Factors influencing length of hospital stay after primary total knee arthroplasty in a fast-track setting

The goal of this study was to identify factors prior to surgery that are associated with an increased length of hospital stay after TKA using a fast-track protocol. In total, 879 consecutive patients who underwent primary TKA were included in this retrospective cohort study. A length of stay greater than or equal to three nights was considered an increased length of hospital stay. Univariable and multivariable generalized linear mixed models were used to identify potential factors associated with increased length of hospital stay. Length of hospital stay was significantly associated with age [OR 1.01 (95 % CI 1.01-1.02); p < 0.001], gender [female vs. male, OR 1.07 (95 % CI 1.00-1.15); p = 0.04], ASA [ASA III/IV vs. ASA I, OR 1.22 (95 % CI 1.06-1.39); p = 0.005], living situation (alone vs. together, OR 1.08 (95 % CI 1.00-1.16); p = 0.04], neurological comorbidities [OR 1.14 (95 % CI 1.06-1.23); p < 0.001], musculoskeletal comorbidities [OR 0.91 (95 % CI 0.85-0.97); p = 0.005], anaesthesia [spinal vs. general, OR 0.86 (95 % CI 0.76-0.97); p = 0.02], and weekday of surgery [Thursday vs. Monday, OR 1.12 (95 % CI 1.02-1.23); p = 0.02]. Older age, female gender, ASA III/IV, people living alone, the presence of neurological comorbidities, general anaesthesia and surgery on Thursday were associated with an increased length of hospital stay. In clinical practice, the knowledge of factors associated with an increased length of hospital stay can be used to further optimize peri-operative protocols for patients at risk for an increased length of hospital stay after TKA. II.