title: High rate of osteolytic lesions in medium-term followup after the AES total ankle replacement.
abstract: BACKGROUND
  Some previous studies have shown a high percentage of early-onset and rapidly progressing osteolysis associated with total ankle arthroplasty (TAA) by the Ankle Evolutive System (AES). The purpose of our study was to analyze medium-term results at our institution.
  
  
  METHODS
  Altogether 38 TAAs using AES prostheses were carried out between 2003 and 2007. Diagnoses were rheumatoid arthritis (71%), post-traumatic and idiopathic osteoarthritis (29%). The mean age was 54 years, followup 28 months. Tibial and talar components had hydroxyapatite coating on metal (Co-Cr) components (HA-coated). Since 2005 the design was changed and components were porous coated with titanium and hydroxyapatite (dual-coated).
  
  
  RESULTS
  Two-year survival was 79% (95% CI: 56 to 98). At followup 34 (89%) primary tibial and talar components were preserved. In 19 (50%) TAAs osteolysis (more than or equal to 2 mm) occurred in the periprosthetic bone area and in nine (24%) comprised large "cyst-like osteolysis''. In HA-coated prostheses radiolucent lines (less than or equal to 2 mm) or osteolysis (more than or equal to 2 mm) were detected in 11 (100%) cases and in dual-coated prostheses in 19 (74%) (p = 0.08). On the other hand there was more large "cyst-like osteolysis'' around the dual-coated prosthesis and lesions were larger (p = 0.017). In rheumatoid arthritis osteolysis was detected in 14 (52%) and large "cyst-like osteolysis'' in seven (26%) prostheses and in the group of traumatic and idiopathic osteoarthritis in six (55%) and two (18%), respectively.
  
  
  CONCLUSIONS
  This study showed a high frequency of osteolysis in medium-term followup after the AES ankle replacement. The outcome was not sufficiently beneficial and we have discontinued use of this prosthesis.
authors.affiliation: Department of Orthopaedics, Rheumatism Foundation Hospital, FIN-18120 Heinola, Finland. ari.kokkonen@reuma.fi
authors.forename: Ari
authors.initials: A
authors.lastname: Kokkonen
authors.forename: Mikko
authors.initials: M
authors.lastname: Ikävalko
authors.forename: Raine
authors.initials: R
authors.lastname: Tiihonen
authors.forename: Hannu
authors.initials: H
authors.lastname: Kautiainen
authors.forename: Eero A
authors.initials: EA
authors.lastname: Belt
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000601:surgery; D058737:Arthroplasty, Replacement, Ankle; D020099:Coated Materials, Biocompatible; D017886:Durapatite; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007595:Joint Prosthesis / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000601:surgery; D010014:Osteolysis / Q000000981:diagnostic imaging / Q000209:etiology*; D011474:Prosthesis Design; D011859:Radiography; D012086:Reoperation; D012189:Retrospective Studies; D014025:Titanium; D055815:Young Adult
chemical_list: D020099:Coated Materials, Biocompatible; D017886:Durapatite; D014025:Titanium