Conditions of the Spine (Non-Trauma)

Anatomy of the spine

The spine consists of 33 vertebrae divided into 5 sections. There are 7 cervical vertebrae (in lordotic alignment), 12 thoracic rib-bearing vertebrae (in kyphotic alignment) and 5 lumbar vertebrae (in lordotic alignment). These upper 24 are articulating vertebrae. The 5 sacral and 4 coccygeal vertebrae are fused together to form the saccrum and coccyx, respectively.

Definition of terms

Term	Definition
Spondylosis	Degeneration of the interfaces between the vertebrae
Spondylytis	General term for an inflammatory disease of the spine
Spondylolysis	A name for a spinal stress fracture
Spondylolysthesis	Malalignment of the vertebra along the intervertebral disk (usually due to repeated spinal stress fracture)
Radiculopathy	Nerve root irritation that causes radicular pain, weakness and numbness
Myelopathy	Spinal cord compression
Sciatica	Lumbar radiculopathy where pain radiates down the lower extremity

Degeneration of the spine

Degeneration of the spine occurs to a certain degree with age. The spine and intervetebral discs undergo significant age-related degeneration. The nucleus pulposus becomes stiffer due to collagen deposition (begins in the 20s). These changes cause decreased stability of the spine leading to osteophyte complex (bone spur formation) around the disk or elswhere (in the laminar or articular facets).

Types of degeneration (spondylosis)

Types of degeneration	Description
Facet arthropathy	Degeneration of the zygapophyseal (facet) joint
Degenerative disc disease	Degeneration of the vertebral disc. Increases the risk of disc herniation
Spinal stenosis	Narrowing of the spinal canal

• Risk factors for degeneration of the spine
  • Elevated BMI
  • Obesity
  • Smoking
  • Alcoholism
  • Occupation: manual labor, athletes
  • Genetics
  • Co-existing conditions
  • Age
• Complications of spondylosis
  • Back pain (ranges from mild to severe)
  • Radiculopathy (due to compression of nerve root)
  • Myelopthy (due to compression of the spinal cord)

Discogenic Low Back Pain

Discogenic low back pain refers to low back pain that results from disc degeneration. It common and occurs in 80% of the general population.

• Pathophysiology of disc degeneration
  • Loss of water from the disc → reduced size and thickness of the disc → more pressure on the vertebrae on either side of the disc
  • Release of inflamamtory mediators → irritation of nerves at the annulus → back pain
  • May be associated with bony osteoarthritic changes of the facet joints and spinal stenosis
• Signs and symptoms
  • Low back pain
    • Worse in the morning
    • Improves throughout the day
• Treatment
  • Physical therapy
  • NSAIDs and muscle relaxants
  • Epidural injections
  • Operative treatment
• Indications for operative treatment
  • Severe spinal stenosis
  • Intractable pain
  • No response to conservative measures

Disc Hernation

Disc herniation – aka bulging disc, slipped disc, or ruptured disc – occurs when a tear in the annulus allows the nucleus pulposus material to extrude through the annulus. It is a type of disc degeneration. The extruding material may compressing exiting or traversing nerve roots resulting in radiculopathy, or compress the spinal cord resulting in myelopathy (common in the cervical spine).

Degrees of herniation

Degree of herniation	Description
Disc bulge	Compression and bulging of > 25% of the circumference (circumferential or asymmetric)
Disc protrusion	Involves < 25% of the circumference and the base is wider than the herniated contents
Disc extrusion	Involves < 25% of the circumference and the base is narrower than the herniated contents
Disc sequestration	Free fragment of the disc material that is not connected to the disc

• Non-operative treatment
  • NSAIDs
  • Physical therapy
  • Self-resolves within about 6 – 8 weeks
• Indications for operative treatment
  • Cauda equina syndrome
  • Persistent pain and weakness beyond 6 – 8 weeks
  • Myelopathy
• Operative treatment
  • Anterior cervical discectomy and fusion (ACDF or anterior cervical decompression) for the cervical spine
  • Discectomy: thoracic and lumbar spine
  • Laminectomy: if there are osteophytes that contribute to the radiculopathy)

Facet Artrhopathy

Lumbar facet arthropathy is a common cause of lower back pain since the lumbar facet joints take a majority of force in rotational motion, as well as significant force in vertical compression and shear. Diagnosis is clinical.

• Risk factors
  • Old age
  • Osteoarthritis
  • Systemic inflammatory arthirtidies: ankylosing spondylitis, rheumatoid arthritis
• Patient history
  • Older patient with chronic low back pain
• Signs and sympoms
  • Chronic lower back pain
    • Dull and wrapping
    • Worse with movement: rotating, bending over
• Physical examination
  • Normal neurological exam
• Investigations
  • Imaging (plain films): to rule out other possible causes of back pain
• Treatment
  • Intra-articular steroid or local-anaesthetic injection under fluoroscopic guidance (retrodiagnostic if successful)
  • NSAIDs

Radiculopathy

Radiculopathy is the compression of a spinal nerve root. This commonly occurs at the lumbar level (L5). Nerve compression can be caused by osteophytes or disc herniation.

Common sites for radiculoapthy

Site	Signs and symptoms
L4	Numbness/weakness of the leg, diminished patellar reflex, foot spared
L5	Numbness of back of the leg and foot, weakness of dorsiflexion (heel-walking)
S1	Numbness of back of the leg and sole, weakness on plantarflexion (tip-toeing), diminished Achilles’ reflex
S2, S3 and S4	Sexual dysfunction, bowel/bladder dysfunction, saddle anaesthesia

• Risk factors
  • Age
  • Heavy manual labour
• Patient history
  • Older patient with a history of chronic back pain and new onset radiculopathic symptoms
  • An inciting event cannot be elicited
• Signs and symptoms
  • Distributed pain radiating downwards
    • Precise location and distribution depends on the spinal nerve root affected
    • Aching, burning, or electric-shock like character
  • Paraesthesia
  • Weakness
  • Numbness
  • Symptoms exacerbated by prolonged activity, extended sitting and certain positions
  • Symptoms may be alleviated by layin gdown
• Physical examination
  • Positive straight leg raise sign (symptoms elicited by flexing the leg at the hip at 90 degrees)
  • Gait abnormalities
• Differentials
  • Cauda equina syndrome: also presents with back pain, referral to the leg and lower extremity weakness. Will also include bowel/bladder dysfunction, sexual dysfunction, and saddle anaesthesia
• Investigations
  • Plain films
  • MRI: most accurate test
• Treatment
  • Operative or non-operative depending on the cause, severity or comorbidities

Spinal Stenosis

Spinal stenosis is narrowing of the spinal canal. It commonly occurs due to aging but multiple factors (including congenital causes, trauma or tumors) can cause narrowing. Cervical and lumbar stenoses are more common than thoracic.

Commonly in patients over 50 years old.

• Causes of spinal stenosia
  • Congenital
  • Trauma
  • Tumor
  • Disc herniation
  • Osteophytes
  • Hypertrophy of the ligamentum flava
• Signs and symptoms
  • Bilateral symptoms (unlike radiculopathy)
  • Chronic neck or lower back pain
  • Numbness, paraesthesia and/or weakness (predominates)
  • Bowel/bladder dysfunciton in lower stenosis
  • Neurogenic claudication (lumbar region): progressive pain and weakness in the legs with ambulation, resolves by sitting down and bending forward
• Investigations
  • MRI: best initial test when stenosis is suspected
• Non-operative treatment
  • Epidural steroid injections
  • Physical therapy to strengthen the core
• Operative treatment (indicated if there is progressive neurological deficits)
  • Decompression and fusion if multiple levels are affected

Ankylosing Spondylitis

Ankylosing spondyltis is a seronegative autoimmune disease that affects the axial skeleton and joints (shoulder and hip). It is HLA-B27 positive.

More predominant in young men (under the age of 40) with a male to female ratio of 4:1.

• Signs and symptoms
  • Persistent and chronic refractory lower back pain
    • Worse in the morning
    • Improves throughout the day (like most autoimmune disease)
• Physical examination
  • Loss of lumbar lordosis (represents fusion of lumbar spinal processes – makes the patient susceptible to spinal fracture)
• Investigations
  • Lumbar spinal X-ray: best initial diagnostic test
    • Bamboo spine (fusion of lumbar spinal vertebral processes)
  • Other imaging tests
• Treatment
  • NSAIDs
  • Physiotherapy
  • TNF blockers (infliximab, adalimumab, etanercept, golimumab): second-line

Cauda Equina Syndrome

Cauda equina syndrome is severe compression of the nerve roots in the cauda equina leading to loss of bowel and bladder function, and saddle anaesthesia. Cauda equina is latin for horse’s tail. They are a set of intradural nerves that provide sensory and motor innervation from L2 to S5. The conus medullaris ends at around L1/L2 in adults . After L2 all nerve roots derive from the cauda equina. The nerve roots innervate hip muscles, lower extremity muscles, urinary and anla sphincters, and muscles important for sexual function. Disc herniation is the most common cause of cauda equina syndrome.

• Causes
  • Disc herniation (most common cause)
  • Lumbar stenosis
  • Trauma
  • Neoplasm
  • Infection or abscess
  • Inflammatory disease: Chronic inflammatory demyelinating polyneuropathy, Paget’s disease, and Ankylosing spondylitis
• Patient history
  • Older patient (due to degenerative changes)
  • Trauma (for acute cauda equina syndrome)
  • Cancer
• Signs and symptoms
  • Unilateral or bilateral symtpoms
  • Chronic lower back pain
  • Lower extremity weakness or sensory deficits, pain, and paraesthesias
  • Urinary and fecal incontinence (due to loss of sphincter tone)
  • Erectile dysfunction
  • Reduced or absent deep tendon relfexes
  • Imbalance
• Physical examination
  • Saddle anaesthesia (S1 – S5 dermatome)
  • Reduced lower extremity strength
  • Reduced sensation over particular dermatomes
  • Reduced or absent deep tendon reflexes
  • Reduced/absent cremasteric refleX (L1/L2)
  • Reduced/absent bulbocavernous reflex (S2-S4)
• Investigations
  • Lumbar spine MRI: most accurate test. First investigation provided the patient is stable
  • CSF analsysis: if there are meningeal signs and symptom
• Treatment
  • Rehabilitation (physiotherapy or occupational therapy)
  • Operative treatment

Spondylolysis

Spondylolysis is a stress fracture that commonly occurs at the pars interarticularis (on the lamina bewteen the transverse and spinal process). It is the most common cause of acute lower back pain in young patients. It is common in young athletes and old patients (with osteoporosis). 95% of cases occur at L5.

• Patient history
  • Repetitive bending and straigtnenign of the spine (gymnastics, football, divers)
• Signs and symptoms
  • Back pain
    • Aggravated by bending (usually backwards)
  • Unremarkable neurological examination
• Investigations
  • Lumbar X-ray (AP, lateral and oblique view)
    • Scotty Dog sign on oblique view (fracture appears as the collar)
• Treatment
  • Rest or activity modification
  • Operative treatment rarely indicated

Metastasis to the spine

Spine metastasis is common, especially from breast and prostate cancer. The median survival after spinal metastasis is 10 months

• Signs and symptoms
  • Back pain
  • Neurological signs and symptoms
  • Bowel/bladder dysfunction
• Investigation
  • Plain films
  • MRI spine
  • Workup for cancer if there is no known history
• Treatment
  • Based on the underlying cancer
  • Palliative care

Scoliosis

Scoliosis is a disorder of spinal alignment that results in right or left curvature of the spine (usually thoracic, most commonly curved to the right). Scoliosis has varying severity (from subclinical to severe deformity affecting pulmonary function). Most cases are mild and asymptomatic. Severity is measured using Cobb angle (angle between the most tilted vertebrae and teh top and bottom of the curvature). Diagnosis is clinical. Treatment focuses on preventing progression over reversing the curvature.

It is common. Occurs in 1.2 – 3.0% of the general population. Has a female preonderance. It is noted during adolescence and worsens until the end of skeletal maturation.

Classification

Cause	Description
Idiopathic	Most common. Presents around puberty as children grow through a growth spurt
Congenital	Related to abnormal morphology of the vertebrae
Syndromic	Associated with a genetic syndrome
Neuromuscular	Associated with neuromuscular disorder such as muscular dystrophy
Degenerative	Results from the aging process

• Causes
  • Idiopathic (most common)
  • Congenital
  • Neuromuscluar causes
• Patient history
  • Female
  • Noted on physical exam
  • Family history
• Signs and symptoms
  • Asymptomatic
  • Pain should raise suscpicion for another diagnosis
• Physical examination
  • Adams forward bend tests: notes abnormal contour of the spine
  • Unlevel shoulders
  • Scapular protrusion
  • Neurological examination to rule out neuromuscluar causes (upper motor neuron signs and gait abnormalities)
• Investigations
  • AP and lateral spine X-rays: to monitor progress
  • Scoliometer: for the severity of curvature
• Differentials
  • Congenital scoliosis: notable from birth or childhood
  • Neuromuscular scoliosis: accompanied by upper motor neuron signs (often the DCML tract) – hyperreflexia, primitive reflexes and gait abnormalitites
  • Syringomyelia: abnormal neurological examination (cape-like distribution of loss of paint and temperature sensation)
• Non-operative treatment
  • Observation (< 20 degrees curvature)
  • Bracing (20 – 45 degrees curvature, especially in young individuals)
  • Regular exercise focusing on core strength
• Indications for operative treatment
  • Progressive curvature that causes thoracic insufficiency or restriction of skeletal maturity
  • Coronal plane or sagittal plane imbalance leading to symptoms of radiculopathy or spinal stenosis in adults
• Operative treatment
  • Arthodesis (> 45 degrees cuvature)