Automated preoperative planning of femoral component for total hip arthroplasty (THA) from 3D CT images

Abstract

This paper describes a method for 3D automated preoperative planning of the femoral stem in total hip arthroplasty (THA). The stem planning is formulated as a problem to determine the optimal position, rotation, and size, on the 3D surface model of femur reconstructed from CT images. We obtain the parameters that maximize the fitness between the femoral canal and stem surfaces subject to the positional and rotational constraints. The maximization is performed by local optimization from multiple initial positions. The proposed method was experimentally evaluated by the difference from planning results of an experienced surgeon in 7 cases. The average positional and rotational differences were 1.9 mm and 2.5 deg., respectively, and there was size difference only in 1 case for the proposed method while these differences were 2.8 mm, 5.0 deg., and 5 cases for an existing method. The proposed method showed better performance than the existing method. © 2008 Springer-Verlag Berlin Heidelberg.