Femur Fracture (Broken Thigh Bone)

First aid for a suspected broken femur

1. Call 911 or your local emergency number. Do not drive the person to the ER yourself.
2. Do not move the person unless they are in danger. Movement increases pain, bleeding and the risk of nerve or vessel damage.
3. Do not try to straighten the leg. Support it in the position found with rolled blankets or clothing on each side.
4. Control bleeding from any wound with firm pressure using a clean cloth.
5. Keep them warm and lying down to reduce the risk of shock.
6. Give nothing to eat or drink, as surgery is likely.

Paramedics often apply a traction splint, which pulls the leg gently to length, reducing pain and bleeding.

Types of femur fracture

The femur has three main regions, and fractures are named by location:

Fractures are also described by pattern: transverse (straight across), oblique (angled), spiral (from a twisting force), comminuted (in several pieces) and open (through the skin).

Atypical femur fractures

A rare type of low-energy shaft fracture is linked to long-term bisphosphonate or denosumab use for osteoporosis. It is often preceded by weeks or months of dull groin or thigh ache. Anyone on these medicines with new thigh pain should tell their doctor, who may order an X-ray of both femurs, as both sides can be affected. The overall benefit of these medicines in preventing hip fractures far outweighs this risk.

Stress fractures

Repeated high-impact training can cause a small stress fracture of the femoral neck or shaft, seen in runners and military recruits. It causes gradual groin or thigh pain with activity. A femoral neck stress fracture needs urgent attention because it can progress to a complete break.

Symptoms

• immediate, severe pain in the thigh, hip or knee
• unable to stand or walk
• swelling and bruising, which can be extensive
• a leg that looks shorter, bent or turned outward
• a grinding feeling with any movement
• numbness or tingling in the foot if nerves are injured

Diagnosis

In the ER, the trauma team first checks breathing, circulation and other injuries, since high-energy femur fractures often occur with pelvic, head, chest or abdominal injuries. They check pulses and sensation in the foot. X-rays of the whole femur, hip and knee confirm the fracture. CT scans help with fractures extending into the hip or knee joint. Blood tests look at hemoglobin, and blood may be cross-matched for transfusion.

Treatment

Surgery

Almost all adult femur fractures are treated with surgery, ideally within 24 hours, because early fixation reduces complications such as pneumonia, blood clots and fat embolism.

• Intramedullary nailing: a metal rod is passed down the hollow center of the bone and locked with screws at each end. This is the standard treatment for shaft fractures and often allows walking within days.
• Plates and screws: used for fractures near the knee or extending into the joint.
• External fixation: a temporary frame outside the leg for open fractures or severely injured patients, swapped for a rod later.

Children

Treatment depends on age. Infants and toddlers are often treated in a spica cast (a body cast from the chest to the legs). School-age children usually have flexible rods; teenagers may have rigid rods like adults. A femur fracture in a baby who is not yet walking should prompt careful assessment for non-accidental injury.

After surgery

• Pain relief with prescribed medicines, moving to over-the-counter options as pain eases.
• Blood clot prevention with injections or tablets for several weeks.
• Early mobilization: most people stand with a walker within 1 to 2 days. How much weight you may put on the leg depends on the fracture and fixation.
• Physical therapy to restore hip and knee movement, thigh muscle strength and walking.

Recovery time

Smoking, diabetes, NSAID overuse and open fractures slow healing. Some people have a limp, thigh weakness or knee stiffness for months, and occasionally discomfort from the rod.

Complications

• Blood loss and shock at the time of injury
• Fat embolism: fat from the bone marrow travels to the lungs and brain, usually 1 to 3 days after injury, causing breathlessness, confusion and a pinpoint rash
• Deep vein thrombosis and pulmonary embolism
• Compartment syndrome in the thigh
• Infection, particularly after open fractures
• Nonunion or malunion: the bone fails to heal or heals out of alignment, sometimes leaving one leg shorter
• Knee stiffness and muscle weakness

Frequently asked questions

How long does a broken femur take to heal?

The bone typically takes 3 to 6 months to heal, and full recovery of strength and walking can take 6 to 12 months. Healing is faster in children: a toddler's femur often heals in 6 to 8 weeks.

Can you walk with a broken femur?

Not before treatment: a broken femur cannot support weight. After surgery with an intramedullary rod, many people are encouraged to walk with a walker or crutches within a day or two, often bearing as much weight as is comfortable.

Is a broken femur life-threatening?

It can be. A shaft fracture can cause major internal blood loss, and high-energy accidents often cause other serious injuries. Fat embolism and blood clots are additional risks. With prompt emergency care and surgery, most people survive and recover well.

Is the rod removed after a femur fracture?

Usually not. The rod is designed to stay in permanently. It may be removed if it causes ongoing pain, irritation at the hip or knee, or infection, but only after the bone has fully healed, typically at least 12 to 18 months later.

What is the difference between a femur fracture and a hip fracture?

A hip fracture is a break in the top part of the femur, near the hip joint. "Femur fracture" covers the whole bone but usually refers to the shaft or the lower end above the knee. Hip fractures mostly affect older adults; shaft fractures are typical of high-energy trauma.