The majority of claims made by 175 male patients who received Smith & Nephew hip implants were ejected from a larger multidistrict litigation (MDL) by a Maryland federal judge on Feb. 28. 

U.S. District Judge Catherine Blake rejected the patients’ claims for failure to warn, negligence, failure to train surgeons, and false advertising after determining that the plaintiffs did not have the evidence or expert testimony to substantiate these specific claims, reported.

The majority of plaintiffs in this MDL received Smith & Nephew’s Birmingham Hip Resurfacing (BHR) implant. Plaintiffs allege that the implants were defective, with metal components from the implant breaking off, entering the circulation and subsequently causing bodily injury.  

In her opinion, Judge Blake notes that after a 2010 label change, Smith & Nephew eventually recalled all femoral head implants sized 46mm and smaller as well as indicating that the BHR implant should not be used in women. The bulk of tossed claims came from 175 patients who had larger implants that remained on the market and retained FDA approval for male use following the recall.

Plaintiffs in the MDL all underwent hip resurfacing surgery. The procedure trims the ball-shaped bone that fits in the socket joint at the top of the thigh called the femoral head. The surgery resurfaces the femoral head with a smooth metal covering and shell while removing damaged bone and cartilage within the hip socket. 

According to the United States District Court, District of Maryland, the BHR system uses a cobalt-chromium alloy for both parts. The plaintiffs in their complaints allege that this “metal-on-metal” design caused components from the implants to migrate into surrounding tissues. The inflammation in the tissues would then cause pain, metallosis, and bone and tissue necrosis.