ISSN:
0021-9304
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
,
Technology
Notes:
The use of conventional rigid metal plates (modulus of elasticity 30 × 106 psi) for internal fixation of difficult long bone fractures may paradoxically weaken the fractured bone through a process of osteoporosis secondary to protection of the bone from stress. The hypothesis being studied which has stimulated the present work is that a new composite plate made of less rigid material but with similar geometry to stainless steel plates may promote fracture union without the complication of osteopenia. This new composite material has a modulus of elasticity similar to that of bone (approximately 3 × 106 psi) which is more than an order of magnitude lower than that of stainless steel, yet the fracture strength of this new composite material (35,000 psi) is approximately one-half that of stainless steel.The ability to fix diaphyseal fractures by composite plates was studied by implanting these plates in the left (experimental) radii of six dogs with transverse mid-shaft osteotomies. The right (control) radii had similar transverse osteotomies, but were plated by conventional metal plates equal in size to the new composite plates. Four months postsurgery, all experimental and control fractures had healed.Biomechanical tests of the excised radii using a torsional loading apparatus showed there were no significant differences in strength, fracture energy, angular deformation, or maximum shearing stress when comparing the experimental to the control radii. The results are sufficiently promising to warrant additional long-term experiments investigating this concept of internal fixation.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jbm.820080513
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