title: Long-term (20- to 25-year) results of an uncemented tapered titanium femoral component and factors affecting survivorship.
abstract: BACKGROUND
  Uncemented femoral components in primary total hip arthroplasty (THA) are commonly used today, but few studies have evaluated their survival into the third decade.
  
  
  OBJECTIVE
  We evaluated (1) survivorship using femoral revision for any reason as the end point; (2) survivorship using femoral revision for aseptic loosening as the end point; and (3) patient-related and surgical risk factors for aseptic stem loosening at a minimum 20-year followup with an uncemented tapered titanium stem.
  
  
  METHODS
  We reviewed the clinical and radiographic results of 354 THAs in 326 patients performed between January 1985 and December 1989 using an uncemented grit-blasted, tapered titanium femoral stem. Mean age at surgery was 57 years (range, 13-81 years). Kaplan-Meier survivorship analysis was used to estimate long-term survival. Minimum followup evaluation was 20 years (mean, 22 years; range, 20-25 years); at that time, 120 patients (127 hips) had died, and four patients (five hips) were lost to followup. Multivariate survival analysis using a Cox regression model was performed.
  
  
  RESULTS
  Survivorship at 22 years with revision of the femoral component for any reason as the end point was 86% (95% confidence interval [CI], 81%-90%). Survivorship for femoral revision for aseptic loosening as the end point was 93% at 22 years (95% CI, 90%-96%). Undersized stems (canal fill index≤80%) and stems in hips with cup revision were at higher risk for aseptic loosening (hazard ratio, 4.2 and 4.3, respectively). There was a high rate of acetabular revision in this series (38%), mostly related to smooth-threaded, cementless sockets.
  
  
  CONCLUSIONS
  Uncemented femoral fixation was reliable into the third decade. Age, male sex, and diagnosis were not associated with a higher risk of aseptic loosening.
  
  
  METHODS
  Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedic and Trauma Surgery, University of Heidelberg, Schlierbacher Landstrasse 200a, 69118, Heidelberg, Germany.
authors.forename: Marcus R
authors.initials: MR
authors.lastname: Streit
authors.forename: Moritz M
authors.initials: MM
authors.lastname: Innmann
authors.forename: Christian
authors.initials: C
authors.lastname: Merle
authors.forename: Thomas
authors.initials: T
authors.lastname: Bruckner
authors.forename: Peter R
authors.initials: PR
authors.lastname: Aldinger
authors.forename: Tobias
authors.initials: T
authors.lastname: Gotterbarm
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D001843:Bone Cements; D005260:Female; D005269:Femur / Q000601:surgery*; D005500:Follow-Up Studies; D006621:Hip Joint / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D012307:Risk Factors; D014025:Titanium; D016896:Treatment Outcome
chemical_list: D001843:Bone Cements; D014025:Titanium