Do Diabetic Patients Have Poorer Clinical and Radiological Outcomes Following Minimally Invasive Transforaminal Lumbar Interbody Fusion?

Background: The number of patients with diabetes mellitus (DM) seeking treatment for degenerative spondylolisthesis is expected to increase. However, there is a paucity of studies examining the patient-reported outcomes (PROs) and subjective measures in patients with DM following minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). The present study aimed to compare PROs, satisfaction, and radiological fusion between DM and non -DM patients following MIS- TLIF. Methods: The authors identified 30 patients with DM who underwent primary, single -level MIS- TLIF for degenerative spondylolisthesis from a spine registry. Each patient was matched 1:1 with 30 controls without DM using propensity scores to adjust for age, sex, body mass index, American Society of Anesthesiologists class, and baseline PROs. Visual analog scale leg pain, back pain, Oswestry Disability Index (ODI), SF -36 physical component score and mental component scores were compared at 1, 3, 6, and 24 months. Patients also completed a satisfaction questionnaire during these visits. Radiographic fusion was analyzed according to Bridwell grades. Results: There was no difference in PROs between non -DM and DM patients at 2 years. However, a higher proportion of non -DM patients attained minimal clinically important difference for ODI (90.0% vs 66.7% P = 0.028) and SF -36 physical component score (90.0% vs 53.3% P = 0.002) at 3 months and ODI (96.7% vs 80.0%) at 6 months. A similar proportion of patients in each group were satisfied and had expectations fulfilled. A higher proportion of non -DM patients attained a grade 1 or 2 fusion (93.3%), as compared with DM patients (80.0%), although this did not reach statistical significance (P = 0.129). Conclusions: DM patients have poorer initial PROs, which reach comparable levels to those in non -DM patients in the longer -term. Fusion rates of DM patients were poorer compared with non -DM patients.