Lucie Hucke (Frankfurt a. M.; Cádiz / ES), Sonia Vincenti (Frankfurt a. M.; Offenburg), Dr. Jana Holder (Salzburg / AT; Frankfurt a. M.), Dr. Stefan van Drongelen (Frankfurt a. M.), Sebastian Braun (Berlin; Frankfurt a. M.), Jonas Schwer (Ulm), Dr. Andreas M. Seitz (Ulm), Dr. Felix Stief (Frankfurt a. M.), Prof. Dr. Armin Huß (Frankfurt a. M.), Prof. Dr. Antonio Gámez (Cádiz / ES), Dr. Andreas Wittek (Frankfurt a. M.)
Abstract-Text (inkl. Referenzen und Bildunterschriften)
In the case of guided growth, positioning of the tension band implant is crucial and subject to significant variability [1]. This directly impacts treatment success, as it influences growth in the blocked joint by altering stress distribution in the growth plate (GP) [2]. The influence of the implant on stress distribution was investigated in a previous study [3] using a personalized finite element (FE) simulation for three patients; however, the model was not validated and the influence of different implant positions not analysed. In this study after FE model validation, the GP stress distribution was evaluated based on different tension band implant positioning.
For model validation, six porcine knees were subjected to loads up to twice their body weight, with GP deformation measured using MRI [4]. An FE model was generated from the MRI images of the unloaded knee and simulated using known boundary conditions from the test setup. For the study of the positioning parameters, surgical data from guided growth treatments of 34 patients with malalignment were evaluated [1] and the minima and maxima of each parameter were determined and applied to the validated FE model. Stress distributions resulting from these implant positions were compared to those observed when the implant was positioned according to the manufacturer"s recommendations.
Initial FE simulation results indicated that different implant and screw positions affected stress across the entire GP, not just on the implant side. The study identified the positioning parameters that have a significant influence on the stress in the GP.
This study was conducted using the same geometry to isolate the influence of the positioning parameters from the geometrical influence; it may help better understand the influence of implant positioning.
[1] Brau(2023); Children-Basel,10(4)
[2] Willegger(2022); Orthopädie,51(5)
[3] Hucke(2023); Front. Bioeng. Biotechnol.;11
[4] Schwer(2020); Front. Bioeng. Biotechnol.;8