It has been widely reported that metal on metal hip implants such as the DePuy ASR are failing at an alarmingly high rate. An article in today’s New York Times newspaper provides a scientific explaination for how the metal debris from these hips interacts with the body to cause these failures.
The process of injury to the tissue of the hip compartment starts when metal debris from the friction of the metal ball on the femur moves on the metal liner in the acetabular cup in the hip. These metal fragments are released into the body and then scavenger cells arrive to attack these foreign substances. The scavenger cells ingest and partially digest the metal fragments. During this process the metal fragments are broken down into ions which are positively electrically charged. These charged ions then react with human tissue. Positively charged ions are known to cause chemical changes in human tissue which can damage the tissue and cause necrosis of death of the human cells. It can also trigger an immune response called metallosis which can cause a loosening of the acetabular cup.
Positively charged ions are known to be travel to different locations in the body through a process caledl electrolysis or electro-osmosis. In short, if there are parts of the body where the ph levels have a gradient change in electrical charge this can cause the charged ions to travel. This scientific theory has not been the subject of any studies that I have seen involving hips and was not discussed in the New York Times article but it could provide an explaination for some of the extensive damage that continues to be found in metal on metal hip implant patients.
It has been known for over a decade that metal on metal hip implants can release metallic ions into the hip compartment but it appears that the hip implant manufacturers ignored this risk in a rush to compete with each other to gain market share and increase profits.
Our law firm is seeing cases involving all of the manufacturers including DePuy, Biomet, Wright, and Smith and Nephew. The DePuy ASR litigation is the most advanced with the DePuy Pinnacle litigation following close behind. Few Bioment cases have been filed but we expect those to increase and we are seeing significant numbers of Biomet hip failures. Smith and Nephew makes the Birmingham Hip Replacement known as the BHR. These have the best success rate so far but there are still failures of the BHR that are clearly caused by the metal ion debris exposure.
The U.S. Food and Drug Administration (FDA) is conducting a study across all manufacturers whoich should shed more light on the differences among manufacturers but it appears that they all suffer from this unacceptable risk of failure posed by the metal on metal articulation. Many surgeons that I have spoken with will not use and metal on metal hip implant because they believe the risk of failure from the metallosis does not justify the purported benefit of longer implant life.
Admitted to practice law in all federal multidistrict litigation courts, the California State Bar and the Florida Bar. His philosophy is to provide aggressive, quality representations and seek fair compensation for individuals and their families who have suffered injury, death, or sexual abuse.