Study Design.A retrospective matched-pair comparison of coronal curve correction in all-pedicle screw (PS) and hybrid hook-screw (HS) instrumentation in idiopathic adolescent scoliosis (AIS).Objective.To eliminate differences in preoperative curve flexibility in a comparison of all-pedicle screw and hybrid hook-screw efficacy in idiopathic adolescent scoliosis.Summary of Background Information.Although all-pedicle screw instrumentation is clearly superior to all-hook instrumentation in the treatment of AIS, comparisons of all-pedicle screw and hybrid hook-screw instrumentation have produced conflicting results.Because the preoperative flexibility of a curve affects the amount of correction achievable, a comparison of the two instrumentation methods under conditions in which preoperative flexibility is closely matched might clarify the situation.Methods.To obtain all-pedicle screw and hybrid hook-screw study groups for comparison, 16 all-pediele screw/hybrid hook-screw pairs of Lenke type 1 AIS patients matched for age, sex, and preoperative curve flexibility were retrospectively selected from 154 patients who had received posterior correction and fusion between January 2000 and October 2006.Post-operative and 2-year postoperative coronal curve correction and post-operative kyphosis for the two groups were measured analyzed statistically.Results.Post-operative coronal curve correction was significantly better for all-pedicle screw than hybrid hook-screw instrumentation (74.56% and 70.63% respectively), as was 2-year postoperative coronal correction (70.63% and 63.38% respectively).Post-operative kyphosis (T2-T12) was not significantly different.Conclusions.Under conditions in which patients are matched for preoperative curve flexibility,all-pedicle screw instrumentation provides better curve correction and maintenance of that correction than hybrid hook-screw instrumentation.