"Floating knee," an Uncommon Injury: Analysis of 12 Cases

Neglected infected floating knee injury: evaluation of closed reduction techniques

PURPOSE

Floating knee injury is uncommon yet challenging problem. The situation is more complicated by presence of infection, open comminuted fractures, and late presentation. The aim of this study was to evaluate the closed reduction techniques by circular external fixation in a single stage to treat patients having infected neglected floating knee injuries.

METHODS

This retrospective study included 19 patients with a mean age of 34.4 years. The average duration from trauma to surgery was 51.1 days. All patients had at least one infected open fracture. According to Fraser's classification, ten injuries were type I, one case was type IIa, four were type IIb, and four were type IIc. Patients were treated by closed reduction techniques using the Ilizarov principles. Orthoplastic procedures were done in four cases in the same surgical setting.

RESULTS

Closed reduction and union were achieved in all cases with control of infection in 17 cases. The follow-up period averaged 41 months. The mean knee flexion was 97.4°. The complications included 5° extension lag (two cases), malunion (three cases), refracture (two cases), and DVT (four cases). The bone results were excellent (12 cases), good (5 cases), and poor (2 cases). The functional results were excellent (two cases), good (seven cases), acceptable (seven cases), and poor (three cases).

CONCLUSIONS

Closed reduction techniques using a circular frame provided a valid treatment option for infected neglected floating knee injuries in one stage without bone grafting. However, the high rate of complications and the diminished knee range of motion should be considered.

INCIDENCE OF DEEP VEIN THROMBOSIS IN FLOATING KNEE

OBJECTIVE

To report the incidence of deep vein thrombosis (DVT) in ipsilateral femur and tibial fractures (floating knee).

METHODS

This is a retrospective, analytical, observational study conducted with the medical records of thirty patients admitted to a trauma hospital between October 2016 and July 2017 with floating knee.

RESULTS

Patients aged between 21-30 years were the most affected by the condition (36%). Seventeen patients affected the dominant limb (57%); 19 (63%) patients were classified as Fraser type I, 18 (60%) had open (compound) fractures, 16 (53%) tibial fractures, and 8 (26%) femoral fractures. External fixation of the femur and tibia (25 patients = 83%) was the most common emergency treatment. In total, 17% of patients presented deep venous thrombosis (p = 0.409).

CONCLUSION

Despite antithrombotic prophylaxis, the incidence of DVT in the affected limb of patients with floating knee was high. We found patients with Fraser I fractures, male, and with fractures in the non-dominant limb to present a higher chance of developing DVT. Level of Evidence III, Comparative retrospective study .