Nuclear Cardiology in the COVID-19 pandemic La Cardiología Nuclear en la pandemia COVID-19

ABSTRACT

Introduction Total knee replacement is one of the most frequent surgical procedures in orthopaedic surgery, the alignment of the lower extremity in the coronal plane should be taken into account for preoperative planning and should be restored during surgery. This study evaluates the diagnostic performance of plain radiography compared to orthoradiography in determining limb alignment. Methods Preoperative and postoperative radiographs and orthoradiographs of 132 knees were analysed sequentially, coronal plane measurements of the two studies were performed, and their sensitivity and specificity were determined on plain radiography. Results The femorotibial angle on pre- or postoperative plain radiograph is the highest performing with sensitivity ranging from 51.81% to 86.96% and specificity 33.33% to 50% when compared to the mechanical axis and increasing as abnormal coronal plane measurements are combined. With respect to the anatomical femorotibial angle on orthoradiography the femorotibial angle on pre- or postoperative plain radiograph also has the highest yield with sensitivity between 36.84% to 88% and specificity between 63.64% to 100% respectively. Conclusions The overall trend in relation to the performance of radiography shows higher sensitivity in preoperative measurements and higher specificity in postoperative measurements evidencing to be a useful test in the determination of mechanical axis deviation mainly when the combination of two (α angle + femorotibial angle) or more abnormal or normal measurements respectively are considered as positive or negative test.