SPINE (CERVICAL , THORACIC , LUMBER , SACRAL , COCCYGEAL) SURGICAL MCQs

Which surgical approach for thoracic disk herniations is associated with the highest rate of neurologic injury? 

1. Costotransversectomy 
2. Lateral extracavitary 
3. Midline laminectomy 
4. Transpedicular 
5. Transthoracic

ANSWER Midline laminectomy Costotransversectomy , lateral extracavitary , transpedicular ,and transthoracic  approaches all facilitate access to the thoracic disk space without the need for retraction on the thecal sac. Approaching a thoracic disk herniation through a simple laminectomy  would require thecal sac retraction and risk resultant neurologic injury. Posterior decom pression alone (laminectomy  without diskectomy) is unlikely to im prove symptoms as the pathologic process involves ventral compression across an already kyphotic spinal segment. The risk of either neurologic deterioration or no benefit with laminectomies for thoracic disk herniation is 45%.

Each of the following is characteristic of complex regional pain syndrome II (causalgia) except 

1.  Atrophic changes in the limb 
2.  Hypesthesia 
3.  Increased sweating 
4. Lack of major motor defcit 
5. Good relief with sympathetic block

ANSWER Hypesthesia Complex regional pain syndrome type II (CRPS II, form erly causalgia) is characterized by atrophic changes in the affected limb , increased sweating , absence of a major motor defcit , good response to sympathetic blockade , and hyperesthesia (increased sensitivity to stimulus). CRPS II is diagnosed in the setting of a know n nerve injury. The diagnosis CRPS I (form erly refex sympathetic dystrophy or Sudeck’s atrophy) is made only in the absence of known nerve injury. Neither condition is associated with hypesthesia , decreased sense of touch or sensation

 Which of the following fractures has the poorest prognosis for healing without surgical intervention?

1.  Hangman’s 
2. Jeferson’s fracture with 4 mm displacement of lateral masses 
3. Type I odontoid 
4. Type II odontoid E. Type III odontoid

ANSWER Type II odontoid fracture Type II odontoid (D) fractures have the worst prognosis for healing of the choices presented. Type I (C) and type III (E) fractures generally heal well with immobilization. The burst fracture of C1 (Jeferson’s fracture) (B) usually heals by rigid immobilization unless the transverse ligament is disrupted (lateral masses displaced more than 7 mm ) or the patient is elderly.

Sprengel’s deform ity refers to a(n): 

1.  Congenital elevation of the scapula 
2. Congenital fusion of the upper cervical vertebrae 
3. Intravertebral disk herniation 
4. Post laminectomy kyphosis 
5. Scoliosis resulting from tethering of the spinal cord

ANSWER Congenital elevation of the scapula Sprengel’s deformity refers to a congenital asymmetry of the scapula, with failure of one scapula to completely descend during development. Sprengel’s deformity is often associated with the Klippel-Feil syndrome (congenital fusion of the upper cervical vertebrae [B]). Intravertebral disk herniation (C) is known as a Schmorl’s node. Post laminectomy kyphosis (D) and scoliosis resulting from tethering of the spinal cord (E) are incorrect responses.

Match the fracture type w ith the mechanism . Each response may be used once, more than once, or not at all: 

 A-Distracting extended 

 B-Compression neutral 

 C-Flexing axially rotated 

 D-Compressing Flexed 

 E-Flexing flexed 

 F-Compressing laterally bent 

 G-Compressing neutral

ANSWERS

D- Hangman’s fracture 

 C- Burst fracture 

 E- Unilateral facet dislocation 

 B-Teardrop fracture 

 A-Bilateral facet dislocation 

 F-Horizontal facet fracture 

 C-Jeferson’s fracture

Lateral recess stenosis in spondylosis is most commonly caused by 

1. Disk herniation 
2. Hypertrophied pedicles 
3. Inferior articular facet hypertrophy 
4. Ligamentum flavum hypertrophy 
5. Superior articular facet hypertrophy

ANSWER Superior articular facet hypertrophy This question tests the examinee’s understanding of lumbar anatomy as well as the pathogenesis of lumbar stenosis. The superior articular facet is situated anterolaterally to the inferior articular facet of the level above, and makes up much of the posterior limit of the lateral recess of the lumbar spinal canal. Therefore, superior articular facet hypertrophy (E) is the most common cause of lateral recess stenosis in spondylosis. Disk herniation (A) and ligamentum flavum hypertrophy (D) may contribute to lateral recess stenosis but are less likely to cause lateral recess stenosis than superior articular facet hypertrophy (E). Inferior articular facet hypertrophy (C) is incorrect because the superior articular facet is more closely associated with the lateral recess. Hypertrophy of the pedicles (B) does not contribute to lateral recess stenosis

The syndrome of weakness in one upper extremity followed by lower extremity weakness on the same side, then contralateral lower extrem ity weakness, is most characteristic of a meningioma involving the: 

1. Clivus 
2. Falx 
3. Foramen magnum 
4. Olfactory groove 
5. Tuberculum sella

ANSWER Foramen magnum The “clockwise” progression of weakness described in the vignette is classically associated with lesions at the foramen magnum (C) such as a meningioma. Meningiomas of the clivus (A) may present with cranial nerve palsies. Olfactory groove (D) and tuberculum sella (E) meningiom as may present with visual symptom s, behavioral disturbances, or symptoms from increased intracranial pressure. Parafalcine (B) meningiom as are not associated with the “clockwise” pattern of quadriparesis described.

The most common upper thoracic spine injury is a

1. Burst fracture
2. Compression fracture
3. Fracture-dislocation
4. Seat belt injury

ANSWER : Compression fracture

Which is true of thoracolumbar spine fractures?

1. Burst fractures are the most common.
2. Fracture-dislocations involve all three columns.
3. Seat belt type injuries are generally stable.
4. Wedge compression fractures are generally unstable.
5. Wedge compression fractures involve the middle column.

ANSWER : Fracture-dislocations involve all three columns.

Neural tube defects can be reduced by maternal supplementation of which multivitamin/s :

1.  Vitamin B12 (cyanocobalamin) 
2. Folate
3. Aminopterin 
4. Vitamin C (ascorbic acid) 
5. Vitamin E

ANSWER : Folate

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Which parameters regulate nerve conduction velocity in a myelinated fiber?

1. Axonal diameter, myelin thickness, internode length 
2.  Dendrite length, internode length, axonal length 
3.  Myelin length, number of synapses, axonal diameter 
4.  Cell body size, myelin thickness, dendrite length

ANSWER : Axonal diameter, myelin thickness, internode length 

The cleft in the spinal cord associated with diastematomyelia is most commonly located in the:

1. Cervical region
2. Lumbar region
3. Sacral region
4. Thoracic region

ANSWER : Lumbar region

Approximately what percentage of infants with myelomeningocele have  MRI evidence of a Chiari II malformation?

1. 20%
2. 40%
3. 60%
4. 80%
5. 100%

ANSWER : 100% (due to CSF leaking through the myelomeningocele during development)

Which of the following structures provides a marker for the most dorsal extent of the incision for anterolateral cordotomy for pain control?

1.  Dentate ligament
2.  Dorsal root entry zone
3.  Posterior interm ediate sulcus
4.  Posterior m edian sulcus
5.  Zone of Lissauer

ANSWER : Dentate ligament

The most common etiology of os odontoideum is:

1. Congenital
2. Iatrogenic
3. Infectious
4. Neoplastic
5. Traumatic

ANSWER : Traumatic (Os odontoideum is a segment of odontoid that is well-corticated and is not

fused with the body of the dens. The condition m ay be congenital (1) or traumatic (5); trauma is the more common cause.)

The most common mechanism of translational C1–C2 subluxation is:

1.  Axial loading
2.  Distraction
3.  Extension
4.  Flexion

ANSWER : Flexion

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