Study Warns Women Away from Hip Resurfacing

The results of a new study published in The Lancet reports that women and small men should avoid hip resurfacing surgeries. The bone-sparing alternatives to total hip replacement surgery are often recommended to younger patients needing hip replacements, but research from thousands of such operations show that many of these implants failed within the first seven years.

This warning adds to the concerns that patients already have concerning certain hip devices, including the Biomet M2A-Magnum. The M2A is an all-metal implant, which increases the risk of metal contamination in surrounding tissues and bone, and can increase risk of premature implant failure and required revision surgery.

What is Hip Resurfacing?

During a traditional hip replacement surgery, the entire ball of the hip joint is replaced with a metal or ceramic ball, which then fits inside a metal or polyurethane cup or liner inside the hip socket. This is considered best when the patient suffers from osteoarthritis, which weakens and deteriorates the bone.

In a hip resurfacing surgery, on the other hand, instead of completely replacing the ball, the damaged hip ball is reshaped and then capped with a metal prosthesis. The procedure leaves some of the bone intact, which theoretically, may make it easier to perform a total hip replacement if needed later in life. Therefore, hip resurfacing surgeries are often recommended for younger patients.

Hip resurfacing, however, is considered a more difficult surgery, and requires a larger incision.

What the Study Found

The study, conducted on behalf of the National Joint Registry for England and Wales, looked at data taken from 434,650 hip operations completed between April 2003 and September 2011. A total of 31,932 of these were hip resurfacing operations.

Researchers from the Bristol University reviewed the data and concluded that resurfacing has an unacceptably high early failure rate during the first seven years in women when compared to traditional hip replacement. Smaller men also experienced a high rate of failures. Only middle-aged men of larger stature experienced results about equal to those experienced with total hip replacements.

Professor Ashley Blom, lead author of the study, noted that 55-year-old women going through a hip resurfacing surgery would have an 11 percent chance of needing revision surgery within seven years, compared to two percent of those going through a traditional hip replacement.

She also noted that the Smith & Nephew Birmingham resurfacing device was used in about 50 percent of all resurfacing procedures captured by the registry.

Metal Contamination a Concern with Both Types of Implants

Many hip resurfacing devices place a metal ball inside a metal socket liner. Research and reports over the last few years have indicated that these devices can shed small particles of cobalt and chromium into the surrounding tissue and bone, causing inflammation, pockets of swelling, tissue damage and death, bone loss, and premature loosening of the implant.

Several traditional hip replacement devices are also made of all metal materials that can increase risk of metal contamination. In June 2012, an independent FDA panel said there are few reasons to continue to use metal-on-metal implants, amid growing evidence that they can break down early and shed dangerous metallic particles.

Recent research has recommended that patients consider carefully their options before choosing these types of implants, which include the recalled DePuy ASR, as well as the Zimmer Durom Cup, DePuy Pinnacle, Smith & Nephew R3, Smith & Nephew Rejuvenate, and Wright Conserve.