title: Effects of total knee arthroplasty on ankle alignment in patients with varus gonarthrosis: Do we sacrifice ankle to the knee?
abstract: OBJECTIVE
  Total knee arthroplasty is one of the most commonly preferred surgical methods in the treatment of patients with varus gonarthrosis. In this study, we aimed to evaluate the radiological changes observed in the ankles after total knee arthroplasty.
  
  
  METHODS
  Between May 2012 and June 2013, 80 knees of 78 patients with varus deformity over 10° underwent total knee arthroplasty. For each patient, full-leg standing radiographs were obtained pre- and post-operatively. Mechanical and anatomical axes (HKA and AA), lateral distal femoral angle, medial proximal tibial angle, lateral distal tibial angle (LDTA), ankle joint line orientation angle (AJOA), tibial plafond talus angle (PTA) and talar shift were measured for each patient both pre- and post-operatively.
  
  
  RESULTS
  Pre-operatively, the mean HKA was 16.6° and the mean AA was 10.41°, both in favour of varus alignment. Post-operatively, the mean HKA decreased to 3.6° and the mean AA to -2.1. The mean LDTA was 87.3°. Before the operation, the mean AJOA was -7.6°, opening to the medial aspect of the ankle, and it was 0.04° after the operation and opening to the lateral aspect (p < 0.05).
  
  
  CONCLUSIONS
  Our study reveals the changes occurring in the ankle after acute correction of long-standing varus deformity of the knee using total knee arthroplasty. In cases undergoing knee arthroplasty, effect of the acute change in the alignment of the knee on the ankle should be taken into consideration and the amount of correction should be calculated carefully in order not to damage the alignment of the ankle.
  
  
  METHODS
  IV.
authors.affiliation: Baltalimanı Bone and Joint Diseases Education and Research Hospital, Rumelihisari caddesi No: 62, Sariyer, 34470, Istanbul, Turkey. sarper154@yahoo.com.
authors.forename: Sarper
authors.initials: S
authors.lastname: Gursu
authors.affiliation: Erzincan University Faculty of Medicine, Erzincan, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Sofu
authors.affiliation: Antwerp Orthopedic Center, Monica Hospitals, Antwerp, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Verdonk
authors.affiliation: Erzincan University Faculty of Medicine, Erzincan, Turkey.
authors.forename: Vedat
authors.initials: V
authors.lastname: Sahin
mesh_terms: D000368:Aged; D000843:Ankle Joint / Q000502:physiology*; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D017760:Bone Malalignment; D005260:Female; D005269:Femur / Q000601:surgery; D006801:Humans; D007719:Knee Joint / Q000502:physiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery; D011184:Postoperative Period; D011859:Radiography; D013628:Talus / Q000601:surgery; D013977:Tibia / Q000601:surgery
keywords: Alignment; Ankle; Arthroplasty; Knee; Varus gonarthrosis