Use of Ceramic & Metal Surfaces in Total Hip Replacement
Total hip replacement (hip arthroplasty or THA) is a successful surgery for the relief of pain from various forms of degenerative hip disease. The longevity of replacements in general have improved over the years, to the point that the most common reason for failure today is plastic (polyethylene) liner wear and resultant bone failure (osteolysis). Although great differences in longevity exists between implants, successful component designs are lasting approximately 15 years before failures start to increase significantly from the wear of the polyethylene liner.
Because it appears that polyethylene is the inherent weakness in the total hip replacement construct, interest has been placed in the use of ceramics and metal bearing surfaces in an attempt to increase longevity of THA by eliminating polyethylene and subsequently decreasing wear rates with the use of these hard bearing surfaces. This is especially attractive when treating younger patients with end-stage degenerative hip disease.
However, with every new material used come new challenges and unknowns. Metal bearings wear very little and have a long track record in Europe. Recently, concerns over high systemic metal ion levels in patients with metal-on-metal (MOM) bearings have been raised. Can this cause a problem such as cancer ? With data available, it looks as if the answer is no, although studies in younger patients with MOM bearing implants for 30-40 years have not been performed.
Ceramics have been available in Europe for over 25 years. They have been used in the U.S. sparingly for well over 10 years. Ceramic-on-ceramic (COC) bearings have only been FDA approved for about four years. Many generations in the quality of ceramics have been developed and much has been learned in making these ceramics strong, wear resistant and chemically stable.
Ceramics, by far, have the best wear potential of any material known currently. The largest worry is the risk of ceramic fracture, currently quoted at 0.004% for one of the most modern ceramics, but has been more frequent with the first and second generation ceramics. Ceramics are currently mated with a ceramic or polyethylene liner, with ceramic-on-ceramic (COC) showing the least wear of all.
In my practice, all of the above materials are used in hip reconstruction, depending on patient’s age, activity level, anatomy and personal comfort with emerging technology. In general, I have my patients up to 55 years old highly consider ceramic or metal bearings, patients 55-70 consider metal bearings and patients greater than 70 either metal or plastic is recommended. These guidelines seem to best balance the currently known risks and benefits of each material with the required longevity of the prosthesis for each age group, assuming roughly a ninety-year life expectancy.
For further information about the use of ceramic and metal surfaces in total hip arthroplasty please, contact Dr. Shreedhar Archik Best Hip Replacement Surgeon in Mumbai.
Total hip replacement (hip arthroplasty or THA) is a successful surgery for the relief of pain from various forms of degenerative hip disease. The longevity of replacements in general have improved over the years, to the point that the most common reason for failure today is plastic (polyethylene) liner wear and resultant bone failure (osteolysis). Although great differences in longevity exists between implants, successful component designs are lasting approximately 15 years before failures start to increase significantly from the wear of the polyethylene liner.
Because it appears that polyethylene is the inherent weakness in the total hip replacement construct, interest has been placed in the use of ceramics and metal bearing surfaces in an attempt to increase longevity of THA by eliminating polyethylene and subsequently decreasing wear rates with the use of these hard bearing surfaces. This is especially attractive when treating younger patients with end-stage degenerative hip disease.
However, with every new material used come new challenges and unknowns. Metal bearings wear very little and have a long track record in Europe. Recently, concerns over high systemic metal ion levels in patients with metal-on-metal (MOM) bearings have been raised. Can this cause a problem such as cancer ? With data available, it looks as if the answer is no, although studies in younger patients with MOM bearing implants for 30-40 years have not been performed.
Ceramics have been available in Europe for over 25 years. They have been used in the U.S. sparingly for well over 10 years. Ceramic-on-ceramic (COC) bearings have only been FDA approved for about four years. Many generations in the quality of ceramics have been developed and much has been learned in making these ceramics strong, wear resistant and chemically stable.
Ceramics, by far, have the best wear potential of any material known currently. The largest worry is the risk of ceramic fracture, currently quoted at 0.004% for one of the most modern ceramics, but has been more frequent with the first and second generation ceramics. Ceramics are currently mated with a ceramic or polyethylene liner, with ceramic-on-ceramic (COC) showing the least wear of all.
In my practice, all of the above materials are used in hip reconstruction, depending on patient’s age, activity level, anatomy and personal comfort with emerging technology. In general, I have my patients up to 55 years old highly consider ceramic or metal bearings, patients 55-70 consider metal bearings and patients greater than 70 either metal or plastic is recommended. These guidelines seem to best balance the currently known risks and benefits of each material with the required longevity of the prosthesis for each age group, assuming roughly a ninety-year life expectancy.
For further information about the use of ceramic and metal surfaces in total hip arthroplasty please, contact Dr. Shreedhar Archik Best Hip Replacement Surgeon in Mumbai.
