Earlier I wrote about how Exactech was recalling many of its ankle, hip and knee liner implants. These recalls were based, at least in part, on several studies about how these implants could suffer from premature wear. This could then require patients to need revision surgery (surgery to repair problems from an earlier surgery) to fix the defective artificial joint.

In this blog post, I’ll take a look at some of these studies and try to explain what these studies found, what their findings mean and why they prompted Exactech to initiate these recalls.

The Materials Used in the Hip, Knee and Ankle Inserts or Liners

The Exactech recalls we are discussing relate to the material used in these implants, which is UHMWPE (ultra-high molecular weight polyethylene). Until the implant gets placed inside a patient, it must be carefully stored in oxygen-resistant packaging. This is to prevent the liners and inserts from coming into contact with too much oxygen (the air we breathe contains about 21% oxygen).

The Basis for the Ankle and Knee Liner Insert Recall

The scientific explanation concerning these recalls is complex. The primary reason for Exactech’s recall of its ankle and knee products appears to be the result of a review of patient data. Specifically, how an unusually high number of patients received revision surgery because of faster-than-expected wear of the liner implant.

Exactech has tried to figure out the exact cause of the higher failure rates. One potential cause may be the result of improper packaging of the product. As mentioned earlier, UHMWPE doesn’t like to be exposed to too much oxygen during storage. If it is, it could result in damage to the liner or insert, which could lead to premature wear once inserted in the human body.

The reason things are unclear is because the data used by Exactech is incomplete. The data doesn’t differentiate between implants that come from production batches that used improper packaging and batches that had proper packaging. To be safe, Exactech has recalled all batches that could contain improper packaging, even though some of the products being recalled might be degrading or defective.

Studies Relating to the Hip Liner Recall

When it comes to the problem with Exactech’s hip liner, what we know is that these hip implants use the same UHMWPE material. It’s not established at this point that the hip products containing this material were improperly packaged. But let’s step back for a minute to help put things into the proper context.

Before Exactech and other companies began using UHMWPE for their implant products, they used conventional polyethylene or highly cross-linked polyethylene. Highly cross-linked polyethylene seemed to work better than conventional polyethylene because it seemed to last longer in patients over the long term. But highly cross-linked polyethylene seemed more likely to suffer from cracks and fractures compared to conventional polyethylene.

Engineers and scientists went back to the drawing board and appeared to come up with the ideal material for hip, knee and ankle joint replacements: UHMWPE. This new material seemed to have the long-term wear properties of highly cross-linked polyethylene, but without the tendency to crack or fracture.

Unfortunately, there are at least three studies that found unusual rates of failure with hip replacements using UHMWPE. All of these studies are from the last few years and examined Exactech’s Connexion GXL liner, a hip implant using UHMWPE.

The first study is titled, “Early Polyethylene Failure in a Modern Total Hip Prosthesis: A Note of Caution.” It looked at individuals who received the hip implant in question during a ten year period and suffered from osteolysis (damage to bone tissue). The study identified twelve patients, nine of whom needed revision surgery.

The authors of the study didn’t identify the cause of these results. But they later speculated that if there wasn’t a problem with the product’s design, the problem could be limited to a specific production batch and be the result of a manufacturing error.

The second study is titled, “Early Failure of a Modern Cross-Linked Polyethylene Acetabular Liner.” It looked at five patients that received the Connexion GXL liner, but suffered from severe osteolysis and wear of the implant within five years of hip implant surgery.

The study did not conclusively identify the cause of the premature wear, but the authors suspected that there could have been a variation in how some of the Connexion GXL liners were produced.

The third study is the most recent and is titled, “Unexpected Wear of a Uniquely Designed Moderately Cross-Linked Polyethylene in Total Hip Arthroplasty.” The researchers examined 38 patients who received Exactech’s Connexion GXL liner. The study found higher-than-anticipated wear, with about half of the patients at risk for osteolysis.

So What Do These Studies Tell Us Exactly?

They tell us that there is likely a problem with Exactech’s ankle, hip and knee implants that use the UHMWPE. Of course, more research and data are needed to understand if the problem comes from the implant’s design or production process, or a combination of factors.

No matter what subsequent research finds, if you think you’ve received one of these joint products, you should talk to your doctor. Depending on what they tell you, if you want to look into your legal options, you should give me a call at (919) 830-5602.

This post was written from publicly available studies and news reports. Photos are for illustrative purposes only.

Many of Exactech’s joint replacement products have performed well and improved the lives of patients. But over the last fear years, Exactech has learned from multiple studies that some of its ankle, knee and hip products can suffer from premature wear or other problems. Many of these issues could result in the need for patients to undergo revision surgery to replace the device and repair any damage it may have caused to the bone and/or soft tissue.

Exactech has initiated various recalls in response to these problems. The purpose of this blog post is to provide a brief overview of which products have been affected, what’s wrong with these products and what you can do if you’ve had one implanted into your body.

Which Exactech Products Are Subject to Recall?

Currently, Exactech’s hip, ankle and knee joint replacement products are having problems. Based on the issues associated with the artificial joints, the recall has been organized into two groups.

The first group involves the knee and ankle polyethylene liners and inserts. The exact products can be found on Exactech’s website, but include products marketed under the following names:

• OPTETRAK®
• OPTETRAK Logic®
• TRULIANT®
• VANTAGE®

If your ankle or knee replacement surgery uses any of these products and it was manufactured in 2004 or later, there’s a good chance you could be affected.

The second group relates to hip polyethylene liners. The affected products are available for review on Exactech’s webpage, but most involve the Connexion GXL branded acetabular polyethylene liners.

What’s Wrong with the Exactech Knee and Ankle Liners and Inserts?

These liners are made out of ultra-high molecular weight polyethylene, or UHMWPE. This requires them to be packaged in special oxygen-resistant vacuum bags.

Unfortunately, the packaging lacked a secondary barrier containing ethylene vinyl alcohol. Without this special ingredient, the insufficient packaging allowed the insert or liner to become exposed to a higher-than-expected amount of oxygen. This could lead to excessive oxidation of the UHMWPE. This can dramatically degrade the physical integrity of the knee or ankle liner or inert. Problems that could arise after joint replacement surgery include:

• Higher-than-expected wear debris in the joint.
• Bone loss
• Fracturing or cracking of the artificial knee or ankle joint.

What’s Wrong with the Exactech Hip Liners?

Unlike the problem with Exactech’s ankle and knee products, the hip acetabular liner issue doesn’t relate to packaging. However, the hip liner is made out of the same ultra-high molecular weight polyethylene, or UHMWPE.

It’s not believed that the UHMWPE was negatively affected by excessive oxygen exposure before use. But there’s still a concern in the form of premature wear of the polyethylene liner. This has caused a variety of problems in patients, such as:

• Destruction of bone tissue (osteolysis)
• Pain
• Limited mobility or range of motion

Not all patients have been affected the same way. Most patients suffering from problems received their hip surgeries about three to six years ago. And problems with the polyethylene hip liners seem to be more common in those who are more physically active and/or received hip replacements that use larger femoral heads and thinner acetabular liners.

What You Should Do If You Think You’ve Been Affected by the Recall

The first thing you should do is contact your doctor. You should reach out to her or him even if you’re not experiencing any problems with your ankle, knee or hip replacement. Your doctor can confirm if you’ve received an Exactech artificial joint that’s been recalled. Your doctor can also properly assess your condition and help you decide what your next steps should be from a medical standpoint.

Depending on what you and your doctor find, revision surgery may be needed. You may also have legal options, including filing a lawsuit. Only after contacting an attorney can you know if you have a case against Exactech and what your potential legal remedies could be.

Exactech is also accepting claims relating to the recall. However, it’s a good idea to first talk to your doctor and have an initial consultation with a lawyer before agreeing to any claims reimbursement from Exactech. You can call me at (919) 830-5602 to discuss your potential case, or another attorney you trust. Good luck.