Are Zimmer Cutbacks Related to Zimmer Knee Replacement Problems?

Warsaw, INIn spite of the appearance of healthy sales in the last quarter of 2010, Zimmer—the manufacturer of Zimmer Knee Replacement—recently implemented a number of "organizational changes as part of the company's transformation initiatives to accelerate growth and customer focus." However, those changes involved the elimination of positions and employees.

Are those changes the result of pending and continuing problems with certain segments of its Zimmer NexGen Knee Replacement line? And are those problems an extension of a policy by the US Food and Drug Administration (FDA) that allows for the fast track of new medical devices that are similar to those already on the market?

To that point, knee replacements are nothing new. However, Zimmer's cementless NexGen CR-Flex implant certainly was in 2003. Prior to the introduction of the revolutionary Zimmer product, most artificial knees were cemented to the bone. Where the cementless Zimmer knee implants differed was through the opportunity and expectation of bone to foster growth into the knee implant, which was comprised of a porous material to foster fusion without the use of cement.

The FDA loophole saves manufacturers the trouble of exhaustive testing so long as a new medical device being introduced is substantially similar to existing devices. The Zimmer NexGen products not requiring cement may have worked well in theory but perhaps not so well in practice, given the number of NexGen patients whose replacement knees loosened or fostered pain when sufficient bone growth did not materialize as expected.

Various components inherent with the NexGen system have been recalled. In March of last year, the FDA issued a Class 2 recall of various lots of the Zimmer NexGen Complete Knee Solution Minimally Invasive Solutions Procedures Trabecular Metal Technology Tibial Tray, fixed bearing, size 8, REF 00-5954-057-02. The problem, as stated in the FDA recall document, was the potential separation of the titanium portion of the implant from the trabecular metal material.

In the recall notice, the FDA characterized the trabecular metal material as a type of cellular structure resembling bone. Highly porous, the material was described as conducive to bone formation allowing for tissue infiltration and attachment. However, that appears to have failed in many patients.

This past December, a similar recall was issued—this time for various components related to the Zimmer NexGen Complete Knee Solution LPS Femoral Component.

In spite of the twin recalls in 2010, Zimmer was reported by the Austin Business Journal to have had Q4 net sales of $1.13 billion in the final three months of 2010, which translated to an increase of 2.5 percent over the same period the year prior. Will continuing troubles with some aspects of the NexGen Knee diffuse that performance? Time will tell...