Final answer:
The Q-angle refers to the angle between the femoral neck and the medial side of the femoral shaft. It affects the tracking and stability of the patella.
Step-by-step explanation:
The significance of the angle within the frontal plane between the femoral neck and the medial side of the femoral shaft is known as the Q-angle. The Q-angle is a measure of how far the femur is angled laterally away from vertical. It is normally 10-15 degrees, with females typically having a larger Q-angle due to their wider pelvis. The Q-angle affects the tracking and stability of the patella or kneecap, and a larger Q-angle in females can make them more vulnerable to developing patellofemoral syndrome.