Hip Replacment Implant Options

3 Implant Options For Patients Who Need Hip Replacement Surgery

hip implants
Hip replacement implants can be made of different materials.. Don Farrall / Getty Images

Hip replacements are among the most common orthopedic procedures. When a hip replacement is performed, the arthritic, damaged hip joint is removed. The ball-and-socket hip joint is then replaced with an artificial implant. The materials used in the implant depend on different factors, including:

  • Age of the patient
  • Activity level of the patient
  • Surgeon's preference
  • Particular deformities/abnormalities of the hip

    Hare are brief descriptions of some of the most commonly used hip replacement implants. Not all implants are options for all patients. 

    Metal and Plastic Implants

    A prosthetic made of metal and plastic are the most commonly used hip replacement implants. Both the ball and the socket of the hip joint are replaced with a metal implant, and a plastic spacer is placed in between.  The most commonly used metals used include titanium and stainless steel. The plastic is called polyethylene. The implant is secured to the bone by one of two methods; it is either press-fit or cemented into place. In the press-fit method, the implant is fit snugly into the bone, and new bone forms around the implant to secure it in position. When an implant is cemented, a special bone cement is used to secure the prosthesis in position.

    New implants are continually being developed in an effort to make these implants last as long as possible.

      One more recent development is improving the longevity of the polyethylene used in the replacement. These so-called 'highly crosslinked' plastics are manufactured in a way that they wear out less quickly than the traditional plastics.

    Metal-on-Metal Implant

    Metal-on-metal implants use similar materials, but there is no plastic spacer inserted between the implants.

    Metal-on-metal implants became very popular because they were found to have very good wear characteristics in the lab.  However, despite the low wear rates, there were problems with the metal-on-metal implants.

    Initially, there were concerns about the wear debris that is generated from the metal-on-metal implants. Metal ions are released into the blood, and these metal ions can be detected throughout the body. Concentrating these metal ions increases over time. There are no data to show that these metal ions lead to increased rates of cancer or disease, but longer term studies still need to be performed.

    In addition, there were some highly publicized recalls of metal-on-metal implants because they were shown to require revision surgery (replacement of the replacement) at a higher rate than standard hip replacement implants.  As a result of this, metal-on-metal implants have gone from being a very popular type of implant to a very rarely used type of implant.

    Ceramic Implants

    Ceramic hip replacement implants also use metal parts that fit within the bone, but the bearing surface (the ball and the socket) can be made of the ceramic material.

      Ceramic hip implants are designed to be the most resistant to wear of all available hip replacement implants. They wear even less than the metal-on-metal implants. Ceramics are more scratch resistant and smoother than any of these other implant materials.  Older versions of ceramic implants had problems because they were prone to breakage, but the newer versions have not had these problems.  For this reason, ceramic hip replacements are becoming a more popular implant.

    Bottom Line: Which Is Best?

    There is no clear "best" implant.  While new implants are being developed to improve upon designs, there are sometimes problems that aren't known as soon as a new implant is released.  For that reason, some surgeons prefer an implant with a good, long track record.  Your surgeon should be able to clearly explain why they are recommending a particular implant for you.

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