en Orthopedic Surgery Orthopedic Surgery Original Research Original Research <p> <strong> Abstract </strong></p><p> <strong> Background: </strong>The purpose of this study was to evaluate the significance of the Q </p><p>  angle with respect to the patella position. We assess the correlation between the Q angles (calculated by clinical exam) in different positions and CT indices (with more </p><p>  impression on TTTG). </p><p> <strong> Method: </strong>Atotal number of 68 knee joints of 50 cases entered the study. Clinical </p><p>  examination was used to measure Q angle (in 3 positions of sitting, standing and </p><p>  supine). CT scan performed in 2 axial view of proximal tibia, and distal femor for </p><p>  measurement of Tibial tuberosity-trochlear groove distance (TTTG) and other CT </p><p>  indices. Correlation between main variables calculated.and analysed with spss. </p><p> <strong> Results: </strong>Supine Q angle were strongly correlated with standing Q angles and </p><p>  moderately with sitting Q angle. Sitting Q angle was moderately correlated with </p><p>  supine and standing Q angle and weakly with PTA. we found no other significant correlation between Q angle and CT indexes. </p><p> <strong> Discussion: </strong>Our findings suggest that Q angle is not a valuable index for predicting </p><p>  the presence of patelofemoral malalignment. </p><p>  </p> Q angle, TTTG. CT scan, patellofemoral malalignment, anterior knee pain 189 199 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1-83&slc_lang=en&sid=1 Abbas Madani 20031947532846001874 20031947532846001874 No Iran University of Medical Sciences and Health Services .Tehran, Iran Alireza Parsaii Sadr 20031947532846001875 20031947532846001875 No Iran University of Medical Sciences and Health Services. Tehran, Iran Ali Yeganeh yeganeh471@yahoo.com 20031947532846001876 20031947532846001876 Yes Iran University of Medical Sciences and Health Services.Tehran, Iran. Gholamreza Shahoseini 20031947532846001877 20031947532846001877 No Iran University of Medical Sciences and Health Services .Tehran, Iran