Since 1996 more than one million metal-on-metal articulations have been implanted worldwide. Adverse reactions to metal debris are escalating. Here we present an algorithmic approach to patient management. The general approach to all arthroplasty patients returning for follow-up begins with a detailed history, querying for pain, discomfort or compromise of function. Symptomatic patients should be evaluated for intra-articular and extra-articular causes of pain. In large head MoM arthroplasty, aseptic loosening may be the source of pain and is frequently difficult to diagnose. Sepsis should be ruled out as a source of pain. Plain radiographs are evaluated to rule out loosening and osteolysis, and assess component position. Laboratory evaluation commences with erythrocyte sedimentation rate and C-reactive protein, which may be elevated. Serum metal ions should be assessed by an approved facility. Aspiration, with manual cell count and culture/sensitivity should be performed, with cloudy to creamy fluid with predominance of monocytes often indicative of failure. Imaging should include ultrasound or metal artifact reduction sequence MRI, specifically evaluating for fluid collections and/or masses about the hip. If adverse reaction to metal debris is suspected then revision to metal or ceramic-on-polyethylene is indicated and can be successful. Delay may be associated with extensive soft-tissue damage and hence poor clinical outcome.
The author or one or more of the authors have received or will receive benefits for personal or professional use from a commercial party related directly or indirectly to the subject of this article.
Some products discussed (Sikomet, Ultima, Lubrimet, Adept, Fitmore, McMinn, Wagner) have not been approved by the U.S. Food and Drug Administration. The DePuy ASR and the Zimmer Durom have been voluntarily recalled by the manufacturers. Although this paper is sponsored by the Hip Society, the opinions discussed are those of the individual authors and do not reflect a consensus by the Hip Society. Algorithms evolve with increasing knowledge and experience.
This paper is based on a study which was presented at the Winter 2011 Current Concepts in Joint Replacement meeting in Orlando, Florida, 7th – 10th December.
- Received August 14, 2012.
- Accepted August 14, 2012.
- ©2012 British Editorial Society of Bone and Joint Surgery