The most popular materials for hip implants recently have been several metals — titanium, stainless steel and chromium. The design is called metal-on-metal because the two main parts of the artificial hip joint, the acetabulum, or hip socket, and the femoral head, a rounded piece of metal that is the ball portion of this ball and socket joint. The femoral head fits into and rotates within the acetabulum, simulating the motion of the natural hip joint.

The metal-on-metal design became popular because this combination lasts longer than metal-on-plastic, the previous hip prosthesis design. A newer combination of materials, metal-on-highly cross-linked polyethylene, a very strong plastic, is being used for some implants. Time will tell if this combination lasts longer than current materials.

Metal-On-Metal Hip Replacement Complications

There are two main problems with the metal-on-metal implants:

• They are failing earlier than normal
• They shed metal debris into the body

About 12 percent of the metal-on-metal implants have been failing in the first three years after implantation. The average life of most implants is 15 years or longer.

Metal Debris

The metal debris results from the friction caused by the implant components rubbing together as a patient walks or runs. The metal debris can cause inflammation of nearby tissue and might destroy the bone holding it. The debris can also travel through the bloodstream and affect different organs and tissues throughout the body. Potential risks include effects on the nervous system, heart and thyroid gland.

FDA Has Concerns

According to the U.S. Food and Drug Administration (FDA), at this point, it is impossible to determine who will have a reaction to the metal debris and how bad the reaction will be. In an effort to determine how bad the risk is, on May 6, 2011, the FDA ordered the 21 manufacturing companies that make metal-on-metal hip implants to conduct safety studies on the metal-on-metal prostheses implanted.

The FDA sent 145 orders to 21 manufacturers. The manufacturers will need to keep track of adverse events that may be associated with increased levels of cobalt and chromium in the bloodstream.

According to an article in the New York Times, a recent editorial in a medical journal for orthopedic surgeons, The Journal of Arthroplasty, urged doctors to use the metal-on-metal devices only with "great caution, if at all."

It is estimated that between 1 and 3 percent of implant recipients have had problems with the metal-on-metal design. That number could quickly add up, however, considering the thousands of implants done every year.

Contact our defective hip attorneys to find our if your hip replacement failure case is eligible for compensation.