UPDATE 3-FDA staff note financial ties in Zimmer spine study

* Researchers in study had financial ties-FDA staff

* No statistical evidence money led to bias-FDA staff

* Advisory panel to weigh wider use of Dynesys device

* Zimmer shares unchanged in after-hours trade (Adds details from FDA summary paragraph 3)

By Lisa Richwine

WASHINGTON, Nov 2 (Reuters) - U.S. reviewers have raised the possibility of bias in the evaluation of a spine device made by Zimmer Holdings Inc (ZMH.N: Quote, Profile, Research), saying a majority of patients in a study were treated by researchers with a financial interest in the company.

In documents released on Monday, Food and Drug Administration reviewers said there was "a trend which suggests the possibility of bias from compensation" when payments or stock holdings were analyzed for any influence in the study of a proposed new use for the Dynesys Spinal System.

One analysis found a positive correlation between payments to doctors and success rates for the device. However, the FDA staff said the results were "far from being statistically significant" -- meaning the results could have been due to chance.

The Dynesys system is already approved as an addition to spinal fusion for treating lower back and leg pain. Zimmer is seeking FDA clearance to market the device for use without fusion. The product employs screws and cables to help keep the spine stable.