Vascular anatomy of the tibiofibular syndesmosis.

Background: Injuries to the tibiofibular syndesmosis commonly cause prolonged ankle pain and disability. Syndesmotic injuries are associated with slower healing rates compared with rates for other ankle ligament injuries and typically result in longer time away from sports. To our knowledge, the vascular supply to the syndesmosis and its clinical implication have not previously been studied. The purpose of this study was to describe the vascular supply to the tibiofibular syndesmosis with use of a method of chemical debridement of cadaveric specimens.

Methods: Twenty-five matched pairs of adult cadaver legs, fifty legs total, were amputated below the knee. India ink, followed by Ward Blue Latex, was injected into the anterior tibial, peroneal, and posterior tibial arteries under constant manual pressure to elucidate the vascular supply of the ankle syndesmotic ligaments. Chemical debridement was performed with 6.0% sodium hypochlorite to remove soft tissue, leaving bones, ligaments, and casts of the vascular anatomy intact. The vascular supply to the syndesmosis was evaluated and recorded.

Results: The anterior vascularity of the syndesmosis was clearly visualized in forty-three of fifty specimens. The peroneal artery supplied an anterior branch (the perforating branch) that perforated the interosseous membrane, an average of 3 cm proximal to the ankle joint. This branch provided the primary vascular supply to the anterior ligaments in twenty-seven specimens (63%). The anterior tibial artery provided additional contribution to the anterior ligaments in the remaining sixteen specimens (37%).

Conclusions: The location of the perforating branch of the peroneal artery places it at risk when injury to the syndesmosis extends to the interosseous membrane 3 cm proximal to the ankle joint. In the majority of specimens, injury to this vessel would result in loss of the primary blood supply to the anterior ligaments.