title: Does computed tomography add information on radiographic analysis in detecting periprosthetic osteolysis after total ankle arthroplasty?
abstract: BACKGROUND
  The major longer term complications of ankle arthroplasty are periprosthetic osteolysis and aseptic loosening. Follow-up studies of total hip arthroplasties show that measurements of periprosthetic osteolytic lesions on radiographs underestimate the size compared with those made on computed tomography (CT), and some of the lesions may even remain undetected on radiographs. However, it is unclear whether the same applies to total ankle arthroplasty (TAA).
  
  
  METHODS
  We retrospectively reviewed the radiographs of 123 patients who had undergone TAA with the Ankle Evolutive System (AES) implant. Of these, 43 (34.9%) had at least 1 large (greater than 10 mm) osteolytic lesion on radiographs at a minimum follow-up of 14 months (mean, 43.1 months; range, 14-85 months). Forty of the 43 patients underwent helical CT imaging.
  
  
  RESULTS
  Computed tomography showed more osteolytic lesions than radiographs around both tibial and talar components. CT also showed larger lesions than radiographs in 9 of 10 zones around prosthetic components. The difference was highly significant in 3 zones around the talar component.
  
  
  CONCLUSIONS
  Computed tomography showed more and larger periprosthetic lesions than radiographs around an ankle prosthesis. Because osteolysis is progressive in nature, it presumably leads to component failure. Considering our results, we recommend adding CT imaging to postoperative follow-up after TAA for patients with suspected or known periprosthetic lucencies on radiographs.
  
  
  METHODS
  Level III, diagnostic study.
authors: University of Turku, Turku, Finland. ia.kohonen@tyks.fi
authors: Ia
authors: Ia
authors: Kohonen
authors: Helka
authors: H
authors: Koivu
authors: Tomi
authors: T
authors: Pudas
authors: Hannu
authors: H
authors: Tiusanen
authors: Tero
authors: T
authors: Vahlberg
authors: Kimmo
authors: K
authors: Mattila
mesh_terms: D000328:Adult; D000368:Aged; D058737:Arthroplasty, Replacement, Ankle / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007595:Joint Prosthesis; D008297:Male; D008875:Middle Aged; D010014:Osteolysis / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D013628:Talus / Q000000981:diagnostic imaging*; D013977:Tibia / Q000000981:diagnostic imaging*; D036542:Tomography, Spiral Computed