Factors affecting postoperative mortality of patients with insufficient union following osteoporotic vertebral fractures and impact of preoperative serum albumin on mortality

BACKGROUND: Numerous comparative studies of surgical procedures have focused on clinical and radiographical outcomes, as well as the effect of bone fragility on the outcome of spinal surgery; however, insights concerning a risk of mortality or morbidity have been limited. Additionally, the effect of surgical therapy on survival after vertebral compression fractures remains controversial. Our aim was to evaluate the preoperative factors that affected the long-term survival of patients who underwent spinal surgery for an insufficient union following osteoporotic vertebral fractures (OVF) and to determine postoperative mortality. METHODS: We retrospectively reviewed the cases of 105 consecutive patients who underwent spinal surgery for OVF. Mortality was estimated using the Kaplan-Meier method and a log-rank test. The preoperative backgrounds of patients were analyzed to determine which risk factors led to death among the OVF cases. Kaplan-Meier curves were used to estimate survival based on preoperative albumin levels of ≤3.5 g/dL (hypoalbuminemia) versus > 3.5 mg/dL. RESULTS: The mean follow-up time was 4.1 ± 0.8 years. Two years after surgery, percentage of patients who had died was 15%. The VAS scores and modified Frankel classification were significantly improved one year after surgery. The ratio of male-to-female was significantly higher for patients with OVF who died than for those who were still alive. No significant difference in mortality was observed among surgical procedures for OVF. The univariate analysis showed that male gender, serum albumin < 3.5 g/dl, creatinine clearance< 60 mg/dl, and the American Society of Anesthesiologists classificat0ion ≥3 were significant risk factors for postoperative mortality. Multivariate analysis revealed that only serum albumin ≤3.5 g/dL was a significant risk factor for long-term postoperative mortality of patients with OVF. CONCLUSIONS: Preoperative hypoalbuminemia was associated with postoperative mortality following surgery for OVF. LEVEL OF EVIDENCE: Level 3.