Vascular perfusion of the long dorsal arm versus chevron osteotomy: a cadaveric injection study.

Iatrogenic disruption of the first metatarsal head's blood supply after a distal osteotomy may lead to adverse events such as delayed union or avascular necrosis of the capital fragment. In this cadaveric study, 2 types of distal first metatarsal osteotomies were performed on 7 fresh-frozen specimens (long dorsal arm osteotomy, N = 4; chevron osteotomy, N = 3). For each specimen, the respective osteotomy was created. The dorsalis pedis artery was cannulated at the midfoot level and infiltrated with methylene blue dye until resistance was felt. The nutrient artery to the first metatarsal shaft was then exposed and the capital fragment was dissected free from the remaining soft tissues and visually inspected for the presence and distribution of dye. One of the chevron specimens was excluded because of technical error during the injection portion of the study. In all 4 of the long dorsal arm specimens, dye was observed in the entire dorsal cortical-cancellous wing and the cancellous metatarsal head region. In contrast, dye was completely absent in the capital fragment of the 2 chevron specimens. This cadaveric study showed that the vascular supply to the long dorsal arm osteotomy includes the nutrient artery, whereas the chevron osteotomy does not. This suggests that the long dorsal arm osteotomy may present a less risk of vascular compromise to the capital fragment.