title: In vivo cancellous bone remodeling on a strontium-containing hydroxyapatite (sr-HA) bioactive cement.
abstract: The purpose of this study was to investigate the in vivo bone response to the strontium-containing hydroxyapatite (Sr-HA) bioactive bone cement injected into the cancellous bone. Sr-HA cement was injected into the iliac crest of rabbits for 1, 3, and 6 months. Active bone formation and remodeling were observed after 1 month. Newly formed bone was observed to grow onto the bone cement after 3 months. Thick osteoid layer with osteoblasts formed along the bone and guided over the bone cement surface reflected the stimulating effect of Sr-HA. From scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis, high calcium and phosphorus levels were detected at the interface with a thick layer of 70 microm in width, and fusion of Sr-HA with the bone was observed. Blood vessels were found developing in remodeling sites. The affinity of bone on Sr-HA cement was increased from 73.55 +/- 3.50% after 3 months up to 85.15 +/- 2.74% after 6 months (p < 0.01). In contrast to Sr-HA cement, poly(methyl methacrylate) (PMMA) bone cement was neither osteoconductive nor bioresorbable. Results show that the Sr-HA cement is biocompatible and osteoconductive, which is suitable for use in treating osteoporotic vertebral fractures.
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, The University of Hong Kong, Hong Kong SAR.
authors.forename: C T
authors.initials: CT
authors.lastname: Wong
authors.forename: W W
authors.initials: WW
authors.lastname: Lu
authors.forename: W K
authors.initials: WK
authors.lastname: Chan
authors.forename: K M C
authors.initials: KM
authors.lastname: Cheung
authors.forename: K D K
authors.initials: KD
authors.lastname: Luk
authors.forename: D S
authors.initials: DS
authors.lastname: Lu
authors.forename: A B M
authors.initials: AB
authors.lastname: Rabie
authors.forename: L F
authors.initials: LF
authors.lastname: Deng
authors.forename: J C Y
authors.initials: JC
authors.lastname: Leong
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D001843:Bone Cements / Q000737:chemistry* / Q000494:pharmacology* / Q000592:standards; D016723:Bone Remodeling / Q000187:drug effects*; D017886:Durapatite; D007085:Ilium; D008422:Materials Testing; D018919:Neovascularization, Physiologic / Q000187:drug effects; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects; D019904:Polymethyl Methacrylate; D011817:Rabbits; D013324:Strontium
chemical_list: D001843:Bone Cements; D019904:Polymethyl Methacrylate; D017886:Durapatite; D013324:Strontium