Orthopaedic Surgery - Femoral Shaft Fracture in the Adult

Basics

Femoral shaft fractures involve the diaphyseal portion of the femur, extending between the proximal and distal metaphyseal regions.

In otherwise normal adult bone, they usually result from high-energy trauma, including motor vehicle collisions, falls from height, pedestrian injuries, and gunshot wounds.

In osteoporotic or pathologic bone, much lower-energy mechanisms may be sufficient to cause a fracture.

Classification

Several classification systems are used to describe femoral shaft fractures.

The Winquist and Hansen classification focuses on the amount of residual cortical contact between the major proximal and distal fragments.

Winquist and Hansen Classification

Type I fractures retain more than approximately 75% cortical contact between the principal fragments.

Type II fractures retain at least approximately 50% cortical contact.

Type III fractures have less than 50% cortical contact.

Type IV fractures have essentially no cortical contact between the main fragments.

Increasing comminution generally corresponds with increasing fracture instability.

AO/OTA Classification

The AO/Orthopaedic Trauma Association classifies femoral shaft fractures as 32A, 32B, or 32C.

Type 32A fractures are simple fractures.

Type 32B fractures contain a wedge fragment.

Type 32C fractures are complex or multifragmentary injuries.

Each group is further subdivided according to fracture morphology and severity.

Prevention

Prevention includes road and pedestrian safety measures, seat-belt and vehicle safety, fall prevention, reduction of firearm-related injury, and treatment of impending pathologic fractures before complete fracture occurs.

Epidemiology

Femoral shaft fractures demonstrate a bimodal age distribution.

They are particularly common in patients younger than approximately 25 years because of high-energy trauma and in adults older than approximately 65 years because of osteoporosis and low-energy falls.

The overall incidence has been estimated at approximately 1 per 10,000 persons per year.

Risk Factors

Young adult males are particularly represented among high-energy femoral shaft injuries.

Additional associations include urban trauma exposure and alcohol or recreational drug use.

In older adults, osteoporosis and fall risk become more important contributors.

Etiology

High-Energy Mechanisms

Common mechanisms include motor vehicle collisions, pedestrian-versus-vehicle injuries, falls from significant height, and gunshot wounds.

These mechanisms should immediately raise concern for associated multisystem trauma.

Low-Energy Mechanisms

A fall from standing height or even a twisting injury may cause a femoral shaft fracture in bone weakened by osteoporosis, metastatic disease, primary bone tumor, or another pathologic process.

Associated Injuries

A femoral shaft fracture in a trauma patient should be considered a marker for potentially severe associated injury.

The entire patient must therefore be evaluated rather than focusing only on the femur.

Ipsilateral Femoral Neck Fracture

An associated ipsilateral femoral neck fracture is uncommon but clinically important.

A substantial proportion may be missed initially, particularly in high-energy trauma.

Dedicated imaging of the femoral neck should therefore be obtained when suspicion exists.

Knee Injury

Ligamentous injury of the ipsilateral knee may accompany the fracture.

Because pain and instability are difficult to assess acutely, the knee should be re-examined after femoral stabilization.

Other Orthopaedic Injuries

Associated injuries may include pelvic fractures, spinal fractures, lower-leg trauma, foot injuries, acetabular fractures, and other fractures of the ipsilateral extremity.

Diagnosis

Signs and Symptoms

The affected thigh is usually painful, swollen, shortened, and deformed.

The patient is typically unable to bear weight.

Blood Loss

An isolated femoral shaft fracture can produce substantial internal hemorrhage into the thigh.

Average blood loss may exceed 1,200 mL, and significant blood loss can contribute to hemorrhagic shock.

Open Fracture

Approximately 5–10% of femoral shaft fractures are open injuries.

Any wound near the thigh should therefore be carefully examined for communication with the fracture.

History

Understanding the mechanism of injury is essential because it helps predict associated injuries and the likelihood of occult fractures elsewhere.

High-energy mechanisms should prompt comprehensive trauma evaluation.

Physical Examination

Trauma Survey

The examination begins with the principles of the Advanced Trauma Life Support primary survey, addressing airway, breathing, circulation, disability, and exposure before definitive management of the limb.

Life-threatening injuries take priority over the femoral fracture.

Neurovascular Examination

The neurovascular status of the entire lower extremity should be carefully examined and documented.

Distal pulses, capillary refill, motor function, and sensation should be recorded.

Hip Examination

The hip must be assessed for an associated femoral neck or acetabular injury.

Because an occult femoral neck fracture may be subtle, imaging is essential in high-energy injuries.

Knee Examination

The knee should be inspected and palpated for associated injury.

A formal ligamentous examination is best performed after the femoral fracture has been stabilized and pain is better controlled.

Laboratory Tests

Trauma and preoperative laboratory studies should be obtained according to injury severity.

These commonly include a complete blood count, metabolic panel, coagulation studies when appropriate, and blood type and cross-match.

Hematocrit and Hemoglobin

Serial hemoglobin or hematocrit measurements may be required because significant blood loss can occur into the thigh even without external hemorrhage.

Imaging

Femur Radiographs

Full-length AP and lateral radiographs of the entire femur, including the hip and knee, should be obtained.

This avoids missing associated injuries at either end of the bone.

Femoral Neck Imaging

An internal-rotation hip view or dedicated CT may be used to evaluate the ipsilateral femoral neck when an occult fracture is suspected.

Trauma Imaging

Depending on the mechanism and examination, cervical spine, chest, and pelvic imaging may also be required as part of the trauma assessment.

Contralateral Femur

Full-length radiographs of the opposite femur may be useful in highly comminuted or long-oblique fractures because they provide a reference for normal limb length and rotation.

Pathological Findings

Femoral shaft injuries commonly involve bone, surrounding muscle, and fascial tissues.

The femoral artery and sciatic nerve are rarely injured in blunt shaft fractures but may be damaged in penetrating trauma.

Pathologic Fracture

A pathologic cause should be suspected when a fracture occurs with little or no trauma, when pain was present before the fracture, or when radiographs demonstrate a destructive or permeative bone lesion.

Evaluation of Suspected Pathologic Fracture

When malignancy or another pathologic process is suspected, staging evaluation may include imaging to identify additional skeletal lesions and cross-sectional imaging of the chest, abdomen, and pelvis.

Definitive fixation should be planned only after the underlying diagnosis has been appropriately considered.

Initial Stabilization

Life-Threatening Injury

Airway, breathing, and major hemorrhage must be treated first.

Resuscitation may require intravenous fluids and blood products.

Limb Splinting

Temporary stabilization with an appropriate traction or long-leg splint can reduce pain, limit motion, and help control bleeding from the fracture.

Open Fractures

Open fractures require prompt intravenous antibiotics, sterile dressings, tetanus assessment, and urgent irrigation and debridement.

Analgesia

Adequate opioid or multimodal analgesia should be provided while monitoring respiratory and hemodynamic status.

General Treatment Principles

Most adult femoral shaft fractures are treated operatively with intramedullary nailing.

This allows reliable alignment, high union rates, and early mobilization.

Damage-Control Orthopaedics

In severely injured or physiologically unstable polytrauma patients, immediate definitive intramedullary nailing may not be appropriate.

A damage-control strategy may instead be used.

Temporary External Fixation

In patients with major hemorrhage, severe chest injury, shock, or a high systemic injury burden, the femur may initially be stabilized with external fixation.

This reduces fracture motion while limiting the additional physiologic stress of a prolonged definitive procedure.

Delayed Definitive Fixation

Once the patient has been adequately resuscitated and the initial systemic inflammatory response has stabilized, the external fixator can be exchanged for definitive fixation.

Activity Before Definitive Fixation

Before stabilization, the patient is generally restricted to bed rest.

If operative fixation must be delayed, skeletal traction may be used selectively.

Nursing Care

Pressure-Injury Prevention

Care should be taken to prevent pressure injuries involving the heels, sacrum, and buttocks, especially in patients immobilized before surgery.

Traction Pin Care

If skeletal traction is used, traction-pin sites should be monitored for skin pressure, infection, and osteomyelitis.

Physical Therapy

Rehabilitation should begin early after stabilization.

Therapy focuses on restoring hip, knee, and ankle motion, lower-extremity strength, gait, and overall mobility.

Medication

Analgesic therapy is required throughout the acute and postoperative period.

Multimodal pain control is preferred when appropriate to reduce excessive opioid use.

Surgery

External Fixation

External fixation is primarily used for damage-control stabilization in unstable polytrauma patients, severe open fractures, and fractures associated with vascular injury.

It may also be used temporarily when the soft tissues or systemic condition do not permit definitive internal fixation.

Plate Fixation

Plate fixation is rarely the first choice for a routine adult femoral shaft fracture.

It may be appropriate in selected situations, including some periprosthetic fractures with a well-fixed implant or fractures unsuitable for intramedullary nailing.

Intramedullary Nailing

Antegrade Nailing

Reamed antegrade intramedullary nailing is the standard treatment for most adult femoral shaft fractures.

The nail is inserted proximally and spans the fracture to provide load-sharing fixation.

Advantages

Intramedullary nailing provides excellent alignment and stability while preserving much of the surrounding soft-tissue blood supply.

It also permits early mobilization and, in many cases, early weight bearing.

Retrograde Intramedullary Nailing

A retrograde nail is inserted from the distal femur and advanced proximally.

It may be particularly useful in selected fracture patterns or polytrauma situations.

Indications

Potential indications include distal femoral shaft fractures, ipsilateral acetabular fractures, bilateral femoral shaft fractures, and situations in which proximal access for antegrade nailing is difficult.

It may also be useful in selected obese patients.

Ipsilateral Femoral Neck Fracture

When a femoral neck fracture is present on the same side, fixation strategy must be carefully planned because preservation and stabilization of the femoral neck are critical.

Follow-Up

Weight Bearing

Many patients can begin early weight bearing after stable intramedullary fixation, depending on fracture pattern, fixation quality, and associated injuries.

Rehabilitation

Physical therapy should emphasize gait training, restoration of hip and knee range of motion, and progressive strengthening.

Prognosis

Approximately 95% of femoral shaft fractures unite successfully without major complication when appropriately treated.

Union rates are particularly high after modern intramedullary nailing.

Complications

Pulmonary Complications

Fat embolization and pulmonary complications may occur after severe femoral trauma.

In critically injured polytrauma patients, intramedullary instrumentation can contribute to an additional inflammatory insult.

Patients with major chest or head trauma require particularly careful perioperative management.

Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome may occur as part of severe trauma, fat embolism, systemic inflammation, or pulmonary injury.

The risk is greatest in critically injured patients with multiple injuries.

Nonunion

Nonunion is relatively uncommon.

When it occurs after intramedullary nailing, exchange nailing is a commonly successful treatment.

Malunion

Rotational malalignment and limb-length discrepancy are recognized complications, particularly with highly comminuted fractures.

Rotational Deformity

Clinically important rotational malalignment may alter gait and limb mechanics.

Rotational errors greater than approximately 15° may warrant correction when symptomatic or functionally significant.

Limb-Length Discrepancy

Length differences greater than approximately 2 cm may be clinically important and should be evaluated for possible correction.

Vascular Injury

Major vascular injury is uncommon in closed femoral shaft fractures.

It is more likely after penetrating trauma or severe open injuries.

Nerve Injury

Primary sciatic or other major nerve injury is also uncommon.

However, positioning-related nerve injuries may occur during surgery.

Pudendal Nerve Palsy

Pudendal nerve palsy has been reported after prolonged pressure from the perineal post on a fracture table.

Careful padding and limiting traction time reduce this risk.

Heterotopic Ossification

Heterotopic ossification may develop around the proximal femur after antegrade nailing.

It is particularly associated with severe trauma and concomitant head injury.

Thigh Compartment Syndrome

Compartment syndrome of the thigh is uncommon but potentially limb threatening.

It can develop before or after surgery and requires urgent recognition and decompression.

Patient Monitoring

Postoperative monitoring should include repeated neurovascular examinations and assessment for increasing pain, swelling, tense compartments, or other signs of compartment syndrome.

Radiographic Follow-Up

Serial radiographs are generally obtained approximately every 6–8 weeks until clear bony union is demonstrated.

Imaging should assess alignment, callus formation, implant position, fracture healing, limb length, and evidence of hardware failure or nonunion.