Fresh Cadaveric Study of the Distances between the Deep Plantar Arch and the Lesser Metatarsals at Risk During Osteotomy of the Lesser Metatarsals

CATEGORY: Midfoot/Forefoot INTRODUCTION/PURPOSE: Osteotomy of the lesser metatarsals is useful to treat forefoot deformity. Although there is the possibility that some arteries supplying the lesser metatarsals are injured during osteotomy, there are few informations about the distances from the deep plantar arch to the lesser metatarsals. This study aimed to identify the distances from the deep plantar arch to the lesser metatarsals and to reveal how osteotomy of the lesser metatarsals might injure the deep plantar arch. METHODS: Twenty fresh cadaveric feet were injected with barium through the external iliac artery, and enhanced computed tomography images were assessed. The distance between the deep plantar arch and each lesser metatarsal was measured on both axial and sagittal images. RESULTS: The distances between the deep plantar arch and the second, third, and fourth metatarsals on the axial plane were 0.5, 2.2, and 2.8 mm, respectively. The distances from the distal epiphysis to the line passing through the deep plantar arch perpendicular to the longitudinal axis of the lesser metatarsal on the sagittal plane were 47.0, 45.7, and 46.4 mm, respectively, and those from the proximal epiphysis were 23.0, 21.0, and 18.6 mm, respectively. The deep plantar arch coursed at the level of the middle third, proximal to this third in 11/20 (55.0%), 7/20 (35.0%), and 5/16 (31.2%) feet, respectively. CONCLUSION: This study suggested that overpenetration into the medial-plantar direction of the second metatarsal or the proximal-plantar direction of the fourth metatarsal during the shaft or proximal osteotomy might injure the deep plantar arch easily. This study also suggested that on the plantar aspect, the shaft or proximal osteotomy about 45-47 mm proximal to the distal epiphysis of the lesser metatarsal or 18-23 mm distal to the proximal epiphysis might damage blood flow of the deep plantar arch.