As recipients of DePuy metal-on-metal hips continue to experience premature implant failure, metallosis, and other side effects, the medical device maker... read more
Biomet Hip Implants
How the Hip Replacement Systems Work
People with intractable arthritis or injury of the hip often have a prosthetic hip surgically implanted to replace the defective joint.The hip is a ball and socket joint. The socket is a concave cutout in the pelvis. The ball is a globe-shaped piece of bone attached to the top of the femur, or the thigh bone. It is called the femoral head.
The concave socket is called the acetabulum. When a hip replacement is done, the surgeon removes the parts of the patient's own hip and fits an acetabular cup into the patient's socket which has been prepared to accept the cup. The surgeon thus removes the human portions of the hip joint and replaces them with metal parts.
Formerly, before metal parts were used in the prosthetic joint, the parts of the joint were made of ceramic or polyethylene, a type of hard plastic. These artificial materials were eventually replaced by metal. The thinking was that the metal parts would wear longer and would slide against each other more easily, thus providing the patient more range of motion.
Types of Hip Implant Systems Made by Biomet
Over time, polyethylene degenerates through a process called oxidation. Biomet has developed polyethylene inserts that are made with infused Vitamin E to prevent oxidation. Laboratory tests have shown the E1™ inserts made with Vitamin E do not degrade.
When metal was first introduced into the manufacturing of hip implants, the ball, or femoral head, was replaced with metal which then moved within the hip socket that had been replaced by polyethylene. Then, to increase durability, joint replacement companies made both the cup and the ball out of metal.
According to Biomet, the advantages of using metal are:
- Reduction in wear
- The ability to use larger femoral heads, which have the potential to provide more range of motion as well as greater stability and a reduced tendency to dislocate
Biomet introduced the M2a-Magnum™ hip replacement system which could give the patient over 160 degrees range of motion. The Biomet M2a-Magnum™ provides a large range of head sizes to do a better job of replicating the patient's anatomy.
Risks and Complications Associated with Biomet Hip Implants
Patients should be aware of the possible drawbacks of having a metal-on-metal (MoM) hip implant system. The problems with the MoM systems go beyond the general risks patients face with all types of implant systems, according to the U.S. Food and Drug Administration (FDA).
When a patient walks or runs, the metal parts of the hip implant rub together, casting off tiny metal particles. These particles can enter the space around the implant and inflame surrounding bony or soft tissues. The particles can damage the hip joint to such an extent that some patients will require revision surgery. This means the surgeon removes the original implant and replaces it with another one. Good results of revision hip surgery are often harder to achieve than the surgery to place the original implants and patient recovery may take longer.
In addition to harming nearby tissues, the metal particles sometimes enter the bloodstream, raising the levels of metal in the blood, and possibly causing metal poisoning. Plus, the blood carries the particles around the body, sometimes damaging organs, including the heart, nervous system and thyroid gland.
Important Patient Information
It is important, the FDA says, for hip implant patients to be able to recognize symptoms of problems with their hips, letting them know that the hips aren't functioning properly. These include:
- Pain in the groin, hip or leg
- Swelling at or near the hip join
- Change in the ability to walk or a limp
Other symptoms, according to the FDA, that hip implant patients need to be aware of are:
- Heart (chest pain, shortness of breath)
- Nerves (numbness, weakness, changes in vision or hearing)
- Thyroid (fatigue, weight gain, feeling cold)
- Kidney (change in urinary habits)
Hip implant patients should see their doctor if any of these symptoms occur.
Talk to a Hip Implant Lawyer
If you suffered problems that required revision surgery, you should talk to a hip implant lawyer about your right to seek compensation for your suffering. To learn more, schedule a free review of your case today.