Having read and posted here for 19 months, I can with confidence, say that you need to listen to your own mind. A simple B&W X-ray might reveal much and at a little cost. The old saying is, "What cost peace of mind?" There are somany differing types of PN and symptoms all over the map. At least with the knee there are mechanics involved that can be corrected if need be.In a best case scenario, loss of cartilage and high BMI may be crowding or inflaming a sensory nerve path. In a worst case scenario, your girlfriend may have an agenda,haha.Good Luck, Ken in Texas.