Sven Märdian1, Klaus-Dieter Schaser2, Georg N Duda3, Mark Heyland4. 1. Centre for musculoskeletal surgery, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. Electronic address: sven.maerdian@charite.de. 2. Centre for musculoskeletal surgery, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. Electronic address: klaus-dieter.schaser@charite.de. 3. Julius Wolff Institute for Biomechanics and Musculoskeletal Regeneration, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. Electronic address: georg.duda@charite.de. 4. Julius Wolff Institute for Biomechanics and Musculoskeletal Regeneration, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. Electronic address: mark.heyland@charite.de.
Abstract
BACKGROUND: This study aimed to investigate the influence of the screw location and plate working length of a locking plate construct at the distal femur on interfragmentary movement under physiological loading. METHODS: To quantitatively analyse the influence of plate working length on interfragmentary movements in a locking plate construct bridging a distal femur fracture, a finite element model based on CT (computed tomography) data was physiologically loaded and fracture gap conditions were calculated. Four working lengths with eight screw variations each were systemically analysed. FINDINGS: Interfragmentary movements for axial (12-19%, p<0.001) and shear movements (-7.4-545%, p<0.001) at all tested nodes increased significantly with longer plate working length, whereas screw variations within the groups revealed no significant influence. The working length (defined by screw location) dominates the biomechanical fracture gap conditions. INTERPRETATION: The current finite element analysis demonstrates that plate working length significantly influences interfragmentary movements, thereby affecting the biomechanical consequences of fracture healing.
BACKGROUND: This study aimed to investigate the influence of the screw location and plate working length of a locking plate construct at the distal femur on interfragmentary movement under physiological loading. METHODS: To quantitatively analyse the influence of plate working length on interfragmentary movements in a locking plate construct bridging a distal femur fracture, a finite element model based on CT (computed tomography) data was physiologically loaded and fracture gap conditions were calculated. Four working lengths with eight screw variations each were systemically analysed. FINDINGS: Interfragmentary movements for axial (12-19%, p<0.001) and shear movements (-7.4-545%, p<0.001) at all tested nodes increased significantly with longer plate working length, whereas screw variations within the groups revealed no significant influence. The working length (defined by screw location) dominates the biomechanical fracture gap conditions. INTERPRETATION: The current finite element analysis demonstrates that plate working length significantly influences interfragmentary movements, thereby affecting the biomechanical consequences of fracture healing.
Authors: Gregory S Lewis; Hwabok Wee; Jared Vicory; April D Armstrong; J Spence Reid Journal: J Am Acad Orthop Surg Date: 2022-01-01 Impact factor: 3.020