Dr. Lawrence Dorr, a nationally known orthopedic surgeon in Los Angeles, realized last year that something was very wrong with some of his patients. Months after routine hip replacements, patients who had expected to live without pain were in agony. "The pain was grabbing me around the back," said Stephen Csengeri, who is 54, and a lawyer from Torrance, Calif.

Dr. Dorr found he had implanted the same metal hip socket in each patient. Several needed surgery again — a replacement for their replacement. The doctor first told the device's manufacturer, Zimmer Holdings, last year about his concerns but nothing happened. Then in April, Dr. Dorr, who was a highly paid consultant for Zimmer, sounded an alarm to colleagues in a professional association and soon heard back from doctors with similar experiences.

"I saw one of Zimmer's engineers at a meeting, and I told her that you should pull this cup because you are crippling patients," Dr. Dorr said. Last week, Zimmer announced it was suspending sales of the device, known as the Durom cup, until it trained doctors how best to implant it. The company said a "low" percentage of the 13,000 patients who got the socket would need replacements, but some doctors fear the number could reach into the hundreds.

Learn more about Zimmer hip implant injuries and your legal rights.