Segmental defect in the radius of rabbits repaired by two kinds of bionic biphasic ceramic-like biologic bones

Shouping ZHANG; Xiaoguang XIU; Lili SUN

ABSTRACT

BACKGROUND:

Natural biologic bone-derived products have been prepared by raw ox bone but not by swine vertebra. Previous research has indicated that biphasic ceramic-like biologic active bone made by swine vertebra has osteoinductive ability.

OBJECTIVE:

To investigate the feasibility of biphasic ceramic-like biologic active bone and biphasic ceramic-like biologic bone (BCBB) to repair the segmental defect in radius of rabbits. DESIGN,TIME AND

SETTING:

A randomized controlled animal experiment was performed at Institute of Orthopedics,the Fourth Military Medical University of Chinese PLA and Central Laboratory of Qingdao Medical College from October 2004 to October 2005. MATERIALSBiphasic ceramic biologic bone was made of swine vertebra and sodium pyrophosphate after two calcinations at low temperature. The mixture which consisted of hydroxyapatite and tricalcium phosphate,sizing 0.3 cm ? 0.3 cm ? 1.5 cm was combined with type I collagen to make BCBB. Bone morphogenetic protein was mixed with type I collagen,and then the mixture was combined with biphasic ceramic biologic bone to make biphasic ceramic-like biologic active bone.

METHODS:

A total of 48 healthy Japanese rabbits were randomly divided into biologic active bone group,biologic bone group,and blank control group,with 16 rabbits per group. A segmental defect which was 15 mm along bilateral radius was established. Biphasic ceramic-like biologic active bone and BCBB were implanted into defect region,respectively,but implantation was not treated in the blank control group. MAIN OUTCOME

MEASURES:

Materials were harvested at weeks 2,4,8,12 for the gross observation under microscope. Tissue sections were selected for hematoxylin-eosin (HE) staining and Masson staining.

RESULTS:

① Gross observationAt 2 weeks,there were no differences between the two groups,and the materials were connected to bone bed with fibrous tissues. At 4 and 8 weeks,there was more new callus in biologic active bone group than in biologic bone group. At 12 weeks,some bionic biphasic ceramic-like biologic active bone were absorbed and new bone regenerated in biologic active bone group,being similar to appearance of host bone,but there were few callus in biologic bone group. In blank control group,bone defect could not be repaired and there were fibrous tissue in bone defect. ② Staining

results:

At 2 weeks after operation,there were no differences between the two groups,and the materials were connected to bone bed with fibrous tissues. At 4 and 8 weeks,more vessels and fibrous tissues grew into BCBB,new bone was formed,and bone connect was found between BCBB and bone bed in the biologic active bone group. At 12 weeks,in the biologic active bone group,more materials degraded,new bone was integrated with bone bed,and bone marrow-like structure was formed. At 12 weeks,the broken ends were sclerosis and blocked in the blank control group.

CONCLUSION:

Bionic biphasic ceramic-like biologic active bone characterizing by good bone induction and biocompatibility can remarkably repair the segmental defect in radius of rabbits. BCBB is perspective for repairing the segmental bone defect.