What is a Femur Fracture?
The femur (thighbone) is the longest, largest and strongest bone in your body and extends from the pelvis to the knee. Due to its strength and size, the femur only fractures when it comes under great force. For example, a femur fracture can occur due to a motor vehicle crash, a fall from a significant height, or from a gunshot.
However, femur fractures are not uncommon in children (potential causes include a fall from a play structure or participation in contact sports), and even a fall from a standing position can break an elderly person’s femur. In rare cases, femur fractures in infants under a year old can be due to osteogenesis imperfecta or other medical conditions leading to bone weakness.
Types of Femur Fracture
There are several different classifications of a femur fracture. The classification depends on factors such as the direction of the break and the number of fractured parts.
The most common types of broken femur include:
- Transverse fracture: Your femur can break in different directions. If the break goes straight across your femur in a horizontal line, it is transverse.
- Oblique fracture: In this type of fracture, the break goes across your femur at an angle.
- Spiral fracture: This fracture usually occurs when there is a twisting force to the thigh, causing the fracture to spiral around your femur like stripes on a candy cane.
- Comminuted fracture: If the bone is broken into three or more pieces, it is classified as comminuted. The greater the force applied to the bone, the greater the number of bone fragments.
- Intra-articular fracture: If the fracture extends into the knee joint, damaging the cartilage, it receives this classification.
- Compound fracture: Also known as an open fracture, where pieces of your femur break through your skin, are rare. However, they have a higher risk for complications such as infections, and involve more extensive damage to the surrounding muscles, tendons, and ligaments.
Femurs can also be classified by where the break is located. A femur fracture can occur in any one of these locations:
- Proximal femur: A proximal femur fracture is also known as a hip fracture, and occurs in the top part of the thigh bone, next to the hip.
- Femoral shaft: A break anywhere along the straight part of the femur is called a femoral shaft fracture. This type of fracture usually requires a trip to the operating room.
- Distal femur: A break in the bottom part of your thigh bone is called a distal femur fracture. It can involve your knee joint and affect the cartilage and growth plates around the knee. Most distal femur fractures are treated with surgery to properly realign the bones.
- Supracondylar: A supracondylar femur fracture typically occurs when the foot is planted, and the force fractures the femur just above the knee joint.
Diagnosis of Femur Fractures
Your doctor will first discuss the specifics of how your injury occurred, and review your medical history. A physical examination will follow.
There are several different types of imaging tests your doctor may use to diagnose a femur fracture. You may receive an x-ray, magnetic resonance imaging (MRI), computed tomography scan (CT), or bone scan. X-rays are the most common way to evaluate fractures, as they provide your doctor with information about the type of fracture and where along the femur it is located.
If the fracture lines are too thin to see on an x-ray, your doctor may then order a CT scan or other imaging test to see the lines more clearly.
If the patient is a child, your doctor will also assess the growth plate at the end of the bone.
Treatment of a Femur Fracture
In most cases of a femur fracture, surgical treatment is required in order to heal properly. In very young children, a broken femur may be treated through reduction (a procedure to set the fracture) and casting.
If surgery needs to be delayed while other unstable medical conditions are stabilized, the patient’s leg may be placed in a long-leg splint. This is a temporary solution to relieve pain and keep the broken bones as aligned as possible. Your doctor may also employ traction (weights attached to a frame and pulley that hold the pieces of broken bone together and put gentle pressure on your femur) to maintain leg length.
Depending on the severity of the break, a surgeon may use one of several methods to treat a femur fracture. Typically, they will perform an ORIF (Open Reduction and Internal Fixation) surgery. If this is not possible, they will stabilize your femur with external fixation.
External fixation: This is usually a temporary treatment that gives the patient time to heal from other life-threatening injuries. In this surgery, metal pins are inserted through the skin into the fractured femur. They are secured to a frame that sits outside the skin along the thigh.
Intramedullary nailing: This is the most common method used to treat femoral shaft fractures. In this type of procedure, a surgeon makes tiny incisions into the skin and inserts specially designed nails made of titanium into the bone. A surgeon may also use an intramedullary rod. In this case, they would make an incision at the hip or knee joint to insert a rod into the canal of the femur (where the marrow is stored) for stable, full-length fixation.
You can expect to need physical therapy throughout your recovery, and pain medication may be prescribed as needed. It can take four to six months to fully recover from a femur fracture, and sometimes up to one year.