Assuntos
Antibacterianos/administração & dosagem , Transplante Ósseo , Sulfato de Cálcio , Úmero/cirurgia , Dispositivos para Expansão de Tecidos , Tobramicina/administração & dosagem , Adulto , Animais , Transplante Ósseo/diagnóstico por imagem , Cães , Feminino , Humanos , Úmero/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Masculino , Pessoa de Meia-Idade , Radiografia , Fusão Vertebral/métodos , Transplante AutólogoRESUMO
25 hemispherical acetabular components retrieved from patients who had a total hip arthroplasty (THA) were studied histologically. All of the components had titanium fiber metal porous coatings and were implanted with adjuvant screw fixation, 18 in primary THA and 7 in revision THA. None of the cups had been removed because of infection or failure of fixation. The components had been in place an average of 30 (1-140) weeks. 18 cups had bone ingrowth into the porous coating. Up to one third of the available void space within the porous coating was occupied by bone, while the maximal proportion of the area of the bone-implant interface with bone ingrowth was over 80 percent. Bone ingrowth was more often observed at the dome and in the vicinity of sites of screw fixation than elsewhere. Peripherally, bone ingrowth was less consistent, and in isolated areas fibrocartilage and mineralized fibrocartilage were occasionally observed. The longer-term cases had more bone ingrowth than the shorter-term cases. Apparent metallic debris was observed within histiocytes adjacent to screw holes, and the amount of this material increased with duration of implantation.
Assuntos
Acetábulo/cirurgia , Prótese de Quadril , Osseointegração , Adulto , Idoso , Idoso de 80 Anos ou mais , Ligas , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/ultraestrutura , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Porosidade , Radiografia , Reoperação , TitânioRESUMO
This study evaluated the effect of disodium etidronate (EHDP) on biomechanical and histologic characteristics of bone ingrowth in a porous material. EHDP was administered parenterally to six adult mongrel dogs at a dose of 2 mg/kg/day for eight weeks. Six additional dogs served as controls and were injected with saline. Porous titanium fiber composites were inserted into the proximal humeri and the left olecranons of all animals after the first four weeks of treatment. Upon completing a total of eight weeks of treatment, all animals were sacrificed and the bone-porous implant interfacial shear strength was determined by a pull-out test to failure. Mean shear strength of fixation for the EHDP-treated group was reduced by 76% compared to the control group (p less than 0.001). Bone ingrowth was mineralized in all of the control specimens. Mineralization of tissue ingrowth was inhibited, however, in all specimens from EHDP-treated animals. These findings suggest that cementless skeletal fixation of porous-coated implants by bone ingrowth may be delayed or prevented by the administration of EHDP.