Biomechanical Evaluation of the Less Invasive Stabilization System for the Internal Fixation of Distal Femur Fractures

Abstract

These results suggest an enhanced ability to withstand high loads when using the monocortical screw fixation technique with angular stability. A higher elastic deformation of LISS compared with conventional plating systems in distal femoral fractures can be explained by the lower bending stiffness caused by different design and material properties.

Implant Material and Design Alter Construct Stiffness in Distal Femur Locking Plate Fixation: A Pilot Study

“…Even more, the mean axial stiffness of the AxSOS plate systems tested in our study is similar to that of AxSOS plate systems (110 N/mm) reported by Wähnert et al [20]. The loading regimen for axial loading used in our study is based on comparable testing methodologies used by other authors [14,20]. The incremental axial loading applied in these studies is considered representative of physiologic postoperative loading of the distal femur and based the results of in vivo telemetry studies [6,17,18].…”

“…Our fracture model represents an extraarticular fracture, which is classified as a type of distal femur fracture [15] associated with substantial complication rates [16]. This model is used in multiple biomechanical studies [5,11,14,21,25]. The fracture model used in our study with a fracture gap of 25 mm may not correlate with the clinical fracture pattern; however, it was created to perform a worst case fracture pattern without any inherent stability.…”

“…We applied loads in displacement control using a plunger speed of 0.2 mm/s (axial compression) followed by the torsion test with 0.15°/s (torsion). The loading regimen for loading used in our study is based on comparable testing methodologies used by other authors [14,20] and is considered representative of physiologic postoperative loading of the distal femur based the results of in vivo telemetry studies [6,17,18].…”

Mono- versus polyaxial locking plates in distal femur fractures: a prospective randomized multicentre clinical trial

“…While the fixed connection between screws and plate promotes stability in the system, the higher caliber of LISS® screws leads to a better load distribution. Both factors lead to a lower rate of secondary loosening and screw dislocation [7]. Especially in osteoporotic bones these advantages account for higher stability and reduction of secondary dislocation [2,8].…”

Efeitos mecânicos causados pela variação da inclinação do parafuso excêntrico no orifício da placa de autocompressão

“…Introduzia-se, assim, o conceito de implantes que atuavam como fixadores externos, mas aplicados bem próximo ao osso: os fixadores internos (6)(7)(8) . Os fixadores internos, assim como os externos, asseguravam algum grau de movimento no foco de fratura, agindo pelo princípio da estabilidade relativa e levando à consolidação mediante a formação de calo ósseo (9) .…”