1. A method of mapping a representation of a model bone into an image scan of a target bone: registering a generated portion of the representation into the image scan of the target bone using a translational transformation; registering the generated portion of the representation into the image scan of the target bone using a similarity transformation; registering a boundary portion of the representation into the image scan of the target bone using an affine transformation; and registering the boundary portion of the representation into the image scan of the target bone using a spline transformation.