The
Stryker Rejuvenate hip implant was voluntarily recalled this past July following adverse reports and concerns with fretting and corrosion. Stryker had notified hospitals and physicians of the potential risks of the Rejuvenate in April including: “excessive metal debris and/or ion generation caused by fretting and/or corrosion at or about the modular neck junction.” The safety of the all-metal implant has been in question due to thousands of adverse reports from recipients who have experienced serious pain, inflammation, tissue necrosis and the release of tiny metal ions into the bloodstream leading to symptoms of metallosis.
Although the Rejuvenate is not a total metal-on-metal hip implant—it incorporates a ceramic ball which fits into a plastic-lined socket—the neck is made of cobalt and chromium and the stem is coated with titanium. In addition to the potential for corrosion at the neck juncture of the Rejuvenate, metal trunnions on either side of the neck piece of the Rejuvenate which allow the neck piece to slip into the stem on one side and the ball on the other can also be responsible for metal ion shear. Once these metal parts have rubbed against one another often enough to release the tiny shards of metal into the body, those particles can become lodged in the surrounding tissue, leading to inflammation and possibly even tissue death.
When the tissue inflammation begins, recipients of the Rejuvenate may experience pain although this pain is unlikely to come from the same area as other metal-on-metal hip implants. Those with the Rejuvenate implant may either have localized pain or may not be able to determine exactly where the pain is coming from. The reason for this is that most metal-on-metal hip implants suffer metal ion shear between the acetabular cup and the ball on top of the femoral head. In the Rejuvenate patient the pain will likely come from the areas on the head and neck where the trunnions are located. Any time the patient engages in walking or activity of any type and as soon as immediately following the initial surgery, the recipient of the Stryker Rejuvenate may begin to experience pain.
Microscopic cobalt and chromium ions can corrode at the trunnion locations and because physicians are more accustomed to looking at the area between the acetabular cup and ball when a patient complains of pain, the pain of the Rejuvenate patient may be dismissed. Although a metal toxicity test may show slightly elevated levels of
cobalt and chromium the physician may believe they are so small that they cannot cause the level of pain the patient is experiencing. Even though the amount of metals found in the body with the Rejuvenate are not as great as those in the all-metal types of hip implants, once those metals are in the body, they will always cause problems for the recipient and the pain will not decrease in severity. In some cases patients have undergone one revision surgery after another, each time being implanted with yet another Rejuvenate simply because the surgeon expected the problem to be at the acetabular cup rather than where the trunnions are located.
Those who experience persistent pain from their Rejuvenate hip implant may have no choice but to undergo revision surgery which can be both painful and potentially dangerous, although they should speak with their physician about receiving a different type of implant.