Glycemic Laboratory Values Are Associated With Increased Length of Stay and 90-Day Revision Risk Following Surgical Management of Adult Spinal Deformity
Medical Student Loyola University Chicago Stritch School of Medicine
Disclosure(s):
Benjamin M. Varieur, BS: No financial relationships to disclose
Introduction: Elevated Hemoglobin A1c (HbA1c) and postoperative glucose (PG) have been shown to increase the risk of complications following spine and other orthopaedic surgeries; however, data is limited for adult spinal deformity (ASD).
Methods: All patients undergoing spinal fusion of seven or more levels between 2021 and 2023 at two large academic medical centers were identified. Medical charts were then manually reviewed to obtain and confirm demographic, laboratory, and surgical characteristics, ASD-related indications, and outcomes. Bivariate analysis was performed followed by simple and multiple regression analysis. Odds ratios were established relative to the laboratory threshold values informed by receiver operating characteristics.
Results: Of 872 original procedures identified, 107 patients (12.3%) were adults with preoperative HbA1c and postoperative PG measurements who underwent surgery for a diagnosis of ASD. Median patient age was 67 years (IQR 59-72 years), 60 (56.1%) were female, and 97 (90.7%) were Caucasian. Median length of stay (LOS) was 7 days (IQR 5-10 days); therefore, we defined extended LOS relative to the 70th percentile (≥9 days). Higher preoperative HbA1c was correlated with increased LOS (R=0.22, P=0.022). The odds ratio (OR) for patients requiring extended LOS was 2.54 (95% CI 1.08-5.97, P=0.030) for those with HbA1c ≥6.3%. Multiple regression analysis of LOS identified HbA1c [B= 1.59 (95% CI 0.41-2.78), P=0.009] as a positive predictor of LOS and mean PG [B= -0.06 (95% CI -0.10-(-0.01)), P=0.014] as a weakly negative predictor of LOS. Upon simple logistic regression, the OR for 90-day revision was 1.79 (95% CI 1.03-3.10, P=0.039) for every unit increase in HbA1c. Patients with mean PG ≥165 mg/dL [OR=6.91 (95% CI 1.60-29.90), P=0.009] or maximum PG ≥184 mg/dL [OR=5.78 (95% CI 1.14-29.27), P=0.031] were at increased risk for 90-day revision. Glycemic laboratory values did not seem to be associated with 90-day wound complications or 90-day readmission following ASD surgery.
Conclusion : To our knowledge, this study is the first to evaluate glycemic laboratory values and outcomes following ASD surgery. These findings highlight the importance of glycemic control in ASD patients to potentially minimize the burdens of cost and morbidity on patients, their families, and healthcare systems associated with surgical intervention.