New Technology

Computer-Assisted Surgery

A Giant Step Forward in Joint Replacement

Total hip replacement surgery with the Stryker Navigation System If you’re reading this website, chances are you (or a loved one) are considering or preparing for joint replacement surgery.

As you read, make a note of anything you don’t understand. Your doctor will be happy to answer your questions so that you’ll feel comfortable and confident with your chosen treatment plan.

Leading Technology
During a joint replacement procedure, your surgeon will strive to ensure that everything is aligned properly. Accurate alignment of the hip or knee components is critical to the overall function of your new joint. A well-aligned hip or knee replacement is less likely to dislocate and may last longer.1,2

Orthopaedic surgeons have the ability to navigate joint replacement procedures with more accuracy than ever before.

Stryker’s computer-assisted technology can help your surgeon work more efficiently with less invasive techniques and help align implants to your unique anatomy.

What are some of the reasons orthopaedic surgeons choose computer-assisted technology?

  • Provides your surgeon with comprehensive data about your anatomy which may help determine proper placement of your joint replacement
  • Ability to plan for surgery with a computer generated model of your hip or knee
  • Provides the surgeon with feedback and the ability to correct potential misalignment during the surgery
  • Allows for better visualization of anatomy, which is particularly important when minimally-invasive techniques are used

References:

1. Coventry MB. Two-part total knee arthroplasty: evolution and present status. Clin Orthop 1973; 145: 29-36.
2. Lotke PA, Ecker ML. Influence of positioning of prosthesis in total knee replacement. J Bone Joint Surg [Am] 1977; 59-A: 77-9.

MIS Hip Replacement Using a Direct Anterior Approach

This website can answer some of the questions you may have about Minimally Invasive Hip Procedures using a direct anterior approach.

As you review this material, make note of anything you don’t understand. Your orthopaedic surgeon will be happy to answer your questions so that you’ll feel comfortable with your chosen treatment plan.

Diseased HipReplaced Hip

Minimally Invasive Surgery (MIS) Hip Joint Replacement is an advancement in hip replacement that offers important advantages over standard surgical procedures. Stryker has partnered with surgeons worldwide to develop MIS procedures and surgical instruments that are designed to help your surgeons do their very best to help you recover your lifestyle. These techniques bring together a wide variety of hip implants, new minimally invasive surgical techniques, and new instrumentation.

Over the past 25 years, minimally invasive surgery has revolutionized many fields of medicine. Its key characteristic is the use of specialized techniques and instrumentation that allows the physician to perform major surgery with a smaller incision.

The direct anterior approach is one of the minimally invasive techniques used in hip replacement surgery. Continuing orthopaedic experience suggests that this procedure may offer several advantages over the more traditional surgical approaches to hip replacement.1

Traditional hip replacement techniques involve operating from the side (lateral) or the back (posterior) of the hip, which requires a significant disturbance of the joint and connecting tissues and an incision approximately 8-12 inches long. In comparison, the direct anterior approach requires an incision that is only 3-4 inches in length and located at the front of the hip.1 In this position, the surgeon does not need to detach any of the muscles or tendons.1 Some physicians use a special operating room table to help achieve an optimized surgical position for the patient.2

Potential Advantages

The direct anterior approach allows the surgeon good access to the hip without detaching any of the muscles or tendons. This may allow for a more natural return to normal function and activity.1,3

There is also the potential for rehabilitation to be quicker and for hospital length of stay to be decreased because the hip is replaced with minimized detachment of the muscles from the pelvis or femur.4

The smaller incision and reduced muscle disruption indicate that patients may also have a shorter recovery time and less scarring.1 With this approach and the minimization of tissue damage, there may also be less blood loss, less time in surgery and reduced post-operative pain. 1,3,5

Traditional hip replacement techniques require patients to take special hip precautions to prevent dislocation of the prosthesis. These precautions typically include not crossing your legs, not bending your hips more than a right angle, not turning your feet excessively inward or outward and using a pillow between your legs at night when sleeping.6 Following the anterior approach, the risk of dislocation may be reduced. Under their doctor’s supervision, patients may be immediately allowed to move their hips and potentially avoid these cumbersome restrictions.4 They are often encouraged, under the doctor’s supervision, to weight bear immediately and to discard external support as symptoms permit.1 Complications resulting from immobilization have the potential to be reduced due to immediate hip movement and earlier weight-bearing.5

Discuss Your Options With Your Physician

Hip replacement, no matter how minimally invasive, is major surgery and patients are at risk for complications. However, the complication rate following joint replacement surgery is generally very low. Serious complications, such as joint infection, occur in less than 2% of patients.7 (Besides infection, possible complications include blood clots, lung congestion or pneumonia.) The risks that are normally encountered in conventional hip joint replacement remain.

Recovery success depends on several factors including surgeon training and experience, the surgical approach, the implant and the patient’s health and commitment to post-operative physical therapy. Although the direct anterior approach may make sense for some patients, only your surgeon can help you decide what is best for you. Talk with your doctor if you have any questions about the direct anterior approach for total hip replacement or hip replacement in general.

References:

1. Wenz, J., Gurkan, I. Jibodh, S., “Mini-Incision Total Hip Arthroplasty: A Comparative Assessment of Perioperative Outcomes,” Orthopedics Magazine, 2002.
2. Kreuzer, Stefan, Matta, Joel M., “Single-Incision Anterior Approach for Total Hip Arthroplasty: Smith-Petersen Approach,” American Academy of Orthopedics Surgeons, Chapter 1.
3. Keggi, Kristaps I., “Total Hip Arthroplasty Through a Minimally Invasive Anterior Surgical Approach,” JBJS, Vol. 85-A. 2003.
4. www.anteriorhip.org, Kreuzer, S.
5. Baerga-Varela, L.,Malanga, G.A., “Rehabilitation after Minimally Invasive Surgery.” Hozack,W., Krismer,M., Nogler,M., Bonutti, P., Rachbauer, F., Schaffer, J., Donnelly,W., ed. Minimally Invasive Total Joint Arthroplasty. New York, NY: Springer-Verlag; 2004: 2-5.
6. http://www.orthoinfo.org/topic.cfm?topic=A00377#Other%20Precautions.
7. Hanssen, A.D., et al., “Evaluation and Treatment of Infection at the Site of Total Hip or Knee Arthroplasty,” JBJS, pp. 910-922.

Knee Implants With the Potential to Be Long Lasting

The durability of knee implants depends on many things including patient weight and activity level, as well as the implant’s bearing surface technology.

Improved Wear Performance

The bearing surface is defined as the two parts of the knee that glide together throughout motion. Stryker’s new, advanced bearing technology, called X3®, has demonstrated up to 96% decrease in wear in laboratory testing compared to competitive premium bearing technologies.* This decrease in wear may extend the life of your knee implant. This new technology is particularly important for younger patients.

Ask your doctor if X3® technology is right for you.

Stryker Corporation or its divisions or other corporate affiliated entities own, use or have applied for the following trademarks or service marks: Stryker and X3. All other trademarks are trademarks of their respective owners or holders.

References:

* Stryker Orthopaedics Test Report: 06-013.

Hip Implants With the Potential to Be Long Lasting

The durability of hip implants depends on many things including patient weight and activity level, as well as the implant’s bearing surface technology.

Improved Wear Performance

The bearing surface is defined as the two parts of the hip that glide together throughout motion. Stryker’s new, advanced bearing technology, called X3®, has demonstrated up to 97% decrease in wear in laboratory testing.* This decrease in wear may extend the life of your hip implant. This new technology is particularly important for younger patients.

Ask your doctor if X3® technology is right for you.

Stryker Corporation or its divisions or other corporate affiliated entities own, use or have applied for the following trademarks or service marks: Stryker and X3. All other trademarks are trademarks of their respective owners or holders.

References:

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

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.
* Stryker Orthopaedics Test Report: RD-03-082.