Hi Karen,
I am sorry that Mayo did not have better luck in figuring out what is causing your symptoms... although it does sound like they ruled out quite a bit. I am concerned that a doctor told you that a prednisone taper might help you to heal your injuries. One of the common side effects of prednisone is DELAYED or impaired wound healing -
"SIDE EFFECTS: Side effects of prednisone and other corticosteroids range from mild annoyances to serious, irreversible damage, and they occur more frequently with higher doses and more prolonged treatment. Side effects include retention of sodium (salt) and fluid, weight gain, high blood pressure, loss of potassium, headache and muscle weakness. Prednisone also causes puffiness of the face (moon face), growth of facial hair, thinning and easy bruising of the skin, impaired wound healing, glaucoma, cataracts, ulcers in the stomach and duodenum, worsening of diabetes, irregular menses, rounding of the upper back ("buffalo hump"), obesity, retardation of growth in children, convulsions, and psychiatric disturbances. The psychiatric disturbances include depression, euphoria, insomnia, mood swings, personality changes, and even psychotic behavior."
I would be worried that a pred taper would do you more harm than good. (Although it might rule out AS once and for all as pred does tend to help relieve AS symptoms - briefly anyway - no improvement, probably no AS.) I know that you have mentioned thyroid issues in the past. Did you see an endocrinologist at Mayo, or do you see one at home? Hypothyroidism can cause fatigue, joint or muscle pain and swelling of the ankles, feet and legs. Hyperthyroidism can cause fatigue, tendon rupture and muscle weakness. This sounds an awful lot like your repeated injuries.
Best of luck in figuring out your mystery illness.
