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