title: Seventeen-year survival of the cementless CLS Spotorno stem.
abstract: BACKGROUND
  For primary uncemented hip arthroplasty, various stem designs are available. The cementless CLS((R)) Spotorno stem has been used for more than 20 years. We re-evaluated a group of patients previously examined for a 10-year follow-up to assess the clinical and radiological stem performance in the long run.
  
  
  METHODS
  Between 1987 and 1988, a consecutive series of 107 uncemented CLS((R))-Spotorno stems (Zimmer Ltd., Germany) were implanted in 94 patients. The patients' mean age at the time of surgery was 51 years (range 20-77 years); 80 hips out of 107 (86%) were available for a clinical examination [Harris Hip Score (HHS)] after a mean of 17 years (range 15-18 years). In addition, radiographs were available from 74 out of 80 examined hips (92%) and analyzed for radiolucency, stress shielding, stem migration and heterotopic ossification.
  
  
  RESULTS
  Stable stem fixation was present in 64 hips (98.5%). With "non-traumatic loosening" as an endpoint, stem survival was 100% after 17 years. Two stems (3%) showed mild subsidence already in the 10-year follow-up with no progression after 17 years. The HHS described excellent results in 47 hips (59%), good results in 16 hips (20%) and fair or poor results in 7 hips (9%) and 10 hips (13%), respectively. Radiolucency and grades II and III stress shielding were progressive at 17 years compared with the 10-year results. Grade IV stress shielding associated with osteolysis was seen in 9 hips (14%). Thigh pain was present in 20 hips (25%).
  
  
  CONCLUSIONS
  The CLS((R)) Spotorno stem allows excellent long-term results in cementless hip arthroplasty, leaving only minimal options for substantial improvements. Our findings on progressive stress shielding point towards a more diaphyseal load transfer of the CLS stem.
authors.affiliation: Division of Orthopaedic Rheumatology, Department of Orthopaedic Surgery, Universitiy of Erlangen-Nuremberg, Rathsberger Strasse 57, 91054 Erlangen, Germany.
authors.forename: Lutz Arne
authors.initials: LA
authors.lastname: Müller
authors.forename: Nina
authors.initials: N
authors.lastname: Wenger
authors.forename: Michael
authors.initials: M
authors.lastname: Schramm
authors.forename: Dieter
authors.initials: D
authors.lastname: Hohmann
authors.forename: Raimund
authors.initials: R
authors.lastname: Forst
authors.forename: Hans-Dieter
authors.initials: HD
authors.lastname: Carl
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D001843:Bone Cements; D005260:Female; D005271:Femur Head Necrosis / Q000601:surgery*; D005500:Follow-Up Studies; D006618:Hip Dislocation, Congenital / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery*; D011474:Prosthesis Design; D012086:Reoperation; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D001843:Bone Cements