Orthopaedic Surgery - Fibula Fracture

Basics

Fibular fractures are classified anatomically as proximal, midshaft, or distal fractures.

Because the fibula participates in both the knee and ankle complexes, an apparently isolated fibular fracture may be associated with injury to the tibia, tibiofibular syndesmosis, ankle joint, or knee.

Associated Structural Injury

A truly isolated fibular fracture is relatively uncommon.

In many cases, the amount or direction of force required to fracture the fibula also injures other structures within the leg.

For this reason, examination should never be limited to the site of maximal fibular tenderness.

Distal Fibula Fractures

Fractures of the distal fibula involving the ankle are by far the most common type.

These injuries are generally considered within the broader category of ankle fractures.

Fibular Shaft Fractures

A fibular shaft fracture without an associated ankle injury is frequently accompanied by a tibial shaft fracture.

The tibia therefore must be evaluated carefully when a shaft fracture of the fibula is identified.

Proximal Fibula Fractures

Fractures involving the fibular head or neck may be associated with substantial injury around the knee.

They can occur after a direct blow or as an avulsion injury involving the insertion of the biceps femoris tendon or lateral collateral ligament (LCL).

Because the common peroneal nerve courses around the fibular neck, it is vulnerable in this region.

Maisonneuve Fracture

A Maisonneuve fracture is a proximal fibular fracture associated with disruption of the distal tibiofibular syndesmosis and medial-sided ankle injury.

It results from a rotational mechanism transmitted upward through the ankle and interosseous membrane.

Mechanism

External rotation at the ankle can injure the deltoid ligament or medial malleolus and disrupt the distal tibiofibular ligaments.

The tear may then propagate proximally through the interosseous membrane.

As the rotational force continues upward, stress becomes concentrated in the proximal fibula, producing a fracture.

Clinical Importance

A Maisonneuve fracture may be overlooked if attention is directed only to the ankle.

Conversely, a patient presenting with a proximal fibular fracture must always undergo careful examination of the medial ankle and syndesmosis.

Epidemiology

Fibular fractures, particularly those involving the distal fibula and ankle, are among the most commonly encountered fractures in orthopaedic practice.

Etiology

Common mechanisms include direct trauma, falls, missteps, sports injuries, and penetrating trauma such as gunshot wounds.

The pattern of associated injury depends on the direction and magnitude of force.

Associated Conditions

Fibular fractures may occur together with:

Tibial shaft fractures, tibial plateau fractures, leg compartment syndrome, medial or lateral collateral ligament injuries of the knee, biceps femoris tendon injury, common peroneal nerve palsy, interosseous membrane rupture, deltoid ligament injury, syndesmotic disruption, and medial malleolar fracture.

Classification

Fibular fractures may be broadly divided into:

Proximal fibula fractures, midshaft fibula fractures, and distal fibula or ankle fractures.

Management depends less on the fibular fracture alone and more on the stability of the associated knee, ankle, tibia, and syndesmosis.

Diagnosis

Signs and Symptoms

Patients with fibular head or shaft fractures commonly present with localized tenderness, swelling, and pain over the injured region.

Neurologic Symptoms

Numbness, tingling, or weakness may indicate injury to the common peroneal nerve, particularly with proximal fibular fractures.

Associated Knee Injury

If the knee has also been injured, patients may have knee swelling, instability, and pain with weight bearing or ligament testing.

Maisonneuve Injury

Patients with a Maisonneuve fracture may have tenderness and swelling over the proximal fibula together with medial ankle pain or swelling.

Ankle symptoms may be more prominent than pain at the actual fibular fracture site.

Physical Examination

Fibula

The entire fibula should be palpated for focal tenderness and swelling.

This is particularly important in patients who initially present with an ankle injury.

Ankle Examination

The ankle must always be examined for medial tenderness, instability, syndesmotic pain, and swelling.

A proximal fibular fracture combined with medial ankle tenderness should raise immediate concern for a Maisonneuve injury.

Knee Examination

The knee should be evaluated carefully in proximal fibular fractures.

Assessment should include the medial collateral ligament, lateral collateral ligament, cruciate ligaments, biceps femoris insertion, and proximal tibiofibular region.

Neurovascular Examination

Motor and sensory function of the common peroneal nerve should be documented.

Particular attention should be given to ankle dorsiflexion, toe extension, eversion, and sensation over the dorsum of the foot.

Distal vascular status should also be recorded.

Laboratory Tests

Routine serum laboratory testing is not required for an uncomplicated isolated fibular fracture.

Laboratory studies are obtained when dictated by associated trauma, planned surgery, or medical comorbidities.

Imaging

Tibia and Fibula Radiographs

AP and lateral radiographs of the entire tibia and fibula should be obtained when a shaft fracture is suspected.

This helps identify associated tibial injury and defines the complete fracture pattern.

Knee Radiographs

AP and lateral knee radiographs are useful when a proximal fibular fracture is present or when associated knee injury is suspected.

Ankle Radiographs

A standard ankle series should include AP, lateral, and mortise views.

These images help identify distal fibular fractures, medial malleolar injury, widening of the ankle mortise, and syndesmotic disruption.

Pathological Findings

Fibular fractures may be spiral, transverse, oblique, or comminuted.

The fracture configuration reflects the underlying mechanism and energy of injury.

Pathologic fractures caused by tumor are uncommon.

Differential Diagnosis

Muscle Injury

A gastrocnemius or soleus tear may produce calf pain and swelling without a fracture.

Tendon Rupture

Tendon injury, including injury around the knee or ankle, may mimic symptoms of a fibular fracture.

Syndesmotic Injury

An isolated syndesmotic sprain may cause ankle pain and instability without an obvious fracture.

Knee or Ankle Injury

Ligamentous injuries, sprains, and articular fractures around the knee or ankle should be considered depending on the location of pain and mechanism.

Treatment

General Principles

Management depends primarily on whether the fracture is isolated or accompanied by ankle instability, syndesmotic disruption, tibial fracture, knee injury, or neurovascular compromise.

Isolated Fibular Shaft Fracture

An isolated fibular shaft fracture without involvement of the ankle or knee is generally a relatively stable injury.

The fibula transmits only a minority of axial load through the leg and is surrounded by well-vascularized muscle, allowing reliable healing.

Immobilization

A splint, walking boot, or short period of casting may be used for comfort, but rigid immobilization is often unnecessary.

Symptomatic Treatment

For uncomplicated injuries, treatment may consist of rest, ice, compression, elevation, and appropriate analgesia.

Recovery

Pain and swelling commonly improve significantly within 1–2 weeks.

Activity can then be advanced according to symptoms.

Most isolated shaft fractures heal by approximately 6–8 weeks.

Weight Bearing

For an isolated stable fibular shaft fracture, weight bearing as tolerated is generally permitted.

The patient may initially use crutches and progress according to pain.

Physical Therapy

Patients with isolated shaft fractures can usually begin progressive weight bearing and motion as symptoms improve.

Physical therapy may be useful for persistent weakness, stiffness, gait disturbance, or associated injury.

Unstable Ankle Injuries

Patients with distal fibular fractures associated with ankle instability generally require restricted or non-weight bearing until sufficient healing or surgical stabilization has occurred.

Medication

Analgesic medication should be provided according to the degree of pain.

NSAIDs, acetaminophen, or short-term stronger analgesics may be used when appropriate.

Surgery

Fibula With Tibial Shaft Fracture

When a fibular fracture accompanies a tibial shaft fracture, treatment is usually directed primarily toward stabilization of the tibia.

The fibula frequently heals without separate fixation.

Tibial Plateau Fracture

Similarly, when the fibular injury accompanies a tibial plateau fracture, the principal reconstructive procedure is directed at the tibial injury unless fibular fixation is specifically needed for stability or soft-tissue reconstruction.

Distal Tibial Fractures

In selected distal tibial fractures, fixation of the fibula can assist with restoration of length, rotational alignment, and overall stability of the tibial reconstruction.

Fibular Plate Fixation

The fibula may be stabilized with a small-fragment plate, traditionally a 3.5-mm compression plate, depending on fracture pattern and surgical strategy.

Maisonneuve Fracture Treatment

Maisonneuve fractures represent an unstable rotational ankle injury and usually require operative treatment when the syndesmosis is unstable.

The key objective is restoration of the ankle mortise and anatomic reduction of the syndesmosis.

Proximal Fibula

The proximal fibular fracture itself usually does not require direct plating in a classic Maisonneuve injury.

Treatment is generally directed at the distal syndesmotic and medial ankle instability.

Medial Malleolus

If a medial malleolar fracture is present and displaced or unstable, it may require open reduction and internal fixation.

Deltoid Ligament

Direct repair of the deltoid ligament is not routinely necessary if anatomic reduction of the ankle mortise and syndesmosis restores stability.

Syndesmotic Fixation

The need for syndesmotic fixation is determined by assessment of instability, frequently using an intraoperative external rotation stress test or other fluoroscopic stress maneuver.

Screw Fixation

Syndesmotic screws have traditionally been used to stabilize the distal tibiofibular joint.

Both tricortical and quadricortical fixation techniques have been used, without clear universal superiority of one configuration.

Screw Removal

Whether syndesmotic screws should be removed routinely remains debated.

Management depends on symptoms, implant type, surgeon preference, and whether the screw breaks or limits function.

Reduction

The most important technical principle is anatomic reduction of the syndesmosis.

The exact position of the ankle during screw insertion is less important than accurate restoration of the tibiofibular relationship.

Alternative Fixation

Bioabsorbable screws and modern flexible fixation devices may be used in selected cases to avoid some of the disadvantages associated with rigid metallic screws.

Follow-Up

Referral

Patients with associated tibial fractures, unstable ankle fractures, syndesmotic injuries, significant knee injuries, or neurovascular abnormalities should be referred to an orthopaedic surgeon.

Prognosis

The prognosis is generally excellent.

Most fibular fractures heal reliably, and the majority of patients recover normal long-term function.

Outcome depends largely on the severity of associated ankle, knee, tibial, or neurovascular injury.

Complications

Nonunion

Nonunion is uncommon but may occur, especially with severe trauma, poor vascularity, or persistent instability.

Malunion

Healing in abnormal alignment may lead to persistent symptoms, particularly when the distal fibula and ankle mortise are involved.

Chronic Pain

Persistent pain may result from malunion, nonunion, syndesmotic instability, nerve injury, or associated ankle or knee pathology.

Hardware Problems

Internal fixation can lead to hardware prominence, irritation, or breakage, sometimes requiring later implant removal.

Compartment Syndrome

Leg compartment syndrome may occur, particularly when the fibular fracture accompanies substantial tibial or soft-tissue trauma.

Increasing pain, tense swelling, sensory changes, or pain with passive stretch should prompt urgent evaluation.

Patient Monitoring

Patients are generally followed clinically and radiographically until fracture union and restoration of function.

For fractures requiring surveillance, plain radiographs may be obtained approximately monthly or at similar intervals, depending on fracture type and treatment.

Follow-up should assess pain, fracture healing, ankle and knee stability, syndesmotic alignment, neurovascular status, gait, and return to activity.