Definition
- Kyphosis, scoliosis or both
- Develops after spinal radiotherapy in childhood
Aetiology
- Abdominal or retroperitoneal irradiation for Wilms tumour and neuroblastoma
- Craniospinal irradiation for medulloblastoma
- Mantle field irradiation for lymphoma
- Risk rises with younger age, higher dose and asymmetric fields
- Symmetric whole vertebral body fields and lower doses have reduced incidence and severity
Pathology
- Radiation damages endplate growth zone chondrocytes, arresting vertebral growth
- Asymmetric fields produce scoliosis concave towards the irradiated side
- Anterior growth arrest produces kyphosis, often thoracolumbar
- Soft tissue fibrosis and contracture add to deformity
Clinical Features
- Deformity appears years after treatment and progresses in the adolescent growth spurt
- Ipsilateral hypoplasia of the iliac wing, ribs and soft tissues
- Short trunk
- Abdominal scars and stomas
- Neurological deficit uncommon, possible with severe kyphosis
Investigations
- Standing radiographs show vertebral flattening, endplate irregularity and bone within bone appearance
- MRI and CT for surgical planning
- New pain or rapid change requires exclusion of tumour recurrence and radiation-induced osteosarcoma, osteochondroma or sarcoma
Management
- Clinical and radiographic surveillance until skeletal maturity
- Observe mild deformity
- Bracing poorly tolerated with limited effect, partly due to poor skin
- Progressive deformity needs anterior release and strut grafting with posterior instrumented fusion
- Extend fusion beyond irradiated levels into healthy bone
Complications
- High surgical complication rates
- Pseudarthrosis from poor bone quality and vascularity
- Wound breakdown and infection in irradiated skin
- Anterior approach hampered by previous surgical scarring and radiation fibrosis
- Vascularised fibula or rib graft may be needed for anterior support
- Plastic surgical soft tissue cover may be required
- Neurological injury when correcting a rigid kyphosis
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.