X-ray diffraction of newly formed bone close to alumina- or hydroxyapatite-coated femoral stem.
The study was focused on the bone tissue response to two types of ceramic coating [alumina and hydroxyapatite (HA)] obtained with a plasma-spray technique. The HA coating was performed on titanium stems, while the alumina coating was on chromium-cobalt-molybdenum stems. The investigation was carried out by means of micro-area X-ray diffractometric analyses and microdiffractometric analyses at the bone-implant interface. Moreover, the coating before and after implantation was analysed by means of the conventional powder X-ray diffractometric technique. This study demonstrated that 1 yr after implantation in animals the newly formed bone adjacent to the HA-coated hip prosthesis stems was mineralized as much as the pre-existing bone, while 24-64 months after surgery in humans the newly formed bone close to the alumina-coated hip prosthesis stems showed a lamellar and Haversian structure strongly demineralized, probably due to the release of aluminum ions from the alumina covering. The authors conclude that the X-ray diffraction allows the evaluation of the structural modifications of the ceramic coating, the bone formation rate close to the coating and the chemical nature of the particles released from the coating.
Savarino
L
L
Laboratory for Biocompatibility Research on Implant Materials, Istituti Ortopedici Rizzoli, Bologna, Italy.
Cenni
E
E
Stea
S
S
Donati
M E
ME
Paganetto
G
G
Moroni
A
A
Toni
A
A
Pizzoferrato
A
A
D000537:Aluminum Oxide / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D001861:Bone Regeneration / Q000502:physiology; D001842:Bone and Bones / Q000737:chemistry* / Q000528:radiation effects*; D002858:Chromium Alloys; D018360:Crystallography, X-Ray; D017886:Durapatite / Q000737:chemistry*; D005269:Femur / Q000737:chemistry; D006801:Humans; D019736:Prostheses and Implants; D014961:X-Ray Diffraction
D001672:Biocompatible Materials; D002858:Chromium Alloys; D017886:Durapatite; D000537:Aluminum Oxide