The floating knee: a retrospective analysis of 172 cases]

A retrospective multicentric observational study of 172 floating knee injuries is reviewed. According Fraser's classification 71.5% of the cases are type I and the repartition of the type II in the 3 subgroups is as follow: II A 8.2%, II B 11.6%, et II C 8.7%. At least one of the fractures was open in 69.2% of the patients. The average Injury Severity Score (ISS) was 19.5. The polytraumatized patients (ISS over 18) represented 37.7% of the cases. The surgical procedure started within the 6 first hours in 62% of the injured people. The Intramedullary nailing (IM) was the preferred method at the femur site (73%, 126 cases), at the tibia IM was performed in 54.4% of cases and external fixation was used in one every four patients. The mean operating time was 167 minutes (range: 40'-300') and the total time for the whole procedure was 216 minutes (range: 80'-410'). The mean follow up is 34.2 months. According the functional score of Karlström and Olerud, 23 patients were rated as excellent, 38 as good, 35 as fair and 20 as bad. The contributing factors influencing bad functional outcome are the age, a type II lesion, a femoral fracture located at the distal third, and an open fracture. The IM using a single knee incision does not show in this series better results but the shortening of the operating time was highly significant.