title: High survival of modular tapered stems for proximal femoral bone defects at 5 to 10 years followup.
abstract: BACKGROUND
  Currently, the two most commonly used options for the revision of femoral components in North America are: cylindrical, nonmodular, cobalt-chromium stems and tapered, fluted, modular, titanium (TFMT) stems. Previous reports have cited high failure rates with cylindrical cobalt chrome stems in large femoral defects but the longer term survival of the fluted stems is unknown.
  
  
  OBJECTIVE
  We examined the 5- to 10-year survival of TFMT stems implanted for severe femoral defects.
  
  
  METHODS
  We reviewed all 65 patients with severe proximal bone defects revised with the TMFT stem between January 2000 and 2006. Ten were lost to followup and seven were dead, leaving 48 patients for followup at 5 to 10 years (mean, 84 months; range, 60-120 months). All patients completed five quality-of-life (QOL) questionnaires. Radiographs were evaluated for loosening, subsidence, and preservation of proximal host bone stock.
  
  
  RESULTS
  Implant survivorship was 90%. No patient underwent revision for either subsidence or loosening. Subsidence occurred in seven patients (average, 12.3 mm) but all achieved secondary stability. Five patients underwent revision as a result of fracture of the stem and all had the original standard stem design, which has since been modified. All five implant fractures occurred at the modular stem junction. Mean QOL outcomes were: WOMAC = 81 (pain), Oxford = 75, SF-12 = 54 (mental) and 38 (physical), UCLA Activity = 4, and satisfaction overall = 73.
  
  
  CONCLUSIONS
  Midterm survivorship of modular titanium stems in large femoral defects is high; however, ongoing surveillance of stem junctional fatigue life is required.
  
  
  METHODS
  Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedics, University of British Columbia, Room 3114, 910 West 10th Avenue, Vancouver, British Columbia, V5Z 4E3, Canada.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Van Houwelingen
authors.forename: Clive P
authors.initials: CP
authors.lastname: Duncan
authors.forename: Bassam A
authors.initials: BA
authors.lastname: Masri
authors.forename: Nelson V
authors.initials: NV
authors.lastname: Greidanus
authors.forename: Donald S
authors.initials: DS
authors.lastname: Garbuz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery*; D005500:Follow-Up Studies; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011474:Prosthesis Design; D011788:Quality of Life; D011859:Radiography; D012189:Retrospective Studies