Post-operative adaptation of pre-operative planning for angular deformity correction by radiographic assessment

This report describes newly-added functions to our "Leg Perfect" pre-operative planning systems developed for angular deformity correction of the lower limb. This system works on bone outlines obtained from pre-operative radiographic images and simulates the surgical osteotomy and frame assembly on the bone outline. The newly added functions allow the user to translate, rotate as well as uniformly scale the bone outlines and the assembled apparatus either individually or simultaneously in an interactive way to align them with the overlapped background post-operative radiographic image. The purpose of implementing these functions is to mimic intra-operative deviations from the pre-operative plan by adjusting hinge location, osteotomy level, and frame orientation to that which actually was performed. With these functions, both the angular deformity correction simulation and surgery outcome prediction can be effectively accomplished after surgery.