title: The Use of Structural Distal Femoral Allograft for Acetabular Reconstruction of Paprosky Type IIIA Defects at a Mean 21 Years of Follow-Up.
abstract: BACKGROUND
  Revision total hip arthroplasty in patients with a nonsupportive superior acetabulum often requires secondary augmentation beyond a hemispherical cup to achieve reliable fixation. Treatment options include using a higher hip center, jumbo cup, custom triflange implant, cages, or filling the superior defect with a bilobed implant, structural allograft, or metal augments. We previously reported a cohort of 31 patients treated with porous-coated hemispherical cups and distal femoral allograft for Paprosky type IIIA acetabular defects.
  
  
  METHODS
  The original cohort of 31 hips was retrospectively reviewed. Fourteen patients died with <15 years of follow-up, and 2 were lost to follow-up. This left 15 patients for evaluation including 5 males and 10 females, with an average age of 61 years (range: 37-74 years) at the time of surgery. Acetabular revision was performed with the use of a porous-coated hemispherical cup along with structural distal femoral allograft, cut to resemble the number 7, and secured with 6.5-mm cancellous screws with washers.
  
  
  RESULTS
  Overall, 7 hips failed, resulting in a Kaplan-Meier survivorship of 72% at 25 years of follow-up. In surviving patients, radiographs demonstrated components to be well fixed, and average Merle d'Aubigné score increased from 5 to 10 points. There were a subset of patients that failed early (median: 6.2 years), but the remaining patients demonstrated excellent clinical and radiographic results.
  
  
  CONCLUSIONS
  The use of distal femoral allograft can be considered in young patients with type IIIA acetabular defects that could benefit from restoration of bone stock.
authors.affiliation: Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, Illinois.
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Brown
authors.affiliation: University of Illinois Chicago Medical School, Chicago, Illinois.
authors.forename: Joe
authors.initials: J
authors.lastname: Morrison
authors.affiliation: Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, Illinois; Department of Orthopaedic Surgery, Central Dupage Hospital, Winfield, Illinois.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Sporer
authors.affiliation: Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, Illinois; Department of Orthopaedic Surgery, Central Dupage Hospital, Winfield, Illinois.
authors.forename: Wayne G
authors.initials: WG
authors.lastname: Paprosky
mesh_terms: D000077:Acetabulum / Q000601:surgery*; D000328:Adult; D000368:Aged; D064591:Allografts; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D005260:Female; D005269:Femur / Q000637:transplantation*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012086:Reoperation; D012189:Retrospective Studies; D014184:Transplantation, Homologous; D016896:Treatment Outcome
keywords: Paprosky type IIIA; acetabular defect; distal femoral allograft; revision total hip arthroplasty; structural allograft