Mechanism
Vertebral bodies grow axially by endochondral ossification.
- radiation can inhibit this
Incidence
Spinal deformity is the most common side effect of abdominal irradiation
- Children irradiated at age 2 years or younger are most affected
Study of Wilm's tumour patients
- 7 x incidence scoliosis
Reported 10 to 100%
May get LLD
- femoral head
- ilac crests
Effects
Irradiation of the entire vertebra
- produces a symmetric hypoplastic vertebral body
- without significant malalignment
Irradiation of a portion of the body
- causes segmental loss of growth
- resultant scoliotic deformities
Soft-tissue fibrosis and contracture may be a cause of spinal curvature
Management
Milwaukee brace treatment
- indicated in a young child with a flexible curve caused by irradiation
Early posterior fusion and instrumentation is recommended
- Repeat bone grafting may be necessary
- need longer duration of postoperative immobilization
- several authors recommend a duration of up to 1 year