If your doctor has recommended replacement surgery to treat your hip trouble or you have already had an implant procedure, you're probably quite interested in finding out exactly what the controversy is all about and how all these problems are happening.
Problems and Complications
Rates of early implant failure were high among these recalled hip replacement systems, forcing many patients to undergo painful and costly surgical procedures, called revisions, to remove the faulty implants, repair the damage and install a new replacement system.
The Recalls
Over the past few years, metal-on-metal hip replacement systems made by several manufacturers have been recalled due to higher than normal rates of complications and premature implant failures.
DePuy Orthopaedics, which is a division of Johnson & Johnson, recalled its ASR Hip Resurfacing System and ASR XL Acetabular System. Two implant products made by Stryker Orthopaedics were recalled: the Rejuvenate and the ABG II modular-neck hip stems. Zimmer Holdings recalled its Durom Cup temporarily, returning it to the market with revised instructions, and Smith & Nephew recalled a component of its R3 Acetabular System.
Implant debris is the source of some of the more serious complications seen with these products, shed due to the friction between components as the patient walks. In the recalled replacement systems, design flaws and improper alignment of the components caused more wear and debris than is usual in hip implants, leading to high rates of debris-related complications and revision surgeries.
Among the most serious of these hip replacement complications is metallosis, which occurs when the soft tissues around the implant are contaminated with metallic debris particles. This can lead to severe pain and inflammation, tissue death, and bone death, often causing implant loosening and failure. In some cases, high levels of metal ions were also found to be circulating in the blood system, disbursed throughout the body. The long-term consequences of that widespread metal contamination in the body have yet to be determined. However, the U.S. Food and Drug Administration (FDA) states that metal ions in the blood can cause other symptoms or illnesses in the nervous system, thyroid gland and heart.
FDA Information and Recommendations
The FDA cautions that patients who have metal-on-metal hip replacements should watch for symptoms that include pain in the groin or leg, swelling at or near the hip joint and a limp or change in walking ability. If these symptoms emerge, patients should be thoroughly examined, and may need testing, including imaging tests, joint aspiration and blood tests to measure levels of metal ions in the blood. The agency also recommends that patients watch for general health symptoms, such as chest pain, shortness of breath, changes in vision or hearing, numbness or weakness, weight gain, fatigue and changes in urinary function.
Elizabeth Carrollton writes about defective medical devices and dangerous drugs for Drugwatch.com.
