Incidence
20 - 30 % LLD
Features
Intact femur radiographically +
- foot at contralateral mid-tibial level
- cruciate ligament deficiency
- coxa vara
- hypoplastic lateral femoral condyle with resulting valgus knee
- sclerosed lateral cortex
Amount of femoral shortening is variable patient to patient
Shapiro Type 1 growth disturbance
- i.e. LLD increases with time
Examination
LLD
Genu valgum
Fat thigh
High riding patella
Foot held externally rotated
X-ray
Hypoplastic femur
Coxa vara
Lateral sclerosis
2 groups
Simple femur hypoplasia
Femoral hypoplasia with coxa vara
Management
Align early then lengthen in primary school years
1. Realignment may involve
Coxa vara
- proximal femoral valgising osteotomy
Valgus knee
- Supracondylar osteotomy / guided growth 8 plates
2. Lengthen tibia and femur
Caution for dislocated knee
- ACL deficient
3. Contralateral epiphysiodesis