title: Effect of weight-bearing on bone-bonding behavior of strontium-containing hydroxyapatite bone cement.
abstract: The purpose of this study was to investigate and compare the chemical composition and nanomechanical properties at the bone-cement interface under non-weight-bearing and weight-bearing conditions, in order to understand the effect of weight-bearing on the bone-bonding behavior of strontium-containing hydroxyapatite (Sr-HA) cement. In one group, Sr-HA cement was injected into rabbit ilium (under non-weight-bearing conditions). Unilateral hip replacement was performed with Sr-HA cement (under weight-bearing conditions) in the other group. Six months later, scanning electron microscopy (SEM) with energy-dispersive X-ray (EDX) analysis and nanoindentation tests were conducted on the interfaces between cancellous bone and the Sr-HA cement. The nanoindentation results revealed two different transitional behaviors under different conditions. nder weight-bearing conditions, both the Young modulus and hardness at the interface were considerably higher than those at either the Sr-HA cement or cancellous bone. On the contrary, under non-weight-bearing conditions, both the Young modulus and hardness values at the interface were lower than those at the cancellous bone, but were higher than the Sr-HA cement. In addition, EDX results showed that the calcium and phosphorus contents at the interface under weight-bearing conditions were considerably higher than those under non-weight-bearing conditions. The differences in chemical composition and nanomechanical properties at the cement-bone interface under two different conditions indicate that weight-bearing produces significant effects on the bone-bonding behavior of the Sr-HA cement.
authors.affiliation: Department of Rehabilitation Medicine, Fujian Medical University, Fuzhou, China [corrected]
authors.forename: G X
authors.initials: GX
authors.lastname: Ni
authors.forename: W W
authors.initials: WW
authors.lastname: Lu
authors.forename: B
authors.initials: B
authors.lastname: Tang
authors.forename: A H W
authors.initials: AH
authors.lastname: Ngan
authors.forename: K Y
authors.initials: KY
authors.lastname: Chiu
authors.forename: K M C
authors.initials: KM
authors.lastname: Cheung
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Li
authors.forename: K D K
authors.initials: KD
authors.lastname: Luk
mesh_terms: D000818:Animals; D001843:Bone Cements / Q000378:metabolism*; D001842:Bone and Bones / Q000502:physiology*; D017886:Durapatite / Q000378:metabolism*; D006244:Hardness; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011817:Rabbits; D016474:Weight-Bearing; D014961:X-Ray Diffraction
chemical_list: D001843:Bone Cements; C509320:strontium-containing hydroxyapatite; D017886:Durapatite