A recent article published in The Journal of Bone and Joint Surgery clearly shows that the Stryker Rejuvenate modular hip implant may be as capable of corroding as its metal-on-metal cousins.   This publication is significant because it shows metal-on-metal (MoM) hips are not the only problem. Adverse events were reported with the components in this hip system, which is not a MoM hip but has other metal components.

Early investigation by Searcy Denney allowed us to be one of the first law firms to understand the etiology of the failure, accept clients who had contacted us with problems and now represent patients from 15 states.

This is a stunning find and the report is written by mainstream surgeons at Rush University Medical Center and Northwestern University in Chicago. Dr. Joshua Jacobs is an opinion leader on the topic of hip implants who has been writing about taper-neck failures and metal poisoning from metal hips for more than twenty years. Another author, Richard Wixson is a well-known Stryker consultant.                                                             

Among this group of just 11 patients (12 hips) from five different institutions, this retrospective study found all of the patients experienced failure of their hip implant due to corrosion at the modular neck-body junction.  Of the eight women and three men with an average age of 60.1 yr, all of the patients had a Stryker Rejuvenate Hip System with femoral components made with titanium-molybdenum-zirconium-iron (TMZF) alloy and a cobalt-chromium-alloy modular neck.

The patients experienced problems such as pain in the groin, buttock, hip or thigh. A serious limp often accompanied the pain which began on average at 7.9 months after the hip was implanted. Every patient had to undergo an unnecessary and painful revision surgery to remove the defective implant. Revisions, that is, removal and replacement of the hip prosthesis, averaged just 15.2 months from implantation. This in a hip that was widely thought to perform well for a minimum of 20 years.

All of the patients had soft tissue destruction and corrosion occurred at the femoral neck-body junction. The signs of failure were inflammation, measured by C-reactive protein (CRP) which was elevated in five of the 11 patients. Serum levels of cobalt were elevated, more so than chromium, while titanium levels were within what’s considered a normal range. All of the patients had abnormally high levels of toxic metal ions in their blood.

Excess fluid and necrotic soft tissue around the failed implant were common findings during revision surgery.  Corrosion was obvious in the modular junctions between the neck and the body. The taper experienced fretting, a form of corrosion, and there was a black material at the base of the taper. In all of the hips, the femoral components were removed. On average the doctors took 8.6 months to render a diagnosis of hip failure.

Stryker Orthopaedics voluntarily recalled the Rejuvenate and ABG II modular-neck hip stems last year due to the potential for corrosion around the modular-neck junction which led to early revision of the hip.  This new study indicates patients with a Stryker hip experiencing pain should be evaluated for elevated cobalt and should receive an MRI to determine if there is any local tissue reaction.

Remember these hip implants are supposed to last around 20 years. Each time a hip is removed and replaced, bone and necrotic or dead tissue is removed along with the implant leaving behind less biologic material that is necessary to stabilize the replacement implant.

Any adverse local tissue pain in patients with these components should be examined immediately for C-reactive protein (a sign of inflammation) and serum metal levels. When pain is present, these researchers recommend metal ion blood tests and a specialized MRI for those patients with dual-taper femoral designs and a modular neck component.

Because of the destructive nature of these complications, revision surgery should be considered early.

This is stunning news considering that among the five authors more than one has had an ongoing financial relationship with the industry, usually in the form of educating other doctors or as consultants, so, to speak out like this is highly unusual. This is expected to be the first of many anticipated articles that will be published documenting the failures of Stryker Rejuvenate and ABG II modular hip systems.