Floating knee: epidemiology and results of treatment

Abstract

Introduction: Floating Knee is the term applied to ipsilateral fractures of the femur and tibia. Management of this complex injury has been variously described in the literature. This retrospective study was designed to present our experience with treatment of this injury, its complications and the functional results of these patients. Material and Methods: Between January 2004 and December 2007, all floating knee injuries that were managed during the study period were included. The patients were divided according to Fraser's classification. Functional assessment and final outcome was measured using the Karlstrom and Olerud's criteria. Results: Our study included 43 patients with 43 floating knee injuries. There were 32 males and 11 females with a mean age of 37 years. All patients had sustained their injuries in motor vehicle accidents. Thirty nine associated injuries were noted in the 43 patients. According to Fraser's classification, there were 21 type I, 10 type IIa, 7 type IIb, and 5 type IIc. Most of the floating knee injuries were treated with antegrade intramedullary nailing for both the femur and tibia. The mean follow up was 24.8 months. All the fractures united within a reasonable time except for three femur and 14 tibias. The complications encountered were one case of fat embolism, eight case of knee stiffness, 10 cases of delayed union, nine cases of infections, and seven cases of nonunion. Assessment by the Karlstrom criteria revealed 12 excellent results, 19 good results, 4 acceptable results, and 8 poor results. Analysis showed that surgical results were significantly associated with Fraser type classification of floating knee injuries (p = 0.003), the severity of soft tissue injury in the leg (grade III opened fracture) (p = 0.008), and associate lesions (p = 0.001). Conclusion: In patients suffering from floating knees, early fixation is recommended since it has several advantages with few systemic complications. We found Floating knee injuries to be a group of complex injuries that needed careful assessment to detect poor prognostic factors. Combination of all these would determine the ultimate outcome of these patients.

Key words: Floating knee, Intramedullary fixation, Associate lesions, Surgical treatment.