According to the most recent Zimmer Biomet annual report, knee replacement devices make up the largest portion of the company’s income, accounting for $2.3 billion in sales in 2015 – nearly 40% of the company’s $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 SystemsPartial Knee SystemsKnee 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.

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.

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Zimmer Knee Replacement Recalls

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.

Persona Trabecular Metal Tibial Plate Recall

On January 28, 2015, Zimmer initiated a voluntary recall of its Persona Trabecular Metal Tibial Plate, a component of the company’s Persona-branded knee replacement devices. According to the recall notice, Zimmer had received an increase in complaints that the tibial plates were coming loose and forming “radiolucent lines” – that is, linear spaces between the device and the joint cement holding it in place.

More than 11,600 knee replacement devices were affected by this recall. Zimmer instructed hospitals, orthopedic surgeons, and distributors to return the defective devices. It is unclear from the recall notice how many people may have already had the malfunctioning devices surgically implanted.

Other Zimmer Knee Device Recalls

Zimmer has issued a number of other recalls on parts related to its knee replacement devices. Many of these recalls were instituted before any of the knee replacement components could be surgically implanted into patients. However, there is still the risk that some of the components were not returned by the distributors, hospitals, or doctors to whom they were sent, and it is possible some of them may have been used in arthroplasty operations.

In 2010, Zimmer recalled the MIS Tibial Component after the company received reports about improperly locking screws and stems on the device. Over 100 people filed complaints to the FDA that the device was coming loose, which led to the need for knee revision surgery.

Sulzer Medica, a company acquired by Zimmer in 2003, paid $1 billion in 2002 to settle thousands of legal actions filed by customers who received joint implants in their knees and hips. As it turned out, the manufacturing process for the company’s Natural Knee II Tibial Baseplate implant had left an oily substance on the device, which caused problems for patients up to a year later.

The table below provides a summary of other recalls that Zimmer has conducted over the last several years.

Additional ResourceAdditional Zimmer Knee Recalls
Expand Resource
DateProduct/Component Recalled# Recalled
January 11, 2016NexGen Knee system components88,389
March 17, 2016Persona The Personalized Knee System Articular Surface Posterior Stabilized (PS) LeftUnknown
December 3, 2015NexGEN System REF 5980-37-01 Tibial Component Size Stemmed 3 Precoat384
October 2, 2015Natural Knee II Revision Femoral Stem352
April 30, 2015PRI Femoral Impactor Block1,689
March 10, 2015Persona Anterior Referencing Sizer with Locking Boom688
January 28, 2015Persona Trabecular Metal Tibial Plate11,658
November 24, 2014Zimmer PERSONA Tibial Articular Surface Inserter1,091
October 9, 2014Persona Stemmed 5 Degree Cemented Tibia138
October 7, 2014Persona Tibial Articular Surface Inserter618
August 7, 2014Persona The Personalized Knee System – Constrained Tibial Articular Surface77,737
July 30, 2014Zimmer PERSONA Distal Valgus Alignment Guide2,248
July 22, 2014Knee Instrument Fixation Screws, Knee Stem Extensions & Impactor Sleeve972,125
July 10, 2014Natural-Knee System Patella Bushings8,638
July 1, 2014Persona The Personalized Knee System – Tibial General Instrument Tray190
May 19, 2014NexGen Complete Knee Solution41,180
February 25, 2014Gender Solutions Natural-Knee – Flex System3,638
November 19, 2013NexGen Complete Knee Solution – Patella Drill Guide, Articular Surface Provisional3,027
October 31, 2013NexGen Complete Knee Solutions Stemmed Tibial Component Precoat128
August 30, 2013Natural-Knee Flex – Femoral Component, Natural Knee II – Femoral Component, Zimmer Unicompartmental Knee – Femoral Component80,007
June 10, 2013Persona The Personalized Knee System – Tibial Articular Surface70,986
June 7, 2013NexGen Cruciate Retaining Complete Knee System – Micro Femurs, Articular Surface, Patellae192,355
November 14, 2012Persona Knee System – Natural Tibia, Tibial Sizing Plate, Tibial Drill, Tibial Drill Guide, and Tibial Broach2,482
September 21, 2012NexGen CompleteKnee Solution – Stemmed Nonaugmentable Tibial component123

Zimmer Knee Replacement Lawsuits

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.

MDL lawsuits allow similar cases to be handled by the same judge and court, helping the cases go through the process faster and more efficiently, while allowing individual plaintiffs to keep their cases separate from others (unlike a class action lawsuit). The MDL case for Zimmer knee devices is MDL 2272, MDL In Re: Zimmer Nexgen Knee Implant Products Liability Litigation. The MDL was created in 2011, and the first cases took place in October 2015. As of October 2016, there were more than 1,700 lawsuits that had been transferred to MDL 2272.

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