Repairing big segmental long bone defects in goat tibia using modified heterogeneous deproteinizated bone combined with recombinant human bone morphogenetic protein

Jian Yue-kui, Tian Xiao-bin, Zhao Zhu-chuan, Li Bo, Zhang Mei-xin, Yang Zhen

Department of Orthopaedics, People's Hospital of Guizhou Province, Guiyang   550002, Guizhou Province, China

Jian Yue-kui☆, Doctor, Attending physician, Department of Orthopaedics, People's Hospital of Guizhou Province, Guiyang   550002, Guizhou Province, China
jianyuekui01@163. com

Supported by: Guizhou Provincial Science and Technology Fund, No. 20063053*

Received: 2007-12-04

Abstract
BACKGROUND: For its extensive sources and specific biological characteristics, deproteinized bone (DPB) gets more attention as the scaffold materials of bone tissue engineering.
OBJECTIVE: To evaluate the ability of heterogeneous DPB prepared by modified method compound recombinant human bone morphogenetic protein (rhBMP2) to repair big segmental long bone defect of the animals.
DESIGN, TIME AND SETTING: Randomized control animal experiment was completed in the Animal Center of the Third Military Medical University of Chinese PLA and the Central Laboratory of Southwest Hospital from May 2005 to December 2006.
MATERIALS: Pig femor were used in this study, as well as 24 goats of 10-12 months old and either gender; Half-ring sulcated external fixator (Professor Li Qi-hong of the Third Military Medical University of Chinese PLA, Patent No: CN01256565).
METHODS: According to the implanted materials, 24 goats were randomly divided into 3 groups (n=6), namely DPB group, autograft bone group and DPB+rhBMP2 group. 20% segmental defects of right tibia middle and inferior bone were induced in every goat and then implanted with different materials. Half-ring sulcated external fixator was used for the fixation. DPB was prepared according to the references.
MAIN OUTCOME MEASURES: Bone defect repairs were detected by X-ray photographs every 4 weeks during postoperative 4-24 weeks, and new bone executed dual-energy X-ray absorptiometry, histology and biomechanics at 24 postoperative weeks.
RESULTS: The prepared DPB exhibited three-dimensional porous structure. The porosity was (78.5±6.45)%, and the pore size was (472.5±7.02) μm. The bone repair in each group showed a time-dependent manner. The results of biomechanical test, such as torsional, bending and axial tensile tests, as well as the average new bone quantity in the autograft bone group was greater than that in the DPB+rhBMP2 group, and that in the DPB group was the least. There was no significant difference of the goat tibial bone density and bone mineral content, anti-compression pressure and limit pressure, anti-bending load and limit loading, anti-torsion torque and limit torque among the DPB group, autograft bone group and DPB+rhBMP2 group.
CONCLUSION: Composites of modified heterogeneous DPB/rhBMP2 and autogenous bone have equivalent osteogenesis abilities in repairing goat tibia big segmental bone defects. It can be applied as the scaffold materials in the tissue engineering.

Jian YK, Tian XB, Zhao ZC, Li B, Zhang MX, Yang Z. Repairing big segmental long bone defects in goat tibia using modified heterogeneous deproteinizated bone combined with recombinant human bone morphogenetic protein.Zhongguo Zuzhi Gongcheng Yanjiu yu Linchuang Kangfu 2008;12(27):5219-5222 [www.zglckf.com/zglckf/ejournal/upfiles/08-27/27k-5219(ps).pdf]