FOI release
Cobalt/Chrome/dual taper modular hip stems
Some or all of the information requested was not provided because we determined that the cost to do so would exceed the appropriate limit.
Case reference FOI2026/00004
Received 3 January 2026
Published 5 May 2026
Request
FOI REQUEST: Cobalt / Chrome / Dual-Taper Modular Hip Stems A. Adverse Event & Safety Reporting 1. Please provide the number of Yellow Card reports received by the MHRA relating to: • cobalt or chromium ion release • corrosion, fretting, or taper junction failure • modular neck or dual-taper hip stems broken down by year from 2010 to present. 2. Of these reports, how many: • involved revision surgery • involved systemic cobalt or chromium toxicity • involved local tissue reactions (ALTR / pseudotumours) 3. Please provide any trend analysis or internal summaries held by MHRA regarding increasing or decreasing reports related to modular hip stem designs. ⸻ B. Device Types & Design Risk 4. Does the MHRA classify dual-taper or modular neck hip stems as: • higher risk than monoblock stems? • equivalent risk? Please provide any internal guidance, assessments, or policy documents addressing this. 5. Has the MHRA issued any warnings, alerts, or internal safety concerns specifically regarding: • cobalt-chrome modular necks • mixed-metal taper junctions (e.g. Ti stem + CoCr neck) 6. Please provide copies of any MHRA safety notices, field safety notices, or internal advisories relating to modular hip stems that were not publicly issued. ⸻ C. Manufacturer & Regulatory Oversight 7. Please list all manufacturers for whom the MHRA has: • received adverse event data • conducted post-market surveillance relating to modular hip stems since 2010. 8. Has the MHRA ever: • requested design changes • imposed restrictions • required enhanced surveillance on any modular hip stem system due to cobalt/chromium concerns? If yes, please provide: • dates • manufacturers involved • nature of the action taken ⸻ D. Post-Market Surveillance & Evidence Base 9. What post-market surveillance data does the MHRA rely on to assess the long-term safety of modular hip stems? 10. Has the MHRA identified any evidence gaps relating to: • long-term ion release • taper corrosion • outcomes beyond 5–10 years 11. Please provide any risk–benefit analyses, internal reviews, or expert panel discussions held by the MHRA concerning modular hip stem designs. ⸻ E. Monitoring & Patient Safety Guidance 12. Has the MHRA issued or considered issuing guidance on: • routine cobalt/chromium blood testing • imaging surveillance (MRI / MARS MRI) for patients with modular hip stems? 13. If such guidance exists but is not public, please provide it. 14. If no such guidance exists, please confirm whether the MHRA considers: • systemic metal exposure • delayed corrosion failure to be a recognised patient safety risk. ⸻ F. Comparative Risk & International Context 15. Has the MHRA reviewed or considered: • international regulatory actions • recalls or restrictions in other jurisdictions relating to modular hip stems? 16. Please provide correspondence or reports where the MHRA: • compared UK outcomes to international data • discussed divergence from other regulators’ positions. ⸻ G. Internal Communications (High-Value Question) 17. Please provide copies of internal MHRA emails, memoranda, or briefing papers since 2010 that discuss: • cobalt/chromium risk • modular neck or dual-taper hip stems • corrosion or taper failure concerns (If redaction is required, please redact personal data only.)
Response
See attached
Documents
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