RESUMO
BACKGROUND: The sensitivity of cobalt (Co) and chromium (Cr) ion-levels in detecting poorly performing metal-on-metal hip implants is low. This study proposes that serial changes in ion-levels are a more accurate marker of arthroplasties at risk. METHODS: Serial metal ion-levels and implant data of 285 patients with ASR resurfacing or replacement were studied. Patient and implant characteristics were analysed using univariate and multivariate analyses. RESULTS: 111 (39%) had revision surgery. Time since index surgery (p<0.001), acetabular inclination (p<0.001), their interaction (p<0.001) and femoral head size (p = 0.01) were significant variables. Head size (≤51 mm) had lower Co and Cr levels (p = 0.01). Cr/Co showed marginal decrease over time in the unrevised group and no decrease prerevision. CONCLUSIONS: Repeated measurement of ion-levels were higher in the revision group suggesting that serial measurements rather than absolute values may have a role to play in predicting implant failure.
Assuntos
Artroplastia de Quadril/métodos , Próteses Articulares Metal-Metal , Osteoartrite do Quadril/sangue , Osteoartrite do Quadril/cirurgia , Falha de Prótese , Adulto , Idoso , Artroplastia de Quadril/efeitos adversos , Biomarcadores , Cromo/sangue , Cobalto/sangue , Bases de Dados Factuais , Feminino , Prótese de Quadril , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Osteoartrite do Quadril/diagnóstico por imagem , Valor Preditivo dos Testes , Desenho de Prótese , Reoperação/métodos , Estudos Retrospectivos , Medição de Risco , Tomografia Computadorizada por Raios X/métodos , Resultado do TratamentoRESUMO
Following the global recall of all ASR metal on metal hip products, our aim was to correlate MRI findings with acetabular inclination angles and metal ion levels in patients with these implants. Both cobalt and chromium levels were significantly higher in the presence of a periprosthetic fluid collection. There was no association between the presence of a periprosthetic mass, bone marrow oedema, trochanteric bursitis or greater levels of abductor muscle destruction for cobalt or chromium. There was no association between the level of periprosthetic tissue reaction and the acetabular inclination angle with any of the pathologies identified on MRI. The relationship between MRI pathology, metal ion levels and acetabular inclination angles in patients with ASR implants remains unclear adding to the complexity of managing patients.
Assuntos
Acetábulo/patologia , Acetábulo/cirurgia , Artroplastia de Quadril/efeitos adversos , Prótese de Quadril , Imageamento por Ressonância Magnética , Próteses Articulares Metal-Metal/efeitos adversos , Bursite/etiologia , Bursite/patologia , Cromo/sangue , Cobalto/sangue , Bases de Dados Factuais , Edema/etiologia , Edema/patologia , Quadril/cirurgia , Articulação do Quadril/patologia , Articulação do Quadril/cirurgia , Humanos , Íons/sangue , Recall de Dispositivo Médico , Desenho de PróteseRESUMO
Acetabular inclination angles have been suggested as a principal determinant of circulating metal ion levels in metal-on-metal hip arthroplasties. We aimed to determine whether inclination angle correlates with ion levels in arthroplasties using the Articular Surface Replacement (ASR) system. Patients undergoing ASR arthroplasties had blood metal ion levels and radiograph analysis performed a mean of 3.2 years after surgery. Inclination angle showed only a weak correlation with cobalt (r=0.21) and chromium (r=0.15) levels. The correlation between inclination angle and cobalt levels was significant only with small femoral components, although it was still weak. Multiple regression showed a complex interaction of factors influencing ion levels but inclination angle accounted for little of this variation. We conclude that the acetabular inclination angle is not a meaningful determinant of metal ion levels in ASR arthroplasties.