title: [The significance of postoperative stability for osseous repair of a multiple fragment fracture. Animal experiment studies].
abstract: The significance of postoperative mechanical stability for bony repair of a comminuted fracture was investigated in an animal experimental study comparing four commonly applied operative methods of stabilizing fractures: (1) flate osteosynthesis combined with lag screw fixation after reduction of the fragments; (2) bridging plate osteosynthesis; (3) external fixation; (4) static interlocking intramedullary nailing. As the fracture model, a triple-wedge osteotomy of the right sheep tibia was used. The results of in vitro testing of stiffness (N/mm) of each of the four osteosyntheses was as follows: anatomical plate: 746 N/mm; bridging plate 434 N/mm; external fixation 625 N/mm; nailing 416 N/mm. Eight weeks after the operation, the tibiae were explanted and the contralateral tibiae of six sheep were taken as a control group. The three-point bending test revealed no significant difference in bending deviation: anatomical plate 47.58 +/- 22.57 microns; bridging plate 33.93 +/- 7.67 microns; external fixation 33.83 +/- 8.02 microns; nailing 33.0 +/- 17.23 microns. However, it was noted that there was a slightly higher tendency towards stiffness of the bones after bridging plate osteosynthesis, external fixation and interlocking intramedullary nailing and that the amount of stiffness resembled that in non-operated control animals (25.56 +/- 6.66 microns). On the other hand, anatomical plate osteosynthesis showed less stiffness. To assess the tensile strength at the osteotomy area, bone samples were prepared and tested for failure on a material testing machine. The tensile strength of the bone samples showed a distinct difference in all experimental groups according to their anatomical location.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Berufsgenossenschaftliche Unfallklinik Duisburg-Buchholz, Universität Ulm/Donau.
authors.forename: U
authors.initials: U
authors.lastname: Heitemeyer
authors.forename: L
authors.initials: L
authors.lastname: Claes
authors.forename: G
authors.initials: G
authors.lastname: Hierholzer
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D005593:Fracture Fixation, Internal / Q000379:methods*; D005594:Fracture Fixation, Intramedullary / Q000379:methods*; D005597:Fractures, Open / Q000601:surgery*; D008297:Male; D012756:Sheep; D013977:Tibia / Q000503:physiopathology; D013978:Tibial Fractures / Q000601:surgery; D014945:Wound Healing / Q000502:physiology*
vernacular_title: Die Bedeutung der postoperativen Stabilität für die ossäre Reparation einer Mehrfragmentfraktur. Tierexperimentelle Untersuchungen.