Evaluation of deformable models for femoral neck surgery

Objective: Using fluoroscopic images alone, it is difficult to guarantee that screws are positioned within the femoral head and neck. This study evaluates whether the introduction of deformable 3D models limiting the planning and navigation space is a helpful approach to minimizing the incidence of misplaced screws, thereby enhancing patient safety.Background: Even though a screw may appear to lie within the femoral head and neck on fluoroscopic images, this may not, in fact, be the case. This is a particular problem for interventions such as fixation of a slipped femoral head or osteosynthesis of the femoral neck, where screws must be set close to the cortical bone without penetrating the joint or injuring the cortex of the femoral neck.Methods: A system was developed which permits computer-based planning and navigation of screws for femoral neck fracture fixation based on fluoroscopic images. Different approaches were employed which either a) make use of a deformable model adapted to the femoral head/ne...