Perioperative complications associated with posterolateral spine fusions a study of elderly medicare beneficiaries

Study Design. A retrospective database review. Objective. The aim of this study was to compare the occurrence of complications in patients treated with one to two-level, three to seven-level, and more than eight level fusions. Summary of Background Data. Elderly patients constitute a rapidly growing demographic with an increasing need for spinal procedures. Complication rates for spinal surgery in elderly patients range from 37% to 80% with major complications occurring in 12% to 21% of patients. Methods. The PearlDiver database (20052012) was utilized to compare perioperative complication rates in patients aged 65 years and older undergoing posterolateral fusion of one to two (n90,527); three to seven (n23,827), and more than eight (n2758) thoracolumbar levels. Cohorts were matched by demographics and comorbidities. Ninety-day medical and surgical complication and mortality rates were determined. Results. In the full, unmatched cohort, the major complication rate was 15.9%, with matched cohorts of one to two, three to seven, and eight-level fusions associated with major complication rates of 12.5%, 20.5%, and 35.4%, respectively. Patients treated with 8 level fusions had 3.8 and 2.1 times greater odds of developing a major complication than patients treated with 1 to 2 and 3 to 7-level fusions, respectively (P<0.0001). Patients treated with more than eight-level fusions had 3.9 and 10.8 times increased odds of experiencing mortality than those treated with three to seven-level and one to two-level fusions, respectively. Conclusion. Elderly patients treated with spine fusions spanning more than eight levels experience significantly increased complication rates when compared with patients treated with fusions of shorter length.