What degree angle does the neck of the femur form with its body/shaft?

What degree angle does the neck of the femur form with its body/shaft?

• A. 90°
• B. 120°
• C. 150°
• D. 180°

Answer: (B)

The neck of the femur typically forms an angle of approximately 120 degrees with the body or shaft of the femur. This angle is known as the femoral neck-shaft angle, and it plays a crucial role in the biomechanics of the hip joint.

An angle of 120 degrees provides a balance between stability and mobility, facilitating a greater range of motion at the hip joint while still maintaining structural integrity. This configuration helps to distribute forces during activities such as walking and running.

In contrast, other angles like 90 degrees would create a much more rigid joint, compromising mobility, while 150 degrees would correspond to a greater degree of inclination, which might also lead to instability. An angle of 180 degrees suggests that the neck and shaft are aligned in a straight line, which does not occur in the natural anatomical structure of the femur. Thus, the choice of 120 degrees accurately reflects the typical anatomical configuration of the femur's neck in relation to its shaft.