Hip Distraction Index

The Hip Distraction Index measurement is used for calculating the distraction or deviation index of the Caput Femoris from either the left or right Acetabularis. This measurement requires a radiology image of the patient’s pelvis. Select the Hip Distraction Index measurement from the Advanced Measurement menu and assign the left mouse button to it.

Start the measurement by marking the three points on the articular surface of the Acetabularis.

Designate the left or right Acetabularis bone and mark the three points along the articular surface. A circle will be automatically constructed based on the three placed points.

The image below represents a typical placement of the three points on the articular surface of the Acetabularis.

Mark the three points on the articular surface of the ipsilateral Caput Femoris to calculate the distraction index.

Mark the three points along the articular surface of the ipsilateral Caput Femoris. Regardless of the order, make sure to mark the most cranial point, the most caudal point and the midpoint of the femoral head. A circle will be automatically constructed based on the three placed points.

The Hip Distraction Index will be automatically calculated as the ratio between the distance between the two origos and the radius of the circle along the articular surface of the Caput Femoris.

The image below represents a typical placement of the three points on the articular surface of the Caput Femoris.

Modify the position of each point marked on the Acetabularis or the Caput Femoris to automatically recalculate the Hip Distraction Index.