Prothesenwechsel distales Femur

Abstract With the increasing number of primary knee prosthesis implantations and the demographic changes, the number of periprosthetic fractures is also rising. Their treatment often proves to be challenging.Standard diagnostics consist of conventional X-rays with a calibration object. For prosthesis planning, the adjacent joints should also be image, x-rays of the contralateral side can be helpful. The imaging is usually supplemented by a CT scan to better assess the prosthesis fit and bone quality. Based on the imaging, the fracture can be classified according to Rorabeck or UCS, although the prosthesis fit cannot always be definitively determined. The prosthesis model and implantation date should be identified, ideally through the implant pass and surgical report.In surgical treatment, osteosynthesis aiming to preserve the prosthesis should be attempted, if technically feasible. Indications for a prosthesis exchange include loose prosthesis, a well-fixed prosthesis with poor or reduced bone quality that does not provide sufficient fixation for osteosynthesis, fractures with a high risk of pseudarthrosis, ligamentally unstable prosthesis, or periprosthetic fractures in geriatric patients, when an osteosynthesis doesn’t allow primary full weight bearing. However, due to limited data, no general recommendation or algorithm can be provided; decisions must be made on a case-by-case basis.Until definitive treatment, temporary immobilization with an external fixator may be necessary. Technically, a prosthesis exchange is a complex operation consisting of four main steps: patient in dorsal decubitus and medial arthrotomy, resection of the distal femur and preparation of the femoral canal, removal of the tibial component and tibial preparation, followed by determination of the prosthetic components and implantation.The particular challenge lies in correctly restoring the joint line and especially the femoral rotation.The complication rates and outcomes do not differ significantly from osteosynthesis according to several current reviews and meta-analyses.