Biomechanical analysis of surgical scoliosis treatments

• Applicant: Professor Dr. Hans-Joachim Wilke
• Subject Area: Orthopaedics, Traumatology, Reconstructive Surgery
• Term: since 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 422439870

In the project funded by the German Research Foundation (DFG) at the Institute for Trauma Surgery Research and Biomechanics Ulm, the surgical strategies in the treatment of adolescent idiopathic scoliosis (AIS) are documented and biomechanically analyzed. Surgical correction of AIS is a highly invasive procedure and offers numerous variations with regard to the instrumentation of the spine. As part of the inital application, we conducted an international survey of over 40 experienced scoliosis surgeons from 15 countries in the first of three work packages (WP). This enabled us to document the different surgical strategies depending on the Lenke type of scoliosis. In the second WP, three extensive in-vitro studies were carried out on a total of six human thoracolumbar spines with thoracic cage to investigate the influence of the surgical resection steps and instrumentation strategies from WP-1. The results indicate for instance possible clinical complications, such as degeneration of the adjacent segments, and could explain the associated proximal junctional kyphosis. In WP-3, patient-specific finite element models were created to investigate the effects of resection steps and surgical strategies. However, in order to validate and assess the validity of simulated instrumentation strategies, extensive postoperative clinical data has been lacking. The aim of this follow-up application is to complete the study with regard to the postoperative follow-up. We will evaluate pre- and postoperative radiographs, as well as long-term results of up to 250 AIS patients over a period of up 36 years and analyze the patient-specific biomechanics. Our driving hypothesis is that the postoperative long-term outcome can be better predicted by taking biomechanics into account, which can improve the clinical long-term outcome of the patient. There are still significant clinically and biomechanically relevant questions in the literature at this point. One of these concerns the relationship between spinal parameters pre- and postoperatively and how spinal parameters change over time. This information could help surgeons to plan the operation more precisely and determine which spinal parameters need to be corrected and how in order to achieve the best possible long-term result. To complete the project, we are adding two new work packages (WP) to the research project. In the new WP-4, the long-term clinical results of up to 250 AIS patients will be analyzed and evaluated. In WP-5, finite element models will be created for all patients, the biomechanics of the instrumentation will be investigated, as well as try to develop a model to predict the long-term clinical results using the patient-specific FE models.

• DFG Programme: Research Grants