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Single Level Lumbar Decompression and Fusion (TLIF)

Preoperative Patient Care
Operative Techniques
E

Preoperative Plan

1

Identifies area of decompression on preoperative imaging

2

Template instrumentation on preoperative imaging studies.

3

Execute surgical walkthrough

  • describe the steps of the procedure to the attending prior to the start of the case
  • describe potential complications and steps to avoid them
F

Room Preparation

1

Surgical instrumentation

  • Lumbar Instrumented Fusion System
  • decompression with instrumented fusion is indicated in presence of segmental instability (spondylolisthesis, degenerative scoliosis)
  • structural interbody spacers
  • titanium cages
  • polyetheretherketone cages
  • Autologous or allograft bone for fusion

2

Room setup and equipment

  • table
  • radiolucent Jackson spine flat top table
  • neuromonitoring
  • neuromonitoring leads to upper and lower extremities
  • C-arm
  • c-arm perpendicular to table
  • can take initial Lat fluoro of lumbar spine to localize level
  • highest point in iliac crest marks L4-5 interspace but overlying soft tissue can push you closer to L3-4 interspace
  • microscope
  • microscope in from opposite side of C-arm

3

Patient positioning

  • prone with arms at 90° max abduction and flexion to prevent axillary nerve injury
  • foam padding on chest so that nipples are pointing midline straight down
  • pads over ASIS and gel pads on knees
  • foley in place
  • bilateral TED hose and SCDs
G

Dissection to Spinous Process

1

Localize level of incision with anatomic or radiographic landmarks

2

Make midline incision.

  • midline incision with 10blade overlying the spinous processes between paraspinal muscles (erector spinae)
  • ~3-4cm in length for single level

3

Dissect subcutaneous tissue down to fascia

  • insert cerebellar retractors x2 for fascial exposure

4

Cauterize lumbodorsal fascia over spinous processes to just lateral of midline

H

Dissection to Transverse Process

1

Perform subperiosteal dissections

  • perform dissection with Cobb along spinous processes
  • perform subperiosteal dissection of the lamina in a cranial to caudal direction

2

Place probe under lamina to identify level radiographically

3

Expose the facet capsules

  • use Cobb to strip laterally along lamina until facet capsules exposed

4

Dissect out transverse process

  • dissect paraspinal muscle from intertransverse membrane

5

Place deep retractors for better visualization

I

Laminectomy and Decompression

1

Remove spinous processes of operative levels with rongeur

  • save as bone graft for fusion

2

Remove lamina and identify origin of ligamentum flavum

  • begin with decompression into canal into inferior half of lamina of cephalad vertebrae first with small curette<br />
  • burr lamina and decompress medial aspect of facet on each side (2-3 mm of medial facet)

3

Resect ligamentum flavum

  • gently retract ligamentum flavum with woodsen elevator
  • resect remaining lamina and ligamentum with Kerrison rongeur of cephalad vertebrae
  • resect ligamentum from superior lamina of inferior lamina
  • use Kerrison to resect caudad lamina from inferior vertebra
  • use woodsen to protect dura and nerve roots during entire resection of ligamentum flavum

4

Perform a lateral recess/foraminal decompression

  • locate the pedicle
  • locating pedicle key to safe decompression
  • superior facet much closer to nerve root
  • expose the pedicle
  • use a kerrison to undercut medial edge of superior facet of caudad vertebra until medial edge of pedicle visualized
  • identify osteophytes that could impinge exiting nerve root around pedicle
  • undercut remaining superior facet using kerrison rongeur
  • if not fusing no more than 50% superior facet should be resected
  • dural sac/nerve root may be retracted to see if there is bulging disc is present
J

Instrumentation with Pedicle Screws

1

Identify entry point for instrumentation

  • landmark for pedicle screws is inferolateral aspect of the intersection of facet and transverse process
  • for sacrum landmark is base of facet at S1 (superolatral to sacral foramen)

2

Decorticate entry site

  • use a burr
  • place gearshift probe into pedicle track ~30mm until significant resistance is felt (anterior cortex of vertebral body)

3

Verify entry point

  • insert balltip probe to check floor, medial, inferior walls of pedicle
  • check for canal/nerve root
  • place metallic markers into tracts of all screws to check with fluoro
  • once markers confirmed in correct locations advance gearshift 40-50mm
  • tap 5mm and recheck with balltip probe

4

Insert pedicle screws

  • (i.e. L4, 6.5x50mm screws; L5, 7.5x40mm screws)

5

EMG test all screws to ensure no pedicle wall breach

  • can test nerve first to get baseline reading
  • no screw should trigger less than 10-15mA response

6

Place contoured rods

  • place 2 contoured rods (i.e. 6.0mm rods, use hand benders) for desired lordosis into screw tulips
  • insert set screws
  • distract across rods using hand distractors and tighten set screws
K

Facetectomy and Disk Preparation

1

Complete unilateral facetectomy

  • use an osteotome to expose the inferior articular process of the cephalad vertebra
  • dissect the superior articular process of the caudal vertebra from the ligamentum flavum
  • resect the lateral aspect of the hemilamina and the caudal portion of the pars interarticularis using kerrison rongeurs

2

Prepare disk space

  • mobilze the thecal sac using a nerve root retractor.
  • use a scalpel to incise a rectangular region of the annulus lateral to the traversing nerve root
  • this creates a window to the disk space
  • serially introduce shavers or dilators into the disk space and rotate
  • use curettes and rongeurs to perform a thorough diskectomy.
L

Interbody Arthrodesis

1

Trial implant

  • use graft trials to determine the size of the interbody spacer
  • confirm size with fluoroscopy
  • pack the anterior and lateral aspects of the disk space with morselized bone graft
  • use a graft impactor to maximize the amount of graft that can be use
  • reintroduce the trial to ensure that the morsalized graft has not block the pathway for insertion

2

Place implant

  • remove the trial then place the interbody spacer as anterior and central as possible
  • place additional graft into the posterior aspect of the disc space behind the implant

3

Confirm the implant position with AP and lateral radiographs

N

Prepare Arthrodesis and Wound Closure

1

Decorticate the surrounding bony structures

  • decorticate surrounding transverse processes, facet joints, and pars with burr

2

Place autograft

  • pack posterolateral gutters with autologous/allograft graft

3

Tighten instrumentation

  • final tighten set screws and placecross connector between pedicle screws and tighten

4

Confirm Final Implant Position

  • take final AP/Lat of screws and rods to confirm position and lordosis

5

Irrigation and Hemostasis

  • flush out spine with saline bulb irrigation
  • can use betadine wound lavage or vancomycin powder to decrease infection risk
  • use Floseal for hemostasis
  • place hemovac drain under fascia

6

Close Fascia

  • close fascia with 0-vicryl
  • need water tight closure and need to decrease dead space for hematoma

7

Superficial closure

  • subcutaneous with 2-0 vicryl
  • skin closure with buried 3-0 monocryl

8

Dressing

  • soft incision dressings over spine
Postoperative Patient Care
Private Note