Menu

1. General Principles & Basic Science MCQs

Practice Set 10 of 789

This practice set contains high-yield board review questions covering key concepts in 1. General Principles & Basic Science. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 181

Topic: 1. General Principles & Basic Science

A bilateral cervical facet dislocation is a highly unstable injury. What is the primary mechanism of injury responsible for producing this specific pathologic lesion?

. Severe hyperflexion combined with distraction
. Hyperextension with axial compression
. Pure axial loading
. Lateral bending with rotation
. Pure translational shear

Correct Answer & Explanation

. Severe hyperflexion combined with distraction

Explanation

Bilateral facet dislocations result from severe hyperflexion and distraction forces, leading to complete disruption of the posterior ligamentous complex, facet capsules, and often the posterior annulus.

Question 182

Topic: 1. General Principles & Basic Science

C1 reflexes include which of the following:

. Sternocleidomastoid reflex
. Clavicle reflex
. Deltoid reflex
. Jaw jerk
. Biceps reflex

Correct Answer & Explanation

. Jaw jerk

Explanation

The C 1 reflex, while rarely tested, involves the jaw jerk.

Question 183

Topic: 1. General Principles & Basic Science

In the evaluation of traumatic atlanto-occipital dissociation, the Powers ratio is utilized. Which of the following values definitively indicates anterior atlanto-occipital dislocation?

. Ratio > 0.5
. Ratio > 0.7
. Ratio > 1.0
. Ratio < 0.8
. Ratio < 0.5

Correct Answer & Explanation

. Ratio > 1.0

Explanation

The Powers ratio is the distance from basion to posterior arch of C1 divided by the distance from opisthion to anterior arch of C1. A normal ratio is < 0.9, while a ratio > 1.0 defines anterior translation/dissociation.

Question 184

Topic: Physiology & Rehabilitation

A patient suffers a penetrating knife wound to the thoracic spine resulting in a spinal cord hemisection (Brown-Sequard Syndrome). Which of the following deficit patterns is expected below the level of injury?

. Ipsilateral loss of motor function and contralateral loss of pain/temperature sensation
. Contralateral loss of motor function and ipsilateral loss of pain/temperature sensation
. Bilateral loss of pain and temperature with preserved proprioception
. Bilateral motor loss with preserved proprioception
. Ipsilateral loss of pain sensation and contralateral loss of proprioception

Correct Answer & Explanation

. Ipsilateral loss of motor function and contralateral loss of pain/temperature sensation

Explanation

Brown-Sequard syndrome results from a hemisection of the spinal cord. The patient will exhibit ipsilateral loss of motor function and proprioception (corticospinal tract and dorsal columns) and contralateral loss of pain and temperature (spinothalamic tract).

Question 185

Topic: Physiology & Rehabilitation

During a thoracoabdominal aortic aneurysm repair, the artery of Adamkiewicz is inadvertently ligated. The patient develops paraplegia and loss of pain and temperature sensation, but proprioception and vibratory sense are preserved. What region of the spinal cord is primarily affected?

. Dorsal columns
. Anterior two-thirds
. Posterior one-third
. Central gray matter
. Hemisection

Correct Answer & Explanation

. Anterior two-thirds

Explanation

The artery of Adamkiewicz supplies the anterior two-thirds of the spinal cord. Infarction causes anterior cord syndrome, preserving the dorsally located proprioception and vibration pathways.

Question 186

Topic: Physiology & Rehabilitation

A 28-year-old male sustains a stab wound to the right side of his neck at the C5 level, resulting in a spinal cord hemisection. Which of the following neurological deficits is expected below the level of the lesion?

. Contralateral loss of motor function and ipsilateral loss of pain and temperature
. Ipsilateral loss of motor function and contralateral loss of pain and temperature
. Bilateral loss of motor function and pain sensation
. Ipsilateral loss of pain, temperature, and proprioception
. Contralateral loss of motor, proprioception, and vibration

Correct Answer & Explanation

. Ipsilateral loss of motor function and contralateral loss of pain and temperature

Explanation

Brown-Sequard syndrome presents with ipsilateral loss of motor function and proprioception, and contralateral loss of pain and temperature. This occurs because the spinothalamic tract crosses near the cord entry level.

Question 187

Topic: 1. General Principles & Basic Science

Which of the following instruments are of value to a surgeon when performing minimally invasive lumbar fusions:

. Surgical loupes and headlight
. Operating microscope
. Intraoperative fluoroscopy
. Surgical loupes and headlight and operating microscope
. Surgical loupes and headlight, operating microscope, and intraoperative fluoroscopy

Correct Answer & Explanation

. Surgical loupes and headlight, operating microscope, and intraoperative fluoroscopy

Explanation

All of the above instruments are of value to a surgeon when performing minimally invasive lumbar fusion.

Question 188

Topic: 1. General Principles & Basic Science

Which of the following statements is true regarding minimally invasive posterior lumbar interbody fusion:

. Minimally invasive fusion may be safely performed only with the assistance of endoscopy.
. Minimally invasive fusion increases the risk of nerve root injury.
. Internal fixation with pedicle screws is not possible via the minimally invasive approach.
. Intraoperative fluoroscopy is of great value in minimally invasive fusion.
. Minimally invasive surgery has improved fusion rates.

Correct Answer & Explanation

. Intraoperative fluoroscopy is of great value in minimally invasive fusion.

Explanation

Intraoperative fluoroscopy or radiography is vital for the proper identification of lumbar level and vertebral structures in minimally invasive posterior lumbar interbody fusions. While endoscopic assistance has been well described as a method of minimally invasive fusion, it is not vital to this technique. There is no evidence to date of increased risk of nerve root injury with minimally invasive techniques, and it is possible to internally fixate the lumbar segment with pedicle screws through minimally invasive techniques.

Question 189

Topic: 1. General Principles & Basic Science

Which of the following is not a described technique of minimally invasive anterior lumbar interbody fusion:

. Laparoscopic transperitoneal
. Endoscopic retroperitoneal
. Mini-open retroperitoneal
. All of the above are described techniques
. None of the above are described techniques

Correct Answer & Explanation

. All of the above are described techniques

Explanation

All of the above are well-described techniques of minimally invasive anterior lumbar interbody fusion.

Question 190

Topic: 1. General Principles & Basic Science

To avoid vertebral artery injury during cervical lateral mass screw placement, it is best to:

. Start at the midpoint and aim the screw laterally
. Start at the midpoint and aim the screw medially
. Start medially and aim the screw perpendicular
. Start medially and aim the screw medially
. Start laterally and aim the screw medially.

Correct Answer & Explanation

. Start at the midpoint and aim the screw laterally

Explanation

To avoid injury to the vertebral artery when placing lateral mass screws, it is best to avoid placing the screw in the medial portion of the lateral mass, where the vertebral body is most likely to be found.

Question 191

Topic: 1. General Principles & Basic Science

Which of the following statements is true regarding the C 2 lateral mass:

. The vertebral artery assumes a more lateral position at this level.
. The vertebral artery assumes a more medial position at this level.
. The vertebral artery is found outside of the transverse foramen at this level.
. The vertebral artery precludes placement of lateral mass screws at this level.
. None of the above

Correct Answer & Explanation

. The vertebral artery assumes a more lateral position at this level.

Explanation

The vertebral artery assumes a more lateral position at the C 2 level; therefore, screw placement at this level should follow a medial trajectory to avoid injury to the vertebral artery.

Question 192

Topic: 1. General Principles & Basic Science

The technique for C1-C 2 lateral mass fixation may involve:

. Removal of the posterior arch of C1
. Placing the C2 screws through the pedicle
. Following a medial trajectory with the C 1 screws
. Removal of the posterior arch of C 1, and placing the C 2 screws through the pedicle only
. Removal of the posterior arch of C1, placing the C2 screws through the pedicle, and following a medial trajectory with the C1 screws

Correct Answer & Explanation

. Removal of the posterior arch of C1, placing the C2 screws through the pedicle, and following a medial trajectory with the C1 screws

Explanation

The C 1 and C 2 levels have unique anatomies that require variation in lateral mass screw fixation technique. Removing the C1 arch assists in proper placement of the C 1 screws via a lateral trajectory. The C 2 pedicle is large, and pedicle screws arecommonly placed at this level to avoid vertebral artery injury in the small lateral masses. C 1 lateral mass screws follow the long axis of the C 1 lateral mass as visualized on pre-operative C T scanning.

Question 193

Topic: 1. General Principles & Basic Science

Which of the following pathogens is not typically implicated in diskitis:

. Staphylococcus aureus
. Staphylococcus albus
. Pseudomonas aeruginosa
. Staphylococcus epidermidis
. Gram-positive cocci

Correct Answer & Explanation

. Pseudomonas aeruginosa

Explanation

The gram-positive cocci are typical opportunistic pathogens that are capable of causing infection in the vertebral disk space. Most commonly they seed via the hematogenous route but local translocation has also been implicated. Unless a patient has been hospitalized for a while and iatrogenesis is ruled out, Pseudomonas species usually do not cause diskitis.

Question 194

Topic: 1. General Principles & Basic Science

Which of the following may be used as treatment options for bilateral facet dislocations:

. Traction reduction of dislocations
. Halo fixation
. Open reduction
. Open fixation
. All of the above

Correct Answer & Explanation

. All of the above

Explanation

All of the choices are used in the treatment of bilateral jumped facets, often in combination or sequence.

Question 195

Topic: 1. General Principles & Basic Science

A key theoretical advantage of the paramedian Wiltse approach used in minimally invasive lumbar fusion, as opposed to the traditional midline open approach, is the preservation of which of the following structures?

. Supraspinous ligament
. Medial branch of the dorsal ramus
. Psoas major muscle
. Thoracolumbar fascia
. Iliocostalis muscle

Correct Answer & Explanation

. Medial branch of the dorsal ramus

Explanation

The Wiltse approach uses the natural cleavage plane between the multifidus and longissimus muscles. This minimizes devascularization and denervation of the multifidus by preserving the medial branch of the dorsal ramus.

Question 196

Topic: Surgical Anatomy & Approaches

A 55-year-old female undergoes a minimally invasive lateral lumbar interbody fusion (LLIF) at L4-L5. Postoperatively, she demonstrates weakness in hip flexion and knee extension, along with anterior thigh numbness. Which of the following structures was most likely injured during the retractor docking phase?

. Sciatic nerve
. Obturator nerve
. Femoral nerve
. Ilioinguinal nerve
. Superior gluteal nerve

Correct Answer & Explanation

. Femoral nerve

Explanation

The femoral nerve (L2-L4) lies within the posterior aspect of the psoas muscle at the L4-L5 level. Prolonged retraction or direct injury during the transpsoas approach can lead to iatrogenic femoral nerve palsy, presenting with quadriceps weakness and anterior thigh numbness.

Question 197

Topic: 1. General Principles & Basic Science

Which of the following statements is true regarding radiation exposure to the surgical team during minimally invasive (MIS) lumbar fusions compared to traditional open procedures?

. MIS fusions consistently decrease radiation exposure to both the surgeon and patient.
. MIS fusions are associated with significantly higher radiation exposure to the surgeon.
. The use of robotic assistance increases total fluoroscopy time compared to conventional MIS.
. Surgeon radiation exposure is highest during the interbody cage insertion phase.
. Open fusions require more intraoperative fluoroscopy for pedicle screw placement.

Correct Answer & Explanation

. MIS fusions are associated with significantly higher radiation exposure to the surgeon.

Explanation

Because MIS techniques rely heavily on fluoroscopy for anatomical orientation, percutaneous screw placement, and retractor docking, they are associated with significantly higher radiation exposure to the surgical team compared to open procedures, especially during the learning curve.

Question 198

Topic: 1. General Principles & Basic Science

During a single-level minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) using a non-expandable tubular retractor, a small incidental durotomy occurs. The surgeon assesses the tear to be 2 mm. What is the most appropriate management strategy?

. Immediate conversion to an open procedure for primary repair
. Placement of an intra-dural subarachnoid drain
. Application of an onlay dural substitute and fibrin sealant without primary suture
. Closure of the tubular track with a tightly secured fascial suture alone
. Insertion of a lumbar peritoneal shunt

Correct Answer & Explanation

. Application of an onlay dural substitute and fibrin sealant without primary suture

Explanation

Small dural tears (<3 mm) in MIS tubular approaches are difficult to primarily suture due to limited visualization and working space. They can often be successfully managed with onlay synthetic dural substitutes, fibrin glue, and meticulous watertight closure of the fascia.

Question 199

Topic: 1. General Principles & Basic Science

When comparing minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) to anterior lumbar interbody fusion (ALIF), which of the following is a recognized limitation of the MIS TLIF approach?

. Higher rate of post-operative surgical site infections
. Inferior capacity for restoration of segmental lordosis
. Greater intraoperative blood loss
. Longer hospital length of stay
. Increased rate of symptomatic adjacent segment disease

Correct Answer & Explanation

. Inferior capacity for restoration of segmental lordosis

Explanation

While MIS TLIF reduces soft tissue injury and blood loss, it is generally less effective than ALIF at restoring large degrees of segmental lordosis and correcting global sagittal imbalance.

Question 200

Topic: 1. General Principles & Basic Science

Based on the intraoperative fluoroscopy image,

when placing percutaneous pedicle screws, what is the most common direction of cortical breach that risks injury to the exiting nerve root?

. Superior
. Inferior
. Medial
. Lateral
. Anterior

Correct Answer & Explanation

. Inferior

Explanation

An inferior breach of the pedicle puts the exiting nerve root at risk as it exits the foramen directly caudal to the pedicle. Conversely, a medial breach risks injury to the traversing nerve root and dura.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page