I have always been a thin woman but I have thick ankles and no calf definition...
Based on your description, your treatment choices may be limited. Treatment at the ankles can carry greater risk. Your best option is to see an ASAPS surgeon to assess your particular condition.
Although fat can be liposuctioned from "cankles," I am not aware of any orthopedic procedure, which I guess would be akin to bunion surgery, that reduces the size of the bones of the ankle which is performed for cosmetic reasons.
I have had many very happy patients following liposuction of the lower calf and ankle area. Many people refer to this condition as "cankles." You may want to have a consultation with a plastic surgeon to examine your legs. Even if you are large boned, a small reduction in fat could make a nice difference in the contour of your lower leg.
Stubborn fat in the calves and ankles or “cankles” can be difficult to improve with just diet and exercise and patients who experiences this can benefit from liposuction. Calf and ankle liposuction can be performed as an outpatient procedure in a fully accredited ambulatory surgery facility with "twilight" anesthesia administered by a board certified anesthesiologist. I use several innovative forms of liposuction, including SmartLipo, in order to contour and resculpture the calves and ankles while providing the most beautiful results with minimal scarring. SmartLipo, used in combination with other forms of liposuction or alone, is a procedure that uses laser light to liquefy fat and tighten the surrounding skin. It involves less downtime and side-effects than traditional liposuction and is particularly good for small areas of fat deposits like the ankles. Liposuction works best on patients who are of relatively average weight, but who need help with a problem area. No, reshaping your body isn’t as easy as going to the beauty parlor. Surgery is never 100% risk free and the healing process requires patience and determination.