This is part one of a two-part
article regarding the issues surrounding the Stryker Rejuvenate and ABG II hip
implant devices. Due to the recent number of defective metal-on-metal hip
implants such as DePuy’s ASR, many surgeons placed their trust in a new design
introduced by Stryker in 2008 and 2009. The all-metal implants place a cobalt
and chromium ball inside a cobalt and chromium acetabular cup; those components
rub against one another causing microscopic metal ions to shear away, burrowing
into the hip tissue or entering into the bloodstream.
Stryker’s new design used a
ceramic ball with a metal neck juncture as well as small metal trunnions located on either end of the neck piece. The design also
boasted four component pieces rather than the usual two which allowed surgeons
to choose the individual components based on their patient’s size and level of
activity. Surgeons were finally able to custom-fit a hip implant device, using
the best angles and lengths for their patients.
Relatively soon after the two
Stryker implants were marketed and began being implanted, adverse reports began
coming in from patients and the design which was once believed to be the
greatest innovation in hip implants found itself issuing a recall in July,
2012. By the time 53,000 Rejuvenate and ABG II implants had been marketed and
the majority implanted the recall was issued, stating the risk of fretting and
corrosion as well as early failure. Stryker patients were suffering from pain,
inflammation and symptoms of metal toxicity. When the neck juncture suffers
corrosion toxic metal particles can cause metal toxicity with such symptoms as:
·
Neurological problems
·
Cardiovascular issues
·
Renal and thyroid disorders
·
Loss of vision and hearing
·
The development of potentially dangerous
pseudotumors
·
Disruption of DNA
·
Vertigo
·
Anxiety, irritability and depression
When the metal ions become
lodged in tissues surrounding the hip joint, inflammation, pain, tissue damage
and bone loss can occur, leading to implant failure and the necessity of
revision surgery. Stryker issued an Urgent Field Safety Notice to hospitals and
physicians in May, 2012. This notice—like the recall notice—stated the risks of
the ABG II and Rejuvenate to undergo corrosion, fretting and early implant
failure. Many feel the first notice was an attempt to minimize the fear once a
recall was issued.
While the ABG II and the
Rejuvenate were touted as lasting considerably longer than ceramic and
polyethylene implants—even as long as twenty years—many Stryker patients began
coming in with such severe problems that revision surgery was necessary after
only a few short years. At the time of the recall Stryker stated the failure
rate of the ABG II and Rejuvenate as being approximately 12%. It was later
discovered that the failure rate may actually be as high as 40% as opposed to
the failure rate of a traditional implant of between 4-5%.
The risks of revision
surgery—particularly for the Stryker ABG II and Rejuvenate—are higher than the
risks of the original surgery and even higher than the risks for other implant
revisions. Surgeons dislike performing revision surgery to remove an ABG II or
Rejuvenate because of the method of implantation, yet there may be little
choice in the matter if a patient begins experiencing symptoms of implant
failure or metal toxicity. Part two of this article will more fully detail the
surgical procedure for revision of a Stryker ABG II or Rejuvenate hip implant.
