Background: Fractures of the distal femur include metadiaphyseal fractures and physeal injuries. Treatment with cast alone is often excluded because of the inability to achieve and maintain reduction, polytrauma, and pathological fractures. Furthermore, operative treatment can also be challenging as the physis is still open and can be damaged by the fracture itself or by the fixation device, the metaphyseal fragment is short and problematic to fixate, and some of the fractures are intraarticular.

The goal of the study was to review the pattern of these fractures and report the midterm outcomes of various treatment options.

Study design: Inclusion criteria for this retrospective study were: age 9–16 years, fracture in the distal third of the femur treated surgically, growth plates open and availability to follow-up. From 2003–2006, fourteen children (mean age 11.5 years) met inclusion criteria. Over the same period, a search based on ICD-9 codes identified 49 patients with femur fractures that had undergone surgery.

Patient charts and radiographs were reviewed and the children were evaluated by an orthopedic surgeon not involved in the patient management. Parameters recorded included: time to union, time to achieve 0–110° knee range of motion (ROM), and emergency surgery, limited knee ROM and premature physeal arrest.

Results: Fractures of the distal femur were frequent among teenagers accounting for 28% of all femoral fractures. a) Injury was related to sport activities (n=10), motor vehicle accidents (n=3) and blast injury (n=1). b) Fracture types: Salter-Harris physeal injuries (n=6) and metaphyseal fractures (n=8). Three of the meta-diaphyseal fractures were pathological fractures through bone cysts.

Treatment: The following methods were employed: a) external fixators (n=2), b) screws, pins and cast (n=6), c) Plates (n=5), and d) Titanium elastic nails (n=1). The mean follow-up was 16 months (range 3–38 months). d) There were no major complications. The knee ROM at 6 weeks was 35° after pins and cast, and 80° after other methods. The knee ROM was at least 110° at 3 months after plate fixation and at six months after pins and cast.

Conclusions: We identified two main subgroups of treatment in teenagers: plates in 5, and screws or Kirschner wires with cast augmentation in 6. The teenagers treated with plates had better short-term outcomes but, at 6 months, there was no difference between the groups. It appears that, if fracture configuration allows, the percutaneous locking plates should be the first treatment option. Bone cysts appear to be a significant risk factor in this age group. The midterm outcome of distal femur fractures was overall good without physeal arrest or malalignment.