BackgroundDiabetes mellitus (DM) and osteoarthritis (OA) are common diseases that are predicted to increase in prevalence, and DM is a risk factor for OA progression and has a negative impact on the outcome. However, the evidence remains unclear on how it affects patients’ clinical results of total knee arthroplasty (TKA) under enhanced recovery after surgery (ERAS).MethodsA retrospective single-center study was conducted comparing diabetic and non-diabetic patients who underwent TKA in West China Hospital of Sichuan University between September 2016 to December 2017 under ERAS. Consecutive propensity score matching (PSM) was conducted by 1:1 (DM: non-DM) matching analysis with all baselines as covariates. The primary clinical results were the improvement of knee joint function, the incidence of postoperative complications, and the FJS-12 sensory results 5 years after the operation between DM and Non-DM groups. The secondary clinical results were the postoperative length of stay (LOS), postoperative blood test and total blood loss (TBL).ResultAfter PSM, the final analysis included 84 diabetic patients and 84 non-diabetic patients. Diabetic patients were more likely to experience early postoperative complications (21.4% vs. 4.8%,P= 0.003), of which wound complications are the most significant (10.7% vs. 1.2%,P= 0.022). Diabetic patients experienced longer postoperative LOS with a significant increase in patients with LOS exceeding 3 days (66.7% vs. 50%,P= 0.028) and showed less postoperative range of motion (ROM) (106.43 ± 7.88 vs. 109.50 ± 6.33 degrees,P= 0. 011). Diabetic patients also reported lower Forgotten joint score (FJS-12) than non-diabetic patients (68.16 + 12.16 vs. 71.57 + 10.75,P= 0.020) in the 5-year follow-up and were less likely to achieve a forgotten knee joint (10.7% vs. 1.2%,P= 0.022). In additional, Compared with non-diabetics, diabetic patients showed lower hemoglobin (Hb) (P< 0.001) and hematocrit (HCT) (P< 0.001) and were more likely to suffer from hypertension before TKA (P< 0.001).ConclusionDiabetic patients show increased risk for postoperative complications, and have lower lower postoperative ROM and lower FJS-12 compared with non-diabetic patients after TKA under ERAS. More perioperative protocols are still needed to be investigated and optimized for diabetic patients.