Definition
- Congenital posteromedial bowing of the tibia and fibula
- Apex posteromedial, usually in the distal third
Clinical Features
- Calcaneovalgus foot with marked ankle dorsiflexion at birth
- Foot may rest against the anterior tibia
- Leg shortening evident on examination
- Not associated with neurofibromatosis
- Not predisposed to fracture or pseudarthrosis
- Calf muscles may be smaller on the affected side
Investigations
- Radiographs confirm the bowing and exclude other causes
- Serial scanograms or long leg films to monitor leg length
- Predict final discrepancy with growth charts or multiplier method
Differential Diagnosis
- Anterolateral bowing, associated with NF1 and congenital pseudarthrosis
- Anteromedial bowing, associated with fibular hemimelia
- Isolated calcaneovalgus foot without tibial bowing
Management
- Angular deformity corrects spontaneously, mostly in the first years of life
- Stretching for the calcaneovalgus foot
- Follow leg length until skeletal maturity
- Contralateral epiphysiodesis for moderate predicted discrepancy
- Tibial lengthening for larger discrepancy
- Angular osteotomy rarely needed for residual deformity
- Correct residual deformity at the time of lengthening if present
Prognosis
- Angulation resolves, leg length discrepancy persists
- Discrepancy at maturity is about 3 to 4 cm
- Greater initial bowing predicts greater discrepancy
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.