Clinical and radiological evidence showed that 96 percent of the 124 cementless metal components assessed remained securely fixed in place 20 years post surgery, according to a study published in the May issue of the Journal of Bone and Joint Surgery.
These components, which fit into the cup-shaped hip socket, or acetabulum, were among the first implants designed with a porous structure to allow bone to grow into the surface in the hopes of achieving long-term fixation.
"Our results confirm earlier work done at Rush and at other institutions: that cementless acetabular components work very well and that long-term biological fixation can be obtained," said Dr. Craig Della Valle, an orthopedic surgeon and principal author of the study.
Over the last two decades, the researchers have been studying the results for 204 total hip replacements performed at Rush in the mid-1980s in a group of 184 patients ranging in age from 20 to 84 years. Findings were previously reported at 10 and 15 years.
The implants studied were the Harris-Galante I acetabular component, whose design was based on pioneering research work done by Dr. Jorge Galante, former chairman of orthopedics at Rush and a co-author of this study. Earlier-generation implants, which relied on special cement to secure the device to the patient's bones, had been shown to have higher rates of failure, particularly beyond 10 years.
"The hope was to provide more durable fixation, especially for younger patients with a longer life span," Galante said.
In the present study, the researchers analyzed results for 124 hip replacements in the 111 patients who were still alive 20 years or more after surgery. Since the previous report at 15 years, two metal cup implants, in addition to the three noted earlier, were found to be loose, or 4 percent of the 124 implants. Of the original 204 hip replacements, five cases, or 2.5 percent of the total, had failed. Two of these five implants were revised, but three were left intact because the patients did not suffer significant symptoms.
However, in nearly 20 percent of the patients still living 20 years post surgery, the plastic lining of the metal shell had worn enough that repeat, but less involved, surgery was required or recommended. Younger age strongly correlated with a higher risk of wear-related problems, the study showed.
"The average age of the patients in this study was 52 years, much younger than most patients who underwent hip replacements at the time. So the high rate of wear-related complications was not completely unexpected," Galante said.
Also, with time, the number of surgical revisions has increased due to osteolysis, or bone resorption as a result of the body's reaction to debris created by wear and corrosion of the metal implants.
"With time, the number of repeat surgeries due to wear and osteolysis has increased, as have the numbers of cases of osteolysis we identified radiologically. But with the newer, more wear-resistant bearing surfaces we are now using, we believe that fewer patients today will need revision surgery for these reasons," Della Valle said.
"This longitudinal study gives us a wealth of data to use as we continue to improve on techniques and materials for total hip replacements," Galante said.
Rush University Medical Center's orthopedics program ranks tenth in the nation, according to U.S. News & World Report. Physicians from Rush serve as the team physicians for the Chicago Bulls and the Chicago White Sox. For more information on orthopedics at Rush, visit http://www.rush.edu/rumc/page-R11726.html or call (888) 352-RUSH.
Rush University Medical Center includes the 674-bed (staffed) hospital; the Johnston R. Bowman Health Center; and Rush University (Rush Medical College, College of Nursing, College of Health Sciences and the Graduate College).
Sharon Butler | EurekAlert!
Further reports about: > Cementless Cup > Cementless hip implants > Harris-Galante I acetabular component > Medical Wellness > Total Hip Replacements > acetabulum > bone resorption > corrosion of the metal implants > cup-shaped hip socket > hip replacement > long-term fixation > osteolysis > porous structure
New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)
Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...
Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.
A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
21.04.2017 | Physics and Astronomy
21.04.2017 | Health and Medicine
21.04.2017 | Physics and Astronomy