Entry points of nutrient arteries at risk during osteotomy of the lesser metatarsals: a fresh cadaveric study

Abstract

Background: Osteotomies of the lesser (second to fourth) metatarsals are often used to correct forefoot deformities. However, certain areas of the lesser metatarsals where arteries may be prone to damage during surgery, and the resulting nonunion and delayed union could cause serious problems. This study sought to identify the nutrient arteries of the lesser metatarsals and to determine how osteotomy could injure these vessels.

Methods: Enhanced computed tomography scans of 21 ft (male, n = 10; female, n = 11; mean age 78.6 years at the time of death) were assessed. Twenty-one lower limbs in 21 cadaveric specimens were injected with barium via the external iliac artery, and the points at which the nutrient arteries entered the lesser metatarsals were identified on axial and coronal images.

Results: Each nutrient artery entered the lateral or medial plantar aspect of the lesser metatarsal in the middle third (just proximal to the middle point of the metatarsal) or proximal third obliquely from a distal direction. The mean ± standard deviation (SD) distances from the dorsal plane of the second, third, and fourth metatarsals to the point of entry of the nutrient artery in the axial plane were 8.2 ± 1.5, 7.6 ± 1.2, and 7.6 ± 1.5 mm, respectively. The mean ± SD distances from the distal epiphysis to the point of entry of the nutrient artery into the second, third, and fourth metatarsals in the coronal plane were 3.3 ± 1.1, 3.1 ± 1.0, and 2.8 ± 1.2 mm, respectively. The mean ± SD distances from the distal epiphysis to the point of entry of the nutrient artery into the second, third, and fourth metatarsals in the coronal plane were 46.0 ± 5.2, 40.9 ± 2.6, and 39.1 ± 3.7 mm, respectively. The mean ± SD distances from the proximal epiphysis to the entry point of the nutrient artery into the second, third, and fourth metatarsals in the coronal plane were 23.8 ± 4.7, 25.8 ± 4.3, and 25.0 ± 3.2 mm, respectively.

Conclusions: Distal metatarsal osteotomies might be safer than shaft or proximal osteotomy to avoid disruption of the nutrient artery, leading to delayed consolidation of the osteotomy and nonunion.

Keywords: Cadaver; Lesser metatarsal; Nutrient artery; Osteotomy.

Fig. 1

Enhanced CT images showing the nutrient artery course after entering the lesser metatarsal. The nutrient artery runs within the medullary canal distally and proximally in the sagittal plane (a) and distally (b) and proximally (c) in the axial plane. The arrow head indicates the nutrient artery

Fig. 2

Enhanced CT images showing nutrient artery parameters in relation to the lesser metatarsals. a Distance from the dorsal plane parallel to a line between the most plantar point of the first metatarsal (point A) and fifth metatarsal (point B) to the point of entry of the nutrient artery into the lesser metatarsal (1) and the distance from a line between the most plantar point of the first metatarsal (point A) and fifth metatarsal (point B) to the point of entry of the nutrient artery into the lesser metatarsal (2) in the axial plane. b Distance from the distal epiphysis to the point of entry of the nutrient artery into the lesser metatarsal (3), the distance from the proximal epiphysis to the point of entry of the nutrient artery into the lesser metatarsal (4) in the coronal plane. The arrow head indicates the nutrient artery

Fig. 3

Enhanced CT images showing the nutrient artery entering the lesser metatarsal medially (a) In the axial plane and, (b) in the coronal plane. The arrow head indicates the nutrient artery

Fig. 4

Enhanced CT showing the nutrient artery entering the lesser metatarsal near the mid-point. The nutrient artery enters the lesser metatarsal near the mid-point from a distal direction laterally and obliquely in the coronal plane. The arrow head indicates the nutrient artery

Fig. 5

Diagrammatic a representations of the entry points of the lesser metatarsals in the axial (a) and coronal (b) pla