Stryker Orthopaedics (Mahwah, New Jersey) is among the many orthopedic companies promoting new products this week at the American Academy of Orthopaedic Surgeons (AAOS; Rosemont, Illinois) meeting in New Orleans, which kicked off on Tuesday.
But one system Stryker most likely is not showing off at the meeting is its mobile bearing knee system. The company reported this week that its recent FDA-monitored investigational device exemption study found no statistical difference in clinical outcomes between its mobile bearing and traditional fixed bearing knee systems – and, as a result, it has decided not to sell its mobile bearing knee system in the U.S.
Stryker says it continues to be “very pleased“ with its fixed bearing Triathlon Knee System with X3 Advanced Bearing Technology, which offers “significant advantages“ over mobile bearing knees on wear rates, revision and overall function.
“Because mobile bearing knees in general offer no clinical advantages, carry an increased cost to their fixed bearing counterpart and result in a higher rate of revision surgery than fixed bearing knees, Stryker has decided not to offer a mobile bearing knee system to the U.S. market,“ said Patrick Treacy, VP and general manager of Stryker's Knee business.
The aging boomer generation and young high-intensity athletes have driven increased demand for advancements in the design of knee replacement technology. To capitalize on this demand, several orthopedic device makers have recently introduced updates to previous generations of their mobile bearing knees citing improved motion, lower post-op complications and reduced wear, Stryker noted.
“The results from this IDE study are in line with other studies and national joint registries that suggest the promise of mobile bearing knee systems are not fulfilled when clinically compared to their fixed bearing counterparts,“ Treacy said. “The data to date demonstrate that mobile bearing knee systems offer no clinical advantages over fixed bearing knee systems.“
Comparing a fixed and mobile bearing knee similar to those currently offered on the market, Stryker's IDE study results are consistent with findings published in the Australian National Joint Replacement Registry and recent articles in the Journal of Arthroplasty and Orthopedics Today, according to the company. In addition, laboratory tests demonstrate that Stryker's Triathlon Knee System with X3 Advanced Bearing Technology shows a 97% reduction in total polyethylene volume loss compared with competitive mobile bearing knee systems, the company noted. The Triathlon's high flexion design offers the lowest risk of revision on the National Joint Registry for England and Wales, a risk of revision over four times lower than the best performing mobile bearing knees, Stryker added.
Among the products Stryker is featuring at the AAOS meeting is its ADM X3 Mobile Bearing Acetabular system, which is designed to address one of the top complications of hip replacement surgery – dislocation – without the risk of metal ion release.
To address dislocation, conventional designs focus on the use of metal-on-metal large head technologies, which, based on recent studies, suggest added risk due to metal ion release, Stryker noted. Combining an “evolution in design“ with the only anatomic dual mobility acetabluar system and its X3 Advanced Bearing technology, the company says its mobile bearing hip addresses dislocation without the risk of metal ion release.
“By developing an implant that addresses adverse outcomes associated with hip replacement surgery, we are not only helping surgeons to treat their patients more successfully, but we are also striving to reduce global healthcare costs by minimizing surgical complications,“ said Bill Huffnagle, VP and general manager of hip reconstruction at Stryker.
The company says this mobile bearing hip system is made possible due to its X3 Advanced Bearing Technology, which is designed to increase the longevity of the implant. Laboratory tests have shown a 97% reduction in volumetric wear compared to conventional polyethylene. ADM's anatomic design also has the potential to increase mobility and reduce groin pain. Its dual points of articulation help accommodate multi-directional movement, which provide greater range of motion than fixed implant designs based on laboratory testing. In addition, the anatomic cup design has an iliopsoas tendon cutout aimed at reducing iliopsoas tendon impingement, a key cause of post-operative groin pain.
“We believe that mobile bearing hips will become the new standard of care in total hip replacements and are committed to offering advanced technologies that benefit both surgeons and patients while adding value in ways that have the potential to reduce costs to the healthcare system,“ Huffnagle said.
The company is also featuring its Rejuvenate Modular Primary Hip system at AAOS.
“Our team continues to partner with surgeons to develop and commercialize cutting-edge technologies and products, such as Rejuvenate and ADM, that aim to enhance patient outcomes and streamline surgeons' operating room efficiency,“ said Mike Mogul, group president of Stryker Orthopaedics.
The company said its booth at AAOS would also feature the VersiTomic ACL System, using customized instruments and flexible drill technology, designed to allow for more anatomic placement and drilling of tunnels during ACL reconstruction.
Amanda Pedersen, 229-471-4212