Complications and readmission after lumbar spine surgery in elderly patients: an analysis of 2,320 patients.

BACKGROUND CONTEXT: There is a paucity of literature describing risk factors for adverse outcomes after geriatric lumbar spinal surgery. As the geriatric population increases, so does the number of lumbar spinal surgeries in this cohort.

PURPOSE: The purpose of the study was to determine how safe lumbar surgery is in elderly patients. Does patient selection, type of surgery, length of surgery, and other comorbidities in the elderly patient affect complication and readmission rates after surgery?

STUDY DESIGN/SETTING: This is a retrospective cohort study.

PATIENT SAMPLE: The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) Database was used in the study.

OUTCOME MEASURES: The outcome data that were analyzed were minor and major complications, mortality, and readmissions in geriatric patients who underwent lumbar spinal surgery from 2005 to 2015.

MATERIALS AND METHODS: A retrospective cohort study was performed using data from the ACS NSQIP database. Patients over the age of 80 years who underwent lumbar spinal surgery from 2005 to 2013 were identified using International Statistical Classification of Diseases and Related Health Problems diagnosis codes and Current Procedural Terminology codes. Outcome data were classified as either a major complication, minor complication, readmission, or mortality. Multivariate logistic regression models were used to determine risks for developing adverse outcomes in the initial 30 postoperative days.

RESULTS: A total of 2,320 patients over the age of 80 years who underwent lumbar spine surgery were identified. Overall, 379 (16.34%) patients experienced at least one complication or death. Seventy-five patients (3.23%) experienced a major complication. Three hundred thirty-eight patients (14.57%) experienced a minor complication. Eighty-six patients (6.39%) were readmitted to the hospital within 30 days. Ten deaths (0.43%) were recorded in the initial 30 postoperative days. Increased operative times were strongly associated with perioperative complications (operative time >180 minutes, odds ratio [OR]: 3.07 [95% confidence interval {CI} 2.23-4.22]; operative time 120-180 minutes, OR: 1.77 [95% CI 1.27-2.47]). Instrumentation and fusion procedures were also associated with an increased risk of developing a complication (OR: 2.56 [95% CI 1.66-3.94]). Readmission was strongly associated with patients who were considered underweight (body mass index [BMI] <18.5) and who were functionally debilitated at the time of admission (OR: 4.10 [1.08-15.48] and OR: 2.79 [1.40-5.56], respectively).

CONCLUSIONS: Elderly patients undergoing lumbar spinal surgery have high complications and readmission rates. Risk factors for complications include longer operative time and more extensive procedures involving instrumentation and fusion. Higher readmission rates are associated with low baseline patient functional status and low patient BMI.