Association between Perioperative Blood Glucose Levels and Wound Complications in Diabetic Patients Undergoing Adult Spinal Deformity Surgery: A Retrospective Cohort Study.

INTRODUCTION

Adult spinal deformity (ASD) surgery is highly invasive and carries a substantial risk of postoperative wound complications, particularly in patients with type 2 diabetes mellitus (DM). Perioperative hyperglycemia is a known risk factor for surgical-site infection, but glucose thresholds specific to patients with diabetes and ASD remain unclear.

METHODS

We retrospectively reviewed 437 adults who underwent ASD correction between 2010 and 2020, of whom 50 (11.4%) had type 2 DM. Capillary blood glucose was measured at standardized intervals from the day of surgery through postoperative day 3 and at least once daily thereafter until discharge. For each diabetic patient, we calculated an overall mean perioperative glucose value (mean of all in-hospital measurements from postoperative day 0 to discharge) and maximum/mean glucose during postoperative days 0-3. These patient-level indices were compared between patients with and without wound complications, and receiver operating characteristic (ROC) analysis based on overall mean glucose was used to explore thresholds associated with wound morbidity.

RESULTS

Wound complications occurred more often in patients with DM than those without DM (18.0% vs 3.1%, p<0.001). Among the patients with diabetes, overall mean perioperative glucose was higher in the wound-complication group than in the non-wound group (184.8±35.1 vs 156.1±26.6 mg/dL; p=0.020). ROC analysis of overall mean glucose yielded an area under the curve of 0.75 and suggested an exploratory threshold around 185 mg/dL. Patients with diabetes also had higher rates of systemic complications.

CONCLUSIONS

Type 2 DM was associated with substantially increased wound morbidity and systemic complications after ASD surgery. Higher overall mean perioperative glucose in patients with diabetes was linked to wound complications, and an exploratory threshold near 185 mg/dL showed moderate discriminatory ability. These findings support the concept that tighter perioperative glycemic control may reduce wound morbidity, although the proposed threshold should be regarded as hypothesis-generating and should be confirmed in larger prospective studies.