Some generalizations can be made about femoral shaft fractures in children. The femur heals spontaneously even with widely displaced fragments. Nonunion is rare. The healing rate is age dependent, and the relationship between time of union and age is nearly linear. Overgrowth is greatest during early and middle childhood and is related to the degree of osseous and soft tissue disruption. Because of this overgrowth, childhood femoral fractures should be allowed to override by 1 cm to compensate for the overgrowth. Overgrowth averages 1 cm for femoral fractures in childhood. As compared to adults, blood loss seldom reaches a level that requires replacement. Most femoral fractures heal without disability if complications are avoided. Select management with the least risks. Tailor management based on the age, family situation, and management options available. A general flowchart is useful to guide management decisions.
Consider and rule out nonaccidental trauma.
Early infancy Consider management in a Pavlik harness or in a spica cast. Apply the spica cast under either sedation or anesthesia. Immobilize in the human position as done in DDH management. Flex the hips and knees to about 80°. Abduct the hips to allow easy diapering. See again at about 4 weeks for cast removal. Avoid burdening the family by suggesting they restrict the infant’s activities following cast removal.
Toddler Manage in an early spica cast. Immobilize in the spica cast with the hips flexed to about 45°. Leave the feet free. If the fracture is stable, a single-hip spica is adequate. Immobilize for about 5 weeks.
Early Childhood Management — Spica Casts
Management in early childhood can be provided by early spica cast immobilization with or without initial traction.
Overgrowth corrects shortening, and the immobilization is well tolerated. Although the cast may be applied in the emergency room and the child discharged home (immediate spica), an overnight admission is usually more practical. This allows arranging a convenient time for applying the spica cast, instruction of the family in cast care, and being certain the child is comfortable in the cast before discharge.
Initial traction Apply about 2–3 pounds of longitudinal skin traction during the overnight stay. This provides adequate immobilization and alignment.
Sedation Provide sedation or a light general anesthetic when applying the cast.
Leg position Position the extremity based on the level of the fracture. The objective is to align, not reduce, the fracture. Position the limb to align the distal to the proximal fragment. This position is due to the attachment of the muscles about the femur. Proximal fractures should be immobilized with the hip in about 45° flexion, 45° abduction, and 20° external rotation (45°-45°-20°). Position midshaft fractures in about 30°-30°-10°. Position distal fractures in a more neutral position, about 20°-20°-10°. The young child may stand in the cast.
Avoid excessive shortening The major risk of early spica immobilization is excessive shortening. The amount of acceptable shortening is controversial, but falls between 1.5 and 3 cm. Consider several methods of avoiding this complication.
Resting radiograph of femur Without traction applied, measure the amount of shortening. If the shortening exceeds about 20–25 mm, consider traction treatment.
Fracture mechanism Transverse midshaft fractures secondary to high-velocity injuries are most likely to shorten excessively. Periosteal stripping and hemorrhage may cause swelling. This swelling may hold the fracture out to length. When the swelling subsides, the femur may shorten excessively.
Follow-up radiographs Make radiographs at 1–2 weeks following injury to assess length. If excessive shortening occurs, remove the cast and place the child in skin traction until union has occurred.
Duration of cast immobilization Continue immobilization for a total of 6 weeks in the child under 5 years of age and 8 weeks for children 5–10 years of age.
Post-cast care Allow spontaneous restoration of activity and mobility. Physical therapy is not necessary. Limit vigorous play for 1 month. Reevaluate the child after 6–12 months for range of motion, length, and any residual deformity.
Early Childhood Management — Traction
Traction remains an effective method of managing femoral shaft fractures. For children, traction treatment is safe and complications are uncommon. Because hospitalization is prolonged, however, traction has become less commonly used today. Increased cost is given as a reason for avoiding this treatment. When all expenses are considered, traction is about the same as for other forms of management. Prolonged inpatient management is easier for some families and more difficult for others. Tailor traction to the age and level of the fracture.
Skin traction is suitable for most children under age 8 years with most fracture patterns.
Skeletal traction is useful for the older child and those with subtrochanteric fractures that require 90°–90° positioning. Apply pin traction through a distal femur pin placed at the level of the superior pole of the patella. Insert the pin with the knee flexed to 90° to avoid binding of the iliotibial band.
Length Adjust traction weights to allow about 1 cm of shortening. Be aware that the major risk of 90°–90° traction treatment is excessive length of the fractured limb due to insufficient shortening at the time of union. Overgrowth then lengthens the limb beyond its normal length.
Duration Continue traction until early union has occurred. The callus should be nontender, and moving the leg should not be uncomfortable for the child. The duration may vary from 2 weeks in early childhood, to 3 weeks in middle childhood, and 4 weeks in late childhood. Up to 6–8 weeks is appropriate for the adolescent. Avoid the common error of discontinuing traction too soon. Premature cast application may result in the fracture angulating and shortening in the cast. This complication is usually not diagnosed early enough to correct by reinstituting traction treatment. Correction may require mobilizing the fragments, restoring length, and applying internal or external fixation.
Acceptable alignment Side-to-side apposition is best. Avoid end-to-end reduction, as union is slower and the femur is likely to be longer than the other side.
Frontal plane Align to within about 10°–20°. More deformity is acceptable in the younger patient and with more proximal fractures.
Sagittal plane Accept alignment to within 20°–30°. Because the deformity is in the plane of joint motion, more deformity can be accepted. More procurvatum and recurvatum is acceptable.
Transverse plane This is difficult to measure. Position the limb in about 10°–15° of lateral rotation in traction and the cast.
Align fractures Adjust the position of the controllable distal fragment to be in alignment with the proximal fragment.
Bryant traction This type of traction should be avoided or used with caution. Catastrophic vascular complications are a risk with this treatment.
It is an overused method of fixing femoral fractures, and complications with this fixation are frequent.
Indications for external fixation are limited.
Open fractures Open fractures and concurrent soft tissue injuries are managed effectively by external fixation because this method allows access to the soft tissue injury.
Comminuted fractures Unstable segmental fractures that would shorten excessively if managed by flexible rods provide an indication for external fixation.
Polytrauma Use external fixation when devices can be rapidly applied.
Complications with this method of management are common.
Pin tract infections are common due to the high activity of children and their lack of attention to pin care.
Delayed union is often slow, as the fracture may be reduced or distracted.
Refracture is common following removal of the fixator.
Suggestions Limit use of fixators. Instead, use techniques that cause fewer complications, such as flexible IM rods. Allow fractures to override to enhance union rate and avoid distraction. Dynamize to provide loading to enhance callus formation. Consider applying a single-hip walking spica cast after removal of fixation if the union is tenuous or the patient is uncooperative.
Flexible IM Rod Fixation
Flexible IM rods are an excellent method of fixing femoral shaft fractures. This fixation is adequate, safe, relatively easy to apply and remove, and associated with few complications. Its use is gaining enthusiasts. The technique is detailed on the next page.
Indications for flexible IM rod fixation are quite broad.
Floating knee This method provides fixation of at least one fracture.
Few complications are reported with this technique. Some children complain of discomfort over the ends of the pins if they are left prominent.
Polytrauma Complicating problems necessitate fracture stabilization at any age.