Detection of mechanical reactions during the explantation of hip joint endoprostheses (in vitro)
Motivation
The number of hip and knee prosthesis operations is constantly increasing. In combination with demographic developments and the frequent periprosthetic complications, this means that the need for revision surgery is becoming more and more frequent. The problem is that while the implantation of endoprostheses is more or less standardized, the explantation is a non-standardized task due to the unpredictability of the appropriate loosening method, which can only be performed by experienced surgeons. Often it is not decided until after access to the surgical site which tools and methods may be used to loosen the prosthesis. The time required to loosen the prosthesis is hardly predictable and depends mainly on the skills of the surgeon. The motivation of the working group is to ensure that the explantation of a loosened hip joint endoprosthesis is gentle on the patient and efficient for the person performing the operation. The first step is to obtain objective data on the mechanisms of explantation, which requires new measurement methods. Standard force plates - basic equipment in biomechanical laboratories - can be used as the technical basis for studies on revision procedures. Based on this, the Biomechatronics Group, in cooperation with the University Hospital Bonn, has developed a corresponding test rig, which makes it possible to measure and record forces and moments during explantation (in vitro).
Approach
It is planned to collect data on the forces and moments acting during the hip stem impact and to identify specific impact patterns that lead to success. The objects of the planned in vitro study are femora of sheep with implanted endoprostheses, which are already available from other studies. No animals will be operated or killed for this study.
Student work
Eichelberg, K.: Conception of a module to reproduce the storage reactions during the explantation of hip joint endoprostheses (Master thesis)
Kerbl, J.: Geometrical factors influencing the stability of the femur-joint shaft pairing of a hip joint endoprosthesis (Master thesis)
Kneip, T.: Alternative anchorage options for hip joint endoprostheses (Master thesis)
Schomburg, K.: Utilization of natural frequencies of endoprostheses and surgical tools to optimize the implantation and explantation of endoprostheses (Master thesis)
Ehrhardt, M.: Design and realization of a device for recording mechanical reactions during explantation of hip joint endoprostheses (ex vivo setup); master thesis
Wagner, P. : Methods of preparation of measured data collected during the explantation of hip joint endoprostheses (ex vivo setup); master thesis
Rohrbach, A.: Design of a 6DOF force sensor for recording mechanical reactions during explantation of hip joint endoprostheses (ex vivo setup); bachelor thesis
