There are many causes of knee pain. X-Ray may help to make a diagnosis but not absolutely necessary. Examination by an orthopaedic surgeon is more important because orthopaedic surgeons are trained in that field and by examination alone, most orthopaedic surgeons will know what happened.in your knee. X-Rays only show any bony changes and soft tissues cannot be seen, like ligaments. MRI may be needed for further evaluation. Orthopaedic surgeons will help you.