I was told its uncommon for a woman of 20 years of age to have scoliosis surgery is this true or is it because there would be more complications?

Scoliosis. This is true. Scoliosis surgery is typically not done unless the degree of curvature is high. There is a misconception that scoliosis always causes pain, but in actuality most patients with a mild scoliosis have no pain and have normal lives. If you have pain, it is likely due to benign causes such as soft tissue inflammation/deconditioning, and conservative treatment should help.