Artificial knees are used to replace either the entire knee joint, or only part of it, in people with extensive damage. When the knee joint becomes so damaged, from arthritis, or other conditions, replacement with artificial components can restore mobility and reduce pain. There are many companies that make artificial knees and the technology has come a long way over the years.

DePuy Synthes is a division of Johnson & Johnson, which makes many of the artificial knees that are used in thousands of surgeries every year. Many of these devices have been successfully installed in a variety of patients, giving them a better quality of life, but there can be problems. Some of the devices and components cause complications like wear on the bones, bone loss, and instability in the joint.

One DePuy knee component was recalled in 2013 because of serious issues.

Who Needs Knee Replacement Surgery?

Knee surgery and the replacement of the joint or parts of the joint is major surgery and can be risky, but for many people it means restoring a decent quality of life. Damage to the knee joint over time can lead to a lot of pain as well as a lack of mobility that makes it challenging to engage in normal daily activities. The most common reason for requiring a knee replacement is to repair the damage caused by osteoarthritis, although other conditions can lead to knee replacement. These include bone cancer, rheumatoid arthritis, and osteonecrosis.

Types of Knee Replacement Surgeries

When damage is extensive throughout the knee a patient may require a total knee replacement. This means replacing the entire joint with an artificial system. DePuy makes several such systems including the LCS Complete Knee System, the Sigma Total Knee System, and the Attune Knee System. Knee components may be made from plastic, ceramic, metal, or a combination of these materials.

A partial knee replacement may be done when damage to the joint is not too extensive. The surgeon can save parts of the knee and only replace those parts that are badly damaged. This type of surgery is often less invasive than a total knee replacement and may require less time to recovery. Along with its total knee systems, DePuy makes individual components for partial knee replacement surgeries.

Revision knee surgery is a procedure that is done as a follow-up to a replacement surgery. . When part of an artificial joint fails, if there is an infection or inflammation, or a joint comes loose or dislocated, a revision surgery may be needed to correct the problem. DePuy makes several components used in revision surgeries.

Complications and Risks of Surgery

Knee surgeries can be major and invasive, or for less complicated procedures, may involve only small incisions. The more complicated the surgery, the bigger the risks are. As with any major surgery, the patient may have a bad reaction to anesthesia, bleed excessively, develop blood clots, or have an infection.

With knee replacement surgery there are even more risks and potential complications. These include deep joint infections, fractured leg bones, a change in the length of the legs, a decreased range of motion in the knee joint, a loosening of the artificial joint, shifting in the joint, dislocation, or a sinking of the joint into the soft bone tissue of the leg.

DePuy Knee Systems and Technology

DePuy is a leader in developing a variety of high-tech knees for replacement surgeries. They make fixed bearing knees, which are most commonly used. These have a bearing that remains fixed in position. In rotating platform knees the bearing is not fixed and the joint can rotate more like a natural joint. They are also designed to be more durable and to result in less overall wear and tear.

Some of DePuy’s most high-tech knees are the high flexion knee and the TruMatch system. The high flexion knee with is able to move up to 155 degrees, more than any other type of artificial knee. It is meant to be used in people who need more mobility and range of motion. The TruMatch system is a personalized surgery system that allows surgeons to scan a patient’s legs and design a custom procedure for implanting the artificial knee.

DePuy Knee Recalls

In 2011 DePuy voluntarily recalled several artificial knee components after receiving a warning letter from the U.S. Food and Drug Administration (FDA). The FDA stated that the company was marketing and selling several products that had not received approval. The agency also found that several devices or components had been altered, and were currently misbranded as safe and effective.

The FDA often allows devices to be approved without extensive testing through an expedited 510(k) process. This is allowed when the device is very similar to something else on the market. DePuy failed to go through the correct process for several components and had been selling unapproved products. The company claimed that they were custom devices and did not require approval. The FDA disagreed. By not getting proper approval, DePuy put patients at risk.

Another recall of a DePuy knee product occurred in 2013 when the FDA issued the warning that the LPS Limb Preservation System’s LPS Diaphyseal Sleeve was faulty. This particular component is used in knee revision surgeries to help reconstruct soft tissue and bone. It is inserted into the center of a leg bone to provide support. The FDA discovered that this particular part was not necessarily able to provide enough support based on the load put on it by the patient. The result was bone fractures in some patients, which led in some cases to loss of function of the leg, infections, and even loss of the leg.

Problems with the High Flexion Knee

DePuy’s high flexion knee systems give patients a higher degree of flexibility and movement, but these are newer devices and problems are beginning to emerge. Some studies, which followed patients for a year or more after getting an artificial high flexion knee found mixed results in effectiveness. Some patients saw greater mobility and flexibility, but for others it wasn’t clear that these knees were any better than fixed or rotating artificial knees.

Another problem is that being fitted with the high flexion knee requires greater bone loss. This can lead to greater wear of the bone, instability in the new knee joint and long-term problems with it. One study looked at patients several years after receiving the knee and found that more than one-third of the patients had experienced bone loss and a few needed revision surgeries.

While DePuy has helped millions of patients live better lives with new knees, their products can sometimes cause problems. If you have experienced any of the complications associated with a DePuy knee system, talk to your lawyer about your options.