34.spinal fracture_lux

Question 1

site most often affected with traumatic injury to spinal cord

Answer 1

T3-L3 most commonfollowed by L4-L7

Question 2

percentage of concurrent injuries present in pineal fracture patients

Answer 2

45-83% have concurrent injuryFULL ORTHO, NEURO, PEthoracic, abdominal imagingconcurrent fractures/ortho dz

Question 3

T/Fdogs weight < 15 kg may be more predisposed to multiple spinal fractures when compared to larger dogs

Answer 3

TRUE

Question 4

what is the most important prognostic factor for recovery following spinal cord injury

Answer 4

presence of nociception12% with traumatic TL injury and lack deep pain regained the ability to ambulate80-90% with pain perception can achieve good outcomes

Question 5

T/Fradiography appears to be particularly poor at detecting fractures in the middle and dorsal vertebral components

Answer 5

TRUE

Question 6

T/Fdegree of dislocation/axial deviation of the spinal column on radiographs has been negatively associated with outcome

Answer 6

TRUEdegree of dislocation/axial deviation of the spinal column on radiographs has been negatively associated with outcome

Question 7

three compartment model for spinal stability

Answer 7

1. dorsal: spinous process, laminae, articular processes, pedicles, dorsal ligament complex (supraspinous, ligamentum flavum, interspinous, jointcapsule)2. middle: dorsal longitudinal ligament, dorsal annulus fibrosis, dorsal vertebral body3. ventral:remainder vertebral body, nucleus pulpous, ventral longitudinal ligamentif >1 compartment is compromised–consider unstable and warrants surgical interventionmiddle compartment is difficult to assess without advanced imaging

Question 8

T/Fthe intervertebral disc is the single most important contributor to rotational stability of the TL vertebral motion unit

Answer 8

TRUEthe intervertebral disc is the single most important contributor to rotational stability of the TL vertebral motion unit (also significantly contributes to lateral bending)

Question 9

vertebral body stabilizing force

Answer 9

acts as buttressstabilizes dorsoventral bendingmost fx of vertebral body are very unstable

Question 10

methods of repair of TL spine

Answer 10

–pins + PMMA–locking plates (SOP–accepts std screws, LCP)–ESF***–vertebral body plating–tension band stabilization–spinous process plating

Question 11

ways to increase strength of repair with pins and PMMA

Answer 11

–use of positive profile pins (resist pull out and hardened which increases bending stiffness)–increase pin size (area moment of inertia incr proportionally to radius to the fourth power)–max pin-bone interface (greater resistance to pull out)–incr # of pins (usually 4)

Question 12

pin insertion angle for thoracic vertebrae

Answer 12

30-60 degentry point: at the level of the accessory process or the tubercle of the ribdirected lateromedial, cranioventral cranial to fracturedirected lateromedial, caudoventral caudal to fracture

Question 13

pin insertion angle for lumbar vertebrae

Answer 13

30-60 degentry point: btwn the base of transverse process and base of accessory process

Question 14

T/Fin dogs, failure to purchase the ventral vertebral body cortex may significantly reduce pin pull out strength as well as break out strength

Answer 14

TRUEcaution: right azygous vein, aorta, pleura and lung (pneumothorax, hemorrhage)–especially for thoracic vertebra

Question 15

what vein anastomoses with the internal vertebral sinus

Answer 15

basivertebral veinfig 34-8

Question 16

compare the bending strength btwn3.5 mm SOP3.5 mm LC-DCP3.5 mm LCP3.5 mm broad LC-DCP

Answer 16

3.5 mm SOP bending strength&raquo_space; LC-DCP ,LCP3.5 mm SOP bending strength &laquo_space;3.5 mm broad LC-DCP

Question 17

spinous process plating and types of plates used

Answer 17

Lubra (plastic plates)Auburn (bilateral metal)connect with nuts and bolts passed btwn spinous process (Lubra) or through spinous process (Auburn) plates

Question 18

Spinal stapling

Answer 18

steel pins placed transversely through holes created at the base of spinous process cranial and caudal to fx/luxpins are bent 90 deg to lie along dorsal lamina of affected vertebraecan incorporate orthopedic wire

Question 19

cervical fracture mortality

Answer 19

36%

Question 20

difference in anatomy for pin insertion to repair cervical fx/lux

Answer 20

ventral approachpedicles are narrowaim in a lateral direction from sagittal plane20-35 degrees–>34.2-3.5 degrees

Question 21

CT study evaluating pin penetration in cervical spine with pin angles of 30, 35, and 40 degrees respectively

Answer 21

30 degrees 58% penetrate35 degrees 41% penetrate40 degrees 33% penetratein general, as pin insertion angles incr, the risk of penetration decreases in the canal, penetration increases in transverse foramen

Question 22

average insertion angles for lumbar pin insertion to repair fx/lux

Answer 22

dorsal approachwide pedicles20 degrees transverse, 29 degrees sagittally