title: Sagittal Distal Tibial Articular Angle and the Relationship to Talar Subluxation in Total Ankle Arthroplasty.
abstract: BACKGROUND
  Longevity of total ankle replacement (TAR) depends heavily on anatomic alignment. The lateral talar station (LTS) classifies the sagittal position of the talus relative to the tibia. We hypothesized that correcting the sagittal distal tibial articular angle (sDTAA) during TAR would anatomically realign the tibiotalar joint and potentially reduce the risk of prosthesis subluxation.
  
  
  METHODS
  The LTS (millimeters) and sDTAA (degrees) were measured twice by 2 blinded observers using weight-bearing lateral ankle radiographs obtained before (n = 96) and after (n = 94) TAR, with excellent interobserver and intraobserver reliability (correlation coefficient >0.9).
  
  
  RESULTS
  Preoperative LTS was as follows: anterior (60.4%), posterior (27.1%), and neutral (12.5%). A strong preoperative correlation was found between LTS and sDTAA (r = 0.81; P < .0001). In ankles that were initially anterior and became less anterior postoperatively (n = 41), LTS decreased from an average 8.1 mm to 6.5 mm and the LTS changed 1.1 mm per degree of sDTAA change. In ankles that were initially posterior (n = 25), LTS increased from an average of -5.1 mm to -2.8 mm and the LTS changed 0.6 mm per degree of sDTAA change. The correlation between LTS and sDTAA was reduced postoperatively (r = 0.62; P < .0001).
  
  
  CONCLUSIONS
  Our results suggest that rather than following generic recommendations, the surgeon should customize the sagittal distal tibial cut to the individual patient based on the preoperative LTS in order to achieve neutral TAR alignment.
  
  
  METHODS
  Level III, retrospective comparative series.
authors.affiliation: Division of Distal Extremities, Department of Orthopaedics, University of British Columbia, Victoria, BC, Canada docveljkovic@yahoo.com.
authors.forename: Andrea
authors.initials: A
authors.lastname: Veljkovic
authors.affiliation: Department of Orthopaedics and Rehabilitation, University of Iowa Hospitals and Clinics, Iowa City, IA, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Norton
authors.affiliation: Joint Department of Medical Imaging, University of Toronto, Toronto, ON, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Salat
authors.affiliation: University Health Network-Toronto Western Division, Toronto, ON, Canada.
authors.forename: Kaniza Zahra
authors.initials: KZ
authors.lastname: Abbas
authors.affiliation: Department of Orthopedics, University of Utah, Salt Lake City, UT, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Saltzman
authors.affiliation: Department of Orthopaedics and Rehabilitation, University of Iowa Hospitals and Clinics, Iowa City, IA, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: Femino
authors.affiliation: Department of Orthopaedics and Rehabilitation, University of Iowa Hospitals and Clinics, Iowa City, IA, USA.
authors.forename: Phinit
authors.initials: P
authors.lastname: Phisitkul
authors.affiliation: Department of Orthopaedics and Rehabilitation, University of Iowa Hospitals and Clinics, Iowa City, IA, USA.
authors.forename: Annunziato
authors.initials: A
authors.lastname: Amendola
mesh_terms: D000842:Ankle / Q000503:physiopathology / Q000601:surgery*; D000843:Ankle Joint / Q000503:physiopathology / Q000601:surgery*; D058737:Arthroplasty, Replacement, Ankle / Q000379:methods*; D006801:Humans; D004204:Joint Dislocations / Q000503:physiopathology; D011859:Radiography; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013628:Talus / Q000601:surgery*; D013977:Tibia / Q000601:surgery*; D016474:Weight-Bearing
keywords: and prosthesis subluxation; lateral talar station; sagittal distal tibial articular angle; tibiotalar joint; total ankle replacement