Restoration of Ankle Stability After Complete Traumatic Loss of the Distal Fibula Using Peroneus Brevis Tendon Reconstruction Without Osseous Reconstruction.

The distal fibula plays a key role in ankle stability by forming the ankle mortise and serving as the attachment site for the lateral ligament complex. Traumatic loss of the distal fibula is extremely rare and is associated with ankle instability, valgus deformity, and eventual arthritis if not addressed. We report the case of a 34-year-old female who sustained a high-energy open injury with complete loss of the distal fibula, disruption of the lateral ligament complex, and a comminuted distal tibial fracture following a road traffic accident. Initial management included emergency debridement, application of a joint-spanning external fixator, and serial vacuum-assisted closure (VAC) dressings. Definitive treatment involved intramedullary tibial nailing with tricortical iliac crest bone grafting, reconstruction of the lateral ligament complex using a peroneus brevis tendon split without osseous reconstruction of the distal fibula, and soft-tissue coverage with a gracilis free flap. At two-year follow-up, the patient was pain-free, demonstrated no clinical or radiographic signs of ankle instability, and had returned to full activity without functional limitations. Lateral ligament reconstruction using the peroneus brevis tendon can provide satisfactory ankle stability and function even in the absence of distal fibular reconstruction, when combined with appropriate bony stabilization and soft-tissue coverage. Long-term follow-up is necessary to monitor for potential late degenerative changes.