title: Radiographic assessment of knee-ankle alignment after total knee arthroplasty for varus and valgus knee osteoarthritis.
abstract: BACKGROUND
  There are unanswered questions about knee-ankle alignment after total knee arthroplasty (TKA) for varus and valgus osteoarthritis (OA) of the knee. The aim of this retrospective study was to assess knee-ankle alignment after TKA.
  
  
  METHODS
  The study consisted of 149 patients who had undergone TKA due to varus and valgus knee OA. The alignment and angles in the selected knees and ankles were measured on full-length standing anteroposterior radiographs, both pre-operatively and post-operatively. The paired t-test and Pearson's correlation tests were used for statistical analysis.
  
  
  RESULTS
  The results showed that ankle alignment correlated with knee alignment both pre-operatively and postoperatively (P<0.05). The pre-operative malalignment of the knee was corrected (P<0.05), and the ankle tilt angle was accordingly improved in the operative side after TKA (P<0.05). In addition, TKA had little effect on knee-ankle alignment on the non-operative side (P>0.05).
  
  
  CONCLUSIONS
  These findings indicated that routine TKA could correct the varus or valgus deformity of a knee, and improve the tilt of the ankle. Ankle alignment correlated with knee alignment both pre-operatively and postoperatively. Both pre-operative knee and ankle malalignment can be simultaneously corrected following TKA.
  
  
  METHODS
  Level III.
authors.affiliation: Center for Osteonecrosis and Joint Preserving & Reconstruction, Department of Orthopaedic Surgery, China-Japan Friendship Hospital, Yinghuadong Road, Chaoyang District, Beijing, China. Electronic address: gaofuqiang@bjmu.edu.cn.
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Gao
authors.affiliation: Peking University China-Japan Friendship School of Clinical Medicine, Yinghuadong Road, Chaoyang District, Beijing, China. Electronic address: 1402317340@qq.com.
authors.forename: Jinhui
authors.initials: J
authors.lastname: Ma
authors.affiliation: Center for Osteonecrosis and Joint Preserving & Reconstruction, Department of Orthopaedic Surgery, China-Japan Friendship Hospital, Yinghuadong Road, Chaoyang District, Beijing, China. Electronic address: colinda908@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.affiliation: Center for Osteonecrosis and Joint Preserving & Reconstruction, Department of Orthopaedic Surgery, China-Japan Friendship Hospital, Yinghuadong Road, Chaoyang District, Beijing, China.
authors.forename: Wanshou
authors.initials: W
authors.lastname: Guo
authors.affiliation: Center for Osteonecrosis and Joint Preserving & Reconstruction, Department of Orthopaedic Surgery, China-Japan Friendship Hospital, Yinghuadong Road, Chaoyang District, Beijing, China.
authors.forename: Zirong
authors.initials: Z
authors.lastname: Li
authors.affiliation: Center for Osteonecrosis and Joint Preserving & Reconstruction, Department of Orthopaedic Surgery, China-Japan Friendship Hospital, Yinghuadong Road, Chaoyang District, Beijing, China.
authors.forename: Weiguo
authors.initials: W
authors.lastname: Wang
mesh_terms: D000368:Aged; D000843:Ankle Joint / Q000000981:diagnostic imaging*; D019645:Arthroplasty, Replacement, Knee; D017760:Bone Malalignment / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery*; D011859:Radiography; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: Alignment; Ankle; Knee; Osteoarthritis; Radiographs; Total knee arthroplasty