title: [Measurement of radiological parameters and Logistic regression analysis for adult acquired flatfoot].
abstract: OBJECTIVE
  To evaluate and compare the radiographic parameters between patients of adult acquired flatfoot and normal participants to provide rationales for diagnosis and operative reconstruction.
  
  
  METHODS
  The adult acquired deformity group consisted of 85 patients (85 feet) and normal group 90 normal participants (90 feet) from January 2008 to May 2014. The weight-bearing anteroposterior and lateral foot radiographs were taken. And the following parameters were measured and compared: medial column length (MCL), lateral column length (LCL), medial column height (MCH), lateral column height (LCH), talonavicular uncoverage angle (TNUA), talus-first metatarsal angle (TMTA) and calcaneal pitch angle (CPA). Age and all parameters were included for Logistic regression analysis.
  
  
  RESULTS
  On anteroposterior radiographs, the values of MCL for adult acquired deformity and normal groups were (103.5 ± 9.0),(105.8 ± 7.8)mm and LCL (94.6 ± 6.9),(96.2 ± 6.1)mm respectively.No significant difference existed in MCL or LCL (P > 0.05).However, significant inter-group differences existed in TMTA and TNUA (P < 0.01). The values of TMTA were (18.9 ± 2.5)°,(7.8 ± 2.2)° and TNUA (23.6 ± 3.2)°,(8.0 ± 2.2)°.On lateral radiographs, significant inter-group differences existed in MCH, LCH, CPA and TMTA (P < 0.01). And the values of MCH were (16.3 ± 1.7),(23.6 ± 2.8)mm, LCH (14.9 ± 1.1),(13.96 ± 1.39)mm, CPA (14.86 ± 2.76)°,(22.9 ± 1.9)° and TMTA (10.0 ± 2.0)°,(-3.6 ± 1.0)° respectively. According to Logistic regression analysis, the significance of parameters ranged from lateral TMTA (B = 0.032), anteroposterior TNUA (B = 0.014), anteroposterior TMTA (B = 0.015) to lateral MCH (B = -0.012), lateral CPA B (B = -0.009).
  
  
  CONCLUSIONS
  No differences exist in anteroposterior MCL or LCL. There are positive differences in lateral TMTA, anteroposterior TNUA and anteroposterior TMTA. And negative differences exist in lateral MCH and lateral CPA between adult flatfoot and normal foot. Lateral TMTA may be an excellent radiographic identifier of patients with adult acquired flatfoot during diagnosis and treatment.
authors.affiliation: Department of Orthopedic Surgery, Chengdu Military General Hospital, Chengdu 610083, China.
authors.forename: Meiming
authors.initials: M
authors.lastname: Xie
authors.affiliation: Department of Orthopedic Surgery, Chengdu Military General Hospital, Chengdu 610083, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Fan
authors.affiliation: Department of Orthopedic Surgery, Chengdu Military General Hospital, Chengdu 610083, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Orthopedic Surgery, Chengdu Military General Hospital, Chengdu 610083, China.
authors.forename: Jinbiao
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Orthopedic Surgery, Chengdu Military General Hospital, Chengdu 610083, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Cui
authors.affiliation: Department of Orthopedic Surgery, Chengdu Military General Hospital, Chengdu 610083, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Huang
authors.affiliation: Department of Orthopedic Surgery, Chengdu Military General Hospital, Chengdu 610083, China. Email: panxianming@medmail.com.cn.
authors.forename: Xianming
authors.initials: X
authors.lastname: Pan
mesh_terms: D000328:Adult; D002111:Calcaneus; D005413:Flatfoot; D006801:Humans; D016015:Logistic Models; D008682:Metatarsal Bones; D013628:Talus