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6. Spine MCQs

Practice Set 264 of 379

This practice set contains high-yield board review questions covering key concepts in 6. Spine. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 5261

Topic: Thoracolumbar Spine & Deformity

A 32-year-old male construction worker has a symptomatic Grade II isthmic spondylolisthesis at L5-S1. He complains of severe bilateral leg pain. Which nerve root is most likely being compressed, and at what anatomical location?

. L4 root in the lateral recess
. L5 root in the neural foramen
. S1 root in the lateral recess
. S1 root in the neural foramen
. L5 root in the central canal

Correct Answer & Explanation

. L5 root in the neural foramen

Explanation

In L5-S1 isthmic spondylolisthesis, the L5 exiting nerve root is most commonly compressed in the neural foramen. Compression is typically caused by the hypertrophic fibrocartilage (Gill nodule) at the pars interarticularis defect.

Question 5262

Topic: 6. Spine



A 71-year-old man undergoes a multilevel posterior cervical laminectomy and instrumented fusion for severe cervical spondylotic myelopathy. On postoperative day 2, he develops isolated profound weakness in right shoulder abduction and elbow flexion, with no sensory deficits or leg symptoms. What is the most likely diagnosis?

. Spinal epidural hematoma
. C5 nerve root palsy
. Hardware failure with cord compression
. Cerebrovascular accident
. Parsonage-Turner syndrome

Correct Answer & Explanation

. C5 nerve root palsy

Explanation

C5 palsy is a well-known complication after cervical decompression, particularly posterior laminectomy. It typically presents as a motor-dominant deficit in deltoid and biceps function due to tethering or reperfusion injury of the C5 root.

Question 5263

Topic: 6. Spine

A 45-year-old male intravenous drug user presents with intractable back pain, fevers, and acute urinary retention. MRI reveals an L3-L4 epidural abscess with significant canal compromise. What is the most appropriate next step in management?

. CT-guided aspiration and tailored antibiotics for 6 weeks
. Empiric broad-spectrum intravenous antibiotics and observation
. Urgent surgical decompression and debridement
. Placement of a lumbar drain
. Hyperbaric oxygen therapy

Correct Answer & Explanation

. Urgent surgical decompression and debridement

Explanation

A spinal epidural abscess presenting with acute neurologic deficits (such as urinary retention or profound weakness) is a surgical emergency. Urgent surgical decompression and debridement are required to prevent permanent neurologic damage.

Question 5264

Topic: 6. Spine

During a routine physical exam of a 60-year-old man with neck pain, tapping the distal brachioradialis tendon results in reflexive flexion of the ipsilateral fingers without elbow flexion. What does this specific finding suggest?

. Lower motor neuron lesion at C8
. Cervical myelopathy with a lesion at or above C5-C6
. Normal physiological variant
. Peripheral neuropathy of the median nerve
. Cervical radiculopathy of the C7 root

Correct Answer & Explanation

. Cervical myelopathy with a lesion at or above C5-C6

Explanation

This is an inverted brachioradialis reflex, which is highly specific for cervical myelopathy. It indicates a lesion at the C5 or C6 level, resulting in an absent normal reflex (elbow flexion) and a hyperactive lower-level reflex (finger flexion).

Question 5265

Topic: 6. Spine

A 24-year-old unrestrained passenger in an MVC sustains a traumatic spondylolisthesis of C2 (Hangman's fracture). Radiographs show a fracture through the pars interarticularis with severe angulation but minimal translation. Flexion-extension views demonstrate severe instability in flexion. This is classified as a Type IIA fracture. Which of the following treatments is absolutely contraindicated?

. Cervical collar immobilization
. Halo vest immobilization
. Cervical traction
. Anterior C2-C3 discectomy and fusion
. Posterior C1-C3 fusion

Correct Answer & Explanation

. Cervical collar immobilization

Explanation

Type IIA Hangman's fractures involve severe angulation without significant translation and are caused by flexion-distraction forces. Application of cervical traction is strictly contraindicated as it can cause over-distraction and catastrophic spinal cord injury.

Question 5266

Topic: 6. Spine

A 6-year-old child with progressive bilateral cavovarus foot deformities is noted to have a small sacral dimple and an asymmetric gait. MRI of the lumbar spine reveals the conus medullaris terminating at the L4 level and a thickened filum terminale. What is the most appropriate surgical treatment?

. Posterior spinal fusion from T10 to pelvis
. Release (sectioning) of the filum terminale
. Lumbar laminectomy and duraplasty
. Bilateral selective dorsal rhizotomy
. Observation with serial MRIs

Correct Answer & Explanation

. Release (sectioning) of the filum terminale

Explanation

The patient has tethered cord syndrome, indicated by a low-lying conus (below L2), a thickened filum terminale, and progressive lower extremity neurologic findings (cavovarus feet). The standard surgical treatment is sectioning of the filum terminale to release the tethered cord.

Question 5267

Topic: 6. Spine

A 65-year-old man undergoes an L2-L5 posterior laminectomy and instrumented fusion. Three weeks postoperatively, he presents with worsening back pain, fever, and a purulent draining sinus tract from his incision. His hardware appears well-fixed on radiographs. What is the most appropriate surgical management?

. Removal of all hardware and delayed reconstruction
. Incision and drainage with complete removal of the bone graft only
. Surgical debridement, copious irrigation, and retention of hardware
. Vacuum-assisted closure device application without deep debridement
. Bedside local wound care and oral antibiotics

Correct Answer & Explanation

. Surgical debridement, copious irrigation, and retention of hardware

Explanation

In early postoperative acute deep spinal infections where the hardware remains rigidly fixed and fusion is desired, the standard of care is aggressive surgical irrigation and debridement (I&D) while retaining the spinal instrumentation, followed by culture-directed prolonged antibiotics.

Question 5268

Topic: 6. Spine

A 45-year-old male presents with severe right-sided leg pain and weakness in knee extension. MRI of the lumbar spine reveals a far-lateral (extraforaminal) disc herniation at the L4-L5 level. Which nerve root is most likely compressed in this scenario?

. L3
. L4
. L5
. S1
. S2

Correct Answer & Explanation

. L3

Explanation

In the lumbar spine, far-lateral (extraforaminal) disc herniations compress the exiting nerve root at that given level. Therefore, an L4-L5 far-lateral disc herniation compresses the exiting L4 nerve root.

Question 5269

Topic: Cervical Spine

A 60-year-old male undergoes a C3-C6 cervical laminoplasty for multi-level ossification of the posterior longitudinal ligament (OPLL). On postoperative day three, he develops new-onset, profound weakness in shoulder abduction and elbow flexion, with no sensory deficits. What is the most likely diagnosis?

. Horner syndrome
. C5 nerve root palsy
. Recurrent laryngeal nerve injury
. Vertebral artery injury
. C8 nerve root palsy

Correct Answer & Explanation

. C5 nerve root palsy

Explanation

C5 nerve root palsy is a known complication following cervical laminectomy or laminoplasty, typically presenting 2-3 days postoperatively with deltoid and biceps weakness. It is thought to be caused by tethering of the nerve root as the spinal cord shifts posteriorly.

Question 5270

Topic: Cervical Spine

A 55-year-old female with long-standing rheumatoid arthritis presents with progressive neck pain and myelopathic symptoms. Which of the following radiographic measurements is the strongest indication for surgical stabilization to prevent irreversible neurologic deficit?

. Anterior atlantodental interval (ADI) of 4 mm
. Posterior atlantodental interval (PADI) of 13 mm
. Subaxial translation of 2 mm
. Cervical lordosis of 5 degrees
. Ranawat line measurement of 16 mm

Correct Answer & Explanation

. Posterior atlantodental interval (PADI) of 13 mm

Explanation

In rheumatoid arthritis, a Posterior Atlantodental Interval (PADI) of less than 14 mm is a critical threshold that correlates strongly with an increased risk of neurologic injury and necessitates surgical intervention. The PADI provides a more accurate assessment of the true space available for the spinal cord than the ADI.

Question 5271

Topic: Thoracolumbar Spine & Deformity

In the preoperative planning for adult spinal deformity correction, achieving a harmonious sagittal profile is a primary goal. Which of the following formulas correctly describes the relationship between the pelvic parameters?

. Pelvic Incidence (PI) = Pelvic Tilt (PT) + Sacral Slope (SS)
. Pelvic Tilt (PT) = Pelvic Incidence (PI) + Sacral Slope (SS)
. Sacral Slope (SS) = Pelvic Incidence (PI) + Pelvic Tilt (PT)
. Pelvic Incidence (PI) = Pelvic Tilt (PT) - Sacral Slope (SS)
. Sacral Slope (SS) = Pelvic Tilt (PT) - Pelvic Incidence (PI)

Correct Answer & Explanation

. Pelvic Incidence (PI) = Pelvic Tilt (PT) + Sacral Slope (SS)

Explanation

Pelvic Incidence (PI) is a fixed anatomical parameter defined as the sum of Pelvic Tilt (PT) and Sacral Slope (SS). Surgical correction aims to restore the Lumbar Lordosis (LL) to within 10 degrees of the patient's fixed Pelvic Incidence (PI-LL mismatch < 10 degrees).

Question 5272

Topic: 6. Spine

A 40-year-old male presents to the emergency department with severe lower back pain, bilateral sciatica, and perineal numbness. Which of the following objective findings is most sensitive for diagnosing early cauda equina syndrome?

. Hyperreflexia of the patellar tendon
. Post-void residual bladder volume less than 50 mL
. Post-void residual bladder volume greater than 200 mL
. Positive Babinski sign
. Increased anal sphincter tone

Correct Answer & Explanation

. Post-void residual bladder volume greater than 200 mL

Explanation

Urinary retention is the most consistent and sensitive early finding in cauda equina syndrome. A post-void residual (PVR) volume greater than 100-200 mL strongly supports the diagnosis in the context of typical red-flag symptoms.

Question 5273

Topic: 6. Spine

A 55-year-old male with known Ankylosing Spondylitis presents to the emergency room with acute neck pain after a low-speed motor vehicle collision. A review of the initial lateral cervical radiograph is shown.

What is the most appropriate next step in management?

. Discharge with NSAIDs and muscle relaxants
. Flexion-extension cervical radiographs
. CT scan of the entire cervical spine
. Electromyography (EMG) of the upper extremities
. Cervical collar and outpatient follow-up in 4 weeks

Correct Answer & Explanation

. CT scan of the entire cervical spine

Explanation

Patients with ankylosing spondylitis have highly rigid spines that are prone to unstable, occult fractures even after minor trauma. A CT scan of the cervical spine is mandatory to rule out a fracture when conventional radiographs are negative or difficult to interpret.

Question 5274

Topic: Cervical Spine

The use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in anterior cervical diskectomy and fusion (ACDF) has been associated with which of the following significant postoperative complications?

. High rates of pseudarthrosis
. Severe prevertebral soft tissue swelling and airway compromise
. Delayed C5 nerve root palsy
. Vertebral artery pseudoaneurysm
. Horner syndrome

Correct Answer & Explanation

. Severe prevertebral soft tissue swelling and airway compromise

Explanation

The use of rhBMP-2 in the anterior cervical spine is highly associated with exaggerated prevertebral soft tissue swelling, which can lead to life-threatening dysphagia and airway compromise. As a result, its use in routine ACDF is generally contraindicated or requires extreme caution.

Question 5275

Topic: 6. Spine

During a posterior lumbar spinal fusion, the surgeon prepares to insert a pedicle screw at the L4 level. What is the correct anatomical starting point for a traditional straightforward trajectory L4 pedicle screw?

. Intersection of the pars interarticularis and superior articular facet
. Intersection of the middle of the transverse process and the lateral border of the superior articular facet
. Just inferior to the facet joint capsule
. Medial to the inferior articular process
. Base of the spinous process

Correct Answer & Explanation

. Intersection of the middle of the transverse process and the lateral border of the superior articular facet

Explanation

The classic anatomical starting point for a lumbar pedicle screw (L1-L4) is at the intersection of a line bisecting the transverse process and a vertical line tangential to the lateral border of the superior articular facet.

Question 5276

Topic: Thoracolumbar Spine & Deformity

A 35-year-old male falls from a roof. Review the provided imaging.

When calculating the Thoracolumbar Injury Classification and Severity (TLICS) score to determine the need for operative stabilization, which MRI finding is given the most weight?

. Anterior wedge compression height loss > 50%
. Posterior ligamentous complex (PLC) disruption
. Number of anterior column fracture fragments
. Presence of Schmorl's nodes
. Degree of local kyphosis less than 10 degrees

Correct Answer & Explanation

. Posterior ligamentous complex (PLC) disruption

Explanation

In the TLICS system, disruption of the posterior ligamentous complex (PLC) is assigned 3 points, which is the highest individual score for morphology/ligament status. A total TLICS score > 4 indicates operative management.

Question 5277

Topic: 6. Spine

A 65-year-old diabetic male develops severe, unremitting low back pain and fever. MRI confirms pyogenic spondylodiscitis at L3-L4. What is the most common route of pathogen transmission leading to this condition in an adult?

. Direct extension from the bowel
. Lymphatic spread from a distant focus
. Hematogenous spread via the end-arterioles
. Retrograde perineural tracking
. Cerebrospinal fluid dissemination

Correct Answer & Explanation

. Hematogenous spread via the end-arterioles

Explanation

In adults, pyogenic spondylodiscitis typically occurs via hematogenous spread. The bacteria travel through the nutrient branches of the segmental arteries and lodge in the low-flow end-arterioles adjacent to the vertebral endplates, subsequently infecting the disc space.

Question 5278

Topic: 6. Spine
A 68-year-old female presents with neurogenic claudication. Radiographs reveal an L4-L5 degenerative spondylolisthesis. Anatomically, what is the primary restraint that typically prevents anterior translation of L4 on L5, and becomes compromised in this condition?
. Ligamentum flavum
. Anterior longitudinal ligament
. Sagittally oriented facet joints
. Intervertebral disc
. Interspinous ligament

Correct Answer & Explanation

. Sagittally oriented facet joints

Explanation

Degenerative spondylolisthesis (Wiltse Type III) most commonly occurs at L4-L5. It is primarily caused by long-standing segmental instability and facet joint degeneration, particularly when the facet joints are more sagittally oriented, failing to resist anterior shear forces.

Question 5279

Topic: 6. Spine

A 22-year-old male is involved in a high-speed motorcycle accident resulting in a complete spinal cord injury at the T6 level. He initially presents in a state of spinal shock. What clinical finding definitively marks the end of the spinal shock phase?

. Return of deep tendon reflexes in the lower extremities
. Return of the bulbocavernosus reflex
. Normalization of resting blood pressure
. Return of voluntary motor function
. Resolution of resting bradycardia

Correct Answer & Explanation

. Return of the bulbocavernosus reflex

Explanation

Spinal shock is characterized by flaccid paralysis, areflexia, and anesthesia below the level of injury. The return of the bulbocavernosus reflex marks the resolution of spinal shock, allowing for accurate classification of the spinal cord injury as complete or incomplete.

Question 5280

Topic: 6. Spine

A 48-year-old male presents with shooting pain down his right arm, associated with weakness in wrist extension. The brachioradialis reflex is diminished. Review the MRI shown.

Based on the physical exam, which specific physical examination finding further supports the affected nerve root?

. Deltoid weakness
. Weakness in elbow flexion and numbness in the thumb
. Triceps weakness and numbness in the middle finger
. Finger flexion weakness
. Interossei weakness and numbness in the small finger

Correct Answer & Explanation

. Weakness in elbow flexion and numbness in the thumb

Explanation

The patient's symptoms describe a C6 radiculopathy (wrist extension weakness, diminished brachioradialis reflex). C6 compression also classically causes weakness in elbow flexion (biceps) and sensory deficits over the lateral forearm and thumb.

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