AnnaPurna sums up this complex nicely. And here are some good tech articles on grading the severity of facet arthrosis (there are several):
https://www.adrsupport.org/forums/sh...acet+arthrosis
Mild facet arthrosis is generally OK and not a contraindication. Overseas, they are more accepting and liberal -- because they can be. As well, if things go wrong, it's on the patient and not the doctor.