mechanism
Background
Epidemiology
National Spinal Cord Injury Statistical Center (2021) Facts and figures at a glance
- road traffic accident 40%
- falls 30%
- sports 10%
Chen et al Arch Phys Med Rehab 2016
- 80% male
- cervical (60%), thoracic (30%), lumbar (10%)
Vertical Shear
Definition
Unstable injuries
Complete disruption of both the anterior and posterior ring
5 - 20% of pelvic fractures
Mechanism
Axial load
Motor vehicle accident
Fall from height
Pathology
Anterior ring
Internal snapping hip
Cause
Movement of iliopsoas tendon over femoral head / iliofemoral ridge / iliofemoral ligament
Cuboid Fractures
Types
1. Capsular avulsions
2. Body / Nutcracker fracture
Nutcracker fracture
Epidemiology
- rare
Mechanism
- forced eversion / abduction of forefoot
- cuboid crushed between 4th and 5th MT and calaneum
Pathology
- displaced cuboid fracture with subluxation of tarsus
Hoffa fracture
Definition
Coronal plane fracture of distal femoral condyle
- intra-articular
- often only attachment is posterior capsule
Epidemiology
Rare
Mechanism
Usually a severe valgus trauma
Xray
Central Cord Syndrome
Epidemiology
Most common pattern cord injury
Hyper-extension injury in middle aged man with osteoarthritic spine
Usually C3/4 and C4/5
Mechanism
Most common type / in older patient with pre-existing spondylosis / OPLL
- hyperextension injury
- compression of the cord
- anteriorly by osteophytes
- posteriorly by infolded ligamentum flavum
Facet Joint Dislocation
Definition
Facet joint dislocations secondary flexion distraction injury
Epidemiology
10%
Stages
1. Unifacet subluxation - interspinous process widening
2. Unifacet dislocation - 25% anterolisthesis
3. Bifacet dislocation - 50% anterolisthesis
4. Complete vertebral translation - 100% anterolisthesis
Unilateral Facet Joint Dislocation
DIC
Definition
Disseminated Intravascular Coagulation
Pathology
Results from excessive activation of either extrinsic or intrinsic coagulation pathway
- multiple small clots
- consumptive coagulopathy
1. Excessive Extrinsic Activation
Secondary to extensive cellular destruction
- thromboplastins +++ released into circulation
Sacral Fractures
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