Typical fixed hip replacement components include a stem that inserts into the femur, a ball that replaces the head of the femur or top of the thigh bone, and a shell that lines the hip socket (acetabulum). An innovation in hip replacement design, the Mobile Bearing Hip™ Replacement only from Stryker features a unique polyethylene insert made with X3® Advanced Bearing Technology that is designed to fit snugly within the metal shell and over the ball to secure and buffer the joint. It’s called anatomic dual mobility or ADM. The insert allows both hip components to glide smoothly without the stem making contact with the shell. The Mobile Bearing Hip™’s design allows your doctor to more closely match the implant to your anatomy and provides you with several potential advantages.
The Mobile Bearing Hip™ Replacement is built for more natural movement. Its anatomic cup design offers stability while allowing greater freedom of movement. Test results demonstrated approximately 145º range of motion in a front-to-back sweep of the leg — a full 5% gain in range of motion when compared with fixed-bearing implants of equivalent size.1 Stryker’s Mobile Bearing Hip is designed to better accommodate your natural walking (gait) cycle of movement, both in range of motion and in directional shifts. Greater range of motion may allow you to maintain your active lifestyle with fewer compromises.
Comfort and stability are important to helping you regain your activity level. The Mobile Bearing Hip™ Replacement is designed to help to minimize the potential risks of hip dislocation and irritation of the muscles and tendons that support your hip.2, 3
Until now, in order to reduce the possibility of dislocation, doctors often turned to the use of metal-on-metal large head technologies because of the size of femoral heads (top of thigh bone). The specialized polyethylene insert helps prevent the metal components from moving against each other while the larger head contributes to an increase in joint stability.2
Its specially designed cup is also less likely to impinge on the tendon that runs from the groin toward the front of the pelvic bone (iliopsoas tendon).3 An impingement might result in hip stiffness, groin pain and/or a clicking sensation in the hip — signs that the pelvis catches the tendon when the hip flexes. Stryker’s Mobile Bearing Hip™ features a highly specialized iliopsoas tendon cutout.
Constantly looking to improve orthopaedic medicine, physicians and engineers study closely the “bearing surface” of implants — where the joint comes together to carry your body weight. Stryker’s Mobile Bearing Hip™ with X3® offers wear protection on two fronts. Both its dual mobility and its X3® technology bearing surface help to create a prosthesis that is designed to resist wear and has the potential to last longer.4 Test results demonstrate that X3® has shown a 97% decrease in wear compared to conventional polyethylene in laboratory testing.4 Less wear may mean a longer life for your hip replacement.4
1. Stryker Test Report: RD-06-078.
2. Stryker Test Report: RD-09-068.
3. Tracol P, Vandenbussche E, Deloge N, et al. (2007). Navigation Acetabular Anatomic Study Application in the Development of a New Implant. EFORT Poster.
4. Stryker® Orthopaedics Trident® Acetabular Inserts made of X3® UHMWPE (unsterilized), 721-00-32E, show a 97% reduction in volumetric wear rate versus the same insert fabricated from N2\Vac™ gamma sterilized UHMWPE, 620-00-32E. The insert tested was 7.5mm thick with an inner diameter of 32mm. Testing was conducted under multi-axial hip joint simulation for 5 million cycles using a 32mm CoCr articulating counterface and calf serum lubricant. X3® UHMWPE Trident® Acetabular Inserts showed a net weight gain due to fluid absorption phenomena but yielded a positive slope and wear rate in linear regression analysis. Volumetric wear rates were 46.39 ± 11.42mm3/106 cycles for N2\Vac™ gamma sterilized UHMWPE inserts and 1.35 ± 0.68mm3/106 cycles for X3® UHMWPE (unsterilized) Trident® Acetabular Inserts. Although in-vitro hip wear simulation methods have not been shown to quantitatively predict clinical wear performance, the current model has been able to reproduce correct wear resistance rankings for some materials with documented clinical results.a, b, c.
The information presented is for educational purposes only. Stryker is not dispensing medical advice. Only your doctor can make the medical judgment which products and treatments are right for your own individual condition. Please consult with your own doctor before implementing any of the above suggestions or beginning any new exercise, diet or treatment program.
Stryker Corporation or its divisions or other corporate affiliated entities own, use or have applied for the following trademarks or service marks: Mobile Bearing Hip, Stryker, X3. All other trademarks are trademarks of their respective owners or holders.