J Dehoust1, M Münch2, K Seide2, T Barth2,3, K-H Frosch2,4. 1. Department of Trauma and Orthopaedic Surgery, Sports Traumatology, BG Hospital Hamburg, Hamburg, Germany. j.dehoust@bgk-hamburg.de. 2. Department of Trauma and Orthopaedic Surgery, Sports Traumatology, BG Hospital Hamburg, Hamburg, Germany. 3. Institute for Integrated Circuits, Technical University Hamburg, Hamburg, Germany. 4. Department of Trauma and Orthopaedic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Abstract
PURPOSE: To gain principal insight into fixation techniques of a posteromedial split fragment in bicondylar tibial plateau fractures. METHODS: A computer simulation was performed, applying the finite-element method (FEM) to compare four methods of fixation of the posteromedial split fragment: lateral plate (model 1), lateral plate and kickstand screw (model 2), lateral plate and two antero-posterior lag screws (model 3), and lateral and posteromedial plate (model 4). The displacement of the fragment and material stresses in implants and bone under 2500 N axial load were analyzed. RESULTS: Maximal displacement of the posteromedial split fragment of 2.8 mm was found with a sole lateral plate. An added kickstand screw decreased the displacement to 1.46 mm. Added lag screws improved stability by a factor 4, with a maximal displacement of 0.76 mm. The double-plate configuration revealed 0.27 mm, a decrease of the displacement by a factor 10 compared to model 1. An additional analysis of posteromedial fragment displacements with osteoporotic bone, simulated by dividing the elastic modulus of the bone by a factor 2, turned out to be of relevant impact. For model 1, the calculations did not converge. The influence of bone quality was found to be 70% in model 2, 60% in model 3, and 40% in model 4. CONCLUSIONS: The results indicate that the additional fixation of a posteromedial split fracture by plate osteosynthesis might be advantageous in bicondylar tibial plateau fractures treated with lateral plating. This might be even more important in patients with low bone quality.
PURPOSE: To gain principal insight into fixation techniques of a posteromedial split fragment in bicondylar tibial plateau fractures. METHODS: A computer simulation was performed, applying the finite-element method (FEM) to compare four methods of fixation of the posteromedial split fragment: lateral plate (model 1), lateral plate and kickstand screw (model 2), lateral plate and two antero-posterior lag screws (model 3), and lateral and posteromedial plate (model 4). The displacement of the fragment and material stresses in implants and bone under 2500 N axial load were analyzed. RESULTS: Maximal displacement of the posteromedial split fragment of 2.8 mm was found with a sole lateral plate. An added kickstand screw decreased the displacement to 1.46 mm. Added lag screws improved stability by a factor 4, with a maximal displacement of 0.76 mm. The double-plate configuration revealed 0.27 mm, a decrease of the displacement by a factor 10 compared to model 1. An additional analysis of posteromedial fragment displacements with osteoporotic bone, simulated by dividing the elastic modulus of the bone by a factor 2, turned out to be of relevant impact. For model 1, the calculations did not converge. The influence of bone quality was found to be 70% in model 2, 60% in model 3, and 40% in model 4. CONCLUSIONS: The results indicate that the additional fixation of a posteromedial split fracture by plate osteosynthesis might be advantageous in bicondylar tibial plateau fractures treated with lateral plating. This might be even more important in patients with low bone quality.
Authors: Peter Behrendt; Markus T Berninger; Grégoire Thürig; Julius Dehoust; Jan H Christensen; Karl-Heinz Frosch; Matthias Krause; Maximilian J Hartel Journal: Eur J Trauma Emerg Surg Date: 2022-09-28 Impact factor: 2.374