The headline -- BioMimetic Therapeutics' (Nasdaq: BMTI) Augment Bone Graft Receives Positive Recommendation from FDA Advisory Committee -- sounds good, but the details tell a different story.

While technically the FDA panel vote came up positive, it was close -- just 10-8 in favor -- for both the efficacy of Augment and whether it had a favorable benefit-to-risk profile. Augment is a synthetic material that stimulates broken bones to grow back together.

But the advisory panel is just that, advisory, and the agency has the final say. Unfortunately for BioMimetic, the FDA didn't seem all that supportive of the clinical data testing Augment. The agency didn't seem convinced that Augment was any better than autologous grafts where bone from another part of the patient's body is used.

On Tuesday, after the FDA's briefing documents for the panel were released, BioMimetics stock lost 35% of its value. It recovered a little but has fallen again today after yesterday's vote.

Investors are right to be apprehensive about the likelihood of an approval. There are countless examples of the FDA turning down a drug or device despite a positive panel vote: Dendreon's (Nasdaq: DNDN) Provenge and InterMune's (Nasdaq: ITMN) Esbriet just to name a couple. Investors looking for a preview on the device side should keep their eyes on MELA Sciences (Nasdaq: MELA), which is in the same boat with a positive panel yet a negative FDA pre-panel opinion.

That isn't to say Augment won't ever make it to market -- Provenge did, and Esbriet was approved in Europe -- but BioMimetic may have to run additional preapproval studies before the agency will sign off.

What's interesting about this case is that some members of the panel bashed the FDA for having an agenda against the device. If the vote was more in favor of Augment -- say, 14-4 or better -- I could see the agency taking their opinion into account, but with the vote being so close, I expect the agency won't change its stance much.

Unlike drugs, the FDA doesn't have goals for making decisions about the approval of medical devices. Management expects it could take about six months to hear back from the agency.

In the meantime, keep tabs on BioMimetic by adding it to your watchlist.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.