Grade 5 osteotomy

General

Resection of 1 vertebrae is Grade 5

Resection of >1 vertebrae is Grade 6

Indication

Treatment of sharp, angular, rigid kyphotic deformity in TL and T spine

>90 degree cobb
<25% improvement on bending

Resection of hemivertebrae

Post infection deformity

Intravertebral bony spinal tumors resection

Tethered cord

The shortening of the spine proximal to a tethered region as a novel method of treating tethered spinal cord without the risks of dissection around adhesed nerve roots.

Pre-op

Get CT

Study pedicle anatomy
Identify regions with

Ankylosis or fusion
Pseudoarthrosis (if had previous surgery)

Planning of osteotomies
Complex anatomy

Surgical principles

Anatomical resection

Suk technique

Resection

All posterior elements
Facet joints at the levels above and below
Entire VB
Supra-adjacent/ subjacent discs.

Spine is then disarticulated, and the proximal and distal limbs are slowly brought together.

Anterior fusion is performed with structural support via an anterior cage

This allows for relative anterior lengthening, through the use of an expandable cage implant, which enhances the degree of correction.

Kawahara technique: A closing-opening wedge osteotomy

A kyphotic deformity is reduced by resection of the vertebra through a costotransverse approach → “closing” of the gap with posterior compression → “opening” of the anterior column with cage insertion.

Positioning

Adequate exposure to the surgical site.
Passive spinal column correction.
Minimise the risk of associated pressure-related injuries to the patient.

Common Positions and Historical Context:

Prone most common

Historical descriptions of the prone position, such as the "tuck, knee-chest, and praying position," were associated with high rates of complications.

Vascular injury
Peripheral nerve injury
Muscle necrosis → acute kidney injury

Other position Supine and lateral

Advancements in Positioning Equipment:

Modern frames

has significantly reduced complications.
Designed to:

Pad bony prominences.
Maintain physiological positioning of the limbs.
Reduce intra-abdominal and intra-ocular pressure.
Play a vital role in inducing lordosis or kyphosis on the native spine, depending on surgical goals.

Studies on frame impact:

Hastings, Andrews, and four-poster frames were reported to cause a 50% reduction in overall lumbar lordosis compared to preoperative standing alignment.
OSI Jackson surgical table

Introduced in 1992

Has ability to generate lordosis.

A dual-column design, allowing for an

Unrestricted abdomen
360 degrees of rotation
Complete radiolucency

Leg positioning

Influences spinal lordosis and kyphosis

Placing legs in a sling allows for relative hip flexion, which can facilitate decreasing lumbar lordosis.
Placing legs on flat boards with pillows will extend the hips, thereby inducing lumbar lordosis.

Risks and Complications of Improper Patient Positioning:

Perioperative Peripheral Nerve Injury (PPNI):

Risk of peripheral nerve damage:

Patient factors

Medical conditions – diabetes, smoking, high blood pressure, vascular disease.
Being male.
Increasing age.
Being very overweight or extremely thin.

Surgical factors

More complicated operations which involve more instruments are more likely to damage nerves than simpler operations.
Certain operations, including:

Operations on the spine or brain
Cardiac or vascular operations (on the heart or major blood vessels)
Operations on the neck or parotid (a gland in the face)
Some kinds of breast operation
Operations in which a tourniquet (a tight band around a limb) is used to reduce bleeding.

Positioning

Prone
Lateral

Typically presents as

Neuropraxia or
Axonotmesis.

Lower Extremity Injuries:

Patients with significant fixed sagittal malalignment can sustain various lower extremity nerve compressions, such

As quadriceps palsy, even with appropriate padding, which can be relieved by appropriate recognition and interventions.

Upper Extremity Injuries:

Brachial Plexus

Highly susceptible to stretch injuries due to its fixation at the cervical and axillary fascia and its traversal through bony architecture (clavicle, first rib, humeral head).
Risk factor

Abduction of the arm greater than 90° (Greatest risk)
Extension, external rotation plus abduction of the arm
Rotation plus lateral flexion of the neck in the ipsilateral direction
Application of shoulder braces.

The most common clinical presentation is a motor deficit, with the majority of cases resolving over time.

Specific Peripheral Neuropathies:

Ulnar nerve palsy

Increased risk with

Elbow flexion greater than 90°

Most vulnerable peripheral nerve in the upper extremity to brachial artery ischemia.

Direct pressure to the cubital tunnel

Obesity and preoperative cubital tunnel syndrome are identified risk factors for ulnar nerve injury.

Malpositioning of a blood pressure cuff

Lateral femoral cutaneous neuropathy (meralgia paresthetica)

Reported in up to 24% of patients undergoing prone spinal surgery.
This is believed to be caused by direct compression of the nerve by the pelvic bolsters near the anterior superior iliac spine.

Post-Operative Vision Loss (POVL):

Occurs in 0.03%.

Due to

Ischemic optic neuropathy
Central artery occlusion
Ischemic orbital compartment syndrome
Occipital cerebral infarction.

Proposed pathogenesis involves increased orbital venous and intraocular pressure due to external pressure during surgery.

Risk factors include:

Prolonged operative time.
Intraoperative anaemia.
Hypotension.
High-volume infusions.
Trendelenburg position.
Rotation of the head.
Applied ventral pressure, which may compromise blood flow to the optic nerve.

Mitigation strategies:

Routine use of a skull clamp

(e.g., Gardner-Wells tongs, halo, or Mayfield)
For long-segment spinal deformity surgery in some institutions.
Pros

Not applying external pressure to the orbit compared to horseshoe and foam headrests.
Unobstructed visualisation of the face
Controlled positioning of the cervical spine
Facilitate surgical exposure.

Technical Considerations for VCR:

Rib Resection:

Thoracic VCRs may necessitate unilateral or bilateral resection of ribs (typically 5 cm) and transverse processes to expose the lateral vertebral body.

Nerve Root Management:

Nerve roots on the convexity are clamped for 5 minutes with continuous neuromonitoring before ligation; the concave root may be preserved.

Spinal Stabilization:

The spine should be stabilised with a temporary rod fixed to pedicle screws at least 3 segments above and below the VCR site;
dual stabilization rods are recommended for severe kyphosis.
Hooks can be used for stability and correction in fused segments.

Corpectomy:

The vertebral body is often rotated laterally and dorsally on the convexity to facilitate bony corpectomy. The concave pedicle is removed carefully, potentially after spinal shortening via convex compression to relieve neural tension.

Posterior Wall Removal:

The posterior wall is removed last to minimise epidural bleeding and protect the spinal cord.
A thin portion of the anterior vertebral body can be left intact to promote fusion.

Correction Maneuvers:

Involve shortening and translation of the vertebral column, achieved through direct compression or construct-to-construct compression.

Spinal Cord Monitoring:

TIVA for IOM
The spinal cord must be constantly monitored for stretch or buckling during correction.

Anterior Cage Placement:

An anterior cage is placed to restore anterior column support, serve as a fulcrum for kyphosis correction, and prevent excessive shortening and spinal cord buckling.

Final Rods and Fusion:

After correction, the contralateral final rod and additional support rods are inserted. Structural allograft or autograft may be placed dorsally over the laminectomy site to protect neural elements and facilitate fusion.

Outcome

Degree of correction

Suk's series (70 patients):

61.9% coronal correction,
47.5° sagittal correction,
2.53 cm coronal balance restoration,
2.77 cm sagittal balance restoration.

Lenke et al. (North American series):

Correction rates of 69% for severe scoliosis,
54% for global kyphosis,
63% for angular kyphosis,
54% for kyphoscoliosis.

Lenke et al. (largest paediatric series):

54% improvement in the coronal plane
47% improvement in the sagittal plane.

No difference in complication rates was found between posterior-only VCR (pVCR) and circumferentially performed VCR, or between staged and single-stage VCR procedures.

Bianco 2014

for all 3 column osteotomies Grade 3-6 osteotomies

Op time 456.9 minutes
42% overall complications

Intraoperative complications

Complication	Incidence
Cardiac arrest	0.2%
Spinal cord deficit	2.6%
Death	0.0%
Nerve root injury	1.4%
Optic deficit/blindness	0.0%
Vessel/organ injury	1.7%
Pneumothorax	1.2%
Unplanned staged surgery	1.4%

Post-operative complications

Complication	Incidence
Bowel/bladder dysfunction	6.9%
Death	0.2%
DVT	3.1%
Cauda equina syndrome	0.5%
Deep infection	7.6%
Motor deficit or paralysis	12.1%
Myocardial infarction	0.5%
Visual deficit/blindness	0.5%
Pneumonia	2.8%
PE	2.8%
Reintubation	1.2%
Sepsis	0.7%
Stroke	0.5%
ARDS	4.7%
Pancreatitis	0.0%
Unplanned return to OR	19.4%
Tracheotomy	0.2%
Arrhythmia	1.2%
Major injury to vessel requiring repair	0.3%
Hemopneumothorax	0.7%

Qiao 2018

More complications in the kyphoscoliosis group (30.3%) vs kyphosis group (18.2%)

No difference in neurological complication rates

Wang 2016

For posterior vertebral column resection (PVCR).

Calculation: (Total Deformity angular ratio) T DAR = S DAR + C DAR

(Sagittal) S DAR

Maximum kyphotic angle divided by the number of vertebral levels involved

(Coronal) C DAR

Cobb angle of the maximum scoliosis curve divided by the number of vertebral levels involved

High total DAR (≥25)

More Pre op myelopathic (33.3% vs. 11.7%, P = 0.000)
Needed larger vertebral resections (1.8 vs. 1.3, P = 0.000),
Significantly higher rate of IOM events than seen in the low total DAR (<25) patients (41.1% vs. 10.8%; P = 0.000).

High sagittal DAR (≥15)

Higher rate of SCM events (34.0% vs. 15.1%, P = 0.005)
Greater chance of neurologic deficits postoperatively (12.5% vs. 0, P = 0.000).

Complication

78% at least 1 complication

61% major complication

Posterior-only VCRs

Reduced operative time (from 12 hrs)

Suk 2002 reported mean operative time of 4.5 hours

Reduced perioperative bleeding (5L)

Suk 2002 reported mean EBL of 2333 mL.
Reducing blood loss

Anti-fibrinolytic agents: aprotinin, TXA
Hypotensive anesthesia during exposure
Intrathecal Opioids
Discectomy before vertebrectomy
Meticulous haemostasis
Cell saver

Surgical Site Infection (SSI):

VCRs

Overall SSI rate of 11.1%.

Rates of SSI requiring return to the operating room range from 3% to 9%.

Higher risk of deep SSI (9.7%) compared to PSO (3.4%) and PCO (1.5%)

Neurologic Complications:

Changes in intraoperative neuromonitoring are common (in roughly 1 in 4 cases), with most being correctable.
The risk of permanent neurologic complication (either root or spinal cord) ranges from 2% to 6%.
Risk factors