Navigated femoral nailing including non invasive registration of the contralateral intact femur- first clinical applications

摘要

Introduction: Restoration of anatomic lower extremity ante version (AV) is an essential element of the treatment of femoral shaft fractures. Previous studies have demonstrated the incidence of malrotation using standard techniques after intramedullary nailing of the femur to be high. Clinically significant and symptomatic malrotation, greater than 15? occurs in as many as 28% of patients.While intraoperative assessment and reconstruction of the AV angle remains crucial, conventional measurement techniques do not offer sufficient comparison of the intact contralateral femur as a reference. Recently developed computer navigation modules enable intraoperative fracture reduction and navigated measurement of the AV angle, based on fluorscopic imaging with a defined registration process. Anteversional measurement of the femur using fluoroscopy-based navigation requires intraoperative availability of a standard anterior-posterior (AP) and lateral fluoroscopy views of the femoral neck region, the fracture site and the posterior femoral condyles. Our report describes the first 6 clinical cases of a navigated AV measurment in our clinic using the non invasive femoral AV determination of the contralateral healthy femur.