some acronyms like p.o., q.d. will come only abbreviated and "FP" will fall in the same category and the doctor will require it only abbreviated anywhere in the text. Any medicals here to explain this more clearly otherwise this can be the only explanation. FP without quotes clearly gives the meaning of the acronym "FP joint space meaning oblique view of joint space."

Any way you can try this link http://www.radiologyassistant.nl/en/42a29ec06b9e8. I googled in quotes "oblique view of joint space."

Thanks