What’s Going On In This Joint?

In the last year, there has been an alarming rate of defective and/or recalled orthopedic medical devices, especially those affecting the hip and knee joints. At first blush, the recent spate of dangerous devices might seem purely coincidental. Once the curtain is pulled back, this worrisome pattern is far from coincidental. There are dozens of major orthopedic manufacturers selling knee or hip products in the U.S. By the end of the first decade of this century, the U.S. orthopedic market was a $12billion industry. Almost 50% of the total orthopedic market in the U.S. involves hip or knee implants; knee implants make up 28.4 percent of the U.S. orthopedics market; hip: 20.3 percent. So, with that kind of competition, the rush to create the bigger/stronger/more flexible/lighter/faster recovery/smaller incision device inevitably results in manufacturers putting profits over patient safety. And that profit motive has spilled onto the pages of the litigation scene with a variety of recent device litigations. This blog will highlight those recent litigations and device dangers that consumers should be aware of.

DePuy ASR and the Metal-on-Metal Dangers

The Depuy ASR hip is a medical device product aimed at replacing the worn out hip joint. DePuy claims that the product was developed to improve mobility of people affecting from arthritic hips and other hip joint problems. DePuy holds itself out as a leader in prosthetic products manufacture and metal-on-metal technology.

Hip replacement is a technique used to repair/replace hip joints. In the 1970s, when the technique was invented, the device consisted of a metal cup with a thin polyethylene (or plastic) liner insert between the cup and the metal femoral head/ball. Due to this, there were chances of the polyethylene surface wearing out easily due to the continuous movement of the metal cup against it. However, with advances in medical science and technologies, Depuy came out with a unique metal-on-metal monoblock device that promised to last longer than the earlier form. This design got rid of the liner and consisted of a metal cup and femoral head/ball, both made of cobalt chromium alloy.

The device had several design flaws. The cup failed to bond properly and the result was a loose cup. This requires that the patient undergo revision surgery to repair and replace the device. In short, the product had much higher than normal failure rates. Additionally, the clearance between the cup and the ball was so low that the two components grind and caused microscopic metal ions (cobalt and chromium) to break off into the surrounding tissues and bloodstream. This can cause metallosis, a potentially dangerous and serious condition.

These hip devices have been implanted in hundreds of thousands of patients over the past several years and their early high failure rates seem like only part of the problem. Perhaps the bigger concern should be this risk of blood toxicity and chromium and cobalt poisoning – the potential adverse effects of which are still being investigated but include soft tissue damage, pseudotumors, bone loss and inflammatory reactions. In addition, studies have shown that elevated levels may potentially have harmful effects on immunity, reproduction, kidney function, the nervous system and carcinogenisis. High concentrations of cobalt and chromium have been found in patients with metal-on-metal hip resurfacings. In some cases, it has been reported that patients have been diagnosed with over 100 times the normal levels of these toxic metals.

These hips have cause serious injuries in thousands of unsuspecting patients. The health and well being of patients was replaced with the greed of a corporation who rushed a product to market and failed to perform adequate pre-market testing.