Whilst it would be very nice to be able to determine whether Wikipedia reference-linkfacet joint pathology is present, from memory studies have shown that we are able to localise the source of pain in the cervical spine about 20 percent of the time with manual examination (which is pretty poor).

That said i do believe we are able to locate the specific segment which is pathological with manual examination, although i believe that is also under debate.

My opinion is, whether it is facet or disc or something else, it wont really change the way you should treat your patient. Assess the deep cervical flexors, deep extensors, lifestyle, scapular, posture and somatosensory dysfunction : address any impairments noted in the above and also treat with manual therapy over the pathological segment.

I guess what i am saying is that the diagnosis of facet joint pathology does not guide what treatment you will choose, but rather impairments such as a craniocervical flexion test of 22mmhg would suggest that retraining should be part of the treatment.

That said to know whether facet joint pathology is present may aid in estabilishing a liklelihood of the effectiveness of a physio program, although there would have to be some studies looking into this also.