The microvasculature of the sesamoid complex: its clinical significance

The microvascular anatomy of the sesamoid complex was investigated in 15 cadaver specimens using histology and tissue clearing (Spalteholz) techniques. It was found that both sesamoids appeared equally well vascularized and the vascular supply to each sesamoid originated from two major sources (proximal and plantar) and one minor source (distal). Proximally, vessels originating from the first plantar metatarsal artery enter the sesamoid at its attachment to the flexor hallucis brevis. In addition, vessels enter the plantar surface of the sesamoid near the midline and arborize throughout the bone, anastamosing with the proximal vessels. The distal vascular supply to the sesamoids originates from its distal capsular attachment and appears to contribute minimally to the overall vascular scheme. The lateral attachments of the sesamoids to the plantar plate and joint capsule were relatively avascular. In two bipartite specimens examined, the major blood supply originated from the proximal and distal poles of the sesamoid. No vessels were observed entering the plantar surface of these specimens. The results of this study suggest that injury to the proximal or plantar aspects of the sesamoids could disrupt the vascular supply to these bones. These areas should, therefore, be avoided during the surgical approach to the sesamoids.