 With 60,000 patients having a metal on metal MOM hip implant in the United Kingdom UK, and over a million worldwide, there is need to clarify this important question, which is the source of significant concern amongst patients and surgeons alike. Also, this problem is not unique to MOM hips since all hip implants contain metal and as seen in various case reports high blood cobalt levels have arisen after catastrophic failure e.g. fracture of a ceramic bearing surface leading to abnormal wear of the implant and release of metal ions into the body. In the UK, over 80,000 hip implants are inserted annually. 