LLD Management

Goals

 

1. Equal leg lengths

- goal is mild to moderate isolated discrepancy

 

2. Unequal leg lengths

- goal with paralysis / equinus foot

- aim 1-2 cm short for clearance

 

3. Level Pelvis

- should use blocks to estimate functional correction

 

4. Vertical LS Spine

- vertical spine more important than level pelvis

 

5. Equalisation with Prosthesis

- goal with excessive LLD

- usually femur < 1/2 normal length or LLD >15cm

 

Principles

 

Correct coexisting deformity first

- can decrease discrepancy

 

May require correction of other problems first

- release of contractures

- correct angular deformity

- correct spinal deformity

- excision of bony bridge

- completion of partial arrest

 

Treatment guidelines by projected discrepancy

 

0 - 2 cm

- no treatment, heel raise

 

2- 6 cm

- shoe lift, epiphysiodesis

- maximum subtalar joint can take

 

6 - 15 cm 

- lengthening + epiphysiodesis

 

> 15 cm 

- amputation

 

Prosthesis

 

Shoe Lift / sole raise

 

Good treatment if 2-5 cm

- aim is to improve gait

 

Note

- > 5 cm ankle sprains

- joint unable to cope

- need patten boot (steel reinforcements of STJ)

 

Guidelines

- 0 - 1.5cm heel raise

- 1.5 - 5cm heel and sole raise

- 5 - 12cm patten and boot

- 12 - 20cm patten and AFO / prosthesis

- 20+cm prosthesis

 

Epiphysiodesis

 

Advantage

 

Often treatment of choice

- low morbidity

- accurate

- can shorten at level of deformity

 

Disadvantage

 

Operate on normal leg

- get loss of height & proportions

 

Indications

 

Anticipated LLD 2-6 cm

 

If > 6 cm LLD 

- excessive height loss

- knees at different level 

 

Phemister Technique

 

Create bony bridge

- medial & lateral approaches

- access window removed

- physis excised with curette

 

Percutaneous Technique 

 

Under II guidance

- percutaneous incision

- medial and lateral drilling into physis

- angle drill anterior and posterior

- entry points anterior, middle and posterior

- see white growth plate on drill

 

Complications

 

Continued longitudinal growth or angular deformity

- failure to eliminate growth plate

 

Femoral Shortening

 

Indications

 

Maximum 2 - 6 for reasons above

 

Consider if

- too old, insufficient growth remaining

- can't predict LLD and wait til maturity

 

Usually performed over a nail

 

Tibial Shortening

 

Easier 

Max 3cm

 

Growth Stimulation

 

Stimulate physis by hypervascularity 2° irritative

- insert vicryl into growth plate

- moderate success

 

Leg Lengthening

 

See Limb Lengthening