Orthopedic surgeons who followed manufacturers' instructions and used infusion pain pumps for arthroscopic surgery could be exposed to malpractice lawsuits if a new legal action filed by one of the manufacturers is allowed to stand in a Kentucky court, lawyers familiar with the case say.

I-Flow, a Kimberly-Clark subsidiary that makes a widely used pain pump, is pressing the court to recognize malpractice charges against Bruce Halladay, MD, an orthopedic surgeon in Edgewood, Ky., for unauthorized use of its product in shoulder surgery after it dropped the controversial instructions.

I-Flow and other manufacturers have been facing hundreds of lawsuits from patients that allege they encouraged physicians' off-label use of their pain pumps, but this is the first time a manufacturer has sought to bring a physician into one of these cases, says Ronald E. Johnson Jr., an attorney for Lucas Frietsch, the patient in the Kentucky case.

"For this company to choose one case and sue the doctor is unheard of," says Mr. Johnson. Since the injured patients believe their surgeons were just following manufacturers' instructions, such lawsuits rarely name the physician, he says. Mr. Frietsch's original attorney, however, did name Dr. Halladay in his lawsuit. When Mr. Johnson took over the lawsuit, he attempted to remove the physician's name, but I-Flow argued against this proposed change and is seeking to keep Dr. Halladay in the case.

I-Flow's novel tactic is a worrisome sign of how manufacturers may treat other pain pump lawsuits in the future, says Robert K. Jenner, a Baltimore attorney who also represents Mr. Frietsch. "What makes the situation all the more insidious is that the doctor did nothing more than use the product the way the company and its sales representatives told physicians to use it," he said in a press release. Mr. Jenner adds that I-Flow is under investigation by the Department of Justice for allegedly promoting its devices for uses that weren't approved by the Food and Drug Administration.

For many years, orthopedic surgeons used pain pumps to alleviate post-operative pain for routine arthroscopic surgeries, such as repairing a labral tear in the shoulder, as in Mr. Frietsch's case, Mr. Johnson says. In many cases, these patients, many of whom were young athletes like Mr. Frietsch, then suffered glenohumeral chondrolysis, a long-term deterioration of the cartilage structure.

Patients claiming chondrolysis due to the pain pumps have filed more than 500 lawsuits against the manufacturers, which also include Stryker, Breg and DJO Inc. Mr. Johnson says I-Flow's earlier promotional materials recommended the pain pumps' use in arthroscopic shoulder surgeries, even though the FDA hadn't approved this use. While most of the pain pump lawsuits are pending, 2 cases involving I-Flow have been decided. One resulted in a $5.5 million verdict against the company and the other found it not at fault.

I-Flow's motion to keep Dr. Halladay in the case, filed on Nov. 8, said its pain pump instructions no longer recommended their use in arthroscopic shoulder surgeries by the time of Mr. Frietsch's procedure in 2007. Since Dr. Halladay had not requested updated literature, the company argues, he was at fault.

Mary Kate Molloy, a Covington, Ky., attorney who represents Dr. Halladay, acknowledges that her client used the I-Flow pain pump after the company had stopped recommending the off-label use, but she says Dr. Halladay was unaware of this change, so he didn't know he needed to read the directions again. She asserts that even I-Flow's own sales reps were unaware of the change.

I-Flow issued a statement declining to comment on ongoing case. However, addressing the larger issue of pain pump litigation, the company denied charges that its product damages cartilage. "Numerous peer-reviewed scientific studies conducted by top cartilage research scientists have repudiated plaintiff lawyers who contend that local anesthetics infused intra-articularly into shoulder surgery patients actually caused cartilage damage," it said.

Leigh Page