UPDATE 2-US panel rejects wider use of Zimmer spine device

* FDA advisory committee votes 5-1 against approval

* Advisers say data unclear, question long-term impact

* Zimmer says will make statement later (Adds details from meeting, quotes, byline)

By Susan Heavey

GAITHERSBURG, Md., Nov 4 (Reuters) - A U.S. panel of medical experts on Wednesday recommended against wider use of a Zimmer Holdings Inc (ZMH.N: Quote, Profile, Research) spine stabilization device, questioning the company's data but adding that the device holds promise.

The Food and Drug Administration's advisory panel, in a 5-1 vote, said the company's Dynesys Spinal System data were unclear and that some changes should have been made to its clinical trial. They also questioned how the device would hold up over time and expressed concern about possible breakage.

"I'm unconvinced," panel member Brent Blumenstein, a Washington-based clinical trial consultant, said of the product's efficacy.

Zimmer's device, a series of screws and flexible spacers that aim to help align and support the spine, is already approved for use in patients with back problems who undergo surgical fusion. The company is seeking the agency's permission to market Dynesys for stand-alone use.

The company, which also sells another similar spinal device called Silhouette, has said the Dynesys device can allow a greater range of motion for patients than other products and told the panel it was safe and effective.