Spatial positioning of an hip stem solid model within the CT data set of the host bone.
A new protocol is proposed which allows the spatial registration of a prosthetic hip stem solid model with the CT data set of the host bone collected pre-operatively using a limited number of reference landmarks taken from post-operative images. Although based on well know algorithms, such as the Single Value Decomposition, this method opens new possibilities to the three-dimensional modelling of operated bones. In a preliminary experiment based on a synthetic human femur replica the proposed protocol achieved a global accuracy of 1.53 mm (root mean square error of the centre location of ten control sections) using only six CT post-operative slices. This methodology allows an accurate three-dimensional modelling of operated bone which have been implanted with high density metallic devices which produce relevant artefacts in post-operative CT images.
Viceconti
M
M
Laboratory for Biomaterials Technology, Istituti Ortopedici Rizzoli, Bologna, Italy. viceconti@tecno.ior.it
Zannoni
C
C
Pierotti
L
L
Casali
M
M
D000465:Algorithms; D003198:Computer Simulation; D016208:Databases, Factual; D005269:Femur / Q000033:anatomy & histology / Q000601:surgery; D006621:Hip Joint / Q000000981:diagnostic imaging; D006622:Hip Prosthesis; D006801:Humans; D008953:Models, Anatomic; D011474:Prosthesis Design; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data