Outcomes of lateral approach total knee replacement in the elderly cohort: A focused analysis on patients aged 80 and above

Lateral approach TKR is gaining increasing popularity. The relationship between advanced age and the risk associated with TKR performed through a lateral approach, in an outpatient setting is evaluated. We assessed the association between age 80+ and surgical complications, alongside readmission rates, aiming to evaluate outpatient age-related risks in lateral approach TKR. Our study reveals that selected patients above 80 had readmission rates, complications, and wound healing rates comparable to those of the younger group. They experienced slower but satisfactory functional recovery as indicated by lower KSS Function scores at various postoperative intervals compared to younger cohorts. The readmission rates of 2.7 % in both groups were achieved in an outpatient setting by trained and experienced surgeons and staff. We conducted our study employing a retrospective cohort design, leveraging a comprehensive dataset to explore associations and disparities across different age groups <80 and 80+) undergoing total knee arthroplasty through a lateral approach. To investigate these relationships, we applied Chi-square tests for categorical data and Analysis of Variance (ANOVA) for continuous variables, facilitating a statistical examination of our hypotheses. To elucidate the potential causal pathways and account for confounding variables, we utilized directed acyclic graphs to visually represent and better understand the assumed causal relationships among the variables under study, alongside regression analysis ensuring a more informed interpretation of the associations between patient age, comorbidities, surgical complications, and readmission rates. Our analysis revealed that there was no significant variation in complications, wound healing, readmission or revision rates across the different age categories (<80 and 80+) examined in the study. The elderly cohort had a lower mean BMI and comorbidity score reflecting a bias towards healthier elderly individuals. The readmission rates for both groups was approximately 2.7 %. Our findings highlight the viability of lateral approach total knee arthroplasty (TKA) across a diverse age spectrum, including selected elderly individuals, in outpatient settings without increasing the risk of complications, readmission or the need for revision surgery. This insight is particularly relevant in the context of an aging global population and the growing demand for joint replacement surgeries. By demonstrating that age alone is not a determinant of adverse outcomes, our study supports the broader applicability of the lateral approach for TKA in selected elderly patients in the outpatient setting.