title: In vivo kinematics of three-component mobile-bearing total ankle replacement in rheumatoid ankle with talocalcaneal arthrodesis and spontaneous talocalcaneal fusion.
abstract: OBJECTIVE
  It is often that patients with rheumatoid arthritis (RA) who require ankle surgeries already have the degeneration of talocalcaneal joints. When talocalcaneal joint was fused, whether operatively or spontaneously, ankle kinematics would be affected. The purpose of this paper was to study in vivo kinematics of mobile-bearing total ankle replacement (TAR) in rheumatoid ankle with concomitant talocalcaneal arthrodesis or with preexisting spontaneous talocalcaneal fusion.
  
  
  METHODS
  Thirteen TARs in ten patients with RA, in whom talocalcaneal joints had already been fused spontaneously or surgically, were studied. Fluoroscopic images were obtained while each patient was walking with full weightbearing on the implanted ankle. Thereafter tibio-talar motion was analyzed by 2D/3D registration technique.
  
  
  RESULTS
  Average tibio-talar motion was 4.0 ± 5.3° for plantarflexion and 6.6 ± 0.3° for dorsiflexion. Average range of internal/external rotation, inversion/eversion and AP translation was 3.8 ± 1.3°, 2.7 ± 1.0° and 1.6 ± 0.6 mm, respectively.
  
  
  CONCLUSIONS
  Mobility of mobile-bearing TAR with talocalcaneal fusion was small during the stance phase of gait, but clinically measured ROM was mostly preserved. The movements of internal/external rotation and AP translation were allowed to a certain degree, but not of inversion/eversion. Even though the movement of inversion/eversion is limited, talocalcaneal arthrodesis could be accompanied with mobile-bearing TAR in rheumatoid ankles.
authors: Department of Orthopaedic Biomaterial Science, Osaka University Graduate School of Medicine , Suita , Japan.
authors: Keiji
authors: K
authors: Iwamoto
authors: Kenrin
authors: K
authors: Shi
authors: Tetsuya
authors: T
authors: Tomita
authors: Jun
authors: J
authors: Hashimoto
authors: Takaharu
authors: T
authors: Yamazaki
authors: Hideki
authors: H
authors: Yoshikawa
authors: Kazuomi
authors: K
authors: Sugamoto
mesh_terms: D000368:Aged; D000843:Ankle Joint / Q000503:physiopathology / Q000601:surgery*; D001172:Arthritis, Rheumatoid / Q000503:physiopathology / Q000601:surgery*; D001174:Arthrodesis; D058737:Arthroplasty, Replacement, Ankle / Q000379:methods*; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007595:Joint Prosthesis; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular / Q000502:physiology*; D016896:Treatment Outcome; D016474:Weight-Bearing / Q000502:physiology
keywords: 2D/3D registration technique; In vivo kinematics; Mobile-bearing total ankle replacement; Talocalcaneal arthrodesis; rheumatoid arthritis