Stryker made payments to 328 doctors in 2007 - Stryker Orthopaedics has plants in Cork and Limerick, Ireland.

Five makers of orthopaedic implants paid more than $221 million to surgeon "consultants" in 2007, according to a US Senate committee that plans to question the payments at a hearing today.

The US healthcare industry is a huge business and in the past, issues such as payments to researchers by hedge fund managers for "seminars" on their work and provision by drugs companies of lavish free junkets to doctors, has raised concerns about the use of kickbacks within the law but where an obvious conflict of interest is present.

Today's hearings in Washington DC, are titled: Surgeons for Sale? Conflicts and Consultant Payments in the Medical Device Industry

The companies involved in the payments -- Zimmer Holdings; Biomet; Stryker Corp.; Smith & Nephew PLC and the DePuy Orthopaedics unit of Johnson & Johnson, -- agreed to disclose the payments last September in settling government allegations that they violated anti-kickback laws by paying physicians to use their products exclusively.

Four of the companies, with the exception of Stryker, agreed to pay $310 million to settle claims that the payments were, in reality, rewards to doctors who selected a company's hip and knee implants, even when they weren't necessarily the best for a particular patient. Stryker agreed to government supervision but didn't make a payment. The companies didn't admit any wrongdoing.

The Senate Special Committee on Aging will discuss the practice of device manufacturers retaining surgeons as paid consultants in today's hearing. Sen. Herb Kohl, who is chairman of the committee, has proposed legislation that would mandate disclosure of consulting payments by medical-device makers and drug companies.

The Wall Street Journal says that the government inquiry, by the Justice Department and the Department of Health and Human Services, questioned a range of financial transactions between the orthopedics manufacturers and surgeons.

In some cases, a company sales representative would spend one or two hours in an operating room watching a surgeon implant his company's device. The company would then pay the doctor for eight to 10 hours of "training" services, according to findings that government investigators shared with the committee.

In total, payments to surgeons from these companies amounted to more than $800 million from 2002 through 2006, the investigation found.