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Flashcards in Spine Deck (32):

What are the extrinsic muscles of the back? How are they innervated?

Superficial: movements of the upper limb
- trapezius
- levator scapulae
- rhomboid major and minor
- latissimus dorsi

Intermediate: movements of thoracic wall
- serratus posterior superior
- serratus posterior inferior

Innervated by ant. rami of spinal nerves


What are the intrinsic muscles of the back? How are they innervated?

Erector spinae

Inntervated by pos. rami of spinal nerves

- support head and move vertebral column
- move head
- move ribs relative to vertebral column


What are the different types of spina bifida?

Occulta = defect in posterior arch of vertebra of L5 or S1; asymptomatic; overlying skin intact

Cystica = defect in posterior arch of vertebra of L5 or S1; open defect; visible mass
- meningocoele: swelling of dura mater and arachnoid mater
- myelomeningocoele: swelling of dura mater, arachnoid mater, and spinal neural tissue
- rachischisis: spine lies open and neural plate splayed


Ouline a vertebroplasty. When is it indicated?

Body of vertebra filled with bone cement to increase the strength of the vertebral body (prevent further loss of height) and disrupt the pain nerve endings (via heat generated by cement)

Indicated for:
- vertebral body collapse and pain from vertebral body
- osteoporotic wedge fractures


What is kyphosis? Give some causes.

Abnormal curvature of thoracic vertebrae

Can be secondary to TB of thoracic vertebrae ---> gibbus deformity


What is scoliosis? Give some causes.

Abnormal lateral curvature + rotational element of one vertebra upon another (true scoliosis)

Congenital: associated with abnormalities of chest wall, genitourinary tract, and heart

May be manifestation of central or peripheral nerve abnormalities e.g. cerebral palsy, polio

Muscular dystrophy: abnormal muscle does not retain normal spine alignment

Bone tumours, spinal cord tumours, localised disc tumours also cause scoliosis.


What is lordosis?

Abnormal curvature of lumbar vertebrae ("swayback deformity")


What are the components of a vertebral disc?

Nucleus pulposus = gelatinous centre (absorbs compression forces between vertebrae)

Anulus fibrosis = outer ring of collagen and wider zone of fibrocartilage in lamellar configuration (limits rotation of vertebrae)


What are the ligaments of the vertebral column?

Anterior longitudinal ligament = base of skull to ant. surface of sacrum; attached to vertebral bodies and intervertebral discs

Posterior longitudinal ligament = C2 to base of skull (tectorial membrane) to sacrum

Ligamenta flava = pass between laminae of adjacent vertebrae to form posterior surface of vertebral canal (resists separation of laminae in flexion and assists in extension back to anatomical position)

Supraspinous ligament = vertebral spinous processes from C7 to sacrum

Interspinous ligament = between adjacent vertebral spinous process

Ligamentum nuchae = external occipital protruberance to foramen magnum to tip of spinous process of C7 (supports head, attachment for adjacent muscles)


What are the components of spinal stenosis?

Zygapophyseal joint hypertrophy + ligamenta flava hypertrophy + mild disc protrusion = reduced dimensions of vertebral canal

Caused by degeneration of vertebral column


What are the components of vertebral stability?

Anterior column:
- vertebral bodies
- ant. longitudinal ligament

Middle column:
- vertebral bodies
- pos. longitudinal ligament

Posterior column:
- ligamenta flava
- interspinous ligaments
- supraspinous ligaments
- ligamentum nuchae


What are the results of destruction of the components of vertebral stability?

Destruction of one column ---> stable injury (rest and analgesia)

Destruction of two columns ---> unstable (req. fixation and immobilisation)

Destruction of three columns ---> significant neurological defect (fixation to prevent further extension of neurological defect and stabilise vertebral column)


What are the consequences of injury to the craniocervical junction?

High chance of significant spinal cord injury.

- quadriplegia
- phrenic nerve paralysis ---> resp. depression
- disruption of central part of symp. nerves ---> severe hypotension


What is spondylolisthesis?

Vertebra slips anteriorly due to abnormal anatomy of facet joints or degenerative changes


What is spondylolysis?

Degenerative osteoarthritis of pars interarticularis (region between superior and inferior facets) due to incomplete developlment.

Predisposes to spondylolisthesis.


What is spondylosis deformans?

Growth of osteophytes around a degenerating intervertebral disc


What are the indications for spinal fusion?

- stabilisation after fracture
- stabilisation related to tumour infiltration
- stabilisation when mechanical pain is produced from disc or posterior elements


What results from injury to the accessory nerve?

Weakness of trapezius
- drooping of shoulder
- inability to raise arm above head (impaired rotation scapula)
- weakness attempting to raise shoulder


What results from injury to the thoracodorsal nerve?

Weakness of latissimus dorsi
- reduced capacity to pull body upwards whilst climbing


What results from injury to dorsal scapular nerve?

Weakness of rhomboids
- lateral shift of scapula on affected side (rhomboids cannot oppose lateral pull of antagonist muscles)


What is the origin, insertion, innervation, and function of the trapezius?

Origin: superior nuchal line, external occipital protruberance, ligamentum nuchae, spinous processes of C8 to T12
Insertion: lateral 1/3 of clavicle, acromion, spine of scapula
Innervation: accessory nerve
Function: rotation of scapula when abducting humerus above 90 degrees


What is the origin, insertion, innervation, and function of the latissimus dorsi?

Origin: spinous processes of T7 to L5 and sacrum, ribs 10 to 12
Insertion: floor of intertubercular sulcus of humerus
Innervation: Thoracodorsal nerve (C6-C8)
Function: extension, adduction, medial rotation of humerus


What is the origin, insertion, innervation, and function of levator scapulae?

Origin: transverse processes of C1-C4
Insertion: upper portion of medial border of scapula
Innervation: C3-C4, dorsal scapular nerve
Function: elevation of scapula


What is the origin, insertion, innervation, and function of the rhomboids?

- major = spinous processes of T2-T5
- minor = lower portion of ligamentum nuchae, spinous processes C7 and T1
- major = medial border of scapula, between spine and inferior angle
- minor = medial border of scapula, at spine of scapula
Innervation: dorsal scapular nerve
Function: retraction (adduction) and elevation of scapula


What is the origin, insertion, innervation, and function of serratus posterior superior?

Origin: lower ligamentum nuchae, spinous processes of C8-T3, supraspinous ligaments
Insertion: upper border ot ribs 2-5
Innervation: ant. rami of thoracic nerves (T2-T5)
Function: elevates ribs 2-5


What is the origin, insetion, innervation, and function of serratus posterior inferior?

Origin: spinous processes of T11-L3 and supraspinous ligaments
Insertion: lower border or ribs 9-12
Innervation: ant. rami of thoracic nerves (T9-12)
Function: depresses ribs 9-12


Which nerve does disc herniaton affect?

Traversing nerve root

e.g. C6/C7 ---> C6 nerve affected
e.g. L3/L4 ---> L4 nerve affected


Which way does a disc usually herniate?

Usually posterolateral due to strength of pos. longitudinal ligament

Exception: in cervical spine ant. longitudinal ligament is stronger due to narrow vertebral canal ---> disc herniates centrally


What are the dermatomes and myotomes?

C5 = regimental badge/deltoid, elbow flexion (biceps and brachialis)
C6 = radial arm and forearm, thumb, index (six-shooter), wrist extension
C7 = middle finger (7-up), elbow extension
C8 = ulnar forearm, finger flexion
T1 = medial arm, finger ab/adduction
L1 = inguinal ligament (hands in pockets), cremasteric reflex
L2 = ant. thigh, hip flexion (iliopsoas - straight leg raise)
L3 = knee, knee extension (quadriceps - femoral nerve)
L4 = lat. leg -> shin -> top of foot (dorsiflexion - tibialis anterior)
L5 = big toe, big toe dorsiflexion (extensor hallucis longus)
S1 = sole and lat. aspect of foot, plantarflexion (gastro-soleus complex)
S2-S4 = saddle area, DRE (resting anal tone, sphincter contraction)


What are the signs and symptoms of cauda equina?

- bilateral sciatica/leg pain
- paraesthesia

- faecal incontinence
- painless urinary retention ---> overflow incontinence
- asymmetrical, mild weakness
- decreased knee and ankle reflexes
- positive Babinski reflex
- asymmetrical, radicular pattern of sensory loss ---> , saddle anaesthesia
- paralysis
- pyrexia
- age extremes
- weight loss, night sweats, PMHx cancer


Contrast the symptoms of ischaemic and neurological claudication.

- site of pain = distal (atherosclerosis affects smaller vessels)
- uphill = increases pain (increased muscle work)
- downhill = decresed pain (decreased muscle work)

- site of pain = proximal (larger muscle groups req. more nerve stimulation, therefore affected first)
- uphill = reduced pain (flexion of spine gives more space)
- downhill = increased pain


Give some examples of spinal cord compression.

- pos. longitudinal ligament laxity + disc degeneration ---> disc encroaches on ant. spinal cord (pain leaning forwards)
- facet joints capsular distension/hypertrophy + osteophytes ---> facet joint stenosis (pain leaning backwards)
- hypertrophy of pos. side of ligamentum flavum

note: central stenosis causes pain downwards and "heavy legs"
note: foramenal stenosis causes pain along dermatomes +/- focal weakness