title: [Curved osteotomy technique for intertrochanteric varus surgery--an experimental and computer-assisted surgery].
abstract: OBJECTIVE
  In conventional intertrochanteric varus osteotomy, shortening of the leg and insufficiency of the abductor muscles occur frequently. To avoid these disadvantages, a curved osteotomy is presented.
  
  
  METHODS
  189 intertrochanteric barrel vault and wedge osteotomies were compared. By means of digitized preoperative radiographs the varus osteotomies were planned with a computer program optimising postoperative leg length, bone contact area at the osteotomy site, femoral offset, and abductor muscle length.
  
  
  RESULTS
  The average leg shortening was 3.9 mm (range: 0-5 mm) for barrel vault osteotomy and 13.6 mm (range: 8-22.2 mm) for the wedge technique. After correction the mean contact area at the osteotomy sites was 1731.6 mm2 (range: 1087.8-2341.8 mm2) in the barrel vault technique compared with 783.7 mm2 (range: 563.7-1249.6 mm2) in the wedge procedure (p < 0.001, t-test). Adequate femoral offset was achieved in both types of osteotomy. In all curved osteotomies the length of the abductor muscles remained nearly constant in contrast to the wedge procedure. Additional comparative experimental barrel vault osteotomies in 22 human autopsy femora with a high-speed dissecting tool and round jigs revealed a precise application of the preoperative planning.
  
  
  CONCLUSIONS
  The intertrochanteric curved osteotomy provides minimum leg shortening and increased bone contact area. It can prevent an insufficiency of the abductor muscles, because shortening is minimized.
authors.affiliation: Orthopädische Klinik und Poliklinik, Universität Essen. b.barden@uni-essen.de
authors.forename: B
authors.initials: B
authors.lastname: Barden
authors.forename: B
authors.initials: B
authors.lastname: Wesskamp
authors.forename: J G
authors.initials: JG
authors.lastname: Fitzek
authors.forename: F
authors.initials: F
authors.lastname: Löer
mesh_terms: D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006618:Hip Dislocation, Congenital / Q000000981:diagnostic imaging / Q000601:surgery*; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D007870:Leg Length Inequality / Q000000981:diagnostic imaging / Q000601:surgery*; D007873:Legg-Calve-Perthes Disease / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000379:methods*; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D011856:Radiographic Image Enhancement; D012984:Software; D014584:User-Computer Interface