Your thighbone (femur) is the longest and strongest bone in your body. Because the femur is so strong, it usually takes a lot of force to break it. Motor vehicle collisions, for example, are the number one cause of femur fractures.
The long, straight part of the femur is called the femoral shaft. When there is a break anywhere along this length of bone, it is called a femoral shaft fracture. This type of broken leg almost always requires surgery to heal.
Femur fractures vary greatly, depending on the force that causes the break. The pieces of bone may line up correctly (stable fracture) or be out of alignment (displaced fracture). The skin around the fracture may be intact (closed fracture) or the bone may puncture the skin (open fracture).
Doctors describe fractures to each other using classification systems. Femur fractures are classified depending on:
The most common types of femoral shaft fractures include:
Transverse fracture. In this type of fracture, the break is a straight horizontal line going across the femoral shaft.
Oblique fracture. This type of fracture has an angled line across the shaft.
Spiral fracture. The fracture line encircles the shaft like the stripes on a candy cane. A twisting force to the thigh causes this type of fracture.
Comminuted fracture. In this type of fracture, the bone has broken into three or more pieces. In most cases, the number of bone fragments corresponds with the amount of force needed to break the bone.
Open fracture. If a bone breaks in such a way that bone fragments stick out through the skin or a wound penetrates down to the broken bone, the fracture is called an open or compound fracture. Open fractures often involve much more damage to the surrounding muscles, tendons, and ligaments. They have a higher risk for complications—especially infections—and take a longer time to heal.
Femoral shaft fractures in young people are frequently due to some type of high-energy collision. The most common cause of femoral shaft fracture is a motor vehicle or motorcycle crash. Being hit by a car while walking is another common cause, as are falls from heights and gunshot wounds.
A lower-force incident, such as a fall from standing, may cause a femoral shaft fracture in an older person who has weaker bones.
A femoral shaft fracture usually causes immediate, severe pain. You will not be able to put weight on the injured leg, and it may look deformed—shorter than the other leg and no longer straight.
It is important that your doctor know the specifics of how you hurt your leg. For example, if you were in a car accident, it would help your doctor to know how fast you were going, whether you were the driver or a passenger, whether you were wearing your seat belt, and if the airbags went off. This information will help your doctor determine how you were hurt and whether you may be hurt somewhere else.
It is also important for your doctor to know if you have any other health conditions, such as high blood pressure, diabetes, asthma, or allergies. Your doctor will also ask you if you use tobacco products or are taking any medications.
After discussing your injury and medical history, your doctor will do a careful examination. He or she will assess your overall condition, and then focus on your leg. Your doctor will look for:
After the visual inspection, your doctor will feel along your thigh, leg, and foot looking for abnormalities and checking the tightness of the skin and muscles around your thigh. He or she will also feel for pulses. If you are awake, your doctor will test for sensation and movement in your leg and foot.
Imaging tests will provide your doctor with more information about your injury.
X-rays. The most common way to evaluate a fracture is with x-rays, which provide clear images of bone. X-rays can show whether a bone is intact or broken. They can also show the type of fracture and where it is located within the femur.
Computerized tomography (CT) scans. If your doctor still needs more information after reviewing your x-rays, he or she may order a CT scan. A CT scan shows a cross-sectional image of your limb. It can provide your doctor with valuable information about the severity of the fracture. For example, sometimes the fracture lines can be very thin and hard to see on an x-ray. A CT scan can help your doctor see the lines more clearly.