title: AKILE™ total ankle arthroplasty: Clinical and CT scan analysis of periprosthetic cysts.
abstract: BACKGROUND
  Despite good clinical results following total ankle replacement (TAR), the development of large periprosthetic cysts (>400 mm(2)) in the medium-term is a source of concern.
  
  
  OBJECTIVE
  The primary objective of this study was to detect any large periprosthetic cysts in a cohort of AKILE™ patients using radiographs and CT scans, and then to compare these findings to published ones.
  
  
  METHODS
  A total of 127 TAR procedures were performed between June 1995 and January 2012. We retrospectively reviewed 68 cases with the newest AKILE™ implant design that had a minimum follow-up of 36 months. The average follow-up was 81 ± 33 months; eight patients were lost to follow-up. The outcomes consisted of analyzing radiographs (A/P and lateral weight bearing views, Meary view and lateral views of flexion/extension) and helical CT scans, performing clinical evaluations (range of motion, AOFAS score, Foot Function Index, pain levels) and determining the survivorship of TAR implants.
  
  
  RESULTS
  TAR survival at 5 years was 79% for in situ implants and 62% for revision-free implants. The AOFAS score improved from 33.7 ± 14.7 to 77.1 ± 15.1 (out of 100) and the pain sub-score was 30.2 ± 9.7 (out of 40) at the last follow-up. The average ankle range of motion was 32.3° ± 12.7° on the radiographs. CT scan revealed Type A cysts (<200 mm(2)) under the talar implant in 52% of cases and in the tibia in 50% of cases; these cysts were smaller than 100 mm(2) in 80% of cases and had no effect on the implants. No periprosthetic cysts larger than 400 mm(2) in size were identified.
  
  
  CONCLUSIONS
  The medium-term functional results and survivorship are comparable to those reported for other TAR designs. The incidence of cysts was low overall and there were no large-diameter cysts, which should improve long-term survival. The implant's design and materials likely played a role in preserving the periprosthetic bone stock. The AKILE™ TAR has distinctive features related to the low rate of large periprosthetic cysts in the medium-term.
  
  
  METHODS
  IV (retrospective case series).
authors.affiliation: Orthopédie-traumatologie Pr. Chauveaux, groupe hospitalier Pellegrin, place Amélie Raba-Léon, 33000 Bordeaux, France. Electronic address: julien.lucas@chu-bordeaux.fr.
authors.forename: J
authors.initials: J
authors.lastname: Lucas y Hernandez
authors.affiliation: Orthopédie-traumatologie Pr. Chauveaux, groupe hospitalier Pellegrin, place Amélie Raba-Léon, 33000 Bordeaux, France.
authors.forename: O
authors.initials: O
authors.lastname: Laffenêtre
authors.affiliation: Polyclinique de Bordeaux Tondu, 151, rue du Tondu, 33000 Bordeaux, France.
authors.forename: E
authors.initials: E
authors.lastname: Toullec
authors.affiliation: HIA Robert-Picqué, 351, route de Toulouse, 33882 Villenave-d'Ornon, France.
authors.forename: V
authors.initials: V
authors.lastname: Darcel
authors.affiliation: Orthopédie-traumatologie Pr. Chauveaux, groupe hospitalier Pellegrin, place Amélie Raba-Léon, 33000 Bordeaux, France.
authors.forename: D
authors.initials: D
authors.lastname: Chauveaux
mesh_terms: D000328:Adult; D000368:Aged; D000843:Ankle Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D058737:Arthroplasty, Replacement, Ankle; D003560:Cysts / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007595:Joint Prosthesis; D008297:Male; D008875:Middle Aged; D010014:Osteolysis / Q000000981:diagnostic imaging*; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
keywords: Arthroplasty; Osteolysis; Survivorship; Total ankle replacement