New ceramic-on-ceramic and metal-on-metal hip implants are no more effective than traditional models that include polyethylene and in some cases may pose a greater safety risk, according to a recent study in BMJ.
About 270,000 of the more than 700,000 joint replacements performed in the United States annually are for the hip. Physicians traditionally have used metal-on-polyethylene implants in hip replacement procedures because they are associated with a lower revision risk. Many patients still require revision within 10 years because of dislocation, infection, instability, loosening, mechanical failures, or wear, MedPage Today reports.
Manufacturers have introduced newer, metal-on-metal and ceramic-on-ceramic implants to further curb patients' revision risk; however, increasing reports of problems involving modern metal-on-metal implants have drawn scrutiny from federal officials.
For the study—which was sponsored by FDA—researchers at Weill Cornell Medical College analyzed the results of 18 studies involving 3,139 patients and more than 830,000 hip replacement procedures reported in national orthopedic registries.
The findings showed that all-metal and all-ceramic implants did not improve functioning or quality of life compared with traditional metal-on-polyethylene versions. In addition, patients who received all-metal implants were more likely to require repeat surgery than patients who received traditional plastic ones, Reuters reports.
Study author Art Sedrakyan said the results are "preliminary" and called for additional trials. However, he noted that new studies are unlikely "to change the signal that these metal-on-metal implants are failing at a greater rate" (Clarke, Reuters, 11/29; Neale, MedPage Today, 11/29).