The femur, or thigh bone, is the longest, heaviest, and strongest bone in the human body, extending from the hip to the knee. Fracturing it requires a significant amount of force, typically around 4,000 Newtons in a healthy adult, meaning breaks often result from high-energy trauma like car accidents or falls from height. A femur fracture is considered a medical emergency due to the trauma involved and the potential for serious complications, requiring prompt, specialized medical attention.
Immediate Symptoms and Emergency Care
When a femur fracture occurs, the patient experiences severe, immediate pain in the thigh. This intense pain causes an inability to bear any weight on the injured leg, making standing or walking impossible. Visually, the leg may exhibit a distinct deformity, often appearing shorter than the uninjured leg and possibly rotated due to the powerful pull of the thigh muscles on the broken segments.
A major concern with this type of break is the potential for internal blood loss, as the femur is highly vascular. Internal hemorrhage into the thigh tissue can lead to the loss of up to three units of blood, potentially causing the patient to go into shock if not addressed quickly. Immediate emergency care involves calling 911 and avoiding any attempt to move the limb, which could cause further soft tissue or nerve damage. At the hospital, diagnosis is confirmed using X-rays and sometimes a CT scan, and the limb may be placed in temporary traction to maintain alignment and reduce pain while stabilizing the patient for definitive treatment.
How Femur Fractures Are Treated
Surgical intervention is the standard treatment for adult femur shaft fractures, necessary due to the instability created by the break and the pull of the surrounding powerful muscles. The goal of surgery is to realign the bone fragments and stabilize them to promote proper healing, typically performed within 24 to 48 hours after the patient’s overall medical condition is stable. The most common procedure is intramedullary nailing, which involves inserting a specialized metal rod directly into the hollow center of the femur (the medullary canal). This nail spans the length of the fracture and is secured with screws, providing robust internal support that allows for early mobilization.
For fractures that extend into the joints or are highly complex, plate and screw fixation may be used. This involves placing a metal plate along the outside surface of the bone and securing it with multiple screws. This method is chosen when the fracture pattern makes intramedullary nailing impractical or less effective. Non-surgical options, such as casting or prolonged skeletal traction, are rarely used for adult femur shaft fractures, generally reserved only for young children or patients whose medical conditions prevent surgery. In complex cases, a temporary external fixator may be applied to stabilize the injury until the patient is ready for a final internal fixation.
The Recovery and Rehabilitation Timeline
Recovery from a femur fracture requires time and commitment to rehabilitation, even after surgical fixation is complete. Initial bone healing, where a soft callus forms, typically takes about 6 to 12 weeks, but full structural healing and bone union may require 3 to 6 months or longer. During the earliest phase after surgery, the focus is on pain management, reducing swelling, and beginning gentle range-of-motion exercises for the hip, knee, and ankle joints.
The transition to putting weight on the injured leg is carefully managed by the orthopedic surgeon and physical therapist, starting with non-weight-bearing and gradually progressing. The timing depends on the fracture pattern, the stability of the surgical fixation, and radiographic evidence of healing. Physical therapy is a major component of this phase, working to restore muscle strength, improve joint flexibility, and re-establish a normal walking pattern (gait). Returning to daily activities can take 6 to 12 months, with higher-impact activities requiring up to a year, depending on the injury’s severity and dedication to the prescribed exercise program.
Specific Medical Complications
Despite successful surgical stabilization, a femur fracture carries risks of medical complications. One serious acute risk is deep vein thrombosis (DVT), where blood clots form in the deep veins of the leg, potentially due to trauma and immobilization. If a DVT breaks free and travels to the lungs, it becomes a life-threatening pulmonary embolism (PE). Another complication associated with long bone fractures is fat embolism syndrome, which occurs when fat globules from the bone marrow enter the bloodstream and travel to the lungs or brain.
Longer-term issues include problems with bone healing, such as malunion (where the bone heals in an abnormal position or rotation) or nonunion (a complete failure of the bone fragments to fuse together). Furthermore, any open fracture, where the bone penetrates the skin, carries an increased risk of infection, including osteomyelitis, a severe bone infection that requires aggressive antibiotic therapy.