Hip replacements occur when one or both sides of a hip joint are damaged due to injury or arthritis. Modern implants are made from a combination of materials including ceramics, plastics and metals. Some implants have been made with MOM or metal-on-metal designs that were targeted at younger people with the hope that they would last longer and would provide a larger range of movement than older style replacements.
Typical hip implants include a one-piece neck and stem design that attaches to the Femur (thigh bone) and fits into a cup attached to the pelvis. Stryker’s Rejuvenate is made up of six stems and 16 necks and the ABG II has eight right stems, eight left stems and 10 modular necks so the doctor could better match the implant with the patient. Marketed to younger patients, these modular implants promised longer-lasting devices that offered a better range of motion. The implants are made using a proprietary titanium blend that did not “fret” or flake off of the implant and cause problems with surrounding tissue. Unfortunately data gathered after release of the implants showed the Rejuvenate and ABG II Modular-Neck Hip Stems, can cause complications and were recalled in 2012.
Complications from the corrosion and fretting can include:
- Metallosis – When joints have metal-on-metal wear, metal particles break off into surrounding skin. If the recipient of the new joint has a metal sensitivity, it can lead to metal poisoning and implant failure.
- Osteolysis – When the body senses the particles, it reacts as it if it were a foreign body and tries to dissolve or expel it. The hip becomes inflamed and the body absorbs the bone causing the implant to eventually loosen or fail.
- Necrosis – Infection can cause the cells around the hip to die.
Stryker, the maker of Rejuvenate & ABG II Hip Systems, recalled the devices in 2012 and recommended that patients with the implanted devices get medical tests (x-rays, MRIs, blood tests). The hip may need revision surgery to replace or resurface the hip. If the stem needs replacement there is a risk that the femur may fracture.
Stryker is accused of not properly testing the hip implants before releasing them and of not warning doctors and patients of the risks of side effects and complications. If you or someone you love has an implant of Rejuvenate or ABG II Modular-Neck Hip Stem, contact Nolan Caddell Reynolds for a free consultation about your condition.