Determination of Range of Quadriceps Angle by Computed Tomography

Abstract

Introduction: The Quadriceps angle (Q angle) has come to be accepted as an important factor in assessing knee joint function. Various conditions can affect the Q angle such as increased pelvic width, sociological factors, wearing high heels and certain sports postures such as an increase in pronation can lead to increase in Q angle. Therefore, measurement of Q angle is important in the field of Orthopaedics and sports medicine. Aim: To determine the range of Q angle in right and left lower limbs and among genders and the association of Q angle with Tibial Tuberosity–Trochlear Groove (TT-TG) distance, lateralization of pelvis femur length, weight, height, body mass index and waist to hip ratio. Materials and Methods: A total of 70 subjects were selected from patients who have undergone lower limb angiography in Computed Tomography (CT). The sample size was then categorised into 35 males and 35 females. Both legs of the subject were kept extended and in relaxed position. The images were then reconstructed into volume rendering (3D) and the Q angle, femur length and lateralization of pelvis were measured on volume rendering and TT-TG distance was measured on 2-dimensional axial images. The data were statistically analysed using descriptive statistics where mean, standard deviation, and range was used to report the data. ‘Multiple Logistic Regression’ test was used to analyse the association of Q angle with various factors. Results: The mean Q angle in right leg was 11.76±4° and in left leg was14.76±6.45°. The mean of Q angle in right leg of male was 10.4±3.62°, and in females, it was 13.11±4.25° whereas the mean of Q angle in left leg of male was 12.17±4.59° and in females, it was 17.34±7.05°. The association of Q angle with TT-TG distance, lateralization of pelvis femur length, weight, height, body mass index and waist to hip ratio showed no significant association. Conclusion: The range of the Q angle varies in both legs among gender. Though there was no significant association between Q angle and femur length, the major factor contributing to the varying Q angle was femur length compared to other parameters. Therefore, Q angle increases with increases in femur length and the left Q angle is more than that of right Q angle.

Keywords

• hip ratio
• three dimensional imaging
• tibial tuberosity
• trochlear groove