"Facet Joint Arthropathy" is considered to be an aspect/type of "Arthritis of the Spine," and would fall under M47: Spondylosis, which Includes "degeneration of the facet joints," which is "Facet Joint Arthropathy." Since this is designated as being in the lumbar spine, the only question then is whether there is radiculopathy or not. If not, then the code would be M47.816. If there is radiculopathy, then it would be M47.26.
I hope this helps.
Respectfully submitted, Alan Pechacek, M.D.
icd10orthocoder.com
diagnosis codes, diagnosis coding