I went to the doctor (a well-respected orthopedic surgeon). He said the x-rays didn't show much so he suspects inflammation from over-use
or a physical abnormality. He ruled out RA. He recommended Advil 3x/day for 3 weeks to eliminate any inflammation and to turn down my activity just a notch (I'm not walking now) and see him again in 3 weeks at which time he will order a bone scan. Cycling doesn't bother them, but a lot of walking does. It does not hurt to rotate my hip outward, but inward rotation is painful and limited.
Interestingly, Hubby told me that while riding behind me he noticed that my left foot is turned slightly inward so that my toes point toward my bike, while the right foot is pointing forward as it should. As soon as he told me today, I became aware of it and quickly corrected it, but time and time again my left foot reverted back to that turned-in position. I don't walk that way, and I never have, so why do I automatically turn my foot in on the pedal??? I'm wondering if it could be rotating the hip just enough to bother it, yet my hip doesn't hurt while I ride (though sometimes the hip joint feels like it needs to be popped while riding).
Most of my bikes have 170 cranks. A couple have 175's. The longer cranks flex the joints more. I can feel the difference between the two sizes because of my arthritis and the increased joint flex of the 175's. I discovered Bailey's trike has
140 cranks. (Yes
140) the BB is low and the wheels are 24". The shorter cranks don't flex my hips as much and when my joints are hurting the shorter cranks feel better. I do need time on longer cranks to keep my range of motion better, but the 140's are great when I feel lousy. If you have a bike that is a little on the big side or even exactly the right size, you might feel a lot better with shorter cranks than a person with no joint problems.
I have not found any bike shops or even other cyclists that understand this. They typically only think in "normal" fit solutions. They would probably wrongly advise against this.