An integral part of almost all artificial knee joint replacements is a plastic separator referred to as an insert. As the insert is responsible for bearing the stresses and impacts experienced by the implant, it is imperative that the insert be as durable as possible. Extensive wear of the insert can result in failure of the entire joint replacement device, bone loss, and the release of foreign bodies into the patient. At the very least, extensive wear of the insert will result in the need for a revision surgery to remove the worn insert and to replace it with a new insert.

The inserts used in knee implants are generally manufactured from a type of polyethylene known as ultra-high molecular weight polyethylene or UHMWPE. UHMWPE is used for knee prosthesis inserts because of its extreme durability.

However, some manufacturers continued to use gamma radiation to sterilize their inserts and store them for extended periods even after becoming aware that it rendered their product defective. At least two manufacturers switched to a safer form of sterilization, but instead of discarding their inserts previously sterilized with gamma radiation, they disposed of them by selling the defective inserts for surgical implantation in patients. The sale of gamma irradiated polyethylene knee inserts appears to have continued until fairly recently.

The following companies manufactured implants that may have included defective inserts:

• Biomet Orthopedics, Inc.
• Biopro
• Corin
• Depuy
• Encore Orthopedics
• Endotec
• Hayes Medical
• Howmedica International, Inc.
• Implex
• Johnson & Johnson
• Kinamed
• Link Orthopedics
• Orthomet, Inc.
• OsteoImplant Technology
• Smith & Nephew
• Stelkast
• Stryker Howmedica
• Sulzer
• Whiteside Biomechnicals
• Wright Medical Technology
• Zimmer

Hopefully the number of the above manufacturers that knowingly sold defective knee implants will be few. However, even one patient receiving a knee insert that the manufacturer knew to be defective is one patient too many.

If you believe that your knee prosthesis insert failed because it was defective, the lawyers of the Maglio Christopher & Toale Law Firm will be glad to review your medical records to determine whether we feel there are sufficient grounds for us to represent you in pursuing a case against the manufacturer. Click here for our online potential case evaluation form.

Typically in order to review a case, we need the orthopedic surgeon's office chart, the operative reports for the original joint replacement surgery and the revision surgery, and the device record for the original surgery from the hospital chart (this shows the product and lot numbers of the components of the device). We also like to have the device. Therefore, it is essential that you get possession of the device as soon as it is removed. It may still be possible to do the case with no device, but it will be much more difficult.