title: Conversion of a fused hip to total hip arthroplasty.
abstract: BACKGROUND
  Arthrodesis of the hip remains a viable treatment for severe unilateral arthritis after traumatic injury or infection in a young but otherwise healthy individual. The goal of the present study was to review the long-term clinical and radiographic results after conversion of a fused hip to a total hip arthroplasty and to identify the risk factors that would lead to a higher rate of failure.
  
  
  METHODS
  We performed a retrospective review of the charts and radiographs of 187 patients (208 hips) who had conversion of a fused hip to a total hip arthroplasty. The mean duration of follow-up after the conversion to total hip arthroplasty was 9.2 years (range, two to twenty-six years).
  
  
  RESULTS
  The mean age at time of the arthroplasty was fifty-one years. The mean time-interval between the arthrodesis and the conversion to a total hip arthroplasty was twenty-seven years. According to the information in the charts, at a mean duration of follow-up of 9.2 years after the total hip arthroplasty, 79% of hips were either pain-free or had minimal pain, 83% had good-to-excellent function, and 79% had good-to-excellent range of motion. Complications, which included fifteen nerve palsies, occurred in twenty-four hips. Twenty-eight hips had heterotopic ossification, but it was not associated with a recurrence of ankylosis or a marked reduction of motion. Revision arthroplasty was performed in twelve hips. The probability of survival of the implant was 96.1% (95% confidence interval, 91.5% to 98.2%) at ten years, 89.9% (95% confidence interval, 85.3% to 96.1%) at fifteen years, and 72.8% (95% confidence interval, 36% to 90.6%) at twenty-six years.
  
  
  CONCLUSIONS
  Conversion of a fused hip to a total hip arthroplasty has a favorable outcome. However, the technically demanding nature of the procedure should not be underestimated. Patients should be cautioned with regard to the possibility of a higher rate of complications than that seen with primary total hip arthroplasty.
authors.affiliation: Centre for Hip Surgery, Wrightington Hospital, Wigan, UK. sajoshi@pol.net
authors.forename: Atul B
authors.initials: AB
authors.lastname: Joshi
authors.forename: Ljubisa
authors.initials: L
authors.lastname: Markovic
authors.forename: Kevin
authors.initials: K
authors.lastname: Hardinge
authors.forename: John C M
authors.initials: JC
authors.lastname: Murphy
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001170:Arthritis, Infectious / Q000601:surgery; D001174:Arthrodesis; D019644:Arthroplasty, Replacement, Hip; D002648:Child; D005260:Female; D006615:Hip / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery; D012086:Reoperation; D016896:Treatment Outcome; D014394:Tuberculosis, Osteoarticular / Q000601:surgery