Last Updated: 2007-08-16 13:55:36 -0400 (Reuters Health)

LONDON (Reuters) – Smith & Nephew has recalled 185 hip implants due to a packaging error by a subcontractor, it said on Thursday.

The British firm said different sizes of a part of its Birmingham Hip Resurfacing System had been mixed up during the packaging process.

A spokesman said that two patients were found to have been implanted with the wrong-sized device but that some other cases may come to light during the recall process.

The Birmingham hip was the first of a new kind of less-invasive hip implant to be approved by U.S. regulators, and Smith & Nephew said earlier this month that demand for the device had exceeded its expectations.

"All hospitals and surgeons who have received these implants have either been notified or are in the process of being notified," S&N said in a statement. "A number of implants have already been recovered in their packaging."

It said the devices were distributed to a number of countries including Britain and the United States and that it had notified both the UK Medicines & Healthcare Products Regulatory Agency and the U.S. Food and Drug Administration of the voluntary recall.

"Distribution of the Birmingham Hip Resurfacing product continues as normal and is meeting demand," it added.