Effects of Surgical Angiogenesis on Segmental Bone Reconstruction With Cryopreserved Massive‐Structural Allografts in a Porcine Tibia Model

Abstract

Cryopreserved bone allografts (CBA) used to reconstruct segmental bone defects provide immediate structural stability, but are vulnerable to infection, non-union and late stress fracture as the majority of the allograft remains largely avascular. We sought to improve the bone vascularity and bone formation of CBAs by surgical angiogenesis with an implanted arteriovenous (AV) bundle, using a porcine tibial defect model. Cryopreserved tibial bone allografts were transplanted in swine leukocyte antigen (SLA) mismatched Yucatan minipigs to reconstruct a 3.5 cm segmental tibial defect. A cranial tibial AV-bundle was placed within its intramedullary canal to induce angiogenesis. The AV bundle was patent in eight pigs and ligated in a control group of eight pigs. At 20 weeks neo-angiogenesis was evaluated by microangiography. Bone formation was measured by quantitative histomorphometry and micro-computed tomography. Seven of eight AV-bundles in the revascularized group were patent. One had thrombosed due to allograft displacement. Total vascular volume was higher in the revascularized allografts compared to the ligated group (p = 0.015). Revascularized allografts had increased levels of bone formation on the allograft endosteal surface compared to the ligated control group (p = 0.05). Surgical angiogenesis of porcine tibial CBAs by intramedullary implantation of an AV-bundle creates an enhanced autogenous neoangiogenic circulation and accelerates active bone formation on allograft endosteal surfaces.

The effect of surgical revascularization on the mechanical properties of cryopreserved bone allograft in a porcine tibia model

“…In eight grafts an AV bundle was placed within the medullary canal (revascularization group) (Figure 2). 11 The remaining eight pigs served as a ligated control group. The contralateral, undisturbed tibia provided normative data.…”

“…They are readily available, can be matched to defect size and shape, and provide immediate structural stability. However, they remain largely avascular over time, resulting in a relatively high incidence of complications such as infection, nonunion, and late stress fracture 1–10 Previous studies have demonstrated the ability to create a neoangiogenic circulation in CBAs by surgical angiogenesis 11 . The implantation of an arteriovenous bundle (AV bundle) enhanced bone blood flow and resulted in an increased active bone remodeling in both rat and large animal studies 12–14 .…”

“…The implantation of an arteriovenous bundle (AV bundle) enhanced bone blood flow and resulted in an increased active bone remodeling in both rat and large animal studies 12–14 . Angiogenesis in Yucatan minipig tibiae also resulted in a higher vascular volume and an increased bone turnover 11 …”

Recent Advances of Chitosan-Based Injectable Hydrogels for Bone and Dental Tissue Regeneration

“…Traditional healing strategy includes the autografts, allografts and xenografts that are employed as bone substitutes to promote bone repair. However, these grafts have many disadvantages in repetitive manipulation process, high cost, surgery wound, immune rejection and potential infectious diseases (Visser et al, 2019). The advent of Bone Tissue Engineering (BTE) brings about the advanced development of bone regeneration at the defect host site without any post-operative complications (e.g., morbidity and immunogenicity).…”

Proximal Perineural Femoral Nerve Injection in Pigs Using an Ultrasound-Guided Lateral Subiliac Approach—A Cadaveric Study

“…Pigs are a widely accepted translational animal model that is used in a growing number of experimental orthopedic surgical interventions for humans [1][2][3]. Adequate pain management, however, has not received enough attention to date.…”