Leg length discrepancy

1. How is a true leg length discrepancy assessed?
2. How do you measure for discrepancy in the femur?
3. How do you measure an apparent leg length discrepancy?
4. What are the causes of an apparent leg length discrepancy?

Answers:
1. Measure from ASIS to the medial malleoli.
2. Patient lies supine and flexes knees to 90 degrees, assess if one knee is higher than the other.
3. Measure from umbilicus to medial malleoli.
4. Pelvic obliquities or flexion/adduction deformities of the hip.