Failure of knee implant bone cement might be the unsuspected problem in failed knee replacement surgeries.

In many knee implant procedures, bone cement helps attach the new artificial components to the femur above the knee and the tibia below the knee.

Patients who fight constant pain, newly noticeable chronic pain, knee instability, swelling or decrease range of motion could be a victim of aseptic (no infection) tibial loosening caused by failed knee implant bone cement.

When surgeons perform a total knee replacement procedure, they have a choice of using a low, medium or high-viscosity cement to stabilize the implant parts. Many surgeons prefer the high-viscosity cement because the thickness allows for better control. Unfortunately, recent studies indicate that high-viscosity cement may increase the risk of implant failure.

In 2016, the National Center for Biotechnology Information (NCBI) examined 13 incidents involving knee implant failure because the component either failed to remain attached to the cement or the implant component loosened from the tibial (shin) bone. High-viscosity cement was used in all of the failed knee implant surgeries; in implants that used low or medium viscosity bone cement, there were no such debonding problems.

The NCBI also said that in 2013, an analysis of 3,048 total knee replacement surgeries indicated nine failures. All of the failed implant procedures had been done using high-viscosity knee implant bone cement.

Lawsuits Filed Over Poor Knee Implant Bone Cement

At least one lawsuit has been filed due to knee implant bone cement failure. A woman alleges she had knee replacement surgery in 2009, but by 2011, her knee was in constant pain.

She says that an X-ray didn’t indicate any movement of the knee implant components from their intended positions, but a bone scan allowed the surgeon to see loosening of the tibial component. She had a revision surgery in 2012.

The high-viscosity bone cement used in her original surgery was allegedly approved through the fast-track program that the FDA offers for products that can show they are substantially equivalent to another product that the FDA already approved. The fast-track program allows the proposed medical product to skip certain clinical testing requirements and make it to market faster.

According to her complaint, the high-viscosity cement that was used in her original procedure had undergone a change in the size of the particles used in the manufacturing process. The change allegedly caused the knee implant bone cement to lose some of its ability to adhere. Such a change in the way the cement was made should have been tested before the new formulation was placed on the market, alleges the lawsuit.

Patients who undergo a revision knee replacement surgery are at higher risk of a number of complications. Infection, blood clots, swelling, nerve damage and blood loss are among the dangerous risks a second knee surgery presents. Delicate blood vessels and nearby tissue are more apt to suffer damage with a second knee replacement surgery. With multiple traumas to the same knee, the patient might see a difference in the length of their legs due to the reduction of bone mass in the damaged knee.