Full Article Available Here January 9, 2014 Research into metal-on-metal hip arthroplasty has showed that success with the procedure is multifactorial. Some investigators have found it may be closely related to an exacting surgical technique and the right indications. In an article in a recent issue of Orthopaedics Today Europe, Japanese investigators discussed adverse reactions associated with second generation metal-on-metal hip implants and found 67% of the implants they revised were positioned outside of the safe zone.