Spine Degenerative Flashcards
% of patients >65 years of age demonstrate spondylotic changes regardless of symptomatology
85%
What are the most common levels associated with cervical spondylosis?
C5-6 > C6-7 because they are associated with the most flexion and extension in the subaxial spine
Risk factors for cervical spondylosis?
- excessive driving
- smoking
- lifting
- professional athletes
Etiology of cervical myelopathy
- Degenerative cervical spondylosis (CSM); most common cause ; Compression by osteophytes, discosteophyte complex, degenerative spondylolisthesis and hypertrophy of ligamentum flavum
- Congenital stenosis:symptoms usually begin when congenital narrowing combined with spondylotic degenerative changes in older patients
- OPLL
- tumor
- epidural abscess
- trauma
- cervical kyphosis
What is the mechanism of neurologic injury of cervical myelopathy?
- Direct cord compression
- ischemic injury secondary to compression of anterior spinal artery
What are the associated conditions with cervical myelopathy?
◦ lumbar spinal stenosis
tandem stenosis occurs in lumbar and cervical spine in ~20% of patients
What is the prognosis of cervical myelopathy?
◦ natural history
tends to be slowly progressive and rarely improves with nonoperative modalities
progression characterized by steplike deterioration with periods of stable symptoms
Prognosis: early recognition and treatment prior to spinal cord damage is critical for good clinical outcomes
Ranawat Classification for cervical myelopathy
Class I
Pain, no neurologic deficit
Class II
Subjective weakness, hyperreflexia, dyssthesias
Class IIIA
Objective weakness, long tract signs, ambulatory
Class IIIB
Objective weakness, long tract signs, non-ambulatory
Categories for Japanese Orthopaedic Association Classification for cervical myelopathy
- Upper extremity function
- Lower extremity function
- Sensory (upper, lower, trunk)
- Bladder function
Clinical Presentation of cervical Myelopathy
Symptoms:
Neck pain and stiffness:
Occipital headache common
Extremity Paresthesias: diffuse, bilateral, non-dermatomal numbness and tingling
Weakness and clumsiness: bilateral weakness and decreased manual dexterity (dropping object, difficulty manipulating fine objects)
Gait instability
- patient feels “unstable” on feet
- weakness walking up and down stairs
- gait changes are most important clinical predictor
Urinary retention
rare and only appear late in disease progression
not very useful in diagnosis due to high prevalence of urinary conditions in this patient population
Physical exam
Motor weakness
finger escape sign
when patient holds fingers extended and adducted, the small finger spontaneously abducts due to weakness of intrinsic muscle
grip and release test
normally a patient can make a fist and release 20 times in 10 seconds. myelopathic patients may struggle to do this
Sensory
proprioception dysfunction: associated with poor prognosis
decreased pain sensation
Vibratory changes are usually only found in severe case of long-standing myelopathy
upper motor neuron signs (spasticity) Hyperreflexia
inverted radial reflex: tapping distal brachioradialis tendon produces ipsilateral finger flexion
Hoffmann’s sign
snapping patients distal phalanx of middle finger leads to spontaneous flexion of other fingers
most common physical exam finding
Sustained clonus
> three beats defined as sustained clonus
sustained clonus has poor sensitivity (~13%) but high specificity (~100%) for cervical myelopathy
Babinski test
gait and balance
toe-to-heel walk
Romberg test
Lhermitte Sign
test is positive when extreme cervical flexion leads to electric shock-like sensations that radiate down the spine and into the extremities
When does cervical cord compression occur?
with canal diameter is < 13mm
Measure that suggests a congenitally narrow spinal canal?
Pavlov ratio of less than 0.8 suggest a congenitally narrow spinal canal predisposing to stenosis and cord compression
How to determine the sagittal alignment?
C2 to C7 alignment
determined by tangential lines on the posterior edge of the C2 and C7 body on lateral radiographs in neutral position
local kyphosis angle
the angle between the lines drawn at the posterior margin of most cranial and caudal vertebral bodies forming the maximum local kyphosis
What signs of MRI correlate with poor prognosis for patients with cervical myelopathy?
signal changes on T1-weighted images correlate with a poorer prognosis following surgical decompression
What is the more important determinant for surgery in patients with cervical myelopathy?
function is a more important determinant for surgery than physical exam finding
With what area of spinal cord has non-operative treatment in case of cervical myelopathy shown to be have improved benefits
improved nonoperative outcomes associated with patients with larger transverse area of the spinal cord (>70mm2)
What factors to consider in the surgical treatment of patients with cervical myelpathy?
- cervical alignment
- number of stenotic levels
- location of compression
- medical conditions (e.g., goiter)
What are the treatment procedures for cervical myelopathy?
- anterior cervical diskectomy/corpectomy and fusion
- posterior laminectomy and fusion
- posterior laminoplasty
- combined anterior and posterior procedure
- cervical disk arthroplasty
What are the benefits of surgical treatment in patients with cervical myelpathy?
- Prospective studies show improvement in overall pain, function, and neurologic symptoms with operative treatment
What is the goal of surgical treatment of cervical myelopathy?
Prevention of continued neurologic decline
What are the Things to consider in surgical treatment of cervical myelopathy?
▪ Number of stenotic levels
Sagittal alignment of the spine (>10 rigid kyphosis; <10 rigid kyphosis)
Degree of existing motion and desire to maintain
Medical co-morbidities (eg, dysphasia)
What are the indications of Anterior Decompression and Fusion (ACDF) alone in cervical myelopathy?
- mainstay with single or two level disease
- fixed cervical kyphosis of > 10 degrees
- anterior procedure can correct kyphosis
- compression arising from 2 or fewer disc segments
- pathology is anterior (OPLL, soft discs, disc osteophyte complexes)
What are the indications of Anterior Decompression and Fusion (ACDF) alone in cervical myelopathy?
mainstay with single or two level disease
fixed cervical kyphosis of > 10 degrees
anterior procedure can correct kyphosis
compression arising from 2 or fewer disc segments
pathology is anterior (OPLL, soft discs, disc osteophyte complexes)
What are the pros and cons of Anterior Decompression and Fusion (ACDF) alone in cervical myelopathy?
▪ advantages compared to posterior approach
lower infection rate
less blood loss
less postoperative pain
disadvantages
avoid in patients with poor swallowing function
What are the indications for anterior corpectomy and fusion (ACF)
Extensive retro-vertebral disease
cervical kyphosis preventing from adequate decompression posteriorly
technique
anterior fixation alone
amenable in up to 2-level corpectomy
use of static anterior cervical plate with struct graft
combined anterior and posterior fixation
indicated in 3-level corpectomy and above
use of anterior strut graft and plating combined with posterior lateral mass screw construct
anterior fixation alone in 3-level and aboveresults in a high (>70%) catastrophic failure rate
Laminectomy with posterior fusion for cervical myelopathy: indications and contraindications
▪ multilevel compression with kyphosis of < 10 degrees
> 13 degrees of fixed kyphosis is a contraindication for a posterior procedure
will not adequately decompress spinal cord as it is “bowstringing” anterior
Laminoplasty for cervical myelopathy; Pros Indications and contraindications and Techniques
Pros:
- maintain motion and stability
- Lower complication rates
- avoids non-union
CONS
- higher average blood loss than anterior procedures
- postoperative neck pain
- still associated with loss of motion
Contraindications:
- > 13 degrees is a contraindication to posterior decompression –> “bowstringing” anterior
- severe axial neck pain : relative contraindication and these patients should be fused
Technique
volume of canal is expanded by hinged-door laminoplasty followed by fusion
usually performed from C3 to C7
- Open door technique
hinge created unilateral at junction of lateral mass and lamina and opening on opposite side
opening held open by bone, suture anchors, or special plates
- French door technique
hinge created bilaterally and opening created midline
What is the risk of laminectomy alone?
post-laminectomy kyphosis
For cervical procedures which approach has the highest rate of surgical infection?
Posterior Approach
What is the risk of non-union with anterior approach for a single level and for multiple levels?
12% for single level fusions, 30% for multilevel fusions
Postoperative C5 palsy after cervical procedure
Incidence and risk factors
Prognosis and Risk factors for prolonged recovery
Incidence: 4.6%
Risk factors: Male and posterior laminectomy and fusion
Prognosis: good
Risk Factors for prolonged recovery:
- Multilevel paresis
- Motor Grade ≤2
- sensory involvement with intractable pain
Incidence (side) and Treatment algorithm for recurrent laryngeal injury in anterior cervical procedures
MORE vulnerable to injury on the RIGHT due to a more aberrant pathway
Recent studies have shown there is not an increased injury rate with a right sided approach
Postoperative RLN palsy
- watch over 6 weeks
- Not improved –> ENT consult to scope patient and inject teflon
If performing revision anterior cervical surgery, and suspicion of a RLN from 1st operation
–> ENT consult to establish prior injury
If patient has prior RLN nerve injury
perform revision surgery on the same as the prior injury/approach to prevent a bilateral RLN injury
Novelty practice in the prevention of dysphagia occurence after anterior cervical approach
Multiple studies have demonstrated the application of local steroid in retropharyngeal space prior to wound closure decreases rate of dysphagia
Application of local corticosteroid anterior to ACDF construct
Complications of cervical procedures
1- Infection
2- C5 palsy
3- Dysphagia
4- Non union
5- Migration and hardware failure
6- Recurrent laryngeal nerve injury
7- Vertebral artery injury
8- Esophageal injury
9- Postlaminectomy kyphosis
What is the name of the finger espace sign?
Wartenberg’s sign. Cervical myelopathy is associated with intrinsic weakness. The small finger may drift into extension under the pull of the extensor digiti minimi due to a weakened palmar interossei.
Which physical exam may be found in patients with or without upper motor neurons disease
Hyper-reflexia
Does history of smoking correlate with increased airway complications after ACDF?
NO.
Evidence from the literature suggests that a history of smoking does NOT correlate with an increased risk of airway complications after anterior cervical spinal surgery, which is depicted in Figure A by a two-level anterior cervical discectomy and fusion (ACDF).
Fasciculation sign of UMN or LMN disorder?
LMN
Etiologies of cervical radiculopathies
1- Degenerative cervical spondylosis
2- Disc herniation (“soft disc”)
intraforaminal
Posterolateral: most common
midline herniation: usually presents with myelopathic symptoms
3- Double-crush phenomenon
combined cervical root compression and distal nerve compression
decreased axoplasmic flow from root compression predisposes downstream nerves to peripheral entrapment syndromes
4- Rare Causes
- intraspinal/extraspinal tumors
- trauma with nerve root avulsion
- synovial cysts
- meningeal cysts
- dural arteriovenous fistulae
- tortuous vertebral arteries
What are the symptoms of cervical radiculopathy?
- occipital headache (common)
- trapezial or interscapular pain
- neck pain
- unilateral arm pain
aching pain radiating down arm
often global and nondermatomal
- Unilateral dermatomal numbness & tingling
numbness/tingling in thumb (C6)
numbness/tingling in middle finger (C7)
- Unilateral weakness
difficulty with overhead activities (C7)
difficulty with grip strength (C7)
Exam finding with C4 to T1 radiculopathy
C4 radiculopathy
scapular winging (Long thoracic Nerve)
numbness and pain at the base of the neck
C5 radiculopathy
deltoid and biceps weakness
diminished biceps reflex
pain and numbness in the superior shoulder and lateral upper arm
C6 radiculopathy
brachioradialis and wrist extension weakness
diminished brachioradialis reflex
paresthesias in thumb, index finger
C7 radiculopathy
triceps and wrist flexion weakness
diminished triceps reflex
paresthesia in the middle finger
most commonly affected nerve root in cervical radiculopathy in several studies
C8 radiculopathy
weakness to distal phalanx flexion of middle and index finger (difficulty with fine motor function)
paresthesias in ring and little finger
C8 radiculopathy is extremely rare and often manifests similarly as ulnar neuropathy
T1 radiculopathy
intrinsic hand muscle weakness
axillary numbness
ipsilateral Horner’s syndrome
Physical Exam of patients with cervical radiculopathy
▪ Spurling’s test
simultaneous extension, rotation to affected side, lateral bend, and vertical compression reproduces symptoms in ipsilateral arm
narrowing of the intervertebral foramina causes exacerbation of symptoms
specific, but not sensitive for radiculopathy
shoulder abduction test
shoulder abduction relieves symptoms shoulder abduction (lifting arm above head) often relieves symptoms
decreases tension on affected nerves
valuable physical exam test to differentiate cervical pathology from other causes of shoulder/arm pain
upper limb tension tests
valsalva maneuver
neck distraction test
DDx of cervical radiculopathy
Carpal tunnel syndrome
Cubital tunnel syndrome
Parsonage-Turner Syndrome
Thoracic outlet syndrome
Treatment for majority of patients with cervical radiculopathy?
▪ 75% of patients with radiculopathy improve with nonoperative management
improvement via resorption of soft discs and decreased inflammation around irritated nerve roots
When is return to play indicated in cervical radiculopathy?
after resolution of symptoms and repeat MRI demonstrating no cord compression
How can we accelerate return to play in cervical radiculopathy (conservative treatment)?
Studies have shown return to play expedited with brief course of oral methylprednisolone (medrol dose pack)
Results of Selective nerve root corticosteroid injections for cervical radiculopathy?
may be considered as therapeutic or diagnostic option
provides long-term relief in 40-70% of cases
increased risk when compared to lumbar selective nerve root injections with the following rare but possible complications, including
dural puncture
meningitis
epidural abscess
nerve root injury
Indications for ACDF in case of cervical radiculopathy?
- persistent and disabling pain that has failed three months of conservative management
- progressive and significant neurologic deficits
- static neurologic deficit associated with significant radicular pain
Superficial landmarks for levels when performing an ACDF
C1-2: inferior margin of the mandible
C3-4: hyoid
C4-6: thyroid cartilage
C5-6: cricoid cartilage
3 sites of structural bone graft
▪ iliac crest
fibular strut
patella
What is the incidence Pseudo-arthrosis after ACDF?
5 to 10% for single level fusions, 30% for multilevel fusions
What are the risk factors for pseudo-arthrosis in case of ACDF?
smoking
diabetes
multi-level fusions
revision surgery
What is the treatment of cervical pseudo-arthrosis after ACDF?
if asymptomatic observe
if symptomatic, treat with either posterior cervical fusion or repeat anterior decompression and plating if patient has symptoms of radiculopathy
improved fusion rates seen with posterior fusion
3 possible nerve injuries after ACDF?
Recurrent laryngeal nerve injury (1%)
Hypoglossal nerve injury
Horner’s syndrome
characterized by ptosis, anhydrosis, miosis, enophthalmos and loss of ciliospinal reflex on the affected side of the face
caused by injury to sympathetic chain, which sits on the lateral border of the longus coli muscle at C6
What operated level with ACDF has an increased risk of Dysphagia
◦ higher risk at higher levels (C3-4)
risk can be minimized with the use of zero-profile anchored cages
less prominence of anterior hardware reduces irritation and impingement of prevertebral structures, such as espohagus
Risk factors for Airway complications after ACDF
▪ prolonged surgical duration (>5 hours)
exposure above C4
greater than 4 levels involved in fusion construct
Most common nerve injury with ACDF?
recurrent laryngeal nerve
What is the reason for this finding?
When the upper border of the plate is located in close proximity to the cephalad adjacent disk, there is a higher incidence of osteophyte formation. The clinical implications of this are not yet understood.
If there is an right injury to the hypoglossal nerve the tongue with deviate…
towards the side of the injury.. towards the right
Difference between C8 radiculopathy and peripheral ulnar nerve palsy
C8 radiculopathy would also involve flexion weakness of the long and index fingers
C8 radiculopathy usually presents with sensory symptoms about the medial border of the forearm and hand, as well as finger flexion weakness (the C8 nerve root provides innervation to the flexor digitorum superficialis, flexor digitorum profundus (FDP), and flexor pollicis longus). It is important to differentiate a C8 radiculopathy from a peripheral ulnar neuropathy, which also presents with sensory symptoms in the ulnar hand and fingers. One way to do so is to test DIP flexion of the middle and index fingers. The function of the flexor digitorum profundus in the index and middle fingers can be affected by a C8 cervical radiculopathy, but they are not affected by ulnar nerve entrapment (the FDP of the index and middle fingers is supplied by the median nerve, specifically the anterior interosseous nerve).
physical exam findings supports a cervical radiculopathy as opposed to a peripheral neuropathy
Shoulder Abduction test
what is the Annual cost of low back pain
$100 billion in annual cost
second only to respiratory infection as cause to visit doctors office
Etiology of low back pain
◦ muscle strain: most common cause of low back pain
most common degenerative disorders
lumbar spinal stenosis
lumbar disc herniation
discogenic back pain
Risk factors of low back pain
◦ obesity, smoking, gender
lifting, vibration, prolonged sitting
job dissatisfaction
What are the Red flags of low back pain?
infection (IV drug user, h/o of fever and chills)
tumor (h/o or cancer)
trauma (h/o car accident or fall)
cauda equina syndrome (bowel/bladder changes)
What are the outcomes of low back pain?
90% of low back pain resolves within one year
What are Wadell Signs?
system to evaluate non-organic back pain symptoms. clinically significant if three positive signs are present:
- superficial and non-anatomic tenderness
- pain with axial compression or simulated rotation of the spine
- negative straight-leg raise with patient distraction
- regional disturbances which do not follow dermatomal pattern
- overreaction to physical examination
What are the indications for radiographs in case of low back pain?
- pain lasting > one month and not responding to not nonoperative management
- red flags are present
Patients with myelopathic symptoms worsening
Surgical technique?
thoracic laminectomy is a patient in whom imaging has demonstrated evidence of spinal canal stenosis secondary to hypertrophy of the posterior elements
no herniated disc
What are the advantages of putting cortical bone trajectory in degenerative spondylolisthesis?
lower intraoperative blood loss
smaller skin incision
decreased pain scores at 1-week post-op
greater screw pullout strength given cortical contact of screw
generally smaller than traditional pedicle screws
Diagnosis
Spinal TB with Gibbus
What is the most predictive of deformity progression in spinal TB?
Involvement of anterior and posterior column
Involvement of the anterior and posterior elements is the variable that is most predictive of kyphosis progression once the patient has reached the healed phase.
Factors that suggest further progression of the healed TB spine:
- thoracolumbar level or any of the four radiographic signs of a ‘spine at risk’
- separated facets
- posterior retropulsion
- lateral translation
- toppling sign
Having 2 or more of these signs predicts an increase in 30 degrees of kyphosis and a final angle of 60 degrees for which surgery should be recommended.
