Mechanism
High energy usually
Occasionally osteoporotic fracture in elderly
Other
- radiotherapy
- fatigue fracture in children
Don't present as isolated injury
- associated with pelvic fracture
Denis Classification
Zone 1
- lateral to foramina
- neurologic injury from proximal migration & compression of L5 nerve root
Zone 2
- through foramina
- 28% incidence neurology
- usually S1 compression
Zone 3
- medial to foramina / central canal
- 57% incidence neurology
- loss sphincter tone & cauda eqina
Xray
Zone 1 sacral fracture
Zone 3 sacral fracture
Management
Zone 1
Stable
- symptomatic treatment only
Zone 2 & 3
Non weight bearing 8 weeks