Definition
Deficiency of bony elements on lateral side of lower limb
Characterized by
- partial or complete absence of fibular
- tibial bowing
- abnormal and unstable ankle joint
- missing lateral toes
- leg length discrepancy
Most common congenital deformity of long bones
Types
Terminal - abnormal foot
Intercalary - normal foot
Issues
Leg length discrepancy
- PFFD
- short femur
Anteromedial bowing tibia / pseudoarthrosis / tibial fracture
Foot
- small limb / foot
- absent lateral ray(s)
- lateral tarsal bones fused or absent
Knee
- cruciate deficiency
- hypoplastic LFC / valgus knee
Ankle
- equino-valgus / ball and socket
- tarsal coalition
Classification
Coventry
Type 1:
Short or partial proximal absence unilaterally
1A: Stable ankle joint ± ball & socket joint
1B: Unstable anklejoint / equinovalgus
Type 2: Complete absence unilaterally
- tibia short & bowed anteromedially, dimple at apex
- associated with lateral ray deformity & coalitions
Type 3: Bilateral
- severe
- associated with PFFD & upper limb deficiency
Management
Foot & ankle
Issue
Instability
- < 2 rays
- severe ankle instability
Management
Syme's amputation
Leg length discrepancy
www.boneschool.com/pediatrics/leg-length-discrepancy/management
Usually > 5 inches
Options
- < 2 cm heel lift / shoe raise
- 3-5 epiphysiodesis
- 6-10 limb lengthening
- 10-15 limb lengthening + epiphysiodesis
- > 16 amputate
3. Tibial bowing
Least important
- usually corrects