There are different treatment methods used for femur (thigh bone) fractures depending on the child’s age, location and severity of the fracture, need for traction or surgery, and so on.
The American Academy of Orthopaedic Surgeons (AAOS) has recommended the use of the double-leg cast called a spica cast for diaphyseal (shaft or long part of the bone) fracture of the femur. To prevent movement and allow the bone to heal, the spica cast is used most often. This type of cast starts at the waist and goes all the way down to the toes.
A single leg cast can be used in some situation. This type of cast ends above the hip on the uninjured side and leaves the uninjured leg free to move. The double leg cast immobilizes the injured leg from waist to toes and covers the other hip down to just above the knee. By anchoring both hips and thighs, better control over the fracture site is possible.
The ages of children who would benefit most from spica cast treatment for are between six months and five years old. This approach is actually referred to as “best practice” medicine based on available evidence. Cast immobilization avoids surgery with anesthesia, scarring, and the possibility of complications.
Surgeons recognize that even casting has its downside. Skin problems can develop under the cast. Too much pressure can cause swelling causing a compartment syndrome. And, of course, caring for a child in such a bulky cast is no easy task. Transporting the child in the car seat or car, toileting, and lifting and carrying the child are some of the challenges the family members or caretakers face.
Children with shortening of the bone due to the fracture will require reduction
(restoring the length of the bone) before casting. More than 25 mm of shortening should not be put in a cast until reduction has been done. Surgeons evaluate each individual child when making the decision about treatment. You can certainly bring this question up next time you see the surgeon and find out why the double-leg cast was required. There is likely one or more reasons why this was the recommended treatment.