title: Factors contributing to inherent varus alignment of lower limb in normal Asian adults: role of tibial plateau inclination.
abstract: OBJECTIVE
  This prospective study aimed to evaluate radiographically, mechanical or hip-knee-ankle (HKA) axis in healthy, asymptomatic, Asian (Indian and Korean) adults between 20 and 40 years of age to determine the incidence of inherent varus (mechanical limb alignment of >3° varus) and the factors influencing it.
  
  
  METHODS
  Three hundred and eighty-eight lower limbs were evaluated using full length, standing hip-to-ankle radiographs in 198 healthy, asymptomatic, Asian (Indian and Korean) adults between 20 and 40 years of age to assess the hip-knee-ankle (HKA) angle, medial proximal tibial angle (MPTA), femoral bowing and femoral neck-shaft angle to determine the incidence of inherent varus (mechanical limb alignment of >3° varus) and the factors influencing it.
  
  
  RESULTS
  Overall, the mean HKA angle was 177.6°±2.6° with 34.5% of limbs in inherent varus (mean HKA angle 174.9°±1.8°). The incidence of inherent varus was significantly higher (p=0.01) in males (40%) compared to females (28%) but similar among Indian (34%) and Korean subjects (35%). The hip-knee-ankle (HKA) angle showed significant positive correlation (r=0.82, p<0.001) with only the medial proximal tibial angle (MPTA).
  
  
  CONCLUSIONS
  Inherent varus alignment of the lower limb is fairly common among asymptomatic, Asian adults. These results raise several pertinent questions regarding the role of inherent varus in the aetiopathogenesis of knee osteoarthritis and in lower limb realignment procedures.
authors.affiliation: Department of Orthopaedic Surgery, Breach Candy Hospital, Mumbai, India. Electronic address: gautams10@gmail.com.
authors.forename: Gautam M
authors.initials: GM
authors.lastname: Shetty
authors.affiliation: Department of Orthopaedic Surgery, Breach Candy Hospital, Mumbai, India.
authors.forename: Arun
authors.initials: A
authors.lastname: Mullaji
authors.affiliation: Department of Orthopaedic Surgery, Breach Candy Hospital, Mumbai, India.
authors.forename: Sagar
authors.initials: S
authors.lastname: Bhayde
authors.affiliation: Department of Orthopaedic Surgery, Inje University Ilsanpaik Hospital, Ilsan, Korea.
authors.forename: Kyung Wook
authors.initials: KW
authors.lastname: Nha
authors.affiliation: Department of Orthopaedic Surgery, Inje University Ilsanpaik Hospital, Ilsan, Korea.
authors.forename: Hyoung Keun
authors.initials: HK
authors.lastname: Oh
mesh_terms: D000328:Adult; D001175:Arthrography; D044466:Asian People; D060750:Bone Anteversion / Q000000981:diagnostic imaging*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007194:India; D007867:Leg Bones / Q000000981:diagnostic imaging*; D008297:Male; D011446:Prospective Studies; D056910:Republic of Korea; D012727:Sex Characteristics; D055815:Young Adult
keywords: Alignment; Knee; Osteoarthritis; Tibial inclination; Varus