RESUMO
We analyzed 20 retrieved gamma-sterilized polyethylene liners (Biomet Hexloc). The long-term durability varied significantly depending on shelf-life time before implantation. Liners with a shelf-life time of 3 years or more evinced significantly ( P 0.002) higher volumetric wear than those with a shelf life time less than 3 years. Infrared spectroscopy and scanning calorimetry showed that all explanted implants underwent substantial in vivo oxidation and crystallization. The oxidative ageing of polyethylene renders the polyethylene liner susceptible to severe wear. Scanning electron microscopy of the bearing surface of the liner revealed abrasive wear as a dominant mechanism. Moreover, poor acetabular design produces excessively thin liners, substandard locking mechanism, and backside wear of the liner. The primary reason for severe wear in the Hexloc liner was poor modular design and oxidative degradation of the polyethylene.
Assuntos
Análise de Falha de Equipamento , Prótese de Quadril , Teste de Materiais , Polietileno/química , Falha de Prótese , Adulto , Idoso , Materiais Revestidos Biocompatíveis , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Probabilidade , Desenho de Prótese , Estatísticas não Paramétricas , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração , Fatores de TempoRESUMO
In hip revision restricted to the acetabular component, the taper of a modular stem is in constant danger of scratching. We used a plastic syringe to protect the taper of the femoral component. A plastic syringe of appropriate size remains well in place and offers a novel and inexpensive protective device for the taper of the femoral component available in every operation room.