It was anounced that FDA approved ceramic on metal bearing by depuy for use recently. We have been using this bearing couple over the last 2 years with no untoward problems( 11 cases with 2 year follow up). Ever since J. fishers article in j of biomechanics(2004) suggesting decrease in metal debris as well as decrease chances of liner fracture, this was an option to look forward to.
Does this reduced metal debris cause problems
will this evolve to other new bearing Viz; ceramic on oxinium bearings.
Sir,
ReplyDeletethe use of oxinium heads have been described by Bourne in CORR 2005. Though the oxinium heads are claimed to have the fracture resistance characteristics of Metal and the wear resistance of ceramics, long term outcome studies are still not available. Infact in a case report of usage of oxinium head by Kop AM et al..j Arthroplasty 2007 22(5), 775-779, they report significant damage of the zirconium base, after dislocation in 3 cases.
Shouldnt we take these market driven products with a pinch of salt, since long term outcome studies are still not available.!!For eg., there was so much hype on Hip Resurfacing with MoM, with loads of conferences and CMEs 'teaching' hip resurfacing.And today no one talks about resurfacings!
Any bearing when scratched would wear more. Dislocations would have scratched the head in many areas.
ReplyDeleteResurfacing still has a role in a select population with the correct head neck ratio, acetabular size and correct metallurgy. COM bearing may have a similar role. 2 year results are definetly early and would want to watch closely. If we do not try new bearings we would have still doing only 22mm metal on poly bearings, the so called gold standard. Mind you that some of the fastest cars have ceramic on metal bearings- some of them crash. I think the patient should be given the choice and evidence.