The hip is a ball-and-socket joint. The femoral head (ball) rides in the acetabulum (socket). The joint is lined with a lubricating tissue called cartilage, which cushions the joint as it moves and bears weight.
Hip replacement surgery removes the arthritic ball of the upper femur (thighbone) as well as the damaged bone and cartilage from the hip socket. The damaged bone and cartilage are replaced with implants made from materials including metal alloys, polyethylene (plastic), or ceramic.
The implants are designed to create a new, smoothly functioning joint that replaces painful bone-on-bone contact.
Dual mobility hip replacement is based on two design concepts for the ball-and-socket portion of hip replacement. The two concepts are:
Biomet engineers have combined the benefits of dual mobility hip replacement and E1® antioxidant technology into one hip replacement system called the Active Articulation™ E1® Hip System.The system features two balls (heads). Ball 1 rotates within ball 2, and when needed, ball 2 moves against the cup.
Let's take a look at how the Active Articulation™ hip system works. Traditional hip replacement uses a ball that moves against a cup, much like a normal hip.
Dual mobility hip implants use an additional implant component. The system features a ball that rotates inside a second ball, and the second ball moves against a cup.
During normal movement, the head, or ball, of the implant rotates inside the secondary ball, which normally doesn't move (figure 1). This motion occurs during the majority of regular, every day activities like walking and sitting. When the first ball reaches the limit of its range of motion, the second ball will also move (figure 2). This secondary movement allows a larger range of motion.
There are several benefits to Active Articulation™ E1® Dual Mobility Hip replacement. Some of these benefits include:
Antioxidants are good for your body. Vitamin E is an antioxidant that is now known to be good for polyethylene joint replacement implants, too. Polyethylene inserts can react with oxygen, creating an effect similar to a browning apple. This reaction is known as "oxidation." Over time, oxidation can weaken the polyethylene inserts. Biomet's E1® inserts are produced with Vitamin E, a natural antioxidant which, in laboratory testing, has shown to protect the material from the effects of oxidation.4 Biomet is currently the only company offering Vitamin E antioxidant technology in hip and knee implants in the United States. The Active Articulation™ E1® Hip System merges the benefits of dual mobility with Antioxidant Infused Bearing Technology.
1. Charnley, J. Long Term Results of Low Friction Arthroplasty of Hip as Primary Intervention, Journal of Bone and Joint Surgery (Br). 54: 61-76, 1972.
2. McKee, G., Farrar, J. Replacement of Arthritic Hips by the McKee-Farrar Prosthesis. Journal of Bone and Joint Surgery. 48(2): 245-59, 1966.
3. Beaule, et al. Jumbo Femoral Head for the Treatment of Recurrent Dislocation Following Total Hip Replacement. Journal of Bone and Joint Surgery. 84-A: 2, pp. 256-63, 2002.
4. Data on File at Biomet. Bench test results not necessarily indicative of clinical performance.
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Biomet is a manufacturer of orthopedic implants and does not practice medicine. Only an orthopedic surgeon can determine what treatment is appropriate. Individual results of total joint replacement may vary. The life of any implant will depend on your weight, age, activity level, and other factors. For more information on risks, warnings, and possible adverse effects, see the Patient Risk Information section found within Biomet.com. Always ask your doctor if you have any questions regarding your particular condition or treatment options.