Growing C57Bl/6 Mice Increase Whole Bone Mechanical Properties by Increasing Geometric and Material Properties

Oxford University Press (OUP) - Tập 14 Số 12 - Trang 2159-2166 - 1999
Michael D. Brodt1, Cara B. Ellis1, Matthew J. Silva1
1Biomechanical Engineering Laboratory, Department of Orthopaedic Surgery, Barnes-Jewish Hospital at Washington University, St. Louis, Missouri, U.S.A.

Tóm tắt

Abstract In vivo murine models are becoming increasingly important in bone research. To establish baseline data for researchers using these models, we studied the long bones from C57BL/6 female mice, a strain that is widely used in bone research. We determined the femoral structural and material properties in both torsion and four-point bending for mice at ages 4–24 weeks. Measurements of femoral cross-sectional geometry and tibial densitometric properties were also obtained. Results indicated that all structural properties (except ultimate energy), changed significantly with age (p < 0.001). Ultimate torque, ultimate moment, torsional rigidity, and bending rigidity all increased to peak values at 20 weeks, whereas ultimate rotation and ultimate displacement decreased to minimum values at 20 weeks. Our data indicate that increases in the material properties contributed more than increases in cross-sectional geometry to the changes in structural rigidity and ultimate load. For example, from 4–20 weeks torsional rigidity increased 1030%, while shear modulus increased 610% and the polar moment of inertia (a measure of the geometric resistance to rotation) increased by only 85%. Changes in the cross-sectional geometry with age were due to increases in periosteal diameter and decreases in endosteal diameter. In general, both torsion and bending techniques revealed large changes in structural and material properties with age. We conclude that peak bone strength is not achieved before 20 weeks in C57BL/6 female mice, and that torsion and four-point bending tests are equally well suited for evaluating mechanical properties of murine long bones.

Từ khóa


Tài liệu tham khảo

Lewis, 1993, Osteoporosis induced in mice by overproduction of interleukin 4, Proc Natl Acad Sci USA, 90, 11618, 10.1073/pnas.90.24.11618

Bonadio, 1990, Transgenic mouse model of the mild dominant form of osteogenesis imperfecta, Proc Natl Acad Sci USA, 87, 7145, 10.1073/pnas.87.18.7145

Bonadio, 1993, A murine skeletal adaptation that significantly increases cortical bone mechanical properties, J Clin Invest, 92, 1697, 10.1172/JCI116756

Jepsen, 1992, 93

Mike, 1995, Long bone geometry and strength in adult BMP-5 deficient mice, Bone, 16, 445

Mikic, 1996, Mechanical and geometric changes in the growing femora of BMP-5 deficient mice, Bone, 18, 601, 10.1016/8756-3282(96)00073-7

Tseng, 1996, Local expression of human growth hormone in bone results in impaired mechanical integrity in the skeletal tissue of transgenic mice, J Orthop Res, 14, 598, 10.1002/jor.1100140414

Ekeland, 1981, Mechanical properties of fractured and intact rat femora evaluated by bending, torsional and tensile tests, Acta Orthop Scand, 52, 605, 10.3109/17453678108992155

Keller, 1986, Geometric, elastic, and structural properties of maturing rat femora, J Orthop Res, 4, 57, 10.1002/jor.1100040107

Vogel, 1979, Influence of maturation on mechanical and biochemical parameters of rat bone, Gerontology, 25, 16, 10.1159/000212316

Broz, 1993, Effects of rehydration state on the flexural properties of whole mouse long bones, J Biomech Eng, 115, 447, 10.1115/1.2895510

Engesaeter, 1978, Methods for testing the mechanical properties of the rat femur, Acta Orthop Scand, 49, 512, 10.3109/17453677808993231

Torzilli, 1981, Structural properties of immature canine bone, J Biomech Eng, 103, 232, 10.1115/1.3138286

Weir, 1949, The strength and elasticity of bone in rats on a rachitogenic diet, J Bone Joint Surg, 31, 444, 10.1302/0301-620X.31B3.444

Stromberg, 1976, Experimental measurement of maximum torque capacity of long bones, Acta Orthop Scand, 47, 257, 10.3109/17453677608991987

Burstein, 1971, A standard test for laboratory animal bone, J Biomech, 4, 155, 10.1016/0021-9290(71)90026-1

Turner, 1993, Basic biomechanical measurements of bone: A tutorial, Bone, 14, 595, 10.1016/8756-3282(93)90081-K

Ekeland, 1982, Influence of age on mechanical properties of healing fractures and intact bones in rats, Acta Orthop Scand, 53, 527, 10.3109/17453678208992252

Torzilli, 1982, The material properties of immature bone, J Biomech Eng, 104, 12, 10.1115/1.3138297

Ducy, 1996, Increased bone formation in osteocalcin-deficient mice, Nature, 382, 448, 10.1038/382448a0

Festing, 1994, Inbred strains of mice, Mouse Genome, 92, 373

Levenston, 1994, Improved method for analysis of whole bone torsion tests, J Bone Miner Res, 9, 1459, 10.1002/jbmr.5650090919

Hibbeler, 1991, Mechanics of Materials

Shigley, 1989, Mechanical Engineering Design, 5th Ed.

Beamer, 1996, Genetic variability in adult bone density among inbred strains of mice, Bone, 18, 397, 10.1016/8756-3282(96)00047-6

Simske, 1992, The physical and mechanical effects of suspension-induces osteopenia on mouse long bones, J Biomech, 25, 489, 10.1016/0021-9290(92)90089-J

Engesaeter, 1980, Effects of oxytetracycline on solubility and synthesis of collagen in young rats, Acta Orthop Scand, 51, 43, 10.3109/17453678008990767

Lees, 1977, The role of collagen in the elastic properties of calcified tissues, J Biomech, 10, 473, 10.1016/0021-9290(77)90101-4

Evans, 1973, Mechanical Properties of Bone

Jepsen, 1997, Type I collagen mutation alters the strength and fatigue behavior of Mov13 cortical tissue, J Biomech, 30, 1141, 10.1016/S0021-9290(97)00088-2