Is the fibula necessary for ambulation?

Is the Fibula Necessary for Ambulation?

No, the fibula is not strictly necessary for ambulation—patients can walk after fibular resection or amputation, though the fibula does contribute to mechanical stability and optimal gait when intact.

Role of the Fibula in Weight-Bearing and Stability

The fibula is not a primary weight-bearing bone, but it does provide important mechanical contributions:

• The fibula contributes approximately 10-17% to load transmission at the ankle and provides lateral stability to the knee and ankle joints 1
• In tibial plateau fractures, an intact fibula reduces interfragmentary movement by approximately 30% compared to absence of the fibula, suggesting it provides meaningful mechanical stabilization 1
• The proximal tibiofibular joint contributes to stability of the lateral tibial plateau, particularly under loading conditions 1

Evidence from Fibular Resection and Reconstruction

Multiple lines of evidence demonstrate that ambulation is possible without the fibula:

• Patients undergoing fibular free flap harvest (where the fibula is removed for reconstruction elsewhere) can ambulate early and achieve functional independence 2
• Early ambulation after fibular free flap surgery without boot placement is associated with improved mobility outcomes, shorter hospital stays, and higher rates of discharge to home rather than skilled nursing facilities 2
• In vascularized fibula flap reconstructions for extremity defects, all lower extremity and trunk patients were able to ambulate postoperatively, with mean time to ambulation without assistance of 8 months in pelvic reconstructions 3, 4

Clinical Implications for Fracture Management

The fibula's role becomes more nuanced in fracture scenarios:

• In tibial pilon fractures with associated fibular fractures, routine fibular fixation is not necessary if primary stability can be achieved with tibial fixation alone 5
• There were no statistically significant differences in mechanical complications (malunion, delayed union, nonunion, or implant failure) between patients with and without fibular fixation in tibial pilon fractures 5
• However, fibular fixation should be considered when it aids in reduction or provides additional stability to the overall construct 5

Functional Outcomes and Assistive Devices

When ambulation is compromised (whether from fibular absence or other pathology), multiple supportive interventions exist:

• Assistive devices including canes, walkers, and ankle-foot orthoses (AFOs) can compensate for stability deficits and improve ambulatory function 6
• Single-point canes, quad canes, and walkers increase the base of support and reduce balance requirements for walking 6
• AFOs have demonstrated favorable impact on walking speed, step/stride length, balance, ankle kinematics, and energy cost 6

Key Clinical Considerations

The fibula is not essential for ambulation, but its presence optimizes mechanical stability and gait efficiency. When the fibula must be removed or is fractured:

• Early mobilization protocols can be safely implemented 2
• Assistive devices and orthoses can compensate for stability deficits 6
• In fracture scenarios, the decision to fix the fibula should be based on whether it contributes to overall construct stability rather than being performed routinely 5
• Patients can achieve functional ambulation and good quality of life outcomes even after fibular resection, though some may have a mild limp 3, 4