Following the loosening of components of the metal-on-polyethylene hip implant design, the abandoned metal-on-metal hip design was again considered. The metal-on-metal hip implants were reconsidered to cater the needs of younger patients and whose lifestyles are active. As reported, metal-on-metal implants cause tissue damage.
The articulating surfaces of the all-metal hip implants are made up of cobalt-chrome. Cobalt-chrome offers high wear resistance and has much smaller debris particles than the metal-on-plastic polyethylene plastic articulation. MoM hip implants may be more suitable for younger and physically active patients because the metal is durable enough to last a long time. Although the implant was adopted quickly by surgeons, disapproval was also thrown to it.
Recently, the New York Times had more evidence to provide on the danger brought by metal-on-metal hip replacements. The shedding of metal particles by the MoM hip devices causes tissue damage around the hip, as stated in the report.Corrosion of the metal components of the hip device will result to flaking off of its particles and maybe released into the blood stream. Metallosis or metal toxicity may result if the metal particles in the blood continue to increase.
Patients suffering from metallosis may experience pain around the implanted hip, a rash that indicates a dying tissue, difficulty walking, sitting or standing, pseudotumors or mass filled with fluid and swelling and inflammation around the implant area. Loosening of the implant or detachment from the bone and dislocation or misalignment of the implant and bone may eventually happen. It can also result to destruction of nerve, tissue and muscles.
The ASR XL Acetabular System and the ASR Hip Resurfacing System are the line of MoM hip implants released by the DePuy Orthopedics in 2003. The design of the implant was defective where the ball and socket components do not fit perfectly, according to reports. Metallosis may happen due to corrosion and flaking of metal particles at the femoral head part.On the August 2011 issue of the New York Times, complaints on all-metal hip implants has reached approximately 5,000 and 75% of it were all pertaining to the DePuy ASR hip system.
Complaints on metal-on-metal hip implants have soared and are becoming a health concern. Responses to the complaints of the affected patients have been made by device manufacturers. A worldwide hip replacement recall has been issued by the DePuy Orthopedics on 2010. Conduction of post market surveillance studies by the device manufacturers was ordered by the FDA as an added measure. In 2010, an ASR hip replacement recall was ordered by the DePuy Orthopedics