Houston Methodist. Leading Medicine

Hip News

Accounting for Differences in Rates of Wear Between Identical Hip Joint Implants

Some hip replacements wear out faster than others. In fact, the same joint implant used in a group of adults will vary in its wear pattern.

Researchers aren't sure why this happens. It might be the patient's weight, and therefore, the load on the joint. It could be activity level that affects the rate of wear. This study looked at these two factors in patients with hip replacements on both sides, which is called bilateral total hip arthroplasty.

A small group of patients with the same type of arthroplasty was studied. Each patient had the same operation, cup design, and replacement parts in both hips. No one with a limp was allowed in the study to prevent uneven wear patterns in one hip.

The authors of this study thought that by matching all replacement parts, they would reduce the differences in wear on the implant. They measured the first hip replaced and compared it to the second hip arthroplasty.

As it turned out, the difference in wear rates between the first hip and the second was drastic. In most cases, there was up to a 75 percent difference in the wear between the two implants. With all things considered, identical implants in the same patient with the same activity levels showed marked differences in wear.

The authors conclude that wear and tear on hip arthroplasties depends on more than a patient's weight and activity. At least 40 percent of the differences in wear rate come from other factors that include patient age, joint angle, and bone slivers or metal particles caught between the implant and the joint surface. Doctors can't assume that identical hip replacements will have the same result. This is true even for patients having bilateral hip arthroplasties.


Karl F. Orishimo, MS, et al. Can Component and Patient Factors Account for the Variance in Wear Rates Among Bilateral Total Hip Arthroplasty Patients? In The Journal of Arthroplasty. March 2003. Vol. 18. No. 2. Pp. 154-160.

00/00/0000

*Disclaimer:* The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic.
All content provided by eORTHOPOD® is a registered trademark of Medical Multimedia Group, L.L.C.. Content is the sole property of Medical Multimedia Group, LLC and used herein by permission.

Our Specialties

Where Does It Hurt?

Our Locations

  Follow Us

Follow us on Facebook Follow us on YouTube
Follow us on Twitter