34.spinal fracture_lux Flashcards
site most often affected with traumatic injury to spinal cord
T3-L3 most commonfollowed by L4-L7
percentage of concurrent injuries present in pineal fracture patients
45-83% have concurrent injuryFULL ORTHO, NEURO, PEthoracic, abdominal imagingconcurrent fractures/ortho dz
T/Fdogs weight < 15 kg may be more predisposed to multiple spinal fractures when compared to larger dogs
TRUE
what is the most important prognostic factor for recovery following spinal cord injury
presence of nociception12% with traumatic TL injury and lack deep pain regained the ability to ambulate80-90% with pain perception can achieve good outcomes
T/Fradiography appears to be particularly poor at detecting fractures in the middle and dorsal vertebral components
TRUE
T/Fdegree of dislocation/axial deviation of the spinal column on radiographs has been negatively associated with outcome
TRUEdegree of dislocation/axial deviation of the spinal column on radiographs has been negatively associated with outcome
three compartment model for spinal stability
- 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
T/Fthe intervertebral disc is the single most important contributor to rotational stability of the TL vertebral motion unit
TRUEthe intervertebral disc is the single most important contributor to rotational stability of the TL vertebral motion unit (also significantly contributes to lateral bending)
vertebral body stabilizing force
acts as buttressstabilizes dorsoventral bendingmost fx of vertebral body are very unstable
methods of repair of TL spine
–pins + PMMA–locking plates (SOP–accepts std screws, LCP)–ESF***–vertebral body plating–tension band stabilization–spinous process plating
ways to increase strength of repair with pins and PMMA
–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)
pin insertion angle for thoracic vertebrae
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
pin insertion angle for lumbar vertebrae
30-60 degentry point: btwn the base of transverse process and base of accessory process
T/Fin dogs, failure to purchase the ventral vertebral body cortex may significantly reduce pin pull out strength as well as break out strength
TRUEcaution: right azygous vein, aorta, pleura and lung (pneumothorax, hemorrhage)–especially for thoracic vertebra
what vein anastomoses with the internal vertebral sinus
basivertebral veinfig 34-8
compare the bending strength btwn3.5 mm SOP3.5 mm LC-DCP3.5 mm LCP3.5 mm broad LC-DCP
3.5 mm SOP bending strength»_space; LC-DCP ,LCP3.5 mm SOP bending strength «_space;3.5 mm broad LC-DCP
spinous process plating and types of plates used
Lubra (plastic plates)Auburn (bilateral metal)connect with nuts and bolts passed btwn spinous process (Lubra) or through spinous process (Auburn) plates
Spinal stapling
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
cervical fracture mortality
36%
difference in anatomy for pin insertion to repair cervical fx/lux
ventral approachpedicles are narrowaim in a lateral direction from sagittal plane20-35 degrees–>34.2-3.5 degrees
CT study evaluating pin penetration in cervical spine with pin angles of 30, 35, and 40 degrees respectively
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
average insertion angles for lumbar pin insertion to repair fx/lux
dorsal approachwide pedicles20 degrees transverse, 29 degrees sagittally
