DePuy Orthopaedics and its parent company, Johnson & Johnson, face a product liability lawsuit over its knee replacement SmartSet GHB bone cement, which the plaintiff indicates is prone to fail, resulting in mechanical loosening of knee implants. 

In a complaint (PDF) filed last month in the U.S. District Court for the Western District of Louisiana, Osa Green alleges that DePuy SmartSet GHV Bone Cement is defective and unreasonably dangerous, indicating that if the manufacturer had disclosed known problems with the product, she would not have consented to the bone cement being used in her knee replacement surgery.

Green underwent right total knee replacement surgery in August 2016, during which she received a DePuy PFC Sigma knee replacement system. To bond the components together, DePuy SmartSet GHV Bone Cement was used. However, after the procedure, Green began experiencing severe, persistent pain, instability, discomfort and difficulty walking.

According to allegations raised in the DePuy knee replacement bone cement lawsuit, the failure of the implant caused by asceptic loosening of the cement. A bone scan performed in August 2017 indicated that the tibial baseplate was loosening, and a month later she had to undergo revision surgery.

DePuy SmartSet GHV belongs to a class of bone cements known as high viscosity (HV) cements, which some studies suggest are less effective than low or medium viscosity cements. The lawsuit notes that a study published in the Journal of Arthroplasty indicated that HV bone cements, like SmartSet GHV, are causing tibial component debonding even in implants that are seen as reliable.

“The primary reason the SmartSet GHV Bone Cement fails is mechanical loosening. The mechanical loosening is caused by a failure of the bond between the tibial baseplate at the implant-cement interface,” the lawsuit states. “Mechanical loosening means that the attachment between the artificial knee and the existing bone has become loose. Such loosening will eventually result in failure of the device.”

When the knee replacement loosens, it can cause pain and wear away the bone. This can lead to restricted physical movement and severe pain, which continues until the pain becomes unbearable, or the device fails, resulting in a loss of knee function. At this time is when most decide to undergo revision surgery to have the implant removed.

Tibial baseplate loosening has affected other DePuy knee implants as well, including the DePuy Attune Knee, according to a number of lawsuits filed over those knee replacement systems. However, this lawsuit suggests that the problem lies in the cement used by DePuy products.

In a study published last year in the Journal of Knee Surgery, researchers noted a spike in DePuy Attune knee loosening and failures, raising concerns about problems at the implant-cement interface.

A number of DePuy Attune knee lawsuits are now being pursued by individuals nationwide, each raising similar allegations that the primary reason for the problems is mechanical loosening, which is caused by the failure of the bond between the tibial baseplate and the implant-cement surface.

As of June 2017, the FDA indicated it had received about 1,400 reports involving failure with DePuy Attune knee replacements, including at least 633 cases where individuals have already required revision surgery.

Tags: Attune Knee, Bone Cement, DePuy, Johnson & Johnson, Knee Implant, SmartSet