title: In vivo three-dimensional skeletal alignment analysis of the hindfoot valgus deformity in patients with rheumatoid arthritis.
abstract: The purpose of this study was to analyze the skeletal alignment of the hindfoot valgus deformity in patients with rheumatoid arthritis using bone models reconstructed from three-dimensional computerized tomography data. Computed tomography was performed on 21 feet of patients with rheumatoid arthritis, and magnetic resonance imaging was taken of 10 normal feet of eight volunteers. An image processing system was used to create bone models and analyze the three-dimensional displacement of the calcaneus, talus, navicular, and cuboid bones. With a standard coordinate system in the distal tibia and a local coordinate system in each bone of the hindfoot, three rotational parameters and three translational parameters were used to evaluate the relative displacement. The talus showed plantar flexion. Both the calcaneus and navicular bones had valgus and lateral shift displacements. However, the cuboid had no displacement relative to the calcaneus, and the navicular showed no displacement relative to the cuboid. The calcaneus, navicular, and cuboid bones have the same pattern of deformity in patients with rheumatoid arthritis. This three-dimensional image-based technique successfully quantified the hindfoot valgus deformity resulting from rheumatoid arthritis and is beneficial for better understanding the deformity pathomechanism.
authors.affiliation: Department of Orthopaedic Surgery, Peking Union Medical College Hospital, Beijing, China. liuhongbo1972@yahoo.com.cn
authors.forename: Hongbo
authors.initials: H
authors.lastname: Liu
authors.forename: Kazuomi
authors.initials: K
authors.lastname: Sugamoto
authors.forename: Tomonobu
authors.initials: T
authors.lastname: Itohara
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tomita
authors.forename: Jun
authors.initials: J
authors.lastname: Hashimoto
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging / Q000473:pathology*; D016022:Case-Control Studies; D006365:Heel / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008875:Middle Aged; D036542:Tomography, Spiral Computed