title: Biomechanical evaluation of the fixation methods for transcondylar fracture of the humerus:ONI plate versus conventional plates and screws.
abstract: We biomechanically evaluated the bone fixation rigidity of an ONI plate (Group I) during fixation of experimentally created transcondylar humerus fractures in cadaveric elbows, which are the most frequently observed humeral fractures in the elderly, and compared it with the rigidity achieved by 3 conventional fixation methods:an LCP reconstruction plate 3.5 using a locking mechanism (Group II), a conventional reconstruction plate 3.5 (CRP) with a cannulated cancellous screw (Group III), and a CRP with 2 cannulated cancellous screws (CS) in a crisscross orientation (Group IV). In the axial loading test, the mean failure loads were:Group I, 98.9+/-32.6;Group II, 108.5+/-27.2;Group III, 50.0+/-7.5;and Group IV, 34.5+/-12.2 (N). Group I fixations failed at a significantly higher load than those of Groups III and IV (p<0.05). In the extension loading test, the mean failure loads were:Group I, 34.0+/-12.4;Group II, 51.0+/-14.8;Group III, 19.3+/-6.0;and Group IV, 14.7+/-3.1 (N). Group IV fixations showed a significantly lower failure load than those of Group I (p<0.05). The fixation rigidities against mechanical loading by the ONI plate and LCP plate were comparable. These results suggested that an ONI system might be superior to the CRP and CS method, and comparable to the LCP method in terms of fixation rigidity for distal humerus fractures.
authors.affiliation: Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan. y-shima@md.okayama-u.ac.jp
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Shimamura
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Nishida
authors.forename: Junya
authors.initials: J
authors.lastname: Imatani
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Noda
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hashizume
authors.forename: Aiji
authors.initials: A
authors.lastname: Ohtsuka
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Ozaki
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D005260:Female; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D006810:Humeral Fractures / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged