the occurrence and severity of perioperative complication: no complication versus minor complication versus major complication. The study primarily compared PROMs and minimal clinically important differences (MCIDs) within and between the groups. RESULTS A total of 146 anterior (102 with no complications, 36 with minor complications, 8 with major complications) and 55 posterior (36 with no complications, 13 with minor complications, 6 with major complications) cervical fusion cases were analyzed. Within the anterior or posterior group, there were no significant differences in the PROM change or proportions of patients achieving the MCID. In comparing the anterior group with the posterior group, anterior patients without complications had better improvement in the 3-month Neck Disability Index (coefficient 11.2, p = 0.019), with higher odds of achieving the MCID for the modified Japanese Orthopaedic Association score at 3 months (OR 2.0, p = 0.039). Otherwise, there were no significant differences in the PROM change or proportions of patients achieving the MCID in subsets of anterior or posterior patients with minor or major complications. Furthermore, patients with major complications had higher early readmission rates regardless of the surgical approach. Major complications were also associated with longer and increased rates of intensive care unit stays after posterior fusion compared with anterior fusion. CONCLUSIONS This study suggests that the severity of perioperative complications following anterior or posterior cervical fusion did not predict changes in PROMs or achievement of MCIDs in the anterior or posterior group. Also, PROMs may not fully differentiate the full extent of the impact of perioperative complications following anterior versus posterior cervical fusion. Otherwise, in subsets of patients without complications, anterior compared with posterior patients had improved Neck Disability Index scores at 3 months, with a significant proportion of patients achieving the MCID for the modified Japanese Orthopaedic Association score at 3 months.