The operative treatment of adolescent idiopathic scoliosis (AIS) is still somewhat controversial regarding selection of the appropriate regions to fuse and selection of the specific upper instrumented vertebra (UIV) and lowest instrumented vertebra (LIV). The Lenke classification system helps to determine the appropriate regions of the spine to be fused. The fused regions include the major curve and any structural minor curves. After this, the approach, anteriorly or, more commonly, posteriorly, and the actual UIV and LIV are selected. Ultimately, multicenter studies evaluating large numbers of similar curve patterns treated differently should help to sort out the best treatment for each particular curve pattern, thus optimizing surgical treatment for patients with AIS.