The Dangers of 'Metal on Metal' Hip Replacements
Hip replacement surgery carries a degree of risk even in the best of situations. Unfortunately for thousands of patients, the risk of injury is compounded by the use of dangerous "metal on metal" artificial hips.
The Problem of the Metal on Metal Design
In a metal on metal artificial hip, the hip replacement femoral head (the ball) and the acetabulum (the socket) are both metal. By comparison, successful artificial hip designs mate polyethylene-lined acetabular cups to ceramic or metal femoral heads.
Metal on metal hips do not last longer than alternative hip designs, and in fact may have a shorter life span. This is contrary to the original manufacturers' claims of increased longevity and the need for fewer, future revision surgeries.
The dangers of metal on metal implants are:
- Loosening. The hardware becomes loose, and a reivison surgery is necessary to remove the hardware and implant a new hip. Loosening can occur due to "edge loading", a design flaw in which the artificial hip is not properly engineered to bear the weight and movement of a normal person.
- Illnesses Caused by Metal Shards Released into the Body. The wear and tear of the metal grinding against metal can release metal shards and metal ions (cobalt and chromium) into the body. This may lead to osteolysis (bone less), metallosis (an accumulation of thick, gray fluid at the hip joint which can cause tissue death and bone degradation), and neurological problems (e.g., headaches, persistent metallic taste in the mouth, memory loss, and cardiac issues).
Signs of Trouble
Generally, the first sign of trouble is extreme hip pain. A visit to the surgeon will be necessary.
However, some patients may not experience pain as an early symptom. Those patients should be monitored by both their orthopedist and their internist. Patients should have cobalt and chromium levels in their blood tested regularly.
Pain is a sign that the hip may be loosening or that the surrounding hip tissue is being attacked by metallosis.
Metal on Metal Hips
Listed below are some of the metal on metal hips known to cause injury:
- Zimmer Durom Acetabular Cup. Recalled voluntarily in 2008 when Zimmer found the use and surgical implantation instructions to be inadequate.
- DePuy ASR. The primary issues in the DePuy ASR hip device are loosening and metallosis. DePuy Orthopedics has a program to reimburse patients for expenses related to replacing the DePuy ASR, such as medical costs and lost income. Patients accepting the offer will release their claims for pain and suffering and future medical and lost income losses. Furthermore, DePuy will take-back the defective hardware after its removal, and this will prevent the patient's attorney from having the hardware inspected and evaluated by an expert. We strongly urge that patients do not accept this offer before reviewing it with an attorney.
DePuy Pinnacle. Although the Pinnacle system mostly has ceramicon metal mating, Pinnacle did make metal on metal hardware. Cup loosening and metallosis are a problem.
- Wright Conserve. Wright Medical Technologies had a line of metal on metal implants.
If you or a family member has had a metal on metal hip implant, we recommend that you consult an attorney immediately. We seriously urge that you talk to an attorney if you have had a DePuy hip and if DePuy has made the offer of paying for a new hip implant. You should consult with an attorney before deciding on accepting DePuy's offer.
Please contact us today for a free consultation.