Hip replacement motion and stability

We’re continually striving to make hip replacements more successful by reducing the risk of complications, and improving the performance of your implant. Although infrequent, one complication is the risk of hip dislocation after the surgery.

Hip dislocation occurs when the femoral head slides out of place during extreme motion. Between 3 and 4 per cent of patients receiving a total hip replacement experience hip dislocation.1 

To help prevent dislocation, your doctor will sure that the size of the implant closely matches the size and shape of your anatomy. Larger femoral heads also allow for more motion and enhanced joint stability than smaller femoral heads. Stryker’s Anatomic Femoral Heads are larger in size, similar to the top of your femur, so they are anatomically sized for more natural hip performance – helping to minimise dislocation and increase your range of motion.

 

References
1. Sanchez-Sotelo, J., et al., “Hospital Cost of Dislocation  After Primary Total Hip Arthroplasty” Journal of Bone and Joint Surgery, May 30, 2006, pg. 290.

Stryker’s Mobile Bearing Hip™ 

An innovation in hip replacement design, Stryker’s Mobile Bearing Hip™ replacement has a unique polyethylene insert (called anatomic dual mobility or ADM) made with X3® Advanced Bearing Technology. It fits snugly within the metal shell and over the ball to secure and buffer the joint.

Anatomic Dual Mobility

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). The ADM allows both hip components to glide smoothly without the stem making contact with the shell. So your doctor can closely match the implant to your anatomy, giving you the following potential advantages:

Greater range of motion

The Mobile Bearing Hip™ Replacement is built for more natural 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 It also let you walk more naturally, so you can maintain your active lifestyle with fewer compromises.

More comfortable and stable fit

Comfort and stability help 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

The 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 This avoids hip stiffness, groin pain or a clicking sensation in the hip – signs that the pelvis catches the tendon when the hip flexes. 

Less wear and potential for a longer life

Stryker’s Mobile Bearing Hip™ with X3® offers better wear protection in two ways: dual mobility and the X3® technology bearing surface.4 Test results prove 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

References
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 Triden 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.
  • a. Wang, A., et al., Tribology International, Vol. 31, No. 1-3:17-33, 1998.
  • b. Essner, A., et al., 44th Annual Meeting, ORS, New Orleans, Mar. 16-19, 1998:774.
  • c. Essner, A., et al., 47th Annual Meeting, ORS, San Francisco, Feb. 25-28, 2001:1007.
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.

 

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Learn more about the hip implants your surgeon may use

Learn more about the hip implants your surgeon may use

Ask your surgeon for more details

Your surgeon can provide you with information on the hip replacement they feel is best suited to your situation, should surgery be an option for you. 

If your surgeon uses Stryker products, ask them for a login to the Stryker Online Patient Resources, where you can learn more about the hip implant you may receive, what to expect during surgery, and what rehabilitation exercises you can do during your recovery. 

I am having a hip replacement using Stryker products. Which hip implant is best for me?

Your body is different from everyone else's, and so is your hip pain. Stryker’s personalised hip solutions provide extensive, technologically advanced and customisable options for getting you and your hip functioning again.

Stryker has some of Australia’s leading hip and knee replacement products. These include the most commonly used implants, recognised for their long-lasting performance.1

Your doctor will determine the optimal treatment for your unique anatomy and lifestyle, using Stryker’s portfolio of surgical products and advanced technologies. If you having a total hip replacement, these options include:

References
1 Australian Orthopaedic Association National Joint Replacement Registry. Annual Report. Adelaide: AOA; 2012.
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Next Steps

Contact your GP or health professional to discuss your options