Biomechanical Stability and Osteogenesis in a Tibial Bone Defect Treated by Autologous Ovine Cord Blood Cells—A Pilot Study

Abstract

The aim of this study was to elucidate the impact of autologous umbilical cord blood cells (USSC) on bone regeneration and biomechanical stability in an ovine tibial bone defect. Ovine USSC were harvested and characterized. After 12 months, full-size 2.0 cm mid-diaphyseal bone defects were created and stabilized by an external fixateur containing a rigidity measuring device. Defects were filled with (i) autologous USSC on hydroxyapatite (HA) scaffold (test group), (ii) HA scaffold without cells (HA group), or (iii) left empty (control group). Biomechanical measures, standardized X-rays, and systemic response controls were performed regularly. After six months, bone regeneration was evaluated histomorphometrically and labeled USSC were tracked. In all groups, the torsion distance decreased over time, and radiographies showed comparable bone regeneration. The area of newly formed bone was 82.5 ± 5.5% in the control compared to 59.2 ± 13.0% in the test and 48.6 ± 2.9% in the HA group. Labeled cells could be detected in lymph nodes, liver and pancreas without any signs of tumor formation. Although biomechanical stability was reached earliest in the test group with autologous USSC on HA scaffold, the density of newly formed bone was superior in the control group without any bovine HA.

In vivo investigation of open-pored magnesium scaffolds LAE442 with different coatings in an open wedge defect

“…This phenomenon was also found in other studies with plate-screw systems. 13,74 The transformation of callus/woven bone callus into lamellar bone over time seen in histology is known to occur in the course of secondary bone healing [75][76][77] and was associated with a decrease in periosteal callus at later examination time points. Compared to periosteal callus formation, endosteal callus formation was observed to a lesser extent and was also observed by Hampp et al 78 investigating intramedullary pins of different magnesium alloys in rabbit tibiae.…”

Ceramic Scaffolds in a Vacuum Suction Handle for Intraoperative Stromal Cell Enrichment

“…It is the only tissue which can heal without fibrous scar after damage and is able to adapt to biomechanical forces (“bone remodeling”) [ 2 ]. However, in bone defects of critical size, the self-healing capacity of the bone tissue is limited, resulting in delayed union or non-union [ 3 ]. The manifold reasons for impaired bone healing are often influenced by individual factors such as local vascular supply, infection status, comorbidities and others [ 4 ].…”

An overview of de novo bone generation in animal models

“…Models that incorporate ostectomy or osteotomy require internal or external stabilization. 58,[186][187][188][189][190] Large animal models have advantages of large defects and use of standard surgical tools and devices that are not possible in small animals. 191 As a general rule, long bone diaphyseal CSDs correspond to approximately 2-2.5 times the diaphyseal diameter, about 3-5 cm in ovine 109,[192][193][194] or 3 cm in porcine 195 196 As indicated above, load bearing varies between quadrupeds and bipeds, especially in the forelimb equivalent of human arms.…”

“…Defect creation typically requires minimal soft tissue trauma and internal fixation is not required. Models that incorporate ostectomy or osteotomy require internal or external stabilization 58,186‐190 . Large animal models have advantages of large defects and use of standard surgical tools and devices that are not possible in small animals 191 .…”