The hip head-neck ratio, more specifically known as the femoral head-neck ratio, is a measurement used to compare the size of the rounded top part of the thigh bone (the femoral head) to the narrower section just below it (the femoral neck).
Understanding the Femoral Head-Neck Ratio
This ratio is a key anatomical measurement related to the hip joint. It helps describe the shape relationship between the spherical femoral head and the cylindrical femoral neck.
Calculation of the Ratio
Based on available information, the femoral head-neck ratio is precisely defined and calculated as follows:
- Femoral head-neck ratio = A รท B
Where:
- A represents the largest possible diameter of the femoral head.
- B represents the largest possible diameter of the femoral neck.
Essentially, you divide the measurement of the widest part of the head by the measurement of the widest part of the neck.
What the Ratio Indicates
The resulting number provides insight into the relative proportions of the head and neck.
- A smaller head-neck ratio indicates that the femoral neck is relatively wide compared to the femoral head. As stated in the reference, "The wider the neck the smaller the head-neck ratio."
- A larger head-neck ratio indicates that the neck is relatively narrow compared to the head.
This anatomical proportion is important because the shape of the femoral head and neck can affect the range of motion in the hip joint and may be related to certain hip conditions.
