Complications after lateral unicompartmental knee arthroplasty in a fast-track setting: a prospective cohort study of 170 procedures

Background and purpose - In existing studies on fast -track unicompartmental knee arthroplasty (UKA), the major-ity of surgeries are medial. There are substantial differences between lateral and medial UKA, which is why outcomes cannot automatically be compared. To gain information on the feasibility and safety of fast-track protocols in lateral UKAs, we investigated length of stay (LOS) and early com-plications after lateral UKA, performed using a fast-track protocol in well-established fast-track centers.Patients and methods - We retrospectively evaluated prospectively collected data on patients undergoing lateral UKA in a fast-track setup from 2010 to 2018 at 7 Danish fast-track centers. Data on patient characteristics, LOS, com-plications, reoperations, and revisions was analyzed using descriptive statistics. Safety and feasibility were defined as complication and reoperation rates within 90 days compara-ble to non-fast track lateral UKA or fast-track medial UKA. Results - We included 170 of patients with a mean age of 66 (SD 12) years. Median LOS was 1 day (interquartile range 1-1), which was unchanged from 2012-2018. 18% were discharged on the day of surgery. Within 90 days, 7 patients experienced medical complications and 5 patients experienced surgical complications. 3 patients underwent reoperation, 2 were soft tissue revisions and the third was removal of an exostosis due to catching of the patella. 1 patient was revised due to a bearing dislocation.Conclusion - Our findings suggest that lateral UKA in a fast-track setting is feasible and safe.