A newly developed external fixator combined with tissue engineered bone repair of segmental bone defect

Abstract

Objective To evaluate the efficacy of bone mesenchymal stem cells (BMSCs) combined with biphasic calcium phosphate (BCP) repair of segmental bone defect, which was stabilized with an adaptable external fixation system.Methods In group A, the femoral defect was filled with BCP combined with BMSCs; In group B, the femoral defect was filled with BCP, and in group C, defects were left empty. Animals were sacrificed 12 weeks post-operation.Results In group A, radiographic scores were average 4.17, significantly (P<0.05) greater than in group B (1.18) and group C (1.08). Histological evaluations displayed the bridging of the defect in group A, with remarkable new bone formation. In contrast, group B and group C showed no formation of new bone. The mechanical testing revealed that axial stiffness was (8.09±2.42) N/mm and torsional stiffness was (1.89±0.72) Nmm/deg in group A, and those in group B were (1.75±0.90) N/mm and (0.40±0.21) Nmm/deg respectively. There was significant difference in biomechanical tests between group A and group B (P<0.05).Conclusion External fixator combined with tissue engineered bone can repair segmental bone defect. Key words: Tissue engineering; Bone defect; BMSCs; Biphasic calcium phosphate