On Feb. 10, 2011, the U.S. Food and Drug Administration (FDA) posted a public health communication on metal-on-metal (MoM) hip implants. This was followed by a request, issued on May 9, 2011, to several orthopaedic device makers for postmarket surveillance studies. In particular, the agency expressed interest in information related to adverse events involving these devices that may be associated with increased levels of cobalt and chromium in the bloodstream.

Since then, several studies have been published on adverse events and early failures associated with MoM implants. Earlier this year, the United Kingdom’s Medicines and Healthcare products Regulatory Agency updated its advice to surgeons regarding the monitoring of patients with MoM hip replacements, calling for annual monitoring for the life of the implant, as a precautionary measure. Previous recommendations were for 5 years of monitoring.

In March 2012, the British Hip Society (BHS) advised its members not to use stemmed, large-diameter MoM bearings of 36 mm or greater in primary total hip replacements until more evidence is available, except in properly conducted and ethically approved research studies. The BHS explicitly stated that the advice does not apply to hip resurfacing.

In light of these developments, this issue of AAOS Now has a special focus on MoM hip implants. Featured articles include a summary of the 2012 Annual Meeting Symposium “Metal-on-Metal Hip Replacement: Current Status and Recommendations for Patient Management” (page13), a report on the 2012 Hip Society/American Association of Hip and Knee Surgeons Specialty Day Symposium “The Bearing Dilemma in 2012” (page 9), an interview with Joshua J. Jacobs, MD, AAOS first vice-president and a leading researcher on soft-tissue reactions to MoM implants (page 8), a report on the AAOS technology overview on hip resurfacing and MoM hip replacement (page 44), and an editorial by S. Terry Canale, MD.

AAOS Now invites reader feedback and responses to this issue. Email aaoscomm@aaos.org