Spine Approaches Flashcards
position for posterior approach to the lumbar spine
prone
shoulders forward flexed and abducted to unload brachial plexus
abdomen free to allow venous plexus drainage
pad ulner nerves at elbows
pad median nerves at wrists
head and neck neutral
no eye pressure
hips slightly flexed if decompressing, extended if fusing
knees flexed
pad peroneal nerves at knees
incision for posterior approach to the lumbar spine
ID appropriate spinous process with fluoro
midline incision from level above to level below
internervous plane for posterior approach to the lumbar spine
midline between erector spinae - so between the dorsal rami
superficial dissection for posterior approach to the lumbar spine
incise lumbodorsal fascia
detach paraspinal muscles subperiosteally as one unit
dissect down along lamina to facet joints
continue lateral to strip facet capsule medial (descending part) to lateral (ascending part) of facet joint
can go up and over the lateral part (ascending) facet joint to the TP
deep dissection for posterior approach to the lumbar spine
incise ligamentum flavum along superior edge of lamina
blunt dissection down lateral to dura to floor of spinal canal while retracting cord and nerve root medially
remove inferior aspect of lamina with rongeur
danger for posterior approach to the lumbar spine
1) segmental arteries between TPs near facet joints
2) dorsal rami between TPs near facet joints
3) ID nerve roots individually
4) venous plexi around nerves and on floor of canal
5) iliac vessels anterior to vertebral body if you puncture annulus fibrosis
how is the minimal access posterior approach to the lumbar spine different? i.e. what are the technical difficulties?
first of all, the approach is the same regarding superficial and deep dissection. However:
1) meticulous positioning key - too medial and spinous processes are in the way; too angled and you can’t target the microscope
2) need fluoro to be exact positioning
3) hemostasis very important
which muscles might you encounter during posterior approach to the lumbar spine?
superficial = lat. dorsi.
deep = sacrospinalis, multifidus and rotatores
position for transperitoneal approach to the lumbar spine
supine
abdomen and iliac crest exposed
catheterize to keep bladder empty
incision for transperitoneal approach to the lumbar spine
just below umbilicus to just above symphysis vertically. extend superiorly by curving L around umbilicus
internervous plane for transperitoneal approach to the lumbar spine
between abdominal muscles midline
superficial dissection for transperitoneal approach to the lumbar spine
fibrous rectus sheath
between abdominal muscles
incise parietal peritoneum
deep dissection for transperitoneal approach to the lumbar spine
trendelenberg the table
retract uterus with 0 silk tie
ID presacral nerve plexi (parasympathetic)
incise peritoneum over midline sacral promontory
ligate sacral artery
access L5-S1 disc for discectomy and fusion
danger for transperitoneal approach to the lumbar spine
1) presacral nerve plexi - can use retroperitoneal saline injection to assist
2) midline sacral artery
3) lumbar vessels carefully dissectedand ligated to access great vessels
4) ureters must be mobilized laterally
position for retroperitoneal approach to lumbar spine
supine
incision for retroperitoneal approach to lumbar spine
midline as with transperitoneal, without splitting the parietal peritoneum
internervous plane for retroperitoneal approach to lumbar spine
midline between rectus abdominus muscles
superficial dissection for retroperitoneal approach to lumbar spine
rectus fascia
rectus abdominus
blunt dissection inferiorly
fascia of arcuate line divided
deep dissection for retroperitoneal approach to lumbar spine
blunt dissection toward LLQ - you will encounter retroperitoneal fat, then psoas.
ID genitofemoral nerve
ID ureter on the underside of peritoneum and mobilize medially with peritoneum
ligate sacral veins
dissect proximal to iliac vessels
plane is between iliac vessels and psoas
ligate ascending iliolumbar vein
retract iliac veins
dangers for retroperitoneal approach to lumbar spine
1) presacral nerve plexus should mobilize medial with peritoneum
2) ureters should mobilize medial with peritoneum
3) sympathetic chain on lateral vertebral body
4) segmental arteries and veins if you go above L5
position for anterolateral approach to lumbar spine
semi-lateral on preferred side (aortic approach or caval approach)
incision for anterolateral approach to lumbar spine
oblique from posterior half of 12th rib toward rectus abdominus stopping at its lateral border midway between umbilicus and symphysis
internervous plane for anterolateral approach to lumbar spine
none, however, because external oblique, internal oblique and transverse abdominus are all innervated segmentally, little denervation occurs
superficial dissection for anterolateral approach to lumbar spine
aponeurosis of external oblique parallel to fibres
muscle fibres of internal oblique perpendicularly
divide transverse abdominus in line with incision
ID peritoneum and retroperitoneal fat
blunt dissection of plane between retroperitoneal fat and psoas
retract peritoneum medially
deep dissection for anterolateral approach to lumbar spine
follow psoas medially to reach anerior vertebral body
ligate segmental arteries and veins as needed
ID correct disc with needle and fluoro
dangers for anterolateral approach to lumbar spine
1) sympathetic chain on lateral vertebral body wall
2) genitofemoral nerve on anteromedial surface of psoas
3) segmental arteries and veins (must tie off)
4) vena cava if approaching from R side
5) ureter - retract with peritoneum
position for posterior approach to the cervical spine
prone
neck in slight flexion
apply tongs and fixed brace
incision for posterior approach to the cervical spine
midline, marked at the level of interest with fluoro
internervous plane for posterior approach to the cervical spine
midline between paracervical muscles
superficial dissection for posterior approach to the cervical spine
cauterize venous plexi
incise nuchal ligament
remove paraspinal muscles subperiosteally
move lateral to expose lamina and facets
deep dissection for posterior approach to the cervical spine
remove ligamentum flavum from superior edge of lamina
laminectomy
Id dura, vertebral body, disc
control epidural venous bleeding
danger for posterior approach to the cervical spine
1) don’t traction cord
2) venous plexus bleeding around cord
3) do not enter transverse foramen
4) 3rd occipital nerve lateral to skin incision
which muscles might you encounter during posterior approach to the cervical spine?
superficial = trapezius
intermediate = splenius capitis
deep = semispinalis capitis, semispinalis cervicis, multifidus, short rotators, long rotators
position for posterior approach to C1/C2 specifically
prone
neck flexed
incision for posterior approach to C1/C2 specifically
midline from EOP inferiorly for 6-8 cm
internervous plane for posterior approach to C1/C2 specifically
midline
superficial dissection for posterior approach to C1/C2 specifically
fascia
nuchal ligament
strip subperiosteally from spinous processes of C2/3 and tubercle of C1 and EOP
deep dissection for posterior approach to C1/C2 specifically
remove ligamentum flavum between C1/C2
remove posterior atlanto-occipital ligament
danger for posterior approach to C1/C2 specifically
1) do not retract cord near C1/2!
2) C2 and C3 occipital nerves are lateral to this field
3) vertebral artery crosses the field superior to C1
position for anterior approach to the cervical spine
supine
roll between shoulder blades
extend neck
turn head away
traction if distraction needed later
30° head elevation
arm at side
which vertebrae can you access with anterior approach to C-spine?
C3-T1
incision for anterior approach to the cervical spine
oblique from midline at the level of interest to the lateral edge of SCM
anatomical landmark for C2-3
jaw line
anatomical landmark for C4-5
thyroid cartilage
anatomical landmark for C6
cricoid cartilage
internervous plane for anterior approach to the cervical spine
none superficial, however, between SCM and neck strap muscles intermediate and between R and L longus colli muscles deep
superficial dissection for anterior approach to the cervical spine
fascia
platysma split longitudinally with fingers
fascia immediately anterior to SCM
retract SCM laterally
retract sternohyoid, sternothyroid and trachea medially
develop plane beteen medial edge of carotid sheath and midline structures
incise pretracheal fascia
retract sheath laterally
ligate inferior and superior thyroid arteries if going above C3/4
develop plane posterior to esophagus
deep dissection for anterior approach to the cervical spine
split the longus collin midline and retract with ALL laterally
confirm location with needle and fluoro
danger for anterior approach to the cervical spine
1) protect recurrent laryngeal nerve by placing retractors medial to longus colli
2) avoid sympathetic chain by subperiosteal midline dissection
3) avoid dissecting out to TP
4) avoid self-retainers near carotid sheath
5) take care not to lose the inferior thyroid artery behind the carotid sheath
6) do not extend this approach
position for Wiltse approach to the spine
prone on wilson or jackson table
indications for Wiltse approach to the spine
far lateral disc herniation
pars defect
internervous plane for Wiltse approach to the spine
none. however, intermuscular plane between multifidus and longissimus
incision for Wiltse approach to the spine
3 cm from midline
superficial dissection for Wiltse approach to the spine
find the plane between multifidus and longissimus and develop with blunt dissection
deep dissection for Wiltse approach to the spine
manually palpate TP
place clamp on TP and confirm level with fluoro
dissect TP above and below
ID pars medially
position for posterolateral approach to the thoracic spine
prone
bolsters on each side of chest
incision for posterolateral approach to the thoracic spine
curved linear 8 cm lateral to and centered over the level of pathology, 10-13 cm long
internervous plane for posterolateral approach to the thoracic spine
non. split trapezius (innervated superiorly) and paraspinal muscles (innervated segmentally)
superficial dissection for posterolateral approach to the thoracic spine
fascial incision
incise trapezius parallel to fibres and close to TPs
cut down to posterior aspect of rib
deep dissection for posterolateral approach to the thoracic spine
remove all muscle attachments from rib subperiosteally
dissect laterally on superior border
dissect medially on inferior border
divide rib 6-8 cm from midline
lift and cut costo-transverse ligament
remove rib
remove muscle from TP
remove TP with rongeur
carefully enter retroperitoneal space with blunt dissection to expose vertebral body and disc
danger for posterolateral approach to the thoracic spine
1) intercostal arteries often damaged - this is okay, but bleeding must be controlled with ties
2) if dissection is too intensive you can enter the central canal
3) pleural tears require chest tubes
position for anterior approach to thoracic spine
lateral
arms above head
R sided approach is usually easier (no aorta)
incisionfor anterior approach to thoracic spine
2 cm below tip of scapula curving forward toward inframammary crease.
complete the posterior part by curving rostral to a point half-way up scapula and midway between scapula and SPs
superficial dissection for anterior approach to thoracic spine
divide lat dorsi along skin incision
divide serratus anterior
use 5th intercostal space for T2-9
use 6th intercostal space for T10-12
cut down to periosteum then dissect subperiosteally
resect posterior 3/4 of rib
insert rib spreader and give time for paraspinal muscles to relax
deep dissection for anterior approach to thoracic spine
deflate lung and retract anteriorly
incise pleura over esophagus and retract
may ligate 1 intercostal artery if needed
approach from R side
danger for anterior approach to thoracic spine
1) intercostal arteries are vulnerable at 2 points: during rib resetion and vertebral body approach
2) expand the lungs every 30 min
position for posterior approach in scoliosis
prone
on knees
bolsters for chest
abdomen clear
incision for posterior approach in scoliosis
use C7/T1 and gluteal cleft as a midline guide
internervous plane for posterior approach in scoliosis
midline
superficial dissection for posterior approach in scoliosis
fascia
split transverse processes
dissect muscle subperiosteally
deep dissection for posterior approach in scoliosis
continue muscle dissection along lamina
remove short rotators with cobb
remove muscle to TPs
dangers for posterior approach in scoliosis
1) posterior rami emerge between TPs
2) segmental arteries emerge between TPs
