title: Radiological assessment of the femoral bowing in Japanese population.
abstract: BACKGROUND
  Differences in the magnitude of bowing between races are well-known characteristics of the femur. Asian races have an increased magnitude of femoral bowing but most of the orthopedic implants designed for the femur do not match this exaggerated bowing. We calculated the sagittal and coronal femoral bowing in the Japanese population at different levels of the femur and addressed its surgical significance.
  
  
  METHODS
  We calculated the sagittal and coronal bowing of 132 Japanese femora using CT scan of the femur. A mathematical calculation of the radius of curvature at proximal, middle, and distal regions of the femur was used to determine the degree of femoral bowing.
  
  
  RESULTS
  Mean sagittal bowing of the femur was 581, 188, and 161 mm for the proximal, middle, and distal thirds of the femur and mean lateral bowing was 528, 5092, and 876 mm, respectively. Mean sagittal and coronal bowing for the whole femur was 175 and 2640 mm, respectively. No correlation was found between age, gender, length of femur, and the degree of bowing.
  
  
  CONCLUSIONS
  Our study reveals that femoral bowing in the Japanese population is 175 mm in the sagittal plane and 2640 mm in the coronal plane; these values are greater than the femoral bowing in other ethnic groups studied in the literature. This may result in varying degrees of mismatch between the western-manufactured femoral intramedullary implants and the Japanese femur. We recommend that orthopedic surgeons to accurately perform preoperative evaluation of the femoral bowing to avoid potential malalignment, rotation, and abnormal stresses between the femur and implant.
authors.affiliation: Department of Orthopedic Surgery, Graduate School of Medical Science, Kanazawa University Kanazawa 9208641 Japan ; Department of Orthopedic Surgery, Faculty of Medicine, Sohag University Sohag 82524 Egypt.
authors.forename: Ahmed Hamed Kassem
authors.initials: AH
authors.lastname: Abdelaal
authors.affiliation: Department of Orthopedic Surgery, Graduate School of Medical Science, Kanazawa University Kanazawa 9208641 Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Yamamoto
authors.affiliation: Department of Orthopedic Surgery, Graduate School of Medical Science, Kanazawa University Kanazawa 9208641 Japan.
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: Department of Orthopedic Surgery, Graduate School of Medical Science, Kanazawa University Kanazawa 9208641 Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Takeuchi
authors.affiliation: Department of Orthopedic Surgery, Graduate School of Medical Science, Kanazawa University Kanazawa 9208641 Japan ; Department of Orthopedic Surgery, Faculty of Medicine, Sohag University Sohag 82524 Egypt.
authors.forename: Ahmad Fawaz
authors.initials: AF
authors.lastname: Morsy
authors.affiliation: Department of Orthopedic Surgery, Graduate School of Medical Science, Kanazawa University Kanazawa 9208641 Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Miwa
authors.affiliation: Department of Orthopedic Surgery, Graduate School of Medical Science, Kanazawa University Kanazawa 9208641 Japan.
authors.forename: Yoshitomo
authors.initials: Y
authors.lastname: Kajino
authors.affiliation: Department of Orthopedic Surgery, Graduate School of Medical Science, Kanazawa University Kanazawa 9208641 Japan ; Department of Orthopedics, Philippine General Hospital, University of the Philippines-Manila Ermita Brgy 670 Zone 72, Manila 1000 Metro Manila Philippines.
authors.forename: Donnel A
authors.initials: DA
authors.lastname: Rubio
authors.affiliation: Department of Orthopedic Surgery, Graduate School of Medical Science, Kanazawa University Kanazawa 9208641 Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsuchiya
keywords: Femoral bowing; Japanese population; Radiological assessment