Irradiation Induced

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