Delayed union of fibular fractures accompanying fractures of the tibial shaft.

Among 440 adult patients with tibial shaft fracture and accompanying fibular fracture there were eight cases with radiographically ununited fibulae 4 months after the injury, each with uneventful tibial union. Fractures with severe soft-tissue injuries were excluded from this study. In 293 patients the treatment method of the tibial fracture was conservative, comprising closed reduction and immobilization by long plaster cast. In 147 patients it was intramedullary Küntscher nailing, and all the eight cases with delayed fibular union occurred among these, the frequency being 5.4%. The typical accompanying fibular fracture to develop delayed union was a comminuted one in the middle or distal third of the bone. At a followup examination 5 to 8 years after the original injury four of the eight fractures were found to have ultimately spontaneously united, while three showed a radiographically indisputable nonunion. One patient had undergone segmental fibular ostectomy because of persistent local pain but in the remaining patients the subjective symptoms were negligible. The occurrence of delayed fibular union in association with rigid intramedullary nailing of concomitant tibial shaft fracture is a phenomenon of which trauma surgeons should be aware even if the natural course of the condition often seems to be benign.