title: Clinical outcomes of cemented double-tapered titanium femoral stems: a minimum 5-year follow-up.
abstract: BACKGROUND
  The clinical outcomes and radiological findings for cemented titanium stems remain controversial. In 2004, we produced a straight-collared double-tapered stem made from a titanium alloy with a smooth surface for cemented total hip arthroplasty. In this study, we retrospectively examined the mid-term outcomes of this stem.
  
  
  METHODS
  We retrospectively reviewed 61 hips that had undergone primary cemented total hip arthroplasty with a collared smooth double-tapered titanium alloy femoral stem, after a minimum of 5 years (mean 6.1, range 5.0-7.3). Patients were evaluated preoperatively and postoperatively with the Merle d'Aubigné and Postel hip score. Radiographic examination was performed for evaluation of the cementing technique, the alignment of the stem, subsidence within the cement mantle, radiolucent lines at the cement-bone or cement-stem interface, cortical hypertrophy, and calcar resorption.
  
  
  RESULTS
  The clinical evaluation by the Merle d'Aubigné and Postel hip score was improved from 9.4 ± 1.9 preoperatively to 15.9 ± 1.6 at the time of final follow-up. The overall survival rate was 100% at 7 years, when radiological loosening or revision for any reasons was used as the endpoint. Five stems subsided less than 1 mm vertically. Nonprogressive radiolucence at the cement-bone interface occurred in six hips, without osteolysis. Cortical hypertrophy was observed in five hips and second-degree calcar resorption in 11 hips.
  
  
  CONCLUSIONS
  Our results in this study show good outcomes for cemented, collared, smooth, double-tapered titanium alloy femoral stems at a minimum follow-up of 5 years.
authors.affiliation: Department of Orthopaedics, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo, Kyoto, 606-8507, Japan. hakiyama@kuhp.kyoto-u.ac.jp
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Akiyama
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kawanabe
authors.forename: Koji
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Kazutaka
authors.initials: K
authors.lastname: So
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kuroda
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005269:Femur; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D012189:Retrospective Studies; D013997:Time Factors; D014025:Titanium; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D014025:Titanium