Open Reduction and Internal Fixation of Distal Femoral Fractures in Children

Open reduction and internal fixation (ORIF) is a commonly used treatment for fractures throughout the body, including the distal femur. ^[1] Supracondylar nonphyseal femur fractures are rare in the pediatric population. Although the exact definition of the supracondylar region of the femur is unclear in the pediatric patient, it is often determined by measuring the width of the distal femoral physis, then using that distance to measure proximal to the physis to create a square. This region has been dubbed the supracondylar region of the femur. ^{[2, 3]}

An analysis of data from the Kids' Inpatient Database found that obesity was associated with increased rates of ORIF in children with distal femoral fractures (OR = 2.051, 95% CI, 1.69-3.60). In addition, obese children had significantly increased lengths of stay and complications following treatment. ^[4]

Various studies have described the incidence of distal femur fractures as being in the range of 7-12%. ^{[5, 6]} These injuries are usually the result of direct trauma to the thigh or knee. It is very important to assess for other associated injuries when presented with a supracondylar femur fracture. Often, patients with these injuries may have pathologic bone from diseases such as osteogenesis imperfecta or neuromuscular disease. Also, of utmost importance, with a supracondylar femur fracture in a child younger than 1 year, the physician should be suspicious of child abuse.

Indications for treatment include the following:

• Open fractures
• Fractures associated with neurovascular compromise
• All displaced fractures
• Ipsilateral lower-extremity fractures
• Irreducible fractures
• Pathologic fractures

Careful examination of a distal pulse is important in supracondylar femur fractures because the fracture may injure the nearby superficial femoral artery, as well as neurovascular structures in the area of the popliteal artery.

Treatment of supracondylar femur fractures depends on fracture displacement. Nondisplaced fractures may be treated in a long leg cast, whereas most displaced fractures require operative intervention for fracture reduction.

Patients who are hemodynamically unstable and polytrauma patients may benefit from provisional stabilization of the fracture instead of ORIF. Infections and medical conditions that could pose a life-threatening surgical or anesthetic risk are also contraindications.

Best practices

In preparing for surgical treatment of a supracondylar femur fracture, it is essential to have the necessary tools and equipment in place. It is also essential to have a preoperative template in hand as to what the step-by-step approach to the case will be.

Procedural planning

For polytrauma patients in whom ORIF is precluded, external fixators may be used to maintain overall length and alignment of the limb.

Solid intramedullary nails may be reamed or unreamed. They are ideally suited for children older than 12 years because their intramedullary canal is close to adult proportions. Intramedullary nails are load-sharing devices that may be locked proximally and distally to control rotation of the femur.

Flexible intramedullary nails are typically used in children aged 6-12 years. They can be used in children who are too large for a spica cast and too immature for a solid intramedullary nail. Advantages of flexible intramedullary nails include sparing the growth plate proximally or distally, as well as avoiding the blood supply to the femoral head. ^[7]

Kirschner wires (K-wires) and Steinmann pins may also be used to stabilize supracondylar femur fractures in children who are 6-10 years of age or who weigh less than approximately 50 kg. ^[8] This method of fixation is not as strong as a nail or plate construct. However, it is feasible for low supracondylar fractures close to the physis, where other forms of fixation such as nails would be difficult. The drawback of using K-wire fixation is that a long leg cylinder cast is necessary to protect the construct and to aid in fracture healing.

Plate fixation of supracondylar femur fractures may require ORIF or can be done through percutaneous techniques. The plate construct is a stress shielding construct. The implant will eventually need to be removed in growing children. This method of fixation is one of the most common methods employed for supracondylar femur fractures in children.

In general, given the limited options of surgical fixation of pediatric supracondylar femur fractures, external fixation may be a viable option. A lateral frame or Ilizarov frame may be used. This technique allows the maintenance of overall length and alignment of the limb, but it is cumbersome for patients and is associated with complications such as pin tract infections.