Microvasculature of the Plantar Plate Using Nano-Computed Tomography

Abstract

Category: Basic Sciences/Biologics, Lesser Toes, Midfoot/Forefoot Introduction/Purpose: Lesser toe plantar plate attenuation or disruption is being increasingly implicated in a variety of very common clinical complaints including metatarsalgia, metatarsal-phalangeal (MTP) joint subluxation and dislocation, hammertoe, crossover toe, etc. A multitude of surgical techniques and devices have been recently developed to facilitate surgical repair of the plantar plate. However, the microvascular anatomy, and therefore the healing potential in large part, has not been addressed. We sought to answer this question by employing a novel technique involving microvascular perfusion and nano-computed tomography (Nano-CT) imaging. Methods: 12 human adult cadaveric lower extremities were amputated distal to the knee. The anterior and posterior tibial arteries were dissected and cannulated proximal to the ankle joint and were perfused with a barium solution. The soft tissues of each foot were then counterstained with phosphomolybdic acid (PMA). The 2nd through 4th toe MTP joints of 12 feet were imaged with Nano-CT at 14-micron resolution. Images were then reconstructed for three-dimensional analysis of the plantar plate microvasculature and calculation of the vascular density along the length of the plantar plate. Results: A microvascular network extends from the surrounding soft tissues at the attachments of the plantar plate on both the metatarsal and proximal phalanx. The mid-substance of the plantar plate appears to be relatively hypovascular. Analysis of the vascular density along the length of the plantar plate demonstrated a consistent trend with increased vascular density at approximately the proximal 30% and distal 20% of the plantar plate (Figure 1). Conclusion: There is a vascular network extending from the surrounding soft tissues into approximately the proximal 30% and the distal 20% of the plantar plate. The hypovascular mid-portion of the plantar plate may play an important role in the underlying patho-anatomy and pathophysiology of this area. We believe our findings likely have significant clinical implications for the reparative potential of this region, and therefore the surgical procedures currently described to accomplish anatomic plantar plate repair.