title: Long-term results for minor column allografts in revision hip arthroplasty.
abstract: BACKGROUND
  While acetabular structural allografts provide an important alternative for reconstructions, concerns remain with long-term graft resorption, collapse, and failure. Midterm studies of minor column (shelf) allograft suggest reasonable survival but long-term survival is unknown.
  
  
  OBJECTIVE
  We therefore assessed long-term graft/cup survivorship, functional scores, radiographic resorption, and complications associated with minor column allograft.
  
  
  METHODS
  We retrospectively reviewed 74 patients (85 hips) with a mean age of 54 years (range, 28-83 years) undergoing acetabular cup revision using a minor column allograft. A minor column allograft was used in uncontained acetabular bone defects sized between 30% and 50% of the acetabulum. Graft failure was considered to occur when the graft required revision with another graft, metal augment, reconstruction cage, or excision arthroplasty. The minimum followup was 5 years (mean, 16 years; range, 5.3-25 years).
  
  
  RESULTS
  Twenty-three patients (27 hips) had rerevision for all causes at a mean time to rerevision of 6.9 years (range, 0.1-23). Fifteen grafts failed at a mean time-to-rerevision of 6.1 years (range, 0.5-23.2). The 15- and 20-year Kaplan-Meier survivorships were 61% and 55% for cups and 78% for grafts with rerevision for all causes as end point. With rerevision for aseptic loosening as end point, survivorships were 67% and 61% for cups and 81% for grafts. The mean modified Harris hip scores were 41 (range, 20-60) preoperatively, 73 (range, 40-95) at 1 year postoperatively and 73 (range, 26-93) at last followup.
  
  
  CONCLUSIONS
  The data may provide a long-term benchmark by which future treatments for Type III defects can be measured.
authors.affiliation: Division of Orthopaedic Surgery, Mount Sinai Hospital, 600 University Avenue, Suite 476A, Toronto, ON, M5G 1X5, Canada.
authors.forename: Paul T H
authors.initials: PT
authors.lastname: Lee
authors.forename: Guy
authors.initials: G
authors.lastname: Raz
authors.forename: Oleg A
authors.initials: OA
authors.lastname: Safir
authors.forename: David J
authors.initials: DJ
authors.lastname: Backstein
authors.forename: Allan E
authors.initials: AE
authors.lastname: Gross
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation; D016025:Bone Transplantation / Q000009:adverse effects; D006085:Graft Survival; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D009864:Ontario; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation; D012189:Retrospective Studies; D013997:Time Factors; D014184:Transplantation, Homologous; D016896:Treatment Outcome