Leg Length Discrepancy LLD

• proximal femur grows 2mm/yr
• distal femur grows 9mm/yr
• proximal tibia grows 6mm/yr
• distal tibia =grows 4mm/yr
• Mosely graph
• girls generally grow to age 14, boys=16
• distal femur accounts for 37% of total LE growth
• proximal tibia =28% of total LE growth
• LLD<3% not associated c compensatory walking mechanisms
• LLD>5% difficult to compensate(toe walking etc) for
• LLD xray
• scanogram=hip,knee,ankle
• orthoroentogram=3films tied together gives leg length and alignment
• Predictiors of LLD: (Paley D, JBJS 2000;82A:1432)

LLD Treatment

• shoe lift for <2.5cm
• epiphysiodesis for 2.5-4cm
• lengthening for >4cm
• prosthesis for 30% or more shortening

LLD Differential Diagnosis

• Fibular hemimelia
• PFFD
• hemihypertrophy(must U/S abdomin to r/u Wilm's tumor yearly to age 6-8)

LLD References

• Moseley CF, ICL 1989;38:325