In re DePuy Orthopaedics, Inc., Pinnacle Hip Implant Product Liability Litigation

The components of a prosthetic hip included a cup placed in the patient’s hip socket, a liner inside the cup, and a head placed atop the patient’s femur. Together, these components replicated the patient’s ball-and-socket hip joint. Some prosthetic hips had metal liners and metal heads—a metal-on-metal (MoM) design. Some had a metal-on-ceramic design. Others had plastic liners and metal heads—a metal-on-plastic (MoP) design. The MoP hip joints could cause osteolysis, that is, bone loss in the area near the hip joint. Using a cross-linked plastic liner (a liner treated with radiation) reduced the risk of osteolysis. Several thousand patients (plaintiffs) received the Ultamet, an MoM prosthetic hip produced by DePuy Orthopaedics, Inc. (DePuy) (defendant). Later, the patients’ MoM implants failed and had to be replaced with metal-on-ceramic or MoP designs. The patients sued DePuy based on a theory of defective design. DePuy argued that MoM designs were introduced to replace MoP designs to address the problem of osteolysis and to give younger patients the option of a more durable prosthetic. Also, DePuy argued that MoP designs could not be considered safer than MoM designs because MoP hips were an entirely different product. The patients presented evidence that cross-linked MoP hips would be preferable to and were safer than MoM designs. The patients asserted that DePuy had brought Ultamet to market without adequate testing and had fomented misinformation to discourage use of cross-linked MoP designs. The jury awarded the patients $502 million. DePuy asked for a judgment as a matter of law, which the trial judge refused. DePuy appealed.