title: [Cement-free diaphyseal fixation principle for hip shaft exchange in large bone defects--analysis of 12 years experience with the Wagner revision shaft].
abstract: OBJECTIVE
  Considering the increasing incidence of revision for failed total hip arthroplasty, we evaluated if the principle of uncemented diaphyseal fixation which is realised with the Wagner SL revision stem, can solve the technical problems of significant bone loss of the proximal femur and can offer good preconditions for bony restoration in the medium term.
  
  
  METHODS
  A consecutive series of 129 femoral revisions with the Wagner SL revisions stem was evaluated. In 87 cases, the acetabular component was revised simultaneously. The revision was indicated in 97 cases of aseptic loosening, in 13 periprosthetic fractures (12 aseptic and 1 septic hip), in 16 cases of septic loosening and in 3 Girdlestone-hips after chronic deep infection. At the time of revision, the mean age of the patients was 64.9 (36.7-86.3) years. For classification of the preoperative defects, both the classification system proposed by Pak et al. and our own classification system were used.
  
  
  RESULTS
  The mean period of time between operation and latest follow-up examination, rerevision, or death of the patient was 5.4 years (0.13-11.7 years). Six revision stems required rerevision because of malpositioning (1), significant subsidence (1), periprosthetic fracture (1), and deep infection (3). The mean Merle d'Aubigné score improved from preoperatively 7.7 points to 14.8 at follow-up. Cumulative survival (end point removal of the stem for any cause) was 94.4 percent at 11.7 years. A clear, good, or excellent bony restoration of the proximal femur was seen in 87.6 percent of the cases. The cumulative survival of the revised acetabular components was 97.7 percent at 11.7 years and for the non-revised cups it was 86.9 percent at 10.9 years.
  
  
  CONCLUSIONS
  Due to the encouraging results with the Wagner revision stem, the principle of uncemented diaphyseal fixation seems to us to be able to solve most of the technical problems in cases of significant bone loss and obviously offers good preconditions for bony restoration. Our own classification system was effective and useful for preoperative planning.
authors.affiliation: Orthopädische Klinik der Eberhard-Karls-Universität Tübingen. paul.boehm@med.uni-tuebingen.de
authors.forename: P
authors.initials: P
authors.lastname: Böhm
authors.forename: O
authors.initials: O
authors.lastname: Bischel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D019544:Equipment Failure Analysis; D005260:Female; D005264:Femoral Fractures / Q000000981:diagnostic imaging / Q000601:surgery; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000601:surgery*; D011474:Prosthesis Design; D011859:Radiography; D013530:Surgical Wound Infection / Q000000981:diagnostic imaging / Q000601:surgery; D016019:Survival Analysis