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Broken Femur (Thigh Bone)

  • Overview

    What is a broken femur?

    A broken femur (thigh bone) is a break in your child’s longest, largest, heaviest and strongest bone. The femur makes normal standing and walking possible. Although it’s a difficult bone to break, femur fractures in childhood are not uncommon.

    Because of the femur’s great strength and size, fractures tend to occur only when the bone is hit with a very strong force. Femur fractures are serious injuries but most can heal without surgical treatment.

    Broken femur: Reviewed by Travis H. Matheney, MD, MLA
    © Boston Children’s Hospital, 2012

    Boston Children's Hospital
    300 Longwood Avenue
    Fegan 2
    Boston MA 02115


  • In-Depth

    What differentiates the femur from the other bones in a child’s leg?

    The leg extends from the pelvis to the knee (thigh) and from the knee to the ankle (lower leg). The leg has three long bones—the femur, tibia and fibula—as well as a fourth bone, the patella, also known as the kneecap.


    What are the different types of fractures?

    Learn more about common fractures in children.

    One way to classify fractures in the femur is by the location of the break. A femur fracture can occur at several places in this long bone, including:

    • Proximal femur fracture (hip fracture):a break in the uppermost part of thigh bone next to the hip joint.
    • Femoral shaft fracture: a break in the bone shaft. This type of fracture is very serious and almost always requires surgical correction.
    • Supracondylar femur fracture: a break just above the knee joint. This type of fracture is an uncommon break, especially in children.
    • Distal femur fracture: a break in the top part of the knee joint.  A distal femur fracture can extend into the knee joint and disturb knee cartilage and growth plates. If the bone pierces through the skin (open fracture) there is a high chance that there will be damage to the muscles, tendons and ligaments.


    What causes broken femurs?

    A bone break happens when there’s more force applied to the bone than it can absorb. These breaks in bones can occur from falls, trauma or a direct blow.

    Most childhood fractures result from:

    • Falling, as from stairs or jungle gym
    • Trauma (moderate to severe) that may happen in a car accident or while they’re participating in contact sports.

    Femur fractures in infants (0-1 year old) are unusual, but can occur:

    • In babies born with a condition that causes weak bones, such as osteogenesis imperfecta
    • Following a very difficult delivery
    • In cases of child abuse

    Certain risk factors may also increase a child’s chances of breaking a femur. 

    Signs and symptoms

    The signs and symptoms of a broken femur in children include:

    • Pain or swelling in the thigh, possibly with bruising
    • Difficulty moving the leg
    • Inability to stand or walk
    • Deformity (abnormal shape) of the leg
    • In severe fractures, the bone may come through the skin and be visible.
  • Tests

    At Boston Children’s Hospital, the first step in treating broken legs in children is to form an accurate and complete diagnosis.

    A doctor will use different diagnostic tests to get detailed images of your child’s fracture. Typical tests include:           

    • X-raya diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones and organs onto film; usually sufficient for the majority of fractures.
    • Magnetic resonance imaging(MRI): a diagnostic procedure that uses a combination of large magnets, radiofrequencies and a computer to produce detailed images of organs and structures within the body.
    • Computed tomography scan (CT, CAT scan): a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body.
    • Bone scan: a painless  procedure that uses a radioactive substance to detect changes in joints and bones and determine the cause of unexplained pain
  • How are broken femurs in children treated?


    Non-surgical treatment

    Closed reduction surgery

    • Closed reduction surgery is a non-surgical procedure used to reduce and set the fracture. Using an anesthetic (typically given through an IV), the doctor realigns the bone fragments from outside the body and holds it in place with a spica cast.


    • After surgical treatment for a broken femur, children are usually put in a spica cast, which extends from mid-chest down the length of the affected leg and halfway down the other leg.
    • After a cast is removed, the child may need a special brace and physical therapy exercises to strengthen the muscles and regain flexibility in the joints.
    Type Location Uses
    Unilateral hip spica cast Applied from the chest to the foot on one leg

    Thigh fractures.Also used to hold the hip or thigh muscles and tendons in place after surgery to allow healing.

    One and one-half hip spica cast Applied from the chest to the foot on one leg to the knee of the other leg. A bar is placed between both legs to keep the hips and legs immobilized.

    Thigh fractures. Also used to hold the hip or thigh muscles and tendons in place after surgery to allow healing.

    Bilateral long leg hip spica cast Applied from the chest to the feet. A bar is placed between both legs to keep the hips and legs immobilized.

    Pelvis, hip, or thigh fractures. Also used to hold the hip or thigh muscles and tendons in place after surgery to allow healing.


     Click to enlarge

    Short leg hip spica cast Applied from the chest to the thighs or knees. To hold the hip muscles and tendons in place after surgery to allow healing.



    Since non-surgical treatment of a broken femur is generally ineffective for a child once they can walk, the following surgeries may be needed to put broken bones back into place:

    • Internal fixation: In severe or complicated fractures, a surgeon may insert metal rods or pins into the femur to hold the fractured bone in place while it heals.
    • External fixation: If internal fixation is not an option, metal pins can be put through skin into the fractured bone. These pins are attached to a bar that sits outside the skin on the child's thigh. The pins and bar hold bone fragments in place to allow for alignment and to help the bone heal.
    • Intramedullary nails or rods: For children who are older than 5 but don't yet have mature “adult” bones, the surgeon can make small incisions in the skin and insert flexible nails into the bone using miniaturized surgical tools and cameras. This type of procedure, known as “minimally invasive surgery” (MIS), results in less pain, less scarring and a quicker recovery time. These flexible nails realign the bone and hold it in place while still allowing growth and natural remodeling. This allows the child to begin walking right away.
    • In adolescence through adulthood, a rigid nail may be inserted. This also allows the patient to walk immediately.
    • Both flexible and rigid nails can either remain in place permanently or be removed.
  • Research & Innovation

    For more than a century, orthopedic surgeons and investigators at Boston Children's Hospital have played a vital role in the field of musculoskeletal research, pioneering treatment approaches and major advances in the care and treatment of ailments such as scoliosis, polio, tuberculosis, hip dysplasias and traumas to the hand and upper extremities.

    Our pioneering research helps answer the most pressing questions in pediatric orthopedics today—providing children with the most innovative care available.

    Orthopedic basic science laboratories

    Working in our labs are some of the leading musculoskeletal researchers in the nation. These labs include:

    • Orthopedic basic science research
    • Center for the study of genetic skeletal disorders
    • Sports Medicine research laboratory
    • Bone cell biology laboratory
    • Matthew Harris laboratory
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