[Biomechanical strength of bone cement impregnated with diphosphonate].
OBJECTIVE
To investigate the biomechanical strength of diphosphonate impregnated bone cement (DIBC).


METHODS
DIBC specimens were manufactured and randomly assigned to the control groups and the DIBC groups. According to the corresponding ASTM/ISO standards, the static biomechanical strength and the fatigue limit were tested systematically. The particle size distribution of diphosphonate powder was analyzed with the laser light scattering method. The fatigue test results, given as number of cycles-to-failure, were analyzed using the linearized format of the two-parameter Weibull function.


RESULTS
With the drug load increased, there was a slight increase in static biomechanical strength and a moderate decrease in fatigue limit, both with statistical significance. When immersed in PBS before the tests, the DIBC specimens presented an overall significant decrease of static biomechanical strength and fatigue limit. The profile of drug particle sizes presented a normal distribution.


CONCLUSIONS
The adopted diphosphonate is a much homogeneous powder which contains particles with a low range of sizes. The impregnation of diphosphonate exerted no or less negative effect on the biomechanical strength of the acrylic bone cement, of which the static strength of DIBC is maintained high above the ASTM/ISO standards.
Cai
Xun-Zi
XZ
Department of Orthopaedic Surgery & Orthopaedic Research Laboratory, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China.
Yan
Shi-Gui
SG
Ying
Zhi-Min
ZM
Xu
Yun-Qin
YQ
Lü
Rong-Kun
RK
D001696:Biomechanical Phenomena; D001843:Bone Cements; D019245:Compressive Strength; D004164:Diphosphonates; D004548:Elasticity; D008422:Materials Testing; D013718:Tensile Strength
D001843:Bone Cements; D004164:Diphosphonates