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
Multi-year study finds 'hotspots' of ammonia over world's major agricultural areas
17.03.2017 | University of Maryland
Diabetes Drug May Improve Bone Fat-induced Defects of Fracture Healing
17.03.2017 | Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy