Revascularisation of bone allografts following vascular bundle implantation: an experimental study in rats

Revascularisation and cellular repopulation of fresh and cryopreserved allografts was observed following implantation of a vascular bundle in an experimental study in rats. Fresh and cryopreserved rat allografts were harvested from Lewis rats and implanted into Spraque-Dawley rats. The femoral vascular bundle was implanted into 2-cm segments of allograft placed in the medial aspect of the thigh of the recipient rats. Non-vascularised controls were used for comparison. Histological studies indicated the revascularisation pattern. Cryopreserved allografts with vascular bundle implantation showed early neovascularisation from the endosteal surface, 20% of the necrotic lacunae was repopulated with living cells at the end of 24 weeks. Fresh allografts with vascular implantation were rejected by the host immune mechanisms and showed early breakdown and fragmentation. Cellular repopulation was not observed in the non-vascularized allografts. Secondary vascularization following a vascular bundle implantation may enhance the biological properties of an allograft and therefore has significant potential clinical applications.