By: Michael Werner, Esq.
The British Hip Society (BHS), as a representative of British hip replacement surgeons, has advised the discontinuance of the metal-on-metal hip implant due to significant failure rates.
To put the issue in proper perspective, within five years of use approximately 5.5% of large metal-on-metal implants needed replacement due to erosion concerns, as compared to approximately 2% of the comparable and standard metal-on-plastic implants. Ironically, the metal-on-metal implants were designed for durability and longevity. As the President of the British Orthopaedic Association (BOA) explained: “It is clear that as a class these large metal-on-metal implants, which were introduced to make the implant last longer in younger patients, are not fulfilling that aspiration. Because they are not fulfilling that aspiration . . . it does not make sense that surgeons continue to use them.”
The BHS’ comments come only days after the Medicines and Healthcare products Regulatory Agency (MHRA) warned that all hip patients with large diameter metal-on-metal joints should have MRI scans and annual blood tests for rising levels of cobalt and chromium. The MHRA’s warning stems from concerns attributed to the friction caused by the rubbing together of the metal-on-metal joints; the friction creates minute metal shavings that become embedded in surrounding tissue and blood. Bristol experts have discovered abnormal cells in metal-on-metal hip patients, sparking cancer fears. These findings were precipitated by metal-on-metal patients complaining of pain and swelling of the joints.
Currently, there are approximately 49,000 people in Britain with large metal-on-metal hip joint implants—the implants at issue. Patients with replacement joints measuring less than 36mm, or who have undergone only hip resurfacing procedures, are not affected by the above findings.
It should be noted that the BHS and BOA’s recommendations to discontinue use of the metal-on-metal replacement is based exclusively on failure rates, and not on the potential increased risk of cancer due to particle shedding cited by Bristol experts.
Nevertheless, it is clear that metal-on-metal patients are vulnerable to serious replacement complications. We will keep you informed on all developments.
For further information relating to the failure of hip implants, see my February 22, 2012 blog “Flawed DePuy Hip Implant Had Early F.D.A. Notice” here: http://www.yourlawyer.com/blog/flawed-depuy-hip-implant-had-early-f-d-a-notice/