FDA 522 Postmarket Surveillance Order for Metal-on-Metal Hip Replacements

On May 6, 2011, the FDA issued 522 postmarket surveillance orders to manufacturers of Metal-on-Metal (MoM) hip replacements marketed in the United States. The purpose of these 522 orders was to continue longer-term monitoring of the MoM devices.

Exponent is uniquely qualified to assist device manufacturers in the development and implementation of their post-market surveillance plans, including analysis and reporting of findings. Our professionals have extensive experience in orthopaedic device design, materials, metallurgy, retrieval/explant analysis, manufacturing, material toxicology, epidemiology, biomechanics, labeling, warnings, regulatory affairs, complaint analysis, clinical study design, and biostatistics.


Specifically, Exponent can provide the following services related to the 522 order for MoM devices:

  • Compose strategic elements of the manufacturer’s postmarket surveillance plan in response to FDA, execute the manufacturer’s postmarket surveillance program, and generate critical report elements upon completion of the clinical studies and retrieval analyses.
  • Establish, implement, and manage an explant retrieval program to characterize mechanisms of bearing surface wear, trunnion material loss, and corrosion (if any).
  • Conduct retrieval analysis of MoM explants to include tribological, metallurgical, elemental, and dimensional analysis of each explant.
  • Assist with identification of certified laboratories for analysis of serum and whole-blood cobalt-chromium ion levels.
  • Analyze, interpret, and report findings from toxicological analysis of laboratory findings.
  • Propose methods for conducting both cross-sectional and prospective clinical studies to identify rates of adverse events associated with MoM implants that leverage existing manufacturer, clinical site, and registry data.
  • Manage relationships with clinical research organizations engaged for prospective patient follow-up.
  • Analyze, interpret, and summarize data obtained from postmarket analysis of the manufacturer’s MoM device postmarket surveillance programs.
  • Review clinical medical records including radiographic/imaging analysis, identification of contributing factors, and biomechanical evaluation.
  • Evaluate the Magnetic Resonance Imaging (MRI) compatibility of MoM devices for the development of device specific labeling for MR Conditions.

FDA 522 graph



News & Events