ANTERIOR PROCEDURES
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- Deep cervical fascia
- Pretracheal fascia
- Prevertebral fascia
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- RLN
- Vagus nerves travels in the carotid sheath
- Left RLN branches off at the arch of aorta
- Right RLN branches off at the subclavian artery
- left arises goes under arch of aorta; right hooks around subclavian artery
- Goes within the tracheo-esophageal groove ➔ gentle retraction
- Supply - supplies all the intrinsic muscles of the larynx, with the exception of the cricothyroid muscles
- No difference in injury rates thought LEFT is more consistent
- https://www.sciencedirect.com/science/article/pii/S1743919117300766
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- Refer ENT for laryngoscopy to check vocal cord function
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- Theoretically motion preserving ➔ thoretically lower risk of ASD
- but will not choose for patients with axial neck pain or instability
- However, conflicting data on Adjacent segment disease
- Systematic review JBJS 2018 Findlay et al. 14 RCT, 3160 patients ➔ Similar outcomes. BUT ADR reduces risk of ASD both short and long term. (controversial, some papers say same)
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- Controversial which is better:
- ACCF Pros = minimizes the number of graft-host interfaces, allows more extensive decompression, and provides a source for bony autograft to promote fusion
- ACCF Cons = potential for graft extrusion due to the fewer possible points for ventral plate screw fixation
- ACDF Pros = lower risk of graft extrusion
- ACDF Cons = incomplete decompression behind vertebral body, higher risk of pseudoarthrosis
- Study show similar postoperative alignment, ASD, Pseudoarthrosis, pain relief. ACCF has higher estimated blood loss.
[Journal of Neurosurgery_ Spine] Two-level corpectomy versus three-level discectomy for cervical spondylotic myelopathy_ a comparison of perioperative, radiographic, and clinical outcomes.pdf3903.4KB
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- Early vs Late
- Early
- Number 1 = dysphagia!
- RLN injury -Constant hoarseness,
- Seroma/ Hematoma formation
- Wound healing/ infection
- Vertebral artery injury
- Late
- Hilibrand et al. 10 year follow up - annual incidence 2.9%, 5 year 11.7%, 10 year 25% for SYMPTOMATIC ASD
- Risk factors for ASD - single level fusion involving the 5th or 6th vertebrae; pre-existing radiographic evidence of degeneration
- ➔ more than 2/3 in whom ASD develop fail Non op.
- ➔ paper proposes that all degenerative segments should be included in cervical fusion
- ADR vs ACDF - no diference at 10 years.
- Definition of pseudoarthrosis? (3)
- 1. persistent or worsening axial pain 6/12 after index procedure
- 2. Radiolucency at host graft interface
- 3. Vertebral motion > 2mm or 4 ° on flex extension
- usually occurs at caudal level (bottom)
- Mx = may remain asymptomatic. So only treat symptomatic pseudoarthrosis
- Risk factors? = number of levels of fusion, use of plate
- 1 level - ACDF + plate is better than no plate (97% vs 92%)
- 2 level - ACDF = Corpectomy (similar rates of fusion 95%)
- 3 level - Corpectomy is better (95% vs 90%)
- Stiffness!
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- Dysphagia
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- C5 palsy
- Horner’s syndrome
- Dysphagia, Dysphonia
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- Multilevel, long surgery, elderly, high cervical surgery (C3/C4)
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- IV Steroids
- Paper by Jenkins et al. RCT of 75 patients undergoing ACDF randomized to 3 groups - No steroids, IV steroid, Local steroid. Both steroid groups had significant reduced dysphagia rates compared to control group.at 2 week, 6 week, 3 months and 1 year.
jenkins2018.pdf1851.9KB
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- Refer ENT because could have asymptomatic damage to unilateral recurrent laryngeal nerve on the side of the previous approach
- If nerve is damaged then will use the same approach and be careful of contralateral side.
POSTERIOR PROCEDURES
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- “indirect” decompression via float back of spinal cord
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- P – prone with Mayfield clamps (3 prongs),
- Pins tightened to 60lbs
- Preparation - shave hair, tape down shoulders, ensure pressure points well padded - knee, ankles, iliac crests
- Pre op Localisation
- I – longitudinal midline
- D – Incise down through fascia and Nuchal ligament ➔ Cobb elevator to Elevate cervical muscles ➔ expose to facet joints and beginnings of transverse processes ➔ identify ligamentum flavum and release from leading edge at inferior vertebrae ➔ perform superior lamina laminectomy as necessary to see the dura
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- Open door vs French door; more familiar with open door
- Open door = Hirayabashi technique
- Hinge created at junction of lateral mass and lamina
- Held opened by plates
- French Door = Kurokawa
- + : Motion Preserving
- C5 palsy
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- Technique - lateral mass screw vs pedicle screw
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- Rarely indicated due to risk of post laminectomy kyphosis
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- Controversial mechanism of injury
- In laminectomy, thought to be due to tethering of nerve root with dorsal migration of spinal Cord, resulting in stretching of the C5 nerve root
- HOWEVER, incidence found to be no difference in anterior or posterior surgeries. Incidence ~4.6%