Can a sheriff impose a writ of fieri facias on someone who owns property jointly with a spouse who is not named?

'Property' refers to real estate. Perhaps you mean a vehicle or other belongings? The items owned jointly can be seized by the sheriff, yes.

Real property (real estate) can have the writ filed against it as a lien, which will stay until the owner(s) sell, at which time the lien is paid.

A writ of fieri facias is another term for a writ of execution.

And, Joypulv, actually in all states of which I am aware, execution of such a writ by a sheriff wouldn't just create a lien (The property sheriff would be "seized of" the property following the levy, but I suppose there might be, in some places, some sort of a "lien" or lis pendens the sheriff could file to prevent it being sold anyway to a third party without knowledge of the levy.); the property (real or personal) can be sold and the proceeds used to satisfy senior liens and (if there are any proceeds remaining) the judgment.

Yes, I stand corrected.

(Just to add that In my state there are ways that a homeowner can remain in the residence or even get it back after seizure, even after a subsequent sale.)