Researchers using data from the National Joint Registry (NJR) for England, Wales, Northern Ireland and the Isle of Man studied five-year revision rates for patients who underwent total hip arthroplasty after 2007. They compared data with that of patient who had surgery prior to 2007. According to the NJR, “the rate of metal-on-metal (MoM) hip implant patients undergoing revision (or re-do) surgery has increased over time. The observed differences are in part due to increased patient surveillance and a lowering of the threshold for further surgery, researchers at the Universities of Oxford and Bristol have suggested.” The study was published in the January issue of The Bone & Joint Journal.