Return to site

Q-Angle of the Knee

· Healthcare,knee,Medical Education,Orthopaedics,Orthopedic Surgery

A well-functioning knee joint is important for mobility. The knee must be able to support the weight of the body during activities such as walking or running. The Q-angle refers to the quadriceps angle. The Q-angle is the angle between the quadriceps tendon and the patellar tendon. An increased Q-angle is a risk factor for patellar subluxation. In order to measure the Q-angle, you will first find the patella and its border, the center of the patella, and the tibial tubercle. Then, the physician will draw a line from the ASIS to the center of the patella and a second line from the tibial tubercle through the center of the patella. The Q-angle (quadriceps angle) is formed in the frontal plane by the two line segments. The Q-angle is the angle formed by a line drawn from the Anterior Superior Iliac Spine (ASIS) to the center of the patella. A second line is drawn from the center of the patella to the tibial tubercle. The angle formed by the two lines is called the Q-angle. The normal Q-angle is variable. The normal Q-angle for males is usually 14 degrees and 17 degrees in females. A wider pelvis and an increased Q-angle in females is linked to knee pain, patellofemoral pain, and ACL injury. The alignment of the patellofemoral joint is effected by the patellar tendon length and the Q-angle. It is best to measure the Q-angle with the knee in extension as well as flexion. Larger Q-angle plus a strong quadriceps contraction can dislocate the patella.

The Q-angle is increased by:

  • Genu valgum

  • External tibial torsion

  • Femoral anteversion

  • Lateral positioned tibial tuberosity

  • Tight lateral retinaculum

A CT scan study of the patellofemoral articulation is found to be very helpful.

All Posts

Almost done…

We just sent you an email. Please click the link in the email to confirm your subscription!

OKSubscriptions powered by Strikingly