Metal-on-metal hip implants more likely to fail

Hip replacements are now a common surgery. All hip replacement patients are monitored to make sure their replacement hip is functioning properly, but new research is showing that certain types of hip replacements fare worse than others. Researchers analyzed data from 402,051 hip replacements tracked in the National Joint Registry of England and Wales. They found that metal-on-metal implants had high fail rates, with implants with larger heads failing earlier (3.2 percent replacement for 28 mm and 5.1 percent for 52 mm head at five years in men 60 and older). Metal-on-polyethylene implants fared better and, interestingly, in ceramic-on-ceramic articulations larger head sizes were associated with improved survival (five year replacement rate of 3.3 percent with 28 mm and 2.0 percent with 40 mm for men aged 60 years). According to the authors, “Metal-on-metal stemmed articulations give poor implant survival compared with other options and should not be implanted.”