Comparison of Surgical Outcome Between Diabetic Versus Nondiabetic Patients After Lumbar Fusion.

Background: The prevalence of diabetes mellitus (DM) is increasing worldwide. Thereby, an increasing rate of patients with DM are subjecting to spine surgery. Reviewing the literature, a higher rate of surgery-related complications is reported in DM patients. There is no prospective study comparing the outcomes of lumbar fusion surgery in patients with and without DM. We aimed to investigate whether DM is associated with worse patient-reported outcomes, lower fusion rate, and higher complication rate in subjects undergoing spinal lumbar fusion surgery.

Methods: Forty-eight subjects with DM (DM group) and 48 controls (control group) were recruited. Data regarding age, duration of diabetes, comorbidities, fasting blood sugar, HbA1c, insulin dependence, duration of operation and the volume of bleeding, and the number of infused packed cell were recorded for all patients. Pain and functional status of the patients using the visual analogue scale (VAS) and Oswestry Disability Index (ODI) were measured before operation and 2 weeks, 6 months, and 1 year after lumbar spinal fusion surgery. Using lumbar computed tomography scan and anteroposterior and lateral x-ray 1 year after the surgery, fusion was assessed.

Results: Fusion rate after 1 year was 78% in the control group and 53% in the DM group ( P = .02). Patients with DM had higher VAS scores comparing to controls 1 year after the operation, but the difference was not significant ( P = .07). However, comparing the functional status of the subjects, significantly higher ODI scores were found among DM patients comparing to controls ( P = .002).

Conclusion: Rate of fusion among diabetic patients who undergo lumbar spinal fusion surgery is lower than healthy controls. Spine surgeons should consider this to provide the best possible facilities during the surgery to increase the fusion rate in these patients.