Might not make a great deal of difference anyway. I failed an ESA medical 6 months after having an artificial spinal disc. I took a letter from my surgeon stating that the recovery time is 2 yrs. Still failed me.They only briefly mentioned the operation as " back operation" despite it being major abdominal surgery. I have an 8 inch scar on my tummy but he said he didn't want to see it. Mind you, he did put in the report that I have a colostomy- WHICH I DONT- but still failed me. Basically, they put whatever they want in the report and ignore whatever they want.
When I was a student, I did a temp job in a hospital filing library and they kept files for 20 years, but that was a long time ago. Nevertheless, taking into account what others here have said, it does show that different hospitals have different policies, so it's worth asking even if the x-rays/reports are very old.