The wife of a man who developed a serious post-surgical infection that he blames on a patient-warming system from 3M Co. testified in U.S. District Court in Minneapolis Wednesday about the difficulties he endured following a hip replacement.

"I wasn't sure if he would pull through it. With this infection, I wasn't sure if it would spread through the rest of his body," a tearful Lillian Gareis told jurors during the second day of the trial over 3M's Bair Hugger device. After months of antibiotics and a second hip replacement, her husband's hip is still "weak. It's not like it was before," she said.

Her husband, Louis Gareis, alleges in a lawsuit that his hip infection was caused by a 3M Bair Hugger, a device widely used during surgeries to prevent patient hypothermia. His suit is the first of several thousand Bair Hugger suits to reach trial.

Maplewood-based 3M has denied the allegations and said no one knows where the bacteria originated that caused Gareis' infection. The company acquired the device in October 2010 when it bought the product maker Arizant Inc.

Gareis, who had his right hip replaced in 2010 and re-replaced in 2011, alleges that the Bair Hugger was defectively designed. The suit contends that the forced-air warming device disrupted the normal "top-down" airflow of a filtered and vented operating room, and that the device moved air particles "in close proximity to the surgical site."

His wife testified that the infection he developed left him unable to play with grandkids, work in the softball coaching business he founded or engage in intimate relations. His lawsuit seeks compensation for the disruptions to his life.

An orthopedic surgeon who appeared for the plaintiffs, Dr. Michael Stonnington of Hattiesburg, Miss., testified that he had concerns about the Bair Hugger's airflow safety and stopped using it in his operating room.

Dee DePass • 612-673-7725