title: Periprosthetic osteolysis after AES total ankle replacement: Conventional radiography versus CT-scan.
abstract: BACKGROUND
  The aim of this study was to compare conventional X-rays and CT-scan in detecting peri-prosthetic osteolytic lesions, a major concern after total ankle replacement (TAR).
  
  
  METHODS
  We prospectively assessed 50 patients (mean age 56 years), consecutively operated on by the same senior surgeon, between 2003 and 2006 and with a mean follow-up period of 4 years (range, 2-6.2). The component used was AES total ankle replacement. The etiologies for total ankle arthroplasty were: posttraumatic in 50%, osteoarthritis secondary to instability in 36%. Plain radiographs were analyzed by 4 independent observers, using a 10-zone protocol (location) and 5 size categories.
  
  
  RESULTS
  At 4-year follow-up, all patients had been CT-scan assessed with the same protocol by 2 independent observers. Plain radiographs showed dramatic progression of severe periprosthetic lyses (>10mm): from 14% to 36% of interface cysts for the tibial component respectively at 2 and 4-year follow-up and from 4% to 30% for the talar implant. The talar component was more accurately assessed by CT-scan (mean frontal and sagittal talar lesion: from 270 mm2 to 288 mm2 for CT-scan versus 133 mm2 to 174 mm2 for X-rays). For tibial cysts, axial views showed larger lesions (313 mm2 than frontal (194 mm2) or sagittal (213.5 mm2) views. At 4-year follow-up, 24% of patients had revision with curetage or arthrodesis, and at 7 years follow-up 38% were revised.
  
  
  CONCLUSIONS
  These results are similar to recent AES series, justifying withdrawal of this device. CT-scan was more accurate than X-rays for detecting and quantifying periprosthetic osteolysis. We recommend a yearly radiological control and CT-scan in case of lesion on X-rays.
authors.affiliation: Hospices Civils de Lyon, Centre Hospitalier Lyon-Sud, Service de Chirurgie Orthopédique et Traumatologique, 69495 Pierre-Bénite Cedex, France; Université de Lyon, 69622 Lyon, France; IFSTTAR, UMRT_9406, LBMC Laboratoire de Biomécanique et Mécanique des Chocs, 69675 Bron, France; Université Claude Bernard Lyon 1, Villeurbanne, France. Electronic address: anthony.viste@chu-lyon.fr.
authors.forename: Anthony
authors.initials: A
authors.lastname: Viste
authors.affiliation: King Abdulaziz Medical City, Department of Surgery, Riyadh, Saudi Arabia.
authors.forename: Nader
authors.initials: N
authors.lastname: Al Zahrani
authors.affiliation: Matosinhos, Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Brito
authors.affiliation: Hospices Civils de Lyon, Centre Hospitalier Lyon-Sud, Service de Chirurgie Orthopédique et Traumatologique, 69495 Pierre-Bénite Cedex, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Lienhart
authors.affiliation: Hospices Civils de Lyon, Centre Hospitalier Lyon-Sud, Service de Chirurgie Orthopédique et Traumatologique, 69495 Pierre-Bénite Cedex, France; Université de Lyon, 69622 Lyon, France; IFSTTAR, UMRT_9406, LBMC Laboratoire de Biomécanique et Mécanique des Chocs, 69675 Bron, France; Université Claude Bernard Lyon 1, Villeurbanne, France.
authors.forename: Michel Henri
authors.initials: MH
authors.lastname: Fessy
authors.affiliation: Hospices Civils de Lyon, Centre Hospitalier Lyon-Sud, Service de Chirurgie Orthopédique et Traumatologique, 69495 Pierre-Bénite Cedex, France; Université de Lyon, 69622 Lyon, France; IFSTTAR, UMRT_9406, LBMC Laboratoire de Biomécanique et Mécanique des Chocs, 69675 Bron, France; Université Claude Bernard Lyon 1, Villeurbanne, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Besse
mesh_terms: D000328:Adult; D000368:Aged; D000843:Ankle Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D001175:Arthrography / Q000379:methods*; D058737:Arthroplasty, Replacement, Ankle / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007595:Joint Prosthesis; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000000981:diagnostic imaging / Q000601:surgery*; D010014:Osteolysis / Q000000981:diagnostic imaging* / Q000209:etiology; D011446:Prospective Studies; D011474:Prosthesis Design; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
keywords: AES(®); Cysts; Osteolysis; Total ankle replacement