Quantitative assessment of the vascularity of the talus with gadolinium-enhanced magnetic resonance imaging.

BACKGROUND: The purpose of this study was to quantify the various arterial contributions to the talus with use of magnetic resonance imaging (MRI).

METHODS: The arterial anatomy of the talus was studied in ten pairs of fresh-frozen cadaver limbs with use of gadolinium-enhanced MRI in addition to gross dissection following latex injection. MRI proved useful to confirm the presence of specific arterial branches in situ as well as to demonstrate the rich anastomosis network in and around the talus. We further examined the MRI studies to delineate the quantitative contribution of each of the three main arteries to the talus and to each quadrant of the talus (anteromedial [0], anterolateral [1], posterolateral [2], and posteromedial [3]).

RESULTS: The peroneal artery contributed 16.9% of the blood supply to the talus; the anterior tibial artery, 36.2%; and the posterior tibial artery, 47.0%. The contribution of the anterior tibial artery was greatest in quadrant 0, whereas the contribution of the posterior tibial artery was greatest in quadrants 1, 2, and 3. The peroneal artery did not make the greatest contribution in any quadrant.

CONCLUSIONS: In contrast to the findings in previous studies, we found that a substantial portion of the talar blood supply can enter posteriorly, which helps to explain why all talar neck fractures do not result in osteonecrosis. This finding, along with a very rich and redundant intraosseous pattern of anastomosis with contributions from all three vessels in each quadrant of the talus, may explain the low occurrence of osteonecrosis in association with talar neck fractures.