Comparative Outcomes of Lower Extremity Fractures in Patients With Type 1 and Type 2 Diabetes: A Retrospective Database Analysis

Background: Diabetes mellitus (DM) is a major risk factor for adverse outcomes following orthopedic trauma. Although both type 1 (T1DM) and type 2 (T2DM) diabetes mellitus increase complication risk after lower extremity fracture fixation, their relative impacts remain poorly characterized. Materials and Methods: We performed a retrospective cohort analysis to compare postoperative outcomes in patients with T1DM and T2DM who underwent surgical fixation of lower extremity fractures. Propensity score matching was performed within anatomical fracture subgroups based on age, sex, race, body mass index, hemoglobin A 1c , and nicotine dependence. Outcomes were compared using appropriate statistical tests and survival analysis. Results: A total of 10 464 patient-fracture encounters across 4 anatomic subgroups met inclusion criteria. After propensity score matching within each subgroup, 1 776 matched pairs (3 552 encounters) were analyzed. T1DM patients experienced higher rates of adverse outcomes compared to T2DM patients, with the greatest differences observed for infection (tibia: 7.3% vs 3.1%, P = .009; foot/ankle: 9.8% vs 1.8%, P < .001), amputation (femur: 2.9% vs 0.0%, P = .001; tibia: 2.6% vs 0.0%, P = .001), and mortality (hip: 21.8% vs 15.1%, P = .003; femur: 12.3% vs 4.4%, P < .001; tibia: 9.9% vs 2.5%, P < .001; foot/ankle: 7.5% vs 2.0%, P < .001). These risks appeared to increase distally, with the highest complication rates seen in the tibial and foot/ankle subgroups. Conclusions T1DM confers a distinctly higher risk of infection, limb loss, and mortality following operative fixation of lower extremity fractures compared to T2DM, despite similar baseline characteristics after matching. These findings highlight the need for diabetes-subtype-specific perioperative management strategies to optimize outcomes in this high-risk population.