Femur, the thighbone, is the strongest, longest and heaviest bone in the human body. The straight part of the femur is called the shaft. A femoral shaft fracture is a break that occurs along this long, central portion of the thighbone. These fractures are typically the result of high-energy trauma, such as motor vehicle accidents, falls from significant heights, or sports-related injuries.
Not all femoral shaft fractures are caused by such dramatic events. In older adults, low energy trauma—like a simple fall from standing height—can lead to shaft fractures, especially when bone mineral density is reduced due to conditions like osteoporosis. Pathologic fractures may also occur when the femoral shaft is weakened by diseases such as cancer or infection, making it more susceptible to breaking even with minimal force.
Additionally, stress fractures can develop over time from repetitive activities that place continuous strain on the femur shaft, such as long-distance running. In some cases, a combination of factors, such as a pre-existing bone condition and a traumatic event, can contribute to the occurrence of femoral shaft fractures.
Your Guide to Femoral Shaft Fractures
Types of Femur Shaft Fractures
The type of femur shaft fracture depends on the amount and direction of force applied to the bone, as well as the cause of injury. Fractures are classified based on their location, the pattern of the break, and whether the surrounding muscle and skin are damaged.
Common types of femur shaft fractures include:
- Oblique fracture: a diagonal break across the bone, usually caused by an angled impact.
- Transverse fracture: A straight, horizontal break across the bone, often resulting from a direct blow.
- Comminuted fracture: The bone is shattered into three or more pieces, typically due to high-impact trauma.
- Spiral fracture: The break wraps around the bone, caused by a twisting or rotational force.
- Open (compound) fracture: The broken bone pierces the skin, creating a high risk of infection.
Causes
Some of the common causes of femoral shaft fractures are:
- High-impact collision
- Motor vehicle accidents
- Gunshot wounds
- Fall from a height
- Fall on hard surface in old age, as the bone grows weak
- Osteoporosis
Symptoms
Some of the symptoms that occur due to femur shaft fracture include:
- Severe and sharp pain
- Inability to put weight on the injured leg
- Swelling
- Bruising
- Pain on touching the thigh that worsens with movement
- Deformity
- Numbness in the thigh, lower leg, ankle, foot, knee
Diagnosis
To diagnose a femur shaft fracture, the orthopedic physician begins by examining the injury and the affected thigh. Determining the cause of the injury helps guide treatment decisions and identify any possible related injuries.
The doctor reviews the patient’s medical history, including existing health conditions such as asthma, diabetes, or high blood pressure, and asks about any medications the patient is currently taking. A physical examination follows, checking for bruising, open wounds, visible bone fragments, and leg deformity. The physician also assesses sensation and movement in the leg to evaluate nerve and muscle function.
Imaging tests are then used to confirm the diagnosis and assess the extent of the injury. Common imaging methods include X-rays, CT scans, and MRI.
X-rays and CT scans help visualize fracture lines, determine the pattern and alignment of the break, and detect associated injuries in nearby areas such as the distal femur, proximal femur, femoral neck, or knee joint.
MRI is especially useful for identifying subtle or insufficiency fractures, femoral neck fractures, and intertrochanteric fractures that may not be visible on standard X-rays.
Because femoral neck fractures can sometimes occur alongside femoral shaft fractures and may be missed in early imaging, careful evaluation is essential. Ongoing imaging is also important to monitor fracture healing, alignment, and progression over time.
Treatment
The femur shaft, also known as the diaphysis, forms the long, straight portion of the thighbone stretching from the hip to the knee. This section of the femur is composed primarily of dense cortical bone, which gives the femoral shaft its remarkable strength and ability to withstand significant forces. Encased within this sturdy outer layer is the bone marrow, a vital tissue that plays a key role in the healing process of femoral shaft fractures by producing new blood cells and aiding in bone repair. The smooth, cylindrical shape of the femur shaft not only supports the body’s weight but also provides an ideal surface for surgical fixation when treating femoral shaft fractures.
The femur shaft treatment includes both surgical and non-surgical treatment. Although femur shaft fractures often require surgery due to the severity of the injury, children may sometimes be treated with a cast instead, as their bones heal more quickly and effectively.
An open (compounded) fracture exposes the bone and surrounding tissue to the external environment, increasing the risk of serious infection. For this reason, prompt surgical intervention is essential to clean the wound, prevent infection, and stabilize the fracture.
The orthopedic surgeon aligns the bone straight with the help of skeletal traction or long-leg splint. They may even use metal pins and screws into the bone. The pins are attached to a metal bar, which assists in keeping the leg in position. Besides this external fixation, the surgeons also use intramedullary nailing, which involves inserting a metal rod into the marrow of the femur. Plates and screws are also used. After external fixation, external fixators and external fixator devices are often used as temporary treatment in patients with multiple injuries or when immediate surgery is not possible.
Most femur fractures and most femur bones are treated with intramedullary nailing, but plate fixation may be used for distal femoral fractures or fractures extending into the knee joints. Achieving proper fracture alignment and a stable fracture is important for optimal fracture healing. Delayed fracture healing can occur, especially if blood flow from the deep femoral artery is compromised, or if there is vascular injury. There is also a risk of bone infection, compartment syndrome, and acute respiratory distress syndrome as potential complications of femoral shaft fractures, especially in cases of open fracture or multiple injuries.
Physical and occupational therapy play a key role in rehabilitation after femoral shaft fracture surgery. Femoral shaft fractures are a type of long bone fracture. Broken bones in this region require careful management to restore function. Trauma acute care surgical teams are often involved in the management of complex femoral shaft fractures, especially when there are associated injuries or polytrauma. Lower energy trauma can cause femoral shaft fractures in elderly patients, and these injuries may be associated with osteoporosis or pathologic fractures. Bone joint surgical techniques are important in the operative management of femoral shaft fractures, especially when the fracture extends into the hip or knee joint.
