Updated on July 20, 2020 — Knee replacements are some of the most common surgeries performed in the United States, and can help people regain mobility and reduce pain in their joints. These surgeries have become more and more popular in the past couple decades. Knee replacements were among the top 5 most common inpatient procedures among adults. These numbers are only expected to rise as medical device companies continue to introduce new implant products to the market.
Like all surgeries, knee replacements carry certain risks, and people undergoing these types of procedures should be aware of the potential complications that could occur. Some of these risks are inherent in all surgeries, while other risks may be due to the type of implant the surgeon uses to replace the joint. Knee implants can made from a number of different materials, and some implants can increase a person’s risk for complications more than others.
Knee replacements are most common in adults aged 45 and older, and doctors take into account a person’s overall health when determining whether or not surgery is the best option. Implants typically last about 15 to 20 years, and surgeries to replace worn implants are riskier and usually have worse outcomes than the first surgery.
Knee Replacement Check for motion
Before deciding if knee replacement surgery is right for a patient, doctors will typically check the range of motion in the knee, its stability and strength. Doctors may also use a patient’s age, weight, activity level, knee size and shape when determining knee replacement surgery.
There are different types of procedures when it comes to knee replacements. Some patients retain some mobility in parts of their knees and may be candidates for partial replacement surgery. Other patients with extensive damage or severe pain may need a total knee replacement. Your doctor will help you determine whether or not surgery is the right option for.
During a total knee replacement, or total knee arthroplasty, surgeons remove damaged portions of the joint and reshape the bone to accommodate the implant. Surgeons remove damage from the ends of the femur (thighbone) and tibia (shinbone), and may also remove damage from underneath the kneecap (patella). Metal implants are used to cover the ends of the femur and tibia and a plastic spacer is inserted between the metal pieces to create a smooth surface.
Knee replacements are designed to mimic the natural knee joints. Knee implants can differ in both design and materials used. Some of the materials used in knee implants have come under scrutiny for their potential to cause increased complications.
The knee is a complex “hinge” joint and there are several different kinds of knee implants on the market today that mimic the motion of a normal knee. Some implants use the body’s own ligaments to stabilize the knee, while others replace them. There are also gender specific implants and implants that use different materials.
1. Posterior-Stabilized Designs
This is one of the most common types of knee implants. This design uses parts of the implant to replace the ligament that prevents the thigh bone from sliding forward too far onto the shinbone when the knee bends. It does this using the tibial and femoral components; the tibial component fits into the femoral component using a special bar, and together they do what the ligament does.
2. Cruciate-Retaining Designs
In these types of knee implants, the natural ligament that helps stabilize the knee is preserved. These types of implants may be suitable in patients whose ligament is healthy enough to stabilize the knee joint.
3. Bicruciate-Retaining Design
This type of knee implant is relatively new to the market and preserves all of the natural ligaments within the knee joint. This implant is meant to feel most like a natural knee joint because all of the ligaments are retained, however, not many studies have been conducted to show the pros and cons of this design.
4. Unicompartmental Implants
This type of knee implant is used in partial knee replacement surgeries — where instead of removing the entire knee joint, only a portion of the joint is replaced by an implant. These implants are smaller and are used to resurface just one side of the knee joint.
Fixed-bearing implants – This is the most common type of tibial component used. In this design, the plastic portion of the tibial component is attached to the metal implant beneath it, allowing the femoral component to roll on the cushioned surface. High-intensity activity can cause these types of implants to wear down more quickly than other types of implants and cause loosening. Loosening is one of the major reasons why joints fail and patients need revision surgery.
Mobile-bearing implants – This type of tibial component allows the plastic insert to rotate slightly inside the metal tibial component. This is meant to give patients a little more range of motion in the sides of their knees. This design is meant to last longer than fixed-bearing designs, however, little research has established the durability of these implants. These types of implants can also be more expensive than fixed-bearing.
There are over 150 types of knee implants on the market today and they may use different materials for each component. Some implants are made from metal (titanium or cobalt-chromium based alloys) and use plastic spacers made from polyethylene. Other implants may use ceramic or a ceramic and metal mixture. Implants that are made from all-metal materials have been associated with increased complications because of the potential for the metal parts to rub against each other and release particles into the bloodstream.
There are certain risks inherent in all knee replacement surgeries, just like there are risks involved with any type of surgery. These risks include:
Other risks may occur following the surgery and may be associated with the knee implant itself, including:
Some of these adverse events may require additional surgery, which carries additional risks for the patient. Device loosening and implant failure are some of the most common reasons why a patient would require revision surgery.
There are dozens of brands of knee implants on the market today and many that have been recalled or withdrawn from the market by their manufacturers. These manufacturers are large medical device companies that often place profit over people.
While we’re not going to review or grade these knee plants, many of the major knee implant brands listed below have come under scrutiny for device problems, including increased rates of failure and the need for revision surgery. Many of these implants are metal-on-metal devices that cause complications when metal ions are released due to the parts rubbing against each other. In other cases, the implants fail sooner than expected to do other reasons.
DePuy Synthes Knee Implant
DePuy faces a number of lawsuits regarding some of its most popular knee implant brands, including its newest line of knee implants. Lawsuits regarding DePuy claim the glue that usually holds the implants in place does not stick properly to the patient’s tibia and can cause early device failure.
Zimmer Biomet NexGen and Persona
Zimmer Biomet is facing lawsuits against a number of its knee implants, including its NexGen and Persona brands.
There are thousands of lawsuits filed against the various manufacturers of certain knee replacement implants. These lawsuits are filed in state and federal courts across the country, and some have been consolidated to streamline the litigation process for lawyers and attorneys on both sides.
When a large number of similar lawsuits are filed in different courts, one or more parties may call on the Judicial Panel on Multidistrict Litigation (JPML) to consolidate their cases into a multidistrict litigation, or MDL. Coordinating similar cases into an MDL helps streamline the discovery process, especially in complex medical device injury lawsuits.
A handful of cases are usually chosen from the MDL’s pool of cases to be tried first. These are called bellwether trials and they help lawyers and attorneys on both sides test legal theories in front of a jury. The outcome of these trials can help move both parties in the direction of a global settlement. MDLs are different from class action lawsuits in that the cases are tried individually and any verdicts or settlements that are reached are specific to the case and not distributed evenly among all plaintiffs in the litigation.
Several knee implant manufacturers are facing lawsuits over their problem implants. These manufacturers may also be facing lawsuits regarding their hip implants as well. Some of these lawsuits have been consolidated into MDLs, including lawsuits over the NexGen system.
Zimmer Biomet has faced over a thousand lawsuits regarding its NexGen Knee Implants. The JPML consolidated federal cases into an MDL in 2011 in the Northern District of Illinois where 290 lawsuits are currently pending. Over the course of the litigation, more than 1,700 lawsuits were filed against the company.
DePuy Synthes is facing scrutiny over its newest generation of knee implants. The first lawsuit over this new-generation implant was filed on Sept. 13, 2017 in Tuscaloosa County, Alabama. The lawsuit comes on the heels of dozens of adverse event reports filed by DePuy with the FDA. These adverse events document premature failures of the knee, which results in loosening and premature failure.
In an article published in the Journal of Knee Surgery, several prominent orthopedic surgeons reported an unusually high premature failure rate related to the knee system. They said the failures may be due to the cement that is used to hold the implant in place. Apparently, the cement does not adequately stick to the tibial component of the implant, which results in loosening and destabilization.
Lawsuits against knee implant manufacturers allege similar claims against the manufacturers of these devices. While the details of the cases may vary, the lawsuits allege similar claims, including:
If you were injured by a defective knee implant, you may be entitled to financial compensation from claims with large cash settlements. People who have experienced the following adverse effects may qualify for a potential lawsuit:
Filing a lawsuit against the manufacturer of a defective product can help patients win back time and money lost due to lost wages, medical expenses, and other problems experienced as a result of the failed device. If you were injured as a result of a defective knee implant, call our offices today to see if you qualify for a lawsuit against the device manufacturer.
OrthoInfo from the American Academy of Orthopaedic Surgeons. “Knee Replacement Implants.” Last updated in April 2016. Retrieved from: https://orthoinfo.aaos.org/en/treatment/knee-replacement-implants
Centers for Disease Control and Prevention. “Hospitalization for Total Knee Replacement Among Inpatients Aged 45 and Over: United States, 2000–2010.” Published in August 2015. Retrieved from: https://www.cdc.gov/nchs/products/databriefs/db210.htm
Smith & Nephew About Us. Accessed Nov. 21, 2017. Retrieved from: http://www.smith-nephew.com/about-us/
DePuy Synthes website. Accessed Nov. 21, 2017. Retrieved from: https://www.depuysynthes.com/
Wright Medical Group website. Accessed Nov. 21, 2017. Retrieved from: http://www.wright.com/
Zimmer Biomet website. Accessed Nov. 21, 2017. Retrieved from: http://www.zimmerbiomet.com/
Judicial Panel on Multidistrict Litigation. “MDL Statistics Report – Distribution of Pending MDL Dockets by District.” Updated Nov. 15, 2017. Retrieved from: http://www.jpml.uscourts.gov/sites/jpml/files/Pending_MDL_Dockets_By_District-November-15-2017.pdf
OrthoInfo from the American Academy of Orthopaedic Surgeons. “Total Knee Replacement.” Last updated August 2015. Retrieved from: https://orthoinfo.aaos.org/en/treatment/total-knee-replacement
Knee Replacement lawsuit page: Updated on July 20, 2020.