Bone Morphology and Vascular Supply of Pedicled Distal Radius Bone Using Nano-Computed Tomography.

BACKGROUND: The goal of this study was to use nano-computed tomography to describe the intraosseous vascularity and structural characteristics of commonly used distal radius vascularized bone grafts for treatment of scaphoid nonunion.

METHODS: We obtained 8 fresh frozen human cadaver forearm specimens for infusion of barium contrast. Specimens were scanned and segmented to quantify the vascular volume and trabecular density within 3 common graft regions, including 1, 2 intercompartmental supraretinacular artery (1,2 ICSRA), fourth extensor compartment artery (4 ECA), and volar carpal artery (VCA), as well as thirds of the scaphoid. Outcomes also included mean and maximum cortical thickness and number of cortical perforators. Single-specimen analyses were also performed comparing vascularity and trabecular density of each graft with scaphoid regions of a single specimen. Statistical analysis was performed using analysis of variance with post hoc Tukey testing when P value was less than .05.

RESULTS: There was no significant difference between groups in the mean percent vascularity ( P = .76). The ratio of trabecular bone in each graft to scaphoid thirds was less than 1. The mean cortical thickness (0.79 mm, 95% confidence interval [CI], 0.66-0.93 mm) and maximum cortical thickness (1.45 mm, 95% CI, 1.27-1.63 mm) of VCA grafts were both significantly greater than those of 4 ECA and 1,2 ICSRA ( P < .001).

CONCLUSIONS: There were no differences between vascular density of the 3 grafts and the scaphoid. Pedicled distal radius bone grafts have similar vascularity but morphometric differences such as cortical thickness and trabecular density which have unclear clinical implications.