Overview: Hip replacements tend to fail more often in women than in men, according to a study published in JAMA Internal Medicine. After controlling for a variety of factors, researchers found that revision rates were 29 percent higher in women. Much of the increased risk was concentrated on metal-on-metal hip implants, which have come under intense scrutiny due to reports of higher revision rates.
- A study published in JAMA Internal Medicine found that hip implants fail more often in women than in men; revision rates were 29 percent higher
- Much of the increased risk was focused on metal-on-metal hip implants; the risk in women was doubled
- There was no increase in risk of septic failure, meaning that the higher failure rates in women have to do with factors other than infection
Product & Manufacturer
|Johnson & Johnson/ DePuy Orthopaedics||Biomet||Smith Nephew||Zimmer||Wright Medical Technology|
|ASR (recalled)||M2a Magnum||Oxinium||Durom||CONSERVE Hip Systems|
Side Effects & Complications
- High failure rate
- Necrosis (tissue death)
- Increased levels of cobalt and chromium ions
- Pain at the implant, sometimes spreading to the groin and back
- Osteolysis (bone loss)
- Fluid collections/solid masses around the hip joint
The study involved 35,140 patients undergoing primary total hip arthroplasty who were followed for a median of three years. MedPage Today reports that the all-cause rate of failure was 2.3 percent for women and 1.9 percent for men. After adjusting for factors such as age, body mass index, diabetes status, degree of presurgical symptom severity, implant fixation method, device category and femoral head size, the authors of the study calculated a hazard ration (HR) for revision of 1.29 for women versus men. This means that the rate of implant failure leading to revision was 29 percent higher in women compared to men. The risk was most prominent for aseptic revision, and larger femoral head sizes appeared to increase the risk of revision for women. When looking at implants 36mm or larger, the adjusted HR for women versus men was 1.49. According to MedPage Today, a large portion of the increased risk seemed focused on metal-on-metal hip implants, with a doubling in risk for women versus men. The study noted that there was no increase in septic failure for women, suggesting that the reasons for increased failure have to do with factors other than infection.
Metal-on-Metal Hip Implants
A total hip replacement consists of a ball or head that sits atop the thighbone rotating within a cup that acts as the hip socket. These hip implants can have different types of bearings, such as metal-on-ceramic, metal-on-polyethylene or metal-on-metal. The metal-on-metal class, such as the DePuy ASR, has come under fire amidst high profile recalls and research showing that they fail more often than other types of hip replacements. Furthermore, the implants reportedly shed metal ion debris when the patient walks or runs. This buildup of metal ions can lead to a variety of complications, including pain, swelling, tissue death, bone damage, metal poisoning and ultimately, the need for early revision surgery.