leg length discrepancy

Leg Length Discrepancy

Samedy Srors, CPO, P&O Lecturer

Real different in skeletal length

Measured from ASIS to MM

True Leg Length Discrepancy

Apparent Leg Length Discrepancy

Different in appearance of the legs, whereby one leg looks longer or shorter than another.

Measured from Umbilicus to MM

No fixed deformities of the hip, knee and spine

Patient lies supine.

Pelvis level and legs in line with trunk

Right SideT = 85 cmA = 90 cm

Left SideT = 82 cmA = 87 cm

Difference

T = 85 cm - 82 cm = 3 cm

A = 90 cm - 87 cm = 3 cm

•The pelvis tilts to short side, and •The spine must curve to compensate.

When sitting, curved spine

disappears!

3cm block under neath left leg

Level pelvis

Straight spine

Patient lies supine.

If no hip contractor, easy to get legs in line with body.

Pelvis remains tilted and spine curved.

Right SideT = 85 cmA = 90 cm

Right SideT = 82 cmA = 85 cm

Difference

T = 85 cm - 82 cm = 3 cm

A = 90 cm - 85 cm = 5 cm

Patient in standing.

Spine deviating to short leg

Scoliosis not allow compensation.

Difference

T = 85 cm - 82 cm = 3 cm

A = 90 cm - 85 cm = 5 cm

Patient cannot stand

this way!

3 cm block raised

Pelvis level

Trunk still deviates to short side.

Difference

T = 85 cm - 82 cm = 3 cm

A = 90 cm - 85 cm = 5 cm

Patient may be

uncomfortable or not

able to stand this way!

5 cm raised block

Trunk upright

Pelvis not level

Spine not straight

Difference

T = 85 cm - 82 cm = 3 cm

A = 90 cm - 85 cm = 5 cm

Patient stands

comfortably

Patient lies supine.

Leg is slightly abducted.

Straight spine

Patient lies supine.

Legs in line with body but spine curves.

Difference

T = 85 cm - 82 cm = 3 cm

A = 90 cm - 88 cm = 2 cm

3 cm raised

Straight spine

Pelvis level

But leg abducted

Difference

T = 85 cm - 82 cm = 3 cm

A = 90 cm - 88 cm = 2 cm

3 cm raised block

Legs in line with body, but tilt pelvis

Unaffected leg appears short

Build-ups is too big

Difference

T = 85 cm - 82 cm = 3 cm

A = 90 cm - 88 cm = 2 cm

2 cm raised block

Legs in line with body but pelvis tilts

Curved spine

Difference

T = 85 cm - 82 cm = 3 cm

A = 90 cm - 88 cm = 2 cm

Patient can stand

comfortably with both feet on the

ground

Lie the patient in supine.

Get the legs in line with body.

Try to get the pelvis level, but do not allow leg abducted or adducted.

Measure from umbilicus to bottom of the heel.

This produced apparent leg length discrepancy

What shall we do?

USE THIS MEASUREMENT FOR BUILD UP!

Patient lying supine

Leg slightly adducted.

Leg in line with body

Tilted pelvis

Curved spine

Right SideT = 85 cmA = 90 cm

Left SideT = 82 cmA = 85 cm

Difference

T = 85 cm - 82 cm = 3 cm

A = 90 cm - 85 cm = 5 cm

3 cm raised block

Straight spine and level pelvis

Slightly adducted leg

Difference

T = 85 cm - 82 cm = 3 cm

A = 90 cm - 85 cm = 5 cm

Patient cannot stand

this way!

Legs in line with body

Tilted pelvis

Curved spine

Build-up not enough

Difference

T = 85 cm - 82 cm = 3 cm

A = 90 cm - 85 cm = 5 cm

5 cm raised block

Leg in line with body

Tilted pelvis

Curved spine

Both feet on the ground

Difference

T = 85 cm - 82 cm = 3 cm

A = 90 cm - 85 cm = 5 cm

Patient can stand

comfortably with both feet on the

ground

Lie the patient in supine.

Get the legs in line with body.

Try to get the pelvis level, but do not allow leg abducted or adducted.

Measure from umbilicus to bottom of the heel.

This produced apparent leg length discrepancy

What shall we do?

USE THIS MEASUREMENT FOR BUILD UP!

Patient lying supine

One leg is abducted

Legs in line with body

Curved spine

Tilted pelvis

Right SideT = 85 cmA = 90 cm

Left SideT = 84 cmA = 92 cm

DifferenceT = 85 cm - 84 cm = 1 cm (left side is

short)A = 92 cm - 90 cm = 2 cm (left side is

long)

2 cm raised block (unaffected side)

Leg in line with body

Tilted pelvis

Curved spine

DifferenceT = 85 cm - 84 cm = 1 cm (left side is

short)A = 92 cm - 90 cm = 2 cm (left side is

long)

True LLD is real shortening of the skeleton.

Apparent LLD is how a patient actually stands.

Buildups should always be done following apparent LLD.

Using pelvis to measure leg length in standing can only be done if no fixed contracture or scoliosis exist.

Q & A