OBJECTIVETo observe the long-term effect of tissue engineering-based repair of large weight-bearing bone defect in goats, and the final outcome of the scaffold material coral hydroxyapatite (CHAP) in vivo.

METHODSFifteen Chinese goats were subjected to operations to induce a 2-cm left tibial diaphyseal defect, which was filled subsequently with CHAP and bone marrow stromal stem cells (BMSCs). The repaired defects were evaluated by ECT, X-ray and histology in the early stage and at 6, 12, 18, and 24 months postoperatively.

RESULTSECT showed good bone regeneration and revascularization within 2 months postoperatively. X-ray and histology displayed eccentric and gradual bone regeneration in the early stage, and the tissue-engineered bone graft was firmly healed with the goat tibia. X-ray and histological examination at 6, 12, 18, 24 months postoperatively revealed moulding of the new bones and medullary cavity recanalization, and the structure of CHAP disappeared and gradually integrated into the new bones.

CONCLUSIONTissue-engineered bone is capable of total repair of large bone defect in goats by forming normal functional new bones. CHAP can be eventually degraded completely and become the component of the newly generated bones.