According to the most recent Zimmer Biomet annual report, knee replacement devices make up the largest portion of the company’s income, accounting for more than $2.7 billion in sales in 2016 – more than a third of the company’s $7.6 billion in annual revenue. Most of those sales take place in the Americas, though the company also sells products in Europe and Asia as well. Zimmer Biomet sells more knee replacement devices than any other company in the world.
Brand names under which Zimmer markets its knee devices include Persona, NexGen, Oxford, and Vanguard. Over the years, Zimmer has experienced a number of problems due to the design of its knee replacement devices, which has caused complications for patients and led to voluntary recalls, regulatory actions, and lawsuits.
Purpose of Zimmer Knee Devices
Knee replacement (arthroplasty) is most commonly used to repair damage to the knee and to reduce or eliminate pain due to joint wear and tear. Damage and joint pain can come about as a result of injury, inflammatory conditions such as arthritis, or simply due to aging. Although most people who undergo a knee replacement surgery are older than 50, there is no specific age at which knee surgery is generally administered. The American Academy of Orthopedic Surgeons estimates that 600,000 knee replacements are performed in the U.S. each year.
Zimmer is one of several medical device companies that makes knee replacement systems. These systems can be used to replace the entire knee joint, a part of the joint, or who need knee joint revision. Which devices are used depends on the needs of the patient and the purpose of the arthroplasty surgery.
Zimmer Knee Replacement Systems
|Total Knee Systems||Partial Knee Systems||Knee Revision Systems|
|Used to replace the entire knee joint with components attached to the fibula and tibia, as well as in place of the cartilage around the knee.||In some cases, only a portion of the knee is damaged and needs replacement. Partial knee systems provide a way to repair knees in such cases. This is sometimes called unicompartmental knee replacement.||Over time, a knee replacement device may wear down, requiring revision surgery to repair the knee replacement.|
In addition, Zimmer sells knee replacement components, instruments, and cartilage repair products.
Knee Replacement Safety Concerns
As the most common type of joint replacement surgery, knee replacements are generally considered safe. More than 90 percent of people who undergo knee surgery experience a reduction in knee pain, and their activities and capabilities often return to at or near pre-pain levels.
That said, there are still a number of safety concerns and problems that can occur when undergoing a knee replacement surgery. These include:
Surgical Complications: Every surgery comes with some risk of complications, such as infection, heart attack, or stroke due to trauma caused by the surgery itself. Small infections are typically treated with antibiotic medications.
Blood Clots: One of the biggest post-surgical risks of knee replacement is blood clots, which can become life threatening if they come loose and travel to the lungs. Preventing blood clots usually involves performing leg exercises and taking blood thinner medications. However, caution must be taken to avoid falls while taking anticoagulants, as they can greatly increase your risk of bleeding. This fact, along with insufficient safety warnings, has lead to a growing number of lawsuits over the blood thinner Xarelto.
Nerve Damage: In very rare cases, nerve damage can occur to the knee and nearby areas of the leg.
In addition to these common safety concerns, in some cases the knee replacement devices themselves may be defective. Medical device companies are required by law to perform clinical trials, follow published regulations, and receive approval from the FDA. Nonetheless, when developing medical devices, design and manufacturing mistakes can occur, causing pain, instability, and other problems down the road for patients who have undergone arthroplasty.
Zimmer Knee Replacement Recalls and Lawsuits
Zimmer and its predecessor companies (such as Biomet) have historically had a number of problems with their knee replacement devices. Some of these have affected large numbers of patients, leading to recalls and additional surgeries required to repair or replace the malfunctioning parts.
Due to various problems related to its NexGen Knee Replacement Systems, including issues that have led to recalls of various components, Zimmer has faced a number of lawsuits from patients around the United States. Most of these knee replacement lawsuits are pending in a federal multidistrict litigation (MDL) system in the Northern District of Illinois.