Pattern and Functional Outcome Of Floating Knee Injury Treated Surgically at Tertiary Hospital, Addis Ababa, Ethiopia. A Retrospective Study

Abstract Introduction: Floating knee injuries, ipsilateral femur, and tibial fractures are uncommon, and the exact frequency is unclear. These complicated injuries have a significant complication rate and may result in a poor prognosis. Methods A retrospective hospital-based cross-sectional study design was conducted among patients with floating knee injuries at AaBET hospital. 71 patients with floating knee injuries were treated at AaBET hospital from January 1, 2016, to December 31, 2021. Binary and multivariate logistic regression was used. The functional results of these injuries were evaluated using the Karlström and Olerud criteria. We assessed functional outcomes at 12-month post-operative follow-up. P-value < 0.05 was considered statistically significant. Results In this study, 71 patients with floating knee injuries were included. Of these, 51 (71.8%) had satisfactory results, 69 (97.2%) were the result of road traffic accident (RTA), 41 (57.7%) had open fractures, 50 (70.4%) had simultaneous injuries, and 20 (28.2%) had postoperative complications, the most common of which were wound and pin site infections (17% ).In binary logistic regression, open floating knee patients with associated injuries, patients with type 2 Fraser’s class floating knee injuries, patients who had a femur fracture treated with an external fixator, patients who underwent repeat surgery, and patients whose repeated surgery done after two weeks and patients with complication are associated with an unsatisfactory outcome. Multivariate analysis showed patients with type 2 Fraser’s classification of floating knee injuries were 8.9 times more likely than those with type 1 to experience a poor outcome (AOR 95% CI: 8.94 (1.81, 44.07), p = 0.007). Conclusion Involvement of the knee joint in floating knee injuries is the most important predictor of an unsatisfactory outcome.