Measurement and clinical significance of elastic modulus of composite of true bone ceramic granule and bone cement

Yucai WANG; Qingyu FAN; Dianzhong ZHANG; Baoan MA; Yong ZHOU; Minghua ZHANG

ABSTRACT

BACKGROUND:

Composite with different ratios has various elastic noduli, and this can cause stress protection in implanted body so as to influence on biological integration between composite and host bone and plerosis of bone defection.

OBJECTIVE:

To measure elastic modulus of tissue engineering bone made of composite between true bone ceramic (TBC) granule and bone cement (BC) and provide experimental data for repairing bone defection at various sites.

DESIGN:

Controlled study.

SETTING:

Military Institute of Bone Tumor, Tangdu Hospital of the Fourth Military Medical University of Chinese PLA.MATERIALS The experiment was carried out in the Military Institute of Bone Tumor, Tangdu Hospital of the Fourth Military Medical niversity of Chinese PLA from August 2002 to March 2003. Ten Kunming mice,weighing 10-15 g, of both genders, were selected in this study. Fresh longtubular cortical bone of 1-year calf, 6 samples of spongy bone at inferior extremity and 6 samples at iddle femur of fresh corpse were also selected in this study.

METHODS:

Bovine bone morphogenetic protein (bBMP) was xtracted to measure osteogenic-induced activity and make TBC granule. bBMP was mixed with TBC as the ratio of 125, and then with BC as the ratios of 010, 46, 55,64 and 7.52.5. In addition, elastic modulus of tissue engineering bone made of TBC-BC composite was measured and compared with elastic modulus of femur and spongy bone of normal adult males.MAIN OUTCOME

MEASURES:

Measurement and comparison of elastic modulus.

RESULTS:

Elastic modulus of composite containing 60% TBC (Ratio between TBC and BC was 64) was no significantly different from that of spongy bone at inferior extremity of femur of normal adult males (P ＞ 0.05),but other comparisons of every two subjects were significant difference [femur of the adults (6.216 7±0.222 9) Mpa; spongy bone (1.351 7±0.306 9) Mpa;TBC/BC (010) (5.710 0±0.166 3) Mpa; TBC/BC (46) (3.510 1±0.205 0) Mpa;TBC/BC (55) (2.004 1±0.150 0) Mpa; TBC/BC (64) (1.501 8±0.005 7) Mpa;TBC/BC (7.52.5) (0.900 4±0.025 1) Mpa, P ＜ 0.01].

CONCLUSION:

Elastic modulus of composite containing 60% tissue engineering bone made of TBC-BC composite is similar to that of spongy bone at inferior extremity of femur of adult males. The composite can be used to repair bone defection near by articular facet so as to prevent from articular degeneration.