title: Olecranon fracture fixation with a new implant: biomechanical and clinical considerations.
abstract: This study aims to describe the first clinical results in the treatment of dislocated olecranon fractures with 2.2-mm, fine-threaded wires with a washer. Furthermore, in the second part of the article, the stability of these new implants has been compared to standard tension band wiring in a sawbone model.
  
  
  METHODS
  The radiological and clinical outcomes in 24 patients (mean age: 53.6 years) with 24 isolated Mayo type I and II fractures of the olecranon were evaluated in a prospective study after open reduction and internal fixation (ORIF) with a new fixation device (FFS; Orthofix). The quality of reduction with the implementation of 24 FFS constructions was compared with 24 tension band-wiring procedures performed by six different surgeons in a standard sawbone Mayo type IIa fracture model. Stability was tested in all constructs using a single cycle load to failure protocol (group I), cyclic loading for 300 cycles between 10 and 500 N (group II) and incremental sinusoidal loading from 10 to 200 N with an incremental increase of 10 N per cycle (group III) in a laboratory study.
  
  
  RESULTS
  The Morrey elbow score was excellent in 23 patients and good in one patient, with mean DASH score of 1.6. No implant migration, secondary dislocation or nonunion was observed. In the sawbone model, the quality of reduction was the same with the FFS implants compared to the tension band wiring in the sawbone model. Here, bending moments in all three groups showed no significant difference, whereas displacement at failure was significantly greater in the tension band-wiring group at a single cycle load (p=0.017).
  
  
  CONCLUSIONS
  Clinical results were comparable to tension band wiring and stability of the implants in the sawbone model was the same; thus, we conclude that the FFS technique can serve as an alternative treatment option for isolated olecranon fractures.
authors.affiliation: Department of Surgery, St. Elisabeth Hospital, Werthmannstrasse 1, D-50935 Cologne, Germany. tkoslowsky@web.de
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Koslowsky
authors.forename: Konrad
authors.initials: K
authors.lastname: Mader
authors.forename: Jens
authors.initials: J
authors.lastname: Dargel
authors.forename: Ruediger
authors.initials: R
authors.lastname: Schadt
authors.forename: Juergen
authors.initials: J
authors.lastname: Koebke
authors.forename: Dietmar
authors.initials: D
authors.lastname: Pennig
mesh_terms: D001696:Biomechanical Phenomena; D001864:Bone Wires; D004551:Elbow Joint / Q000601:surgery; D005260:Female; D005593:Fracture Fixation, Internal / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D004204:Joint Dislocations / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008422:Materials Testing / Q000379:methods; D008875:Middle Aged; D056740:Olecranon Process / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D011475:Prosthesis Failure; D011859:Radiography; D016059:Range of Motion, Articular; D013314:Stress, Mechanical; D013718:Tensile Strength; D013997:Time Factors; D016896:Treatment Outcome; D014458:Ulna Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D000092464:Elbow Injuries