Risk factors for mortality after 3-column osteotomy

Three-column osteotomies (3COs), such as pedicle subtraction osteotomy (PSO) and vertebral column resection (VCR), are used to surgically correct rigid adult spinal deformity (ASD). While extensive research exists about complications associated with 3COs, there remains a paucity of studies analyzing risk factors for mortality following 3CO. We believe the mortality rate after 3-column osteotomy will be low with specific identifiable demographic or medical risk factors.

A retrospective analysis was conducted using the National Surgical Quality Improvement Program (NSQIP) database. Patients undergoing 3CO were identified via CPT codes. The primary outcome of interest was 30-day postoperative mortality. Univariate statistical analysis was performed, followed by multivariable logistic regression controlling for age, sex, and body mass index (BMI).

The analysis included 1,441 patients. 446 patients had thoracic osteotomies, 996 patients had lumbar osteotomies, and 226 had multilevel osteotomies. The overall 30-day mortality rate was 1.2% (18 patients). On univariate analysis, mortality was more likely in patients with diabetes (2.8% vs. 1.2%, P = 0.029) and COPD (7.0% vs. 1.2%, P < 0.001). Mortality was associated with higher 5-factor modified frailty index (P = 0.004). After controlling for age, sex, and BMI, multivariable analysis revealed that mortality rates were independently associated with longer operative times (OR = 1.28, 95% CI:1.06-1.54, P = 0.010) and COPD (OR = 10.36, 95% CI: [2.17-49.47], P = 0.003).

Thirty-day mortality after 3CO is 1.2% globally. The greatest univariate risk factors are diabetes, COPD, and frailty. Regardless of age, sex, or BMI, it was found that COPD and duration of surgery were independently associated with increased rates of mortality.