woman sitting on a bed holding her knee

When a person decides to have a knee replacement, their quality of life has diminished to the point where they chose to give up past enjoyments such as sports or recreational activities to live free from persistent pain. After seeking out the best options and doctors and trusting the implant to complete its function to the safest possible extent,  they do not expect the potential for leaching of metal fragments or faulty devices in an increasingly common surgery.

Knee Replacement Facts by the Numbers

1/5: the ratio of people who experience a complication as a result of a knee replacement

9/10: the number of implants lasting 15 years after being implanted

1: the total number of pounds a knee replacement weighs

50-80: the age range for most people receiving a knee replacement

65.9: the average age for a knee replacement in 2014, reduced from 68 in 2000.

Knee Replacement Implants

image of a knee replacemeKnee replacement implants consist of plastic and metal components. The plastics are polyethylene, which is both light and flexible. The metals used are titanium or cobalt-chromium alloys. To adhere the knee implant to the bone, a surgeon has three options: use cement, do not use cement, or opt for a hybrid of the two. With the cementless option, the bone grows around and into the device. 

Types of Knee Implants

A knee implant utilizes three components: 

  • femoral component – metal and attaches to the end of the femur, allowing the patellar to slide up and down as the knee bends
  • patellar component – plastic, dome-shaped, aligns with the femoral component and held in place by quadricep and patellar tendons
  • tibial component – metal and polyethylene, attached to the tibia and acts as a plastic spacer between the tibial and femoral components

All implants attach to the thigh bone and tibia in some capacity. Depending on needs, they may have a patellar element that replicates the kneecap. Gender-specific devices work with a female’s frame. Doctors evaluate the knee’s condition to determine the appropriate implant for the patient.

Fixed-Bearing

This implant is the most common of replacements and is generally given to the elderly, as it is not appropriate for active or overweight patients. Due to the design, the polyethylene part can wear away from the metal rolling on the plastic, leading to loosening, pain, and device failure. 

Mobile-Bearing

Although similar to fixed-bearing, mobile-bearing allows the polyethylene part to move. The design is more appropriate for younger, active adults. The idea behind this device is to allow more motion and a deeper bend in the knee while theoretically reducing the friction that causes early failure of the device. 

Medial-Bearing

A medial-bearing implant utilizes a mobile-bearing design but takes it a step further. It functions as a ball and socket and allows more area between the parts of the device, in turn reducing friction and wear and tear. In patients with healthy surrounding tissue and ligaments, this design allows those natural components of the body to hold the device in place. It is possible they may become trapped in the component. 

Posterior Cruciate Ligament Retaining (non-constrained)

The posterior cruciate ligament (PCL) is the ligament that connects the femur to the tibia in the back of the knee. If it is healthy and bone structure is sound, this option can be selected. If the PCL is in good condition but too tight, the implant may not work as well and have premature excessive wear.

Posterior Cruciate Ligament Substituting (constrained)

Where the PCL Retaining option retains the ligament, the PCL Substituting option substitutes the ligament. This option is necessary for individuals who have excessive damage to the knee or have had a prior knee replacement surgery. The surgeon removes the ligaments and replaces them with plastic components. 

Knee Replacements Recalls

knee replacement top recalls

Knee replacements fail for various reasons: design fails, poor fitting, loosening, or other unplanned complications. Depending on the defect, the complications can be short or long term. A quick search on the FDA Medical Device Recalls page reveals knee replacement recalls are prevalent. Recalls have already been filed in 2021. 

Most generally, recalls are issued by the manufacturer and not by the FDA. Each can vary from one device to thousands of devices. They are not limited to implants alone; for example, a recall may be the tool used to complete the surgery, which can break, leaving parts inside the patient.

In an often-quoted report released in 2013 by Consumers Union, 709 knee implant device or component recalls were examined. The report noted that the companies manufacturing these implants often did not guarantee their efficiency, durability, or safety. Another significant concern was the fast track method of a 510(k) clearance. This method allows FDA approval by showing that the device is similar enough to one already on the market.

Recognizing that rushing approval was potentially leading to issues with knee implant failures and their subsequent medical complications, an attempt was made to have Congress guarantee more testing on hip and knee replacement parts. The goal was to have this requirement included as a part of the Medical Device User Fee Act. It was, unfortunately, blocked. Consumers Union sent letters to manufacturers attributing to the majority of the recalls requesting assurance of a warranty on their products.

“Medical device companies claim that current law provides adequate protection for patients and that their implants are dependable and safe,” said Lisa McGiffert, director of Consumers Union’s Safe Patient Project.  “If that’s the case, they should have no objection to offering warranties to back up those claims.  Patients and taxpayers shouldn’t be on the hook for the cost of replacing devices when they fail.” 

 

Design Fails

When a design is flawed due to a manufacturing defect, the implant can wear out prematurely. Loosening, when the device comes loose or does not attach to the bone, is another bi-product of design failure. Revision surgery is likely needed to correct both issues.

In other cases, tools used for the surgery could be compromised. Some recalls address tools breaking with undesired consequences such as parts of the tool being left in the patient’s body.

Improper Fit

Knee replacements must fit properly and match with the patient’s lifestyle and circumstances. When they do not, they cause damage to the bone or device.

Label Errors

If a package has errors, particularly on the instructions or labels, it leads to compromised safety. Similarly, if the package components are incorrect, i.e., the left and the right knee parts are switched.

Early wear

Implants should last over fifteen years. Premature wear on the implant can cause the implant to fail or loosen earlier than the patient expects. 

Complications from knee replacements

Knee replacements come with a risk of both long-term and short-term complications. The short-term complications are generally the result of a difficulty with the surgery itself. In contrast, long-term complications are more likely to be due to the implant.

Short-term complications with knee replacements

Infection

Infection is the most serious risk following surgery and occurs when contaminants enter the wound during the surgery. Sometimes the germs are on the implant itself. The infection can be immediate or take weeks, months, or even years to show up. While medications may combat the infection, the surgeon may need to open back up the knee, remove the implant and infected tissue, and implant a new knee. This complication is rare, though, with only 2.5% of the cases ending in infection.

Deep Vein Thrombosis (DVT)

While infection is rare, DVT is much more common. DVT is when a blood clot is formed deep within the veins. If the blood clot were to break free, it could block the blood flow to the lungs. In rare cases, DVT causes death or, in less extreme cases, permanent damage to the veins. DVT does not always have symptoms, and therefore, doctors must emphasize preventing DVT.

According to stoptheclot.org, 80% of orthopedic patients are at risk of developing DVT if no preventative treatment occurs. With treatment, that number drops to 3%. While that is much lower, an estimated 700,000 Americans undergo knee surgery each year, so 21,000 people are at risk of developing DVT even with preventative measures.

Long-Term Complications

Like short-term complications, long-term complications also include infection. However, as stated earlier, most long-term complications are due to the actual implant. Wear on the implant, loosening, bone fractures around the implant, chronic pain, and motion-limiting scarring are all long-term complications of knee replacements. Unfortunately, these often require revision surgery to address.

Polyethylene wear and osteolysis

Osteolysis, the loss of bone tissue leading to loosening, fractures, and other issues, is not completely uncommon with polyethylene wear. In follow-up appointments five to fifteen years post-surgery, osteolysis was seen in 5-15% of the patients

Both cemented and uncemented implants are capable of producing this condition. In some cases, smaller debris of polyethylene, cement, and metal elicit a cellular response. In other cases, larger debris evokes a tissue response which is tied to delamination, pitting, and wear. Delamination is the cracking under the surface, eventually leading to the flaking of material. Pitting and wear is accelerated by the presence of free radicals, causing oxidation.

Infection 

Periprosthetic joint infection has been reported in 1.55-2.5% of total joint arthroplasty, such as you see in total knee replacements. It is quite costly to manage these infections. Per The Journal of Arthroplasty, “the annual cost of infected revisions to US hospitals increased from $320 million to $566 million during the study period and was projected to exceed $1.62 billion by 2020.” 

One study evaluated over 11,000 surgeries performed at their center. They looked specifically at those resulting in revision surgery, finding infection was a leading cause of failure in knee replacements. Further, they undercovered the possibility of total knee replacements attributing to a cytokine immune system response and potential link for inflammation and infection. More research is necessary.

chart from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3953520/chart from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3953520/

Chronic Pain

In a study found in EFORT Open Rev 2018;3:461-470. DOI: 10.1302/2058-5241.3.180004, 10-34% of patients reported an unfavorable amount of pain in the three-month to five-year range following total knee arthroplasty. Other studies simulate the same result, showing that this finding, while the exact percentages may vary slightly, is not unique to the study. Given the vast amount of yearly knee replacements in the United States, and with projections of this number climbing, an unacceptably high number of individuals live in chronic pain after undergoing a surgery intended to reduce it.

Metallosis

When metal parts rub together, microscopic metal particles can rub off and enter the blood and tissues. This metal poisoning, metallosis, can affect the brain, heart, eyes, and other organs, or even cause bone or tissue death. When polyethylene parts wear away, there is a risk for metal on metal contact. Because the polyethylene must be worn away to expose the metal, metallosis is usually seen late in the span of an implant’s life.

Lawsuits from Knee Replacements

Sulzer Medica

In 2000, Sulzer Medica recalled thousands of artificial joints due to manufacturing changes producing an oily substance that remained on the implant. This substance, in turn, prevented the joint from bonding to the bone. In 2002, Seltzer Orthopedics Inc., a subsidiary of Sulzer Medica, announced they would settle by paying $1 billion to around 4,000 lawsuits claiming the company produced faulty hip and knee implants. A representative for the company said this would equate to about $200,000 per patient, yet would not bankrupt Sulzer.

Zimmer’s NexGen

In 1995, Zimmer Biomet introduced its NexGen implant to the market, which utilized the 510(k) method approval method. In 2001, they released the HighFlex version of the knee. Over 1,000 lawsuits have claimed the HighFlex knee caused an increase of pain, loosening of the device, early failure, and necessary revision surgery. 

The lawsuits accuse Zimmer Biomet of misleading marketing and concealing potential health risks, spelling out the resulting unnecessary pain, surgeries, and product defects. The company settled in 2018, leaving many patients still experiencing failing knee replacements out in the cold.

Some signs of an issue with the HighFlex NexGen knee are:

  • Clicking, popping, or crunching sounds in the knee implant
  • Swelling and pain 
  • Difficulty walking or standing
  • Loose feeling in the knee

DePuy Attune Knee

In 2019, Regina Dibala filed a lawsuit in the US District Court for the District of Colorado against DePuy Orthopaedics and Medical Device Business Services, Inc. In her case, Dibala addresses that within five years, the device, Attune Knee, failed. After enduring instability, constant and severe pain, and difficulty walking, her doctors took radiographs of her knee, revealing the device’s loosening. Essentially, the Attune system’s bond between the tibial baseplate and the implant cement interface failed, causing the loosening.  

DePuy is a subsidiary of Johnson & Johnson. In 2011, DePuy’s Attune knee was introduced to the United States market, and three years later, in 2014, the company debuted two new technologies for the implant. Attune utilized the 510(k) FDA approval path, receiving clearance in 2010.  

Two hundred seventy-seven of DePuy’s knee implant components and devices were recalled between 2002 and 2013. Of these, four were Class I recalls as they had a “reasonable probability” use of the products would cause adverse health consequences, up to death. In 2015, a Class II recall of 3,474 Attune Knee Tibial Articulation Surface Instruments took place due to a wire spring coil breaking off during the procedure. Per the FDA site, the reason for the recall reads as follows:


Potential for the Balseal, a small wire spring coil located on the post feature of the ATTUNE Knee Tibial Articulation Surface Instruments used in trialing to become damaged and disassociate (come off). If the Balseal is separated from the post, it has the potential to enter the surgical site and be left in the patient if the surgeon is unaware of the disassociation

Studies on Attune’s knee implants reveal various issues such as pain, decreased range of motion within two years, cement failing to bond parts to the tibia, and tibial loosening. The US Food and Drug Administration has received hundreds of complaints, and yet, DePuy has no warranty on the product. The only way to fix the issue is through revision surgery. The studies also suggest the tibial loosening is underreported. This loosening could cause fractured bones and the implant or its components to wear out quicker.

Signs of tibial loosening in Attune

The following is not meant to be a complete list. Patients who have experienced tibial loosening with their Attune device reported these symptoms:

  • Pain
  • Instability when standing
  • Pain with weight-bearing pressure
  • Swelling 
  • Warmth around the knee months past surgery
  • Backward or sideways movement in the knee

B.Braun

In November of 2020, B. Braun directed customers who had purchased its Aesculap Univation X Knee Replacement system to hold off on implanting them while the company researched a possible malfunction in the system. Surgeons and sales representatives both claim B.Braun knew of the issues and attempted to cover them up. Reports alleged the implant was prone to loosening. 

Lawsuits against B. Braun assert that due to the ceramic coating on the implants, likely put there to prevent metal issues, allowed moisture to collect under the bone cement, causing the implant to move. Not only does this produce pain, but it enables loosening and difficulty walking. One surgeon claimed he could remove the implant with just two fingers.

Side effects of the Aesculap Univation X Knee Replacement System:

  • Knee Pain
  • Infection
  • Decreased or limited range of motion
  • Joint instability
  • Inability to walk

Knee Replacement Questions

When a person recognizes the device is failing early, they may seek out advice from a lawyer. This is important, as there may be statutes of limitations, class acts, recalls, or other specifics a person not versed in the law may be unaware of. 

To help the process move quicker and more effectively, it is good to prepare answers to potential inquiries.

  • When was the knee replacement surgery? 
  • Did you need revision surgery?
  • What complications or short or long-term consequences have you experienced in regards to your implant?
  • What brand or model is your implant?
  • Are you aware of any recalls for your device?
  • What do you do to help with the impact or pain from your implant?

Knee Replacement Implant Lawyers

If you or a loved one has experienced pain, loosening, failure of a knee implant, or have received notice of a recall, we are here to help. Our experienced team matches you with lawyers versed in assisting clients in cases just like yours. You trusted a company to be honest when creating a device to improve your quality of life. It didn’t happen. We are here to help you receive the compensation you deserve. Don’t fight alone. Contact The Hayes Firm today.

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