The femur is one of the largest, and strongest bones in the body. The femur is the thigh bone--it extends from the hip joint down to the knee joint. Because the femur is such a strong bone, it usually requires significant force to cause a femur fracture.
Causes of a Femur Fracture
The femur is a tremendously strong bone--in order for a femur fracture to occur, either a large force must be applied or something is wrong with the bone. In patients with normal bone strength, the most common causes of femur fractures include:
- Car accidents
- Falls from a height
Patients may also have bone that is weakened by osteoporosis, tumor, or infection. These conditions can lead to a so-called pathologic femur fracture. One type of femoral fracture caused by weakening of the bone is seen in patients taking bisphosphonate medications for treatment of osteoporosis.
Femur fractures are generally separated into three broad categories:
Proximal Femur Fractures
Proximal femur fractures, or hip fractures, involve the upper-most portion of the thigh bone, just adjacent to the hip joint. These fractures are further subdivided into different types of hip fractures that are discussed elsewhere. You can find more information about these fractures by going to one of the following pages:
Femoral Shaft Fractures
A femoral shaft fracture is a severe injury that generally occurs in high-speed motor vehicle collisions and significant falls. These injuries are often one of several major injuries experienced by a patient.
The treatment of a femoral shaft facture is almost always with surgery. The most common procedure is to insert a metal rod down the center of the thigh bone called an intramedullary rod. This procedure reconnects the two ends of the bone, and the rod is secured in place with screws both above and below the fracture. The intrameduallary rod generally remains in the bone for the life of the patient, but can be removed if it causes pain or other problems.
Other less commonly used treatments of a femur fracture include a plate and screws or an external fixator. These treatment options may have to be used if an intrameduallary rod cannot be used for some reason. In certain patients, depending on the fracture type and associated injuries, an intramedullary rod may not be an option; in these cases one of the other treatments (plate and screws, external fixator, etc.) will be selected.
Supracondylar Femur Fractures
A supracondylar femur fracture is an unusual injury to the femur just above the knee joint. These fractures often involve the cartilage surface of the knee joint, and must be treated with this cartilage injury in mind. Patients who sustain a supracondylar femur fracture are often at high risk of developing knee arthritis later in life.
Supracondylar femur fractures are more common in patients with severe osteoporosis and in patients who have previously undergone total knee replacement surgery. In these groups of patients the bone just above the knee joint may be weaker than in normal patients, and therefore more prone to fracture. Patients may also sustain a supracondylar femur fracture after high-energy injuries as described above.
The treatment of a supracondylar femur fracture is highly variable, and may utilize a cast or brace, external fixator, plate, screws, or an intramedullary rod. There are many variations to these fractures that affect the best choice for fixation of the fracture.