Many patients who have had knee replacement surgery using DePuy CMW 1 bone cement are having to undergo revision surgery due to product failure. The product in question is used to attach and secure a joint prosthesis to the natural bone. In an alarming number of cases, the cement does not hold its bond. This causes the prosthesis to come loose, resulting in severe pain, instability and decreased range of motion.

In other cases, the toxic ingredients contained in DePuy CMW 1 bone cement leech into the patient’s tissues and blood vessels. This can lead to oxygen deficiency, embolism, heart attacks and in some cases, death. The FDA began investigating DePuy CMW 1 bone cement after receiving an Adverse Event Report in September 2012.

What is DePuy CMW 1 Bone Cement?

According to a DePuy product brochure, the adhesives used by many surgeons for knee replacement procedures was first developed in the late 1950s, and have been in use since 1966. In 1991, DePuy began experimenting with new formulation.

The final result was DePuy CMW 1 bone cement with gentamicin. “CMW 1” designates high viscosity; additional products include “CMW 2” and CMW 3”, which are of medium and low viscosity, respectively. High viscosity cement is the preferred choice among surgeons because it is easier to control and apply.

Independent research indicates that high viscosity CMW 1 is also the product most likely to fail.

Gentamicin is an antibiotic that has been premixed into the cement. The purpose is to reduce the risk of bacterial infection that can occur as a result of joint surgery and lead to “septic loosening” of the prosthesis. Unfortunately, this has not prevented other complications.

What Went Wrong?

The plaintiff in a recent lawsuit believes that large part of the problem with DePuy CMW 1 bone cement lies in the fact that it may not have been adequately tested. According to the complaint, one problem  appears to be a change in the formulation, by which “micronized” particles were replaced with non-micronized ones. Because of these larger particles, the bonding power of DePuy CMW 1 bone cement was compromised.

The present product was FDA approved in November, 2005, via a controversial process known as 510(k) Pre-Market Notification. Because DePuy was able to demonstrate that its new product was “substantially equivalent” to an older version of the same product, the FDA did not require the same rigorous clinical studies that “new” products must undergo.

One Plaintiff’s Experience

The aforementioned lawsuit, filed by a plaintiff from Ohio, highlights some of what can happen when a joint replacement comes loose because the cement failed to hold its bond.

Plaintiff Myrtle T. states that she underwent knee replacement surgery in 2009; the prosthesis was held in place with DePuy CMW 1 bone cement. The Arthritis Foundation and other medical authorities say that under normal circumstances, a joint prosthesis should last at least 20 years, if not longer. However, according to Myrtle’s complaint, she began experiencing chronic knee pain about two years later; however, x-rays revealed nothing out of the ordinary. It was not until April 2012 that she says an actual bone scan showed aseptic loosening of the tibial (shin bone) component of her prosthesis. She finally underwent revision surgery a month later.

Myrtle alleges that the defendant acted with “a flagrant disregard for human life and safety, malice and egregious fraud.” She seeks compensatory, punitive and economic damages in addition to legal fees and court costs.

Myrtle’s DePuy CMW 1 Bone Cement Lawsuit is Civil Action No.1:13-cv-00602 , U.S. District Court, Southern District of Ohio, Western Division.