title: Coronal lower limb alignment in normal knees--A radiographic analysis of 797 normal knee subjects.
abstract: BACKGROUND
  This study aimed to resolve uncertainty regarding sex differences in alignment changes with age.
  
  
  METHODS
  We measured various parameters of weight-bearing long leg radiographs of 797 legs without osteoarthritic changes, which were classified according to sex and age (young [15-39 years], middle-aged [40-54 years], aged [55-69 years], and elderly [≥70 years]), and performed morphological analysis of the lower extremities. The mean measurements in each group were calculated and compared among the groups.
  
  
  RESULTS
  In the young and middle-aged populations, the femorotibial angle was significantly more varus in male than in female participants (p<0.001). In addition, medial femoral bowing was seen both in male and female participants, but it was more significant in male participants (p<0.005). This was due to greater femoral condylar orientation (p<0.01) and tibial plateau inclination (p<0.01) in male participants compared to female participants with nearly identical joint space narrowing. In aged and elderly populations, on the contrary, lateral femoral bowing was seen in both male and female participants, and there were no differences in any measured values, including the femorotibial angle, between male and female participants.
  
  
  CONCLUSIONS
  In relatively young Japanese individuals, male participants' femorotibial angles were more varus and had more medial femoral bowing than female participants, while there was no difference in any measured values between male and female participants in older adults by a radiographic analysis on the alignment of the lower extremities.
  
  
  METHODS
  Level 2.
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Nakano
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan. Electronic address: matsun@m4.dion.ne.jp.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Matsumoto
authors.affiliation: Department of Orthopaedic Surgery, Yasue Orthopaedic Clinic, 3-1-24 Ebisu-cho, Suma-ku, Kobe 654-0023, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Hashimura
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Takayama
authors.affiliation: Department of Orthopaedic Surgery, Kobe Kaisei Hospital, 3-11-15 Shinoharakitamachi, Nada-ku, Kobe 657-0068, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Ishida
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Araki
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Matsushita
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kuroda
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kurosaka
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology; D035002:Lower Extremity / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000175:diagnosis*; D011859:Radiography / Q000379:methods*; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult