High Rate of Vascular Injury and Mortality for Acute Total Knee Arthroplasty Dislocations: A Case Series.

Background: Acute dislocations following total knee arthroplasty (TKA) represent a rare and devastating complication frequently leading to loss of function and mortality. Literature regarding management, risk factors, and mechanisms for acute TKA dislocation is limited to case reports and systematic reviews, thus necessitating the need for further data to better understand these injuries. This case series aims to present our institution's experience with acute TKA dislocations while highlighting risk factors, rates of vascular injury, mortality, and intensive care utilization. Methods: Retrospective review was performed to identify patients presenting to a Level I Academic Trauma center from 2016 to 2021 with radiographic evidence of an acute TKA dislocation. Patient charts were reviewed for past medical history, arthroplasty course, injury characteristics, and course after dislocation. Results: Records review identified 6 patients managed for an acute TKA dislocation. 5/6 patients were female with an average body mass index of 45.1 ±18.2 and average age of 69.2 ± 5.6 years. All patients had a ground level fall as mechanism of injury. Four patients sustained a vascular injury requiring intervention, 5/6 patients required intensive care unit admission, and 5/6 implants were cruciate-retaining (CR). This series was associated with a 50% 30-day mortality rate and 33.3% rate of above knee amputation. Conclusion: This case series demonstrates a high rate of vascular injury, morbidity, and mortality for acute TKA dislocations, emphasizing the importance of multidisciplinary care and neurovascular monitoring. Most patients sustaining dislocation were female, obese, multiply comorbid, with a high rate of subsequent intensive care unit admission. Level of Evidence: V.