The Spine

Herniated disc:

When theNP(jelly-like) leaks through a tear in the AF(strong cartilage wall)
- Causes discomfort and potential nerve compression
- Leads to disc degeneration
- Most common in people 30-50yrs
- 2:1 male to female ratio
Stages
- Normal
- Degeneration
- Prolapse
- Extrusion
- Sequestration - herniation - rupture
Caused by changes in the disc:
- Degeneration: disc water content that acts as a cushion decreases
- Clumping: what makes up the NP becomes clumpy → Difficult to contain
- Mechanical compression: protrusion of the NP can compress the nerve
Most common in lumbar and cervical spine
- Lumbar: greater range of motion, more stress due to curvature and location
- Cervical: aging
- Thoracic: supported by ribs → prevents excessive motion
Causes & risk factors:
- Aging
- Prolonged sitting
- Obesity
- Heavy lifting
- Repetitive bending/twisting
Cervical symptoms:
- Cervical radiculopathy:
  - nerves in spinal column are damaged/irritated (nerve root is compressed/impeded)
- Pain between shoulder blades/neck/chest → radiates to arm/hand
- numbness/tingling in arms
Lumbar symptoms:
- Sciatica:
  - Sciatica nerve pain → shooting pain down leg
- Back pain
- tingling/numbness in legs/feet
- Muscle weakness
Diagnosis - Imaging:
- MRI - most common
  - Shows the disc and each of its parts, location, severity of the herniation and nerve pressure
- X-Ray
  - Rules out other causes of back pain (tumor, infection broken bones, spinal alignment issues)
- CT Scan
  - Helpful if the disc is calcified
- Myelogram
  - Dye is injected into the spinal fluid and shows pressure on the spinal cord/nerves
Management:
- NSAIDs, muscle relaxants, PT, spinal injections (epidural, nerve block, cortisone shot)
  - Inflammation reduction & pain relief
Surgeries:
- Discectomy:
  - Removes herniated portion of NP that bulged through AF → relieves pressure on spinal nerves
  - Most common, less invasive, short recovery period 2-4 weeks
  - Posterior incision for lumbar
  - Anterior for cervical
- Laminectomy:
  - Removes part or all of lamina (bony arch in vertebrae) to relieve pressure on spinal cord/nerves
  - Used when discectomy fails sometimes used together
  - Longer recovery period 4-6 weeks
  - Sometimes remove whole spinous process as well
- ACDF Anterior Cervical Discectomy & Fusion:
  - Used to avoid injury to nerves with brain and spinal cord
  - Used when disc damage is in the front of the spine or multiple fusions are needed
- PLIF Posterior Lumbar Interbody Fusion (ALIF):
  - Lumbar and thoracic herniation
  - Used if disc damage is easier to access posteriorly to avoid organs and muscles
  - Restore the height of a disc
  - Can be done anteriorly depending on location
- Artificial Replacement:
  - Maintains normal spinal mechanics → prevents further damage to other discs
  - Faster recovery → no bone fusion
  - Long-term pain relief
  - eDAPS: Endplate-modified disc-like angle ply structure
    - Designed to mimic natural discs
    - Made of hydrogel seeded with cells between polymer endplates
    - Research has shown that they have maintained compressive strength, biocompatibility, and mimic native motion and function long term
    - Rejection rate is down and motion is up

Scoliosis:

Sideways curvature of the spine
3 types
- Idiopathic
  - Most common
  - Possibly caused by genetics
  - Diagnosed during adolescence
- Congenital
  - Results from embryonic malformation
  - Diagnosed at birth or as young child
- Neuromuscular
  - Occurs after a neurological or muscular disease
  - Cerebral palsy, spinal cord trauma, spina bifida
  - Fastest progressing
Idiopathic
- More common in females
  - Differences in hormones that can affect bone strength
- Severity ranges
  - Cobb angle ~ measured from two most tilted vertebrae above and below the apex
  - Mild curve: cobb angle of 20 degrees or less
  - Moderate curve: cobb angle of between 25-40 degrees
  - Severe curve: cobb angle of more than 50 degrees
Diagnosis
- Identifiable by biological traits
  - Uneven shoulders, hips unevenly raised, rib cage at different heights
  - The entire body leans to one side
  - Experience back pain
- Physical examination
  - “Adam’s Forward Bend Test” ~ bend at the waist and let arms hang loosely by sides
    - One side of the rib cage will be more prominent
- X-ray
  - Confirm diagnosis and determine cobb angle
Non-surgical Treatment
- Mild curves do not require treatment
- Moderate curves treated with braces
  - Bones should still be growing
  - Brace prevents the curve from worsening over time
  - Brace success depends on the length of time worn
    - Recommended 13-16 hours a day
- Modular Italian Brace
  - Rigid push-up brace
  - Module pieces which can be adapted as the patient grows
  - Semi-rigid pelvic material
  - Shown equal effectiveness compared to the Sforzesco brace
  - Users are 5.3 times more likely to improve
    - Increased comfort = increased compliance
- Sforzesco Brace
  - Rigid push-up brace
  - New braces are needed as the patient grows
  - Rigid pelvic material
Surgical Treatments
- Posterior spinal fusion
  - Patient has completed growing or within last 2-3 years of growth
  - Connect 2+ vertebrae
  - Bone material placed in between and secured with metal rods and screws
  - Can reduce curve to 25 degrees or less
    - Bones will not continue to grow
- Expanding rod
  - Used is patient is still growing
  - Expandable rods attached to the sides of the spine which can be adjusted as the child grows
  - Rods help to guide spinal growth straight
  - Procedures must be continually done
- Vertebral body tethering
  - Screws placed on the outside of the spinal curve
  - Strong, flexible cord threaded through screws
  - Cord placed under tension
  - Tether slows the growth of curved side
    - Allows other side to catch up
  - Allows bone to continue to grow
    - Greater spine mobility
  - Recently FDA approved

Spina Bifida:

Congenital neural tube defect where the spine and spinal cord do not develop properly
- Neural tube is not fully closed
3 types
- Occulta
  - Mild, often asymptomatic
- Meningocele
  - Meninges protrude through gap in the spine
- Myelomeningocele
  - Most severe
  - Spinal cord and nerves exposed
Causes and risk factors
- Folate deficiency
  - Folic acid play crucial role in preventing neural tube defects
- Genetics
  - Mutations in genes related to folate metabolism
  - Single-gene mutations and chromosomal aberrations
- Maternal obesity
- Diabetes
- Medication during pregnancy
Symptoms and Complications
- Mobility issues
  - Paralysis or weakness, typically in the legs
- Bowel or bladder dysfunction
- Hydrocephalus
  - Fluid accumulation in the brain
- Neurological issues
  - Learning difficulties
  - Chiari II malformations
Diagnosis
- Prenatal diagnosis
  - Ultrasound
    - Detects physical deformities in the fetus
  - Amniocentesis
    - Tests for elevated alpha-fetoprotein
      - Linked to neural tube defects
- Postnatal diagnosis
  - MRI/CT scan
    - Used to assess severity
Treatment Options
- Surgical interventions
  - Postnatal surgery
    - Closing spinal defect shortly after birth
  - Fetal surgery
    - Emerging techniques showing improved outcomes in preventing neurological damage
  - Stem cell research
    - Early trials
    - Promote spinal cord regeneration
Long term outlooks
- Mobility devices
  - Wheelchairs or leg braces
- Ongoing medical support
  - Management of bladder/bowel issues
  - Surgeries to treat hydrocephalus
- Psychological and social
  - Addressing cognitive delays and depression
Prevention
- Folic acid
  - Daily intake 400mg during pregnancy → reduces risk of neural tube defects by 70%
Research advances
- Genetics
  - How mutations contribute to NTDs (neural tube defects)
- Stem cell treatments
  - Early-stage research → promise in improving mobility, reducing paralysis with in-utero stem cell applications