Principles of Spine Fractures

Anatomy

Spinal cord occupies 35% of canal at the level of the Atlas and 50% of the canal in the lower cervical region (C2-7) and the thoracolumbar spine

History

• Nature of incident 
• Neurological symptoms
• Change in LOC
• Head / pectoral girdle injury

Examination

Observe

• Head control
• Head injuries, pectoral girdle injuries
• Voluntary movement of all 4 limbs
• Priapism
• Any limitation of movement of the patient’s head to either side

Palpate

• Tenderness over head and back 
• Step in spines
• Local haematoma

Neurological exam

Sensory

C2	back of head
C3	front of neck
C4	lateral and inferior over clavicles down to 2nd interspace
C5 – T1	upper limb
T2	below nipple
T10	umbilicus
L1	groin
L2- S2	lower limb
S3- S5 + coccygeal roots	perianal/ saddle

• Once the sensory level is determined, examine distally for any evidence of sparing
• Sacral sparing indicates preservation of the lateral columns and recovery of lost muscle function is quite likely

Motor

• After sensory exam the diagnosis of a root lesion or cord lesion can be made and the completeness determined
• Examine sequential nerve roots

C4	patient breaths diapragmatically
C5/6	biceps
C5	deltoid
C6	ECRL/ECRB
C7/8	triceps
C7	EDC
C8	FDP/FDP
T1	intrinsics
L1/2	adductors
L3/4	knee extension
L5/1	knee flexion
L4	tibialis anterior
L5	EHL/ peronei
S1/2	ankle plantar flexion

• Inability of the patient to feel the finger in the rectum confirms a complete sensory lesion
• If sphincter doesn’t contract voluntarily about the finger and there are no other signs of voluntary motor power, complete motor paralysis is confirmed
• Bulbocavernosus reflex: a squeeze on the glans, a tap on the mons or a tug on the catheter stimulating the trigone of the bladder causes reflex contraction of the anal sphincter about the gloved finger
• If spinal shock is present a complete lesion cannot be diagnosed with certainty
• If the bulbocavernosus has not returned in 24 hours, its absence is due to complete lesion, as spinal shock resolves within 24 hours

Stability

In the 3 column model of spine, the middle column is critical to stability. Failure of middle column bony structures indicated by :

• Wide pedicles
• More than 25% loss of posterior body height
• Presence of fracture lines through posterior body cortex

Failure of middle column ligamentous structures indicated by :

• Interspinous or intervertebral angulation 11 degrees more than adjacent segment (Normal 2 – 4 degrees)
• Horizental translation more than 3.5 mm
• Intervertebral disc space separation more than 1.7 mm

Instability

3 directions

1. Flexion
   1. Distraction, e.g. bilateral facet dislocation. Treatment : posterior wiring
   2. Compression, e.g tear drop fracture with failure of posterior column in tension and failure of anterior column by fracture of anterosuperior vertebral body and middle column remaining intact
   3. Burst fracture, with failure of all 3 columns. Treatment : anterior stabilisation
2. Extension
   1. Treatment : SOMI . Fuse if late instability
3. Rotational
   1. Rotational ligament injuries lead to assymetric disruption of the facet complexes
   2. If combined with lateral compression, a fracture may accompany the ligamentous injury with tendency for continued displacement
   3. Treatment
      1. Unilateral facet dislocation : relocate, SOMI
      2. Unilateral facet dislocation with fracture of either facet or lateral mass : wire facet or lateral mass plating 

 Stable injuries

• Compression fracture of anterior body of less than 25% of body
• Anteroinferior avulsion fracture, where fragment width is less than 20% of body width

Unstable injuries

• Compression fracture more than 25% of body, indicative of PLL rupture
• Fractures through the vertebra 
  

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