Case reports in the medical literature have suggested the potential for systemic effects of elevated metal ion levels resulting from device wear in metal-on-metal (MoM) hip implants. These effects have included:
General hypersensitivity reaction (e.g., skin rash)
Neurological changes including sensory changes (auditory, or visual impairments)
Psychological status change (including depression or cognitive impairment)
Renal function impairment
Thyroid dysfunction (including neck discomfort, fatigue, weight gain or feeling cold
Based on these limited number of case reports in published literature, the true incidence or prevalence of adverse systemic or local effects from MoM hip implants is not known at this time.
A symptomatic patient with MoM hip implant may be more likely to visit his or her general practitioner or medical specialist rather than his or her orthopaedic surgeon. It is imperative that all health care providers be aware of the potential role of metal ions during their evaluation of their patients with MoM hip implants
At the current time, is not enough evidence in the U.S. demonstrating a correlation between a metal ion level in isolation and the presence of localized lesions, clinical outcomes and/or the need for revision surgery.
If the patient's local or systemic findings are thought to be related to the MoM hip implant, the patient should follow-up with his or her orthopaedic surgeon to determine the appropriate course of action.