title: Volar morphology of the distal radius in axial planes: a quantitative analysis.
abstract: To investigate the cause of rupture of the flexor pollicis longus (FPL) after volar plate fixation of distal radius fractures, previous studies have examined the shape of the distal radius in the sagittal plane or in the lateral view. However, there are no reports on the anatomical shape of the volar surface concavity of the distal radius in the axial plane. We hypothesized that this concavity might contribute to the mismatch between the plate and the surface of the radius. To test this hypothesis, we constructed three-dimensional models of the radius and FPL based on computed tomography scans of 70 normal forearms. We analyzed axial cross-sectional views with 2 mm intervals. In all cases, the volar surface of the distal radius was concave in the axial plane. The concavity depth was maximum at 6 mm proximal to the palmar edge of the lunate fossa and progressively decreased toward the proximal radius. FPL was closest to the radius at 2 mm proximal to the palmar edge of the lunate fossa. The volar surface of the distal radius was externally rotated from proximal to distal. These results may help to develop new implants which fit better to the radius and decrease tendon irritation.
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Oura
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Oka
authors.forename: Yohei
authors.initials: Y
authors.lastname: Kawanishi
authors.forename: Kazuomi
authors.initials: K
authors.lastname: Sugamoto
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Murase
mesh_terms: D000013:Congenital Abnormalities / Q000209:etiology / Q000517:prevention & control; D003430:Cross-Sectional Studies; D005542:Forearm / Q000002:abnormalities / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D005593:Fracture Fixation, Internal / Q000009:adverse effects / Q000379:methods; D006801:Humans; D021621:Imaging, Three-Dimensional; D008953:Models, Anatomic; D053401:Palmar Plate / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D011884:Radius / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D011885:Radius Fractures / Q000150:complications / Q000628:therapy; D012421:Rupture / Q000517:prevention & control; D013708:Tendon Injuries / Q000209:etiology / Q000517:prevention & control; D013710:Tendons / Q000033:anatomy & histology*; D014057:Tomography, X-Ray Computed
keywords: morphology of the distal radius; rupture of the flexor pollicis longus; three-dimensional evaluation; volar locking plate