The femur, or thighbone, is the longest, heaviest, and strongest bone within the human body, extending from the hip to the knee and providing the main structural support for standing and walking. A femur fracture is a break occurring anywhere along this powerful bone, almost always resulting from a significant application of force. Because of its involvement in weight-bearing and movement, a fracture to the femur severely affects a person’s mobility and requires immediate medical attention.
Classifying Femur Fractures
Femur fractures are categorized by the specific anatomical location of the break, which influences the required treatment approach. The proximal femur is the uppermost section near the hip joint, where fractures are commonly referred to as hip fractures, particularly those involving the femoral neck or the intertrochanteric area. Breaks in this region are often consequential due to the risk of disrupting the blood supply to the ball of the hip joint.
The femoral shaft constitutes the middle section of the bone, and fractures here are known as femoral shaft fractures. These breaks are further described by their pattern, such as transverse (straight across), oblique (at an angle), spiral (due to twisting), or comminuted (shattering into multiple pieces). The distal femur is the lower end of the bone that widens out to form the top of the knee joint, and breaks here are called supracondylar or condylar fractures. Distal femur fractures can sometimes extend into the knee joint itself, complicating the injury and treatment.
Common Causes of Injury
Femur fractures generally result from mechanisms categorized by the patient’s age and bone health. In younger, otherwise healthy individuals, the strength of the femur means that fractures typically result only from high-energy trauma. Motor vehicle collisions and significant falls from a height are the most frequent causes of these high-energy breaks.
Conversely, in older adults, a fracture can be sustained through a low-energy mechanism, such as a simple fall from a standing height. This vulnerability is attributed to weakened bone structure, often due to an underlying condition like osteoporosis. A less common mechanism involves repetitive stress on the bone, which can cause a non-displaced stress fracture, frequently seen in long-distance runners or military recruits.
Identifying a Femur Fracture
A femur fracture is characterized by immediate physical signs that necessitate emergency care. The patient experiences severe, immediate pain in the thigh or hip area and is almost entirely unable to bear any weight on the injured limb. Swelling and bruising around the fracture site develop rapidly due to significant internal bleeding, as the femur is a very vascular bone.
A visible deformity is common, where the leg may appear crooked or noticeably shorter than the uninjured side because of muscle pull on the broken segments. Medical confirmation of the injury begins with a physical examination, followed promptly by imaging studies. X-rays are the primary diagnostic tool used to verify the location and pattern of the break. For more complex breaks, especially near the hip or knee joint, a computed tomography (CT) scan provides detailed cross-sectional views of the fracture.
Treatment and Repair
Because of the powerful forces involved and the bone’s strength, most adult femur fractures require surgical intervention for proper alignment and healing. The goal of surgery, often termed Open Reduction and Internal Fixation (ORIF), is to restore the bone segments to their correct anatomical position and then stabilize them with specialized hardware. Early surgical stabilization is recommended to reduce complications and allow for earlier mobilization.
The standard approach for fractures of the femoral shaft is intramedullary nailing. This procedure involves inserting a long titanium rod, known as an intramedullary nail, into the hollow center of the femur, spanning the length of the fracture. The rod is secured at both ends with screws to prevent rotation and maintain alignment, providing a strong, stable internal splint for the bone as it heals. The nail can be inserted through an incision near the hip (antegrade) or near the knee (retrograde), depending on the specific fracture pattern and location.
For fractures near the ends of the femur, such as distal or highly complex breaks, plates and screws are often employed. In this method, the bone fragments are repositioned, and a metal plate is affixed to the outer surface of the bone using multiple screws to hold the pieces together. Modern locking plates are frequently used for these cases, as they offer enhanced stability, particularly in patients with poorer bone quality.
Non-surgical management, involving casting or traction, is a rare choice for adult femur fractures because it carries a high risk of poor healing and non-union. This approach is typically reserved for patients who cannot medically tolerate surgery or for specific, stable, and non-displaced fractures. Following surgical stabilization, the patient begins a period of recovery that emphasizes controlled weight-bearing and physical therapy to restore muscle strength and joint function.