Stryker Rejuvenate Failures More Serious than DePuy ASR, Pinnacle and other Metal on Metal Implant Failures

It has been fairly well established that metal on metal hip implants fail earlier and more frequently than other hip implants. The FDA just held two days of hearings to assess the scope and breadth of the problem. DePuy withdrew the ASR from the market and thousands of lawsuits over metal on metal device failures have been filed.

By now, most are familiar with the failure mechanism. Metal rubs on metal and casts off particles of cobalt and chromium causing soft tissue necrosis, metallosis, pseudotumor formation and ultimately the need to remove the device.

It is the type of removal that is important to note. When a DePuy ASR, Pinnacle or other metal on metal device fails, all the surgeon must do is remove the metal acetabular component and replace it with a device made of a different material. The market is full of alternative devices. At the same time, the ball can be replaced as well. In other words, a metal on metal device can be “converted” to a ceramic on poly or metal on poly application thereby avoiding the potential for metal poisoning.

The surgery involved is far less invasive and traumatic than a complete removal of the entire device, including the femoral stem. Removal of the acetabular shell when it has only been implanted a short time is a relatively simple procedure. These failures/removals typically are so early in the device’s life, there is little to no bony ingrowth on the back of the acetabular shell. Some failures are so early, especially in cases of severe metal contamination that there is no bony ingrowth. That makes removing the shell a snap, no pun intended. These are quick, in and out outpatient surgeries.

Therein lies the significant difference in the failure of most metal on metal devices and the Stryker Rejuvenate system. See, the Stryker Rejuvenate does not fail at the bearing surface junction (ball and socket). It fails at the junction between the two piece neck and femoral stem. For example, in the DePuy ASR and Pinnacle, the femoral component of the implant is one piece. The neck (where the ball is mounted) and stem (the part driven down into the femur) are one piece. Typical metal on metal failure does not require removal of the femoral component. Only the socket and possibly the ball are removed and the femoral component is preserved.

In the Stryker Rejuvenate, the failure is in the femoral components and not the ball and socket. The Rejuvenate is a modular device. The stem (part driven down into the femur) and the neck (part of the device between the stem and ball) are two separate pieces. The stem fits into the neck and the ball is mounted on the other end of the neck. It is at the junction between the neck and stem (where metal comes into contact with metal) that it is thought these devices are failing.

The failures are caused by the exact same problems patients suffer with the typical metal on metal devices, however, the metal wear and debris is just coming from a different place.

When a Rejuvenate fails, the femoral component must be removed. Removing an implanted femoral stem is VERY traumatic for the patient. One doctor has told one of our clients it’s like trying to remove rebar from a slab of steel. Once a failed femoral component is removed and replaced, the patient’s ability to have repeat hip replacement when parts wear out over time is severely compromised. This is a terrible complication and is vastly more traumatic and disabling than the repair of a typical metal on metal failure. One client I spoke with told me his surgeon intends to put wire around his femur to “hold it together” once he removes the Rejuvenate stem and pounds a new, bigger, longer revision stem down into his femur.

Today I heard from a woman in England whose husband has been through revision surgery and had a terrible result. Her husband’s doctor has had numerous other failures. They have returned the explanted devices to Stryker for examination only to be told there is nothing wrong with them. I guess these orthopedic surgeons, many of whom are listed on Stryker’s website as having received hundreds of thousands of dollars in “consulting agreements” from Stryker are just yanking these devices out of their patients for no reason.

Time will tell how long Stryker’s sales force has been telling the company about problems with the Rejuvenate. The company’s internal emails on this should prove quite interesting.

It will also be interesting to see what the attitude is of the surgeons who once were Stryker’s fair haired, chosen opinion leaders after they have to remove and replace dozens of these failed devices.