Comorbidities rather than age affect medium-term outcome in octogenarian patients after total knee arthroplasty

PURPOSE: As the population ages, it is important to determine whether total knee arthroplasties (TKA)s are safe and beneficial in the octogenarian population. The aims of the present study were: (1) to assess the effect of comorbidities and age on the incidence of postoperative complications following TKA and (2) to evaluate the mid-term outcome of octogenarian patients. METHODS: A retrospective matched-paired analysis by gender, BMI and duration of follow-up was conducted on 206 patients older than 80 years and younger than 75 years between 2009 and 2016, undergoing primary TKA. The mean follow-up was 5 years. Outcome measures including Oxford Knee Score (OKS), Knee Society Score (KSS), Knee Society Function Score (KSFS), postoperative complications, length of stay (LOS) and survivorship were analysed. The association between complications and comorbidities was assessed using multivariable logistic regression after adjusting for age, Deyo-Charlson Comorbidity Index (D-CCI) and the American Society of Anesthesiologist's (ASA) physical status classification. RESULTS: In the multivariable models, D-CCI class is an independent predictor for postoperative cardiac complications, delirium and transfusion rate (OR ranging from 1.2 to 69.5 in respect to D-CCI reference class 0). Being ≥ 80 years old was associated with an increased risk of transfusion (OR 3.4; 95% CI 1.7-6.8) and 1.7-day increase in LOS (p < 0.001). Both groups showed significant improvement in postoperative knee scores following TKA. CONCLUSION: Octogenarians experienced good clinical results when compared to their younger counterparts. Comorbidities, rather than age itself, are responsible for the increase in postoperative morbidity. Preoperative risk assessment has to be optimized in order to reduce complications.