Hip replacement parts that were previously thought to have to be exchanged every 10 years can actually last twice as long, U.S. researchers suggest.
In the majority of cases (96 per cent), the cementless metal parts of hip implants were securely in place 20 years after surgery, say researchers who examined 124 of the devices for a study published in the May issue of the Journal of Bone and Joint Surgery.
Dr. Craig Della Valle, an orthopedic surgeon at Rush University Medical Center and his colleagues have been studying the results for 204 hip replacements that were done in the mid-1980s in a group of 184 patients age 20 to 84.
Few of the metal implants that fit into the cup-shaped hip socket, or acetabulum, became loose. But in 20 per cent of the patients still living 20 years after surgery, the plastic lining of the metal shell was worn enough that more surgery was required or recommended.