Hi there!
In such a case other possibilities such as infections, inflammation, neurovascular damage, ligamental/ tendon injuries/ osteolysis, synovitis, muscular causes etc may need to be considered. A few of these may not be evident on the x-ray and a clinical evaluation and detailed imaging studies may be needed. It would be best to discuss this with your orthopedician.
Hope this helps.
Take care!
my xrays of knees are normal and show prosthesis in good position.
Hi there!
Well, without an evaluation it would be difficult to point out the cause of your symptoms. Possibilities that may need to be considered are infections, inflammation, neurovascular damage, peri-prosthetic fracture, wearing of the bearings, loosening of the prosthesis, ligamental/ tendon injuries/ inflammation, osteolysis, synovitis etc. It would be best to get this evaluated by your orthopedician to rule out the possibilities and appropriate management.
Hope this was useful.
Take care!