Stryker's ceramic-on-ceramic hip, the Trident, came to market in 2003 with the promise of providing a more durable alternative for younger patients seeking a THA. A traditional metal/poly hip lasts about ten years, so ceramic seemed to be the answer to patients hoping to avoid a traumatic revision. Since the Trident's launch, however, the company has received a number of complaints from patients who say the implant squeaks. Stryker maintained that the squeaking occurred in less than 1% of patients, though a study published in the Journal of Arthroplasty found a squeaking rate closer to 7%; 10 out of 143 patients experienced squeaking, compared to none of the 48 patients in the metal/poly control. While the volume and frequency of the squeaking must certainly vary by patient, one video on YouTube shows just how persistent the noise can be.
Ceramics have been around since the 1960s, and early incarnations were susceptible to cracking - "catastrophic failure." More than just an annoyance, the squeaking serves as a reminder of how the devices could potentially fail, though the material has been improved in the past few decades and there have been no catastrophic failures associated with the Trident or any other ceramic-on-ceramic hip. Of course, there is also limited extended follow-up data with this relatively new technology. Some surgeons identified by the Times say there are dark stripes on removed devices that could suggest accelerated wear, a possible precursor to failure.
This hypothesis was countered by Dr. James A. D'Antonio, a chief investigator on the Trident's PMA trials, who said that approximately 1% of his 400 Trident patients complained of squeaking, and none were able to reproduce the sound in his office. He added simply, "There is no evidence that the wear associated with squeaking would lead systems to fail." The Times was quick to point out that Dr. D'Antonio received $1.1 million in consulting payments from the company in 2007. A Stryker spokesperson also downplayed the squeaking, saying, "Published research shows squeaking is rare compared with other total-hip-related risks like infection, dislocation and leaving patients with uneven leg length."
The FDA does not seem entirely convinced. In November, Stryker received a warning letter from the agency naming concerns, the squeaking among them, with the company's hip products. The letter demanded that the company take immediate action to address the issues, though it is unknown how Stryker responded (the January 2008 voluntary recall of certain hip products is unrelated to the November warning letter.)
