Metal-on-metal hip implant debris causes pseudotumors detected years too late

Metal-on-metal hip replacements shed cobalt and chromium ions into surrounding tissue, which can form destructive pseudotumors (adverse local tissue reactions) that silently destroy muscle and bone for 3-7 years before symptoms appear. By the time a patient notices groin pain or leg weakness, the tissue damage is often so extensive that revision surgery becomes far more complex, with worse outcomes and longer recovery. Over 500,000 patients received these implants before the scale of the problem became clear, and many still have not been screened. This persists because post-market surveillance for implants relies on voluntary surgeon reporting rather than mandatory patient follow-up registries, so slowly-developing complications go undetected until they become catastrophic case reports.