Quadrilateral Modification Quick Reference

Question 1

The quadrilateral socket AP dimension is found by taking the measured anatomical AP and

Answer 1

Subtracting 1/2”

Question 2

In a quadrilateral socket, the ML dimension is calculated by taking the circumference at the ischial level and

Answer 2

Dividing it by 3 and subtracting 1/4”

Question 3

The medial wall in a quadrilateral socket is:

Answer 3

• parallel to the line of progression
• perpendicular to the transverse plane for the first four inches distal to the ischial level
• not perpendicular to the posterior wall

Question 4

The posterior wall in a quadrilateral socket is:

Answer 4

• not perpendicular to the medial wall
• not parallel to the posterior brim
• not perpendicular to the line of progression

Question 5

The ischium should sit on the posterior brim 1/2” posterior and 1” lateral to the medial wall.

Answer 5

True