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Broken Leg

  • Overview

    Boston Children's Hospital provides expert diagnosis, treatment and care for every type and severity of broken leg in children. Read the information in the following pages to learn more about broken legs and fractures in children.

    What is a broken leg?

    A broken leg is also known as a leg fracture. Broken legs occur when there is a crack one of four bones in the leg: the femur (thigh bone), tibia (shin bone), fibula and (calf bone).

    There are different types of leg fractures in children, and they range in severity from a mild stress fracture to a severe open fracture (where the bone breaks through the skin). Broken legs can happen to people of all ages, but they are very common in children, especially those who are active. 

    Broken leg: 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 is a broken leg (leg fracture)?

    If your child has a leg fracture, it means that one of the bones in his leg has partially or completely broken. Fractures can occur in one or more of the three main bones in the leg: the femur, the tibia and (less commonly) the fibula.

    How are the bones of the leg different?

    Femur (thigh bone)

    • The femur is the largest, longest and strongest bone in your child’s body. The upper part of the femur fits into the hip joint at the pelvis. The lower part of the femur connects to the top of the tibia, forming the knee joint.
    • Because of the femur’s great strength, it tends to break only when impacted with great force. A broken femur is a serious injury.

    Tibia (shin bone)

    • The second-largest bone, the tibia supports your child’s weight. The top of the tibia is part of the knee joint at and the lower end of the tibia is part of the ankle joint.
    • A broken tibia is the most common long-bone injury.

    Fibula (calf bone)

    • The fibula is the smaller of the two lower-leg bones. The top end of the fibula serves as an attachment point for a section of the hamstrings. The lower end of the fibula forms part of the ankle joint, helping to stabilize the ankle. 
    • A “broken ankle” is a term that usually refers to a broken fibula.


    What are the causes of  broken legs in children?

    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 (mild to moderate) that happens while they’re playing and participating in sports
    • Overuse, as from repetitive sports or dance motions

    Certain risk factors may also increase a child’s chances of getting a leg fracture.

    Signs and symptoms

    What are the symptoms of a broken leg in children?

    Your child’s leg may be broken if:

    • You hear a “snap” or see a noticeable deformity
    • There is pain, swelling, bruising, redness or tenderness
    • It is painful or difficult to move the leg normally or put weight on it
    • In toddlers: a refusal to walk

    When to see a doctor

    Seek medical care immediately if your child displays any of symptoms of a broken leg.

    Do not move your child and call 911 immediately if:

    • Your child has an open fracture (the bone is visible through the skin)
    • You suspect that your child's neck or back is injured.
  • Tests

    How are broken legs in children diagnosed?

    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 non-invasive imaging technique that uses a radioactive substance to visualize the bones. It’s different from plain X-rays or CT scans in that it shows bone metabolism and cell activity in the bones.
  • Whether your child's broken leg is serious or routine, Boston Children's Hospital orthopedic experts will provide comprehensive treatment.

    Because children's bones heal more quickly than those of adults, they need prompt medical attention to ensure they heal correctly. With treatment, most kids recover completely and regain full use of their leg—sometimes in a matter of weeks with casting.

    What are the treatments for broken legs in children?

    Treatment for a broken leg depends on the location, complexity and severity of your child's break as well as his age and overall health.

    To restore your child's use of his broken leg, his doctor may recommend some combination of these treatments:

    • Splints:  because casts can be too tight and affect circulation, doctors will usually put a splint on a newly broken bone and replace it with a cast once the swelling has gone down. Splints are also used for minor fractures.
    • Casts encircle the entire bone to protect the injured area from motion or impact. Most broken bones require a cast.
    • Traction uses a gentle pulling motion to realign broken bones and reduce painful muscle spasms in the leg and arm.
    • Surgery may be needed to put broken bones back into place. A surgeon may insert metal rods or pins into the bone (internal fixation) or outside the body (external fixation) to hold bone fragments in place to allow alignment and healing.
    • Physical therapy may also be needed to strengthen the leg and help it return to full function.

    What types of casts are used to treat a broken leg?

    Some common types of casting include:

    • Short leg cast
    • Long leg cast
    • Leg cylinder cast
    • Hip spica cast
    • Abduction boot cast


                                                   Broken tibia/fibula (shin bone/calf bone), calf/shin bone cast diagram

                                                                   click to enlarge

    Type Location Uses
    Short leg cast Applied to the area below the knee to the foot Lower leg fractures, severe ankle sprains/strains, or fractures. Also used to hold the leg or foot muscles and tendons in place after surgery to allow healing
    Leg cylinder cast Applied from the upper thigh to the ankle Knee, or lower leg fractures, knee dislocations, or after surgery on the leg or knee area


                                                                       click to enlarge

    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


    Type Location Uses
    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
    Abduction boot cast Applied from the upper thighs to the feet; a bar is placed between both legs to keep the hips and legs immobilized To hold the hip muscles and tendons in place after surgery to allow healing

    How long does it take for a child's broken leg to heal?

    Healing time depends on the child's age and the type of fracture. In general, healing time for a broken leg is about three to six weeks.


    While you can't prevent your child from breaking a bone, you can help minimize the risk by taking simple precautions:

    • Avoid risky behavior that can result in falls or accidents and make sure your child wears proper sports and safety gear.
    • Make sure your child eats a healthful diet that is low in fat and high in protein, nutrients and fiber. Plenty of calcium and vitamin D are also important because they help strengthen bone. 
    • Monitor portions to help control weight, since obesity puts your child at greater risk for breaking a bone.
    • Encourage your child to get a lot of weight-bearing physical exercise.
    • Encourage your young athlete to do some cross-training to decrease the possibility of stress fractures caused by repetitive sports or dance motions.
    • Discourage prolonged time watching TV, playing computer games or other sedentary activities.
  • Research & Innovation

    Boston Children's Hospital's pioneering research in orthopedics helps provide children with the most innovative care available. Read the information below to learn more.

    Clinical research leaders in the Orthopedic Center at Boston Children’s are recognized throughout the world for their respective achievements. Our orthopedic research team includes:

    • Full-time basic scientists
    • More than 28 clinical investigators
    • A team of research coordinators and statisticians

    New trauma/ER database

    Boston Children’s has begun to track and compile data about outcomes in orthopedic ER trauma cases to help us pinpoint the best ways to treat these injuries. Among the details we’re tracking are:

    • Type and location of fractures (such as an end-of-the-radius/wrist fracture)
    • Outcome (quality improvement)
    • Did the injury require admission to the hospital
    • How was the injury initially treated

    The information gathered from this ongoing tracking study will further influence how specialists in Boston Children’s Orthopedic Trauma Program care for children by providing accurate, comprehensive tracking and outcomes data.

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