Isolated fractures of the fibular shaft are uncommon and are usually the result of a direct blow. More commonly, fibular shaft fractures occur in association with fractures of the tibia or ankle injury.
The fibula is a slender bone that lies posterolaterally to the tibia. The shaft of the fibula serves as origin for the peroneus longus, peroneus brevis, peroneus tertius, extensor digitorum longus, extensor hallucis longus, tibialis posterior, soleus and flexor hallucis longus. The interosseus membrane is the stout connection between the tibia and fibula. The vascular anatomy has been described in detail and is important for harvesting of vascularized fibular grafts.
Fibular shaft fractures are classified descriptively according to fracture pattern.
Isolated fibular shaft fracture often presents after the description of a direct blow to the lateral leg and will usually report pain and swelling. The patient may still be able to bear weight. In the absence of a direct blow, a torsional injury to the ankle should be suspected.
Physical examination will reveal swelling and tenderness to palpation over the fracture site. Thorough palpation of the entire leg should be performed with special attention to palpation of the interosseous ligament as this may be sign of a torsional injury to the ankle. Neurovascular exam should be performed. For blunt trauma, a complete musculoskeletal exam with special attention to the tibia and ankle should be perfomed.
AP and lateral radiographs of the tibia and fibula are adequate to diagnose an isolated fibular shaft fracture, however, AP, lateral and mortise views of the ankle should be reviewed if there is ankle tenderness.
Isolated fibular fractures in the absence of an associated ankle injury can be managed with appropriate pain control and weight bearing as tolerated. Immobilization for a brief period may be appropriate if it improves comfort.
Operative stabilization of the fibula may be indicated for fractures that have associated ankle injuries in which the mortise or syndesmosis are unstable.
Red Flags and controversies
There are no outcome studies of isolated fibular shaft fractures