Degenerative Spine DiseasesDegenerative Spine Diseases

Dr. Yue Wang Dr. Yue Wang

Department of Orthopedic SurgeryDepartment of Orthopedic Surgery

The First Affiliated Hospital, college of Medicine, ZheJiang UniversityThe First Affiliated Hospital, college of Medicine, ZheJiang University

A Class for Foreign MD StudentsA Class for Foreign MD StudentsA Class for Foreign MD StudentsA Class for Foreign MD Students

浙江大学医学院附属第一医院骨科

王 跃 王 跃 MD, PhDMD, PhD

Anatomy of the Intervertebral Disc Overview of Spine Degeneration Lumbar Disc Herniation Cervical Spondylosis Lumbar Spinal Stenosis

ContentsContents

Anatomy of the intervertebral discAnatomy of the intervertebral disc

The Intervertebral DiscTwo major components

Annulus fibrosis: thick, fibrous “radial tire” called lamellae

Nucleus pulposus: ball-like gel

The disc

The discThe disc

The disc is the largest The disc is the largest

avascular organ in the avascular organ in the

human body!human body!

Take about 80% loads Take about 80% loads

in the spine!in the spine!

Spine Degeneration A process involving structural changes of

affected joints and intervertebral disc, with thickening of joint capsule, ligaments, appositional bone formation in response to long term mechanical forces.

Epidemiology Very common: By age 50, 95% of people show

radiographic evidence of lumbar disc degeneration. Yet, only a small portion of them have symptoms.

Degenerative changes of the discDegenerative changes of the disc

Pathological changes Water and proteoglycan content decreases

Collagen fibers of AF become distorted

Tears may occur in the lamellae

Results in: Decreased disc height and volume

Decreased resistance to loads

Risk factors

Increasing age; Heredity plays an important role;

Twin studies revealing similar incidence despite different occupations, socioeconomic status

Smoking; Occupation/leisure activity likely does not play a

major role; Body habitus;

Pathophysiology

Decreased water content in nucleus

pulposus Causes loss of disc height, causing facet joints to

override each other;

Facet joints respond with hypertrophy and

osteophyte formation;

Can lead to compression of neurological

structures, and/or to abnormal movement which

worsens the cycle;

Degenerative changes of the Degenerative changes of the vertebral bodyvertebral body

Sclerosis: Increased bone formation at the endplates Reduced nutrition supply Reduced ability to absorb

loads Osteophytes: Formation of

small bony spurs

Degenerative changes of the Degenerative changes of the facet jointfacet joint

Degenerative Changes Cartilage lining loses

water content Cartilage wears away Facets override each

other Leads to abnormal

function of motion segment

Degenerative changes of the Degenerative changes of the ligamentsligaments

Degenerative Changes Partial ruptures, necrosis

and calcifications

Negatively impact function

of motion segment

Clinical implications

Axial pain – neck or back Due to inflammation surrounding diseased

structures or to instability of the spine

Neurologic compression Compresses laterally to nerve root

Radiculopathy Compresses centrally in canal

In cervical spine: myelopathy In lumbar spine: neurogenic claudication or cauda

equina syndrome

Back pain

80% adults will have episode back pain;

Most improve over time, therefore initial rest

period (short) followed by early mobilization, PT,

NSAIDS, lifestyle modification is the treatment;

90% are not associated with specific discernable

cause! (Idiopathic back pain);

Back pain

Red flags (fevers, night sweats, neurological

symptoms, weight loss, cancer), severe pain

not improving warrant further imaging.

Guidelines published on when to image, types

of conservative treatment

Xray, MRI

Radiculopathy

Arm pain; leg pain, sciatica;

Due to compression lateral to the spinal cord in

cervical spine, distal or lateral to nerver root/cauda

equina in lumbar spine;

Thoracic radiculopathy rare

Most common is C5/6, then C6/7;

In L spine most common is L5/S1 then L4/5;

Radiculopathy – clinical

Pain is the most

prominent, along

dermatome of

affected root;

Lumbar disc herniationLumbar disc herniation

With disruption of the anulus, the soft nucleus With disruption of the anulus, the soft nucleus

was pushed through (herniated) the annulus.was pushed through (herniated) the annulus.

Herniation occurs through a tear in the anulus Herniation occurs through a tear in the anulus

fibrosus. fibrosus.

Most common at L4/5 and L5/S1 levels, and Most common at L4/5 and L5/S1 levels, and

then L3/4 level;then L3/4 level;

Herniated disc at upper L spine is rare.Herniated disc at upper L spine is rare.

PathoanatomyPathoanatomy Paracentral herniation is most common;Paracentral herniation is most common;

L3/4 DH: affects L4 root;

L4/5 DH: affects L5 root;

L5/S1 DH: affects S1

root;

Paracentral herniation tends to affect Paracentral herniation tends to affect nerve root of one level lower!nerve root of one level lower!

LDH and SciaticaLDH and Sciatica The most classic symptom of a herniated The most classic symptom of a herniated

disc is radicular pain in the lower disc is radicular pain in the lower

extremity following a dermatomal extremity following a dermatomal

distribution: sciatica. distribution: sciatica.

Mechanical compression;Mechanical compression;

Neuroischemia-->inflammation;Neuroischemia-->inflammation;

Neurochemical factors: immune Neurochemical factors: immune

response response

Focal neurologic deficits; Focal neurologic deficits;

LDH and back painLDH and back pain

Most patients with symptomatic disc Most patients with symptomatic disc

herniations present with leg and back herniations present with leg and back

pain. pain.

The disc is almost aneural, so where The disc is almost aneural, so where

is the pain from? is the pain from?

Mechanical alternation? Innervation Mechanical alternation? Innervation

of a long degenerated disc? of a long degenerated disc?

Biochemical irritation?Biochemical irritation?

Classification of LDHClassification of LDH

ProtrusionsProtrusions

ExtrudedExtruded

SequesteredSequestered

long-standing mild to moderate back pain;

May have a specific incident attributable to the

onset of leg and back pain;

Axial back pain is typically present;

Buttock pain: can be referred or radicular in nature

Radicular pain is more typical and often the more

“treatable” of the complaints;

History and symptomsHistory and symptoms

Patterns of radiculopathyPatterns of radiculopathy

S1 radicular pain may radiate to the

back of the calf or the lateral aspect

or sole of the foot;

L5 radicular pain can lead to

symptoms on the dorsum of the

foot;

L4 radiculopathy: above or below

the knee;

L2 and L3 radiculopathy can

produce anterior or medial thigh

and groin pain

Physical Examinations

Inspection:

Abnormal gait: limping, slapping; footdrop;

Alignment of the spine Extension: loss of

lumbar lordosis, scoliosis;

Palpation and Percussion:

Tenderness at multiple levels;

Local percussion;

Paraspinal muscle spasm;

Neurologic Examination (1)

Sensation: (normal, diminished, or absent )

L4 sensory function is tested at the medial ankle;

L5 at the first webspace between the great and

second toes;

S1 at the lateral aspect of the sole of the foot;

Neurologic Examination (2)

Motor examination

L4 involvement most often affects ankle

dorsiflexion (anterior tibialis);

L5 is tested by toe dorsiflexion, particularly the

great toe (extensor hallucis longus), and hip

abduction.

S1 motor function is assessed by testing plantar

flexion;

Manual muscle test (MMT)

Neurologic Examination (3)

Deep tendon reflexes

The patellar tendon reflex may be diminished

or absent with L3 or L4 involvement;

The Achilles tendon reflex is affected primarily

by S1;

There is no specific reflex that reliably reflects

L5 function.

Specific tests

Straight leg raising test

(SLT): reproduce sciatica

at 35-70 degrees; (for L4,

L5 & S1 radiculopathy);

Lasègue maneuver;

The femoral stretch test:

reproduce anterior thigh

pain (for upper root

pathology);

• X-ray: show spinal degenerative changes

but not a herniated disc; rule out obvious

underlying problems;

• CT: relatively less used;

• MRI: The best;

ImagingImaging

MRIMRI

Axial imagesAxial images

Differential diagnosisDifferential diagnosis

The differential diagnosis should be narrowed The differential diagnosis should be narrowed based on history, physical examination, and based on history, physical examination, and selected imaging tests.selected imaging tests.

idiopathic low back pain; sprain or strain; idiopathic low back pain; sprain or strain;

spinal stenosis;spinal stenosis;

Abscess; tuberculosis; Abscess; tuberculosis;

Tumor;Tumor;

Intrinsic nerve problems; Intrinsic nerve problems;

Nonoperative TreatmentNonoperative Treatment

Physiotherapy: Bed rest should be limited to Physiotherapy: Bed rest should be limited to no more than 2 to 3 days; restore strength, no more than 2 to 3 days; restore strength, flexibility, and function;flexibility, and function;

Pharmacologic Treatment: Nonsteroidal anti-Pharmacologic Treatment: Nonsteroidal anti-inflammatory drugs (NSAIDs) are first-line inflammatory drugs (NSAIDs) are first-line agents; muscle relaxants; agents; muscle relaxants;

Selective transforaminal steroid injections;Selective transforaminal steroid injections;

• A benign disease: Saal and Saal a 90% good or excellent outcome in patients treated nonoperatively;

• Another study: at 1 year, 33% had good results, 49% had a fair result, and 18% had a poor result. At 4 years, good results were reported in 51%, fair results were reported in 39%, and poor or bad results were reported in 10%.

• 10-year follow-up results: 61% improvement in the predominant symptom, 40% resolution of low back symptoms, and 56% satisfaction rate.

Natural HistoryNatural History

Operative TreatmentOperative Treatment

Indications

progressive neurologic deficit;

cauda equina syndrome;

failure of appropriate nonoperative

treatment;

DiscectomyDiscectomy

Release ligamentum

Release ligamentum

Resect laminaResect lamina

Remove disc tissues

Remove disc tissues

Inspect neural foramen

Inspect neural foramen

Cervical discs similar to lumbar discs, but: Nucleus pulpous smaller Discs better supported on lateral margins

Most cervical disc herniations occur in postero-lateral margins

Cervical spondylosisCervical spondylosis

Patients usually present with one or more of: Axial neck pain

Radicular arm pain

Myelopathy

Neurapraxia of upper extremities

Cervical disc herniationCervical disc herniation

Non-specific symptoms: dizzying, nausea, head

ache, upper back pain;

Treatment of radiculopathy

Nonoperative Treatment Cervical radiculopathy often resolves without surgery Conservative methods include PT and anti-

inflammatory medicines

Indications for surgery Continued pain or progressive neurological deficit

indicate need for surgery Anterior and posterior approaches may be used Fusion with or without instrumentation may be done

Typical surgery: ACDF

Anterior cervical decompression and fusion (ACDF);

Anterior discectomy; Bone graft or cage; Instrumentation;

Myelopathy (1)Myelopathy (1)

Hand dysfunction Distal often more affected

Difficulty with buttons, handwriting Otherwise, extensor pattern ‘pyramidal pattern’

Triceps, wrist extension Leg dysfunction

Balance difficulty Staggering gait Tandem gait difficulty very early finding

A group of symptoms resulting from spinal cord A group of symptoms resulting from spinal cord compression, including:compression, including: A group of symptoms resulting from spinal cord A group of symptoms resulting from spinal cord compression, including:compression, including:

Myelopathy (2)Myelopathy (2)

Sensory disturbance

Often bilateral hand difficulty, sensory level as

disease is more severeait

Upper motor neuron signs

Babinski response, hyperreflexia, Hoffman’s

sign, increased tone, stiff gait

Degenerative myelopathy – natural history

Typically that of worsening;

Stepwise in 50%, progressive in 50%;

Therefore, patients with myelopathy are usually

treated surgically;

Surgery typically performed in expedited fashion; Relative to rate of deterioration

Lost neurological function is often not regained – the

reason to perform early surgery

Surgery

LaminectomyLaminectomy LaminaplastyLaminaplasty

Cervical spondylosisCervical spondylosis

After decompressionAfter decompression

A narrowing of the spinal canal;

Lumbar spine stenosis (LSS)Lumbar spine stenosis (LSS)

one of the most common conditions in the elderly;

Can occur in asymptomatic individuals: Radiographic stenosis is common;

in adults older than 65, LSS is the most common reason to undergo lumbar spine surgery;

Three shapes of the Three shapes of the spinal canalspinal canal

The narrowed canal

ClassificationClassification

Central stenosis;

Lateral recess stenosis;

Foramen stenosis;

Clinical presentationClinical presentation

Most commonly present with leg pain:

neurogenic claudication or radicular leg

pain; Low back pain, common;

Bowel and bladder incontinence, uncommon;

Neurogenic claudicationNeurogenic claudication Spinal stenosis compressing central lumbar spine below Spinal stenosis compressing central lumbar spine below

level of spinal cord may cause neurogenic claudication;level of spinal cord may cause neurogenic claudication; Walking induced leg symptoms of heaviness, numbness, Walking induced leg symptoms of heaviness, numbness,

pain, cramping, burning or weakness;pain, cramping, burning or weakness; Leaning forward posture while walking; (why?)Leaning forward posture while walking; (why?) Relieved by sitting;Relieved by sitting; Differential diagnosisDifferential diagnosis

Peripheral neuropathyPeripheral neuropathy Stocking pattern, diabetes Stocking pattern, diabetes

vascular claudicationvascular claudication Look for nail changes, hair loss, pulses on feetLook for nail changes, hair loss, pulses on feet

Typically occurs in older age groups (>65yrs)Typically occurs in older age groups (>65yrs)

Imaging: X-rayImaging: X-ray

Imaging: CTImaging: CT

Imaging: MRIImaging: MRI

TreatmentTreatment

Rarely progresses to severe deficits, is more of Rarely progresses to severe deficits, is more of a pain syndromea pain syndrome

initial treatment is conservativeinitial treatment is conservative Weight loss, smoking cessation, physiotherapyWeight loss, smoking cessation, physiotherapy Decompressive surgery considered:Decompressive surgery considered:

if trial of 3 months conservative therapy fails, AND if trial of 3 months conservative therapy fails, AND disability is bad enough that patient wishes to disability is bad enough that patient wishes to consider surgery, AND patient factors (medical consider surgery, AND patient factors (medical comorbidities) are such that surgery can be comorbidities) are such that surgery can be performedperformed

Operative treatment: Operative treatment: laminectomylaminectomy

The Rock Mountain, 2012