Menu

6. Spine MCQs

Practice Set 342 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 6821

Topic: 6. Spine

A 45-year-old female presents with progressive spastic paraparesis. MRI reveals a large, calcified central disc herniation at T8-T9 causing severe cord compression. Which of the following surgical approaches is absolutely contraindicated?

. Standard posterior decompressive laminectomy
. Transforaminal interbody fusion
. Anterior transthoracic decompression or posterolateral costotransversectomy
. Microendoscopic interlaminar discectomy
. Intradiscal steroid injection

Correct Answer & Explanation

. Anterior transthoracic decompression or posterolateral costotransversectomy

Explanation

A standard posterior laminectomy is contraindicated for a central, calcified thoracic disc herniation. Attempting to retract the thoracic spinal cord from a posterior approach to access a ventral lesion carries an unacceptably high risk of catastrophic cord injury and paralysis.

Question 6822

Topic: 6. Spine

Recombinant human bone morphogenetic protein-2 (rhBMP-2) is utilized off-label in anterior cervical spine surgery to promote fusion. Its use in this anatomical region is most strongly associated with an increased risk of which of the following complications?

. Symptomatic pseudarthrosis
. Significant prevertebral soft tissue swelling and dysphagia
. Late-onset vertebral artery aneurysm
. Accelerated adjacent segment disease
. Systemic toxicity from bone overgrowth

Correct Answer & Explanation

. Significant prevertebral soft tissue swelling and dysphagia

Explanation

The use of rhBMP-2 in the anterior cervical spine is highly associated with massive prevertebral soft tissue swelling. This can lead to severe dysphagia and potentially life-threatening airway compromise.

Question 6823

Topic: 6. Spine

A 70-year-old male is evaluated for mild dysphagia and neck stiffness. Radiographs of the cervical spine reveal flowing ossification along the anterior aspect of 5 contiguous vertebral bodies. The intervertebral disc spaces are well-preserved, and the sacroiliac joints are normal. What is the most likely diagnosis?

. Ankylosing spondylitis
. Diffuse Idiopathic Skeletal Hyperostosis (DISH)
. Ossification of the posterior longitudinal ligament (OPLL)
. Rheumatoid arthritis
. Scheuermann's disease

Correct Answer & Explanation

. Diffuse Idiopathic Skeletal Hyperostosis (DISH)

Explanation

DISH is characterized by flowing ossification of the anterior longitudinal ligament across at least four contiguous vertebral bodies, with preservation of disc height and absence of sacroiliac joint erosions. Large anterior osteophytes in the cervical spine can mechanically cause dysphagia.

Question 6824

Topic: Cervical Spine

A 55-year-old female with long-standing rheumatoid arthritis is scheduled for an elective total knee arthroplasty. Pre-operative flexion-extension cervical spine radiographs reveal an anterior atlantodental interval (ADI) of 11 mm. What is the most appropriate management regarding her cervical spine?

. Observation with yearly radiographs
. Application of a Halo vest prior to intubation
. Pre-intubation posterior C1-C2 instrumented fusion
. Transoral odontoidectomy alone
. Anterior C1-C2 plate fixation

Correct Answer & Explanation

. Pre-intubation posterior C1-C2 instrumented fusion

Explanation

In rheumatoid arthritis, an ADI greater than 9-10 mm or a posterior atlantodental interval (PADI) less than 14 mm indicates severe, unstable atlantoaxial subluxation with a high risk of impending neurologic injury. This requires prophylactic posterior C1-C2 stabilization before elective general anesthesia.

Question 6825

Topic: 6. Spine

A 45-year-old male presents with severe low back pain, bilateral sciatica, and progressive sensory loss in his perineum. MRI confirms a massive central disc herniation at L4-L5. Which of the following findings is considered the most sensitive early clinical indicator for establishing the diagnosis of Cauda Equina Syndrome?

. Saddle anesthesia
. Bilateral absent Achilles reflexes
. Urinary retention
. Fecal incontinence
. Lower extremity paraplegia

Correct Answer & Explanation

. Urinary retention

Explanation

Urinary retention is the most consistent and sensitive early clinical indicator of Cauda Equina Syndrome. A post-void residual (PVR) ultrasound demonstrating >100-200 mL of retained urine is highly suggestive. While saddle anesthesia and loss of rectal tone are hallmark signs, they often appear later in the clinical course or have varying sensitivities compared to urinary dysfunction.

Question 6826

Topic: 6. Spine
According to the Levine and Edwards classification of traumatic spondylolisthesis of the axis (Hangman's fracture), a Type IIA fracture pattern requires extreme caution during non-operative management because it is characterized by which of the following?
. Translation greater than 3 mm with minimal angulation
. Severe angulation with minimal translation and no facet dislocation
. Bilateral locked facets
. Fracture isolated to the odontoid base
. Avulsion of the anterior inferior C2 body

Correct Answer & Explanation

. Severe angulation with minimal translation and no facet dislocation

Explanation

A Type IIA Hangman's fracture features severe angulation with minimal translation. It represents a flexion-distraction injury. It is critical to recognize because the application of traction (used for Type II or III) is strictly contraindicated, as it will exacerbate the deformity. It is treated in a halo vest in slight extension with compression.

Question 6827

Topic: 6. Spine

A 68-year-old man presents with bilateral leg pain when walking. Differentiating neurogenic claudication (lumbar spinal stenosis) from vascular claudication can be clinically challenging. Which of the following historical findings is most specific for a diagnosis of neurogenic claudication?

. Pain is relieved rapidly by standing perfectly still for 1 minute
. Pain is relieved by walking up an incline compared to walking down an incline
. Diminished dorsalis pedis and posterior tibial pulses
. Hair loss and atrophic skin changes on the distal extremities
. Pain is worsened by riding a stationary bicycle

Correct Answer & Explanation

. Pain is relieved by walking up an incline compared to walking down an incline

Explanation

Neurogenic claudication is typically relieved by lumbar flexion, which increases the cross-sectional area of the spinal canal. Walking uphill, pushing a shopping cart, or riding a stationary bicycle maintains a flexed posture and is better tolerated. Vascular claudication is strictly demand-dependent and worsens predictably with uphill walking or cycling.

Question 6828

Topic: 6. Spine

A 14-year-old female gymnast complains of insidious onset, mechanical low back pain that is sharply exacerbated by lumbar extension. Her neurological examination is unremarkable. Standard AP, lateral, and oblique radiographs of the lumbar spine show no abnormalities. What is the most appropriate next imaging study to evaluate for an acute pars interarticularis stress reaction while minimizing ionizing radiation?

. Bone scan with SPECT
. Computed tomography (CT) of the lumbar spine
. Magnetic resonance imaging (MRI) of the lumbar spine
. Dynamic flexion-extension radiographs
. Ultrasound of the lumbar paraspinal musculature

Correct Answer & Explanation

. Magnetic resonance imaging (MRI) of the lumbar spine

Explanation

In a pediatric or adolescent athlete with suspected acute spondylolysis (pars stress reaction) and normal radiographs, MRI of the lumbar spine (specifically utilizing STIR or T2 fat-suppressed sequences) is the diagnostic modality of choice. It is highly sensitive for detecting bone marrow edema indicative of an early stress reaction, without exposing the young patient to the significant ionizing radiation associated with CT scans or SPECT.

Question 6829

Topic: 6. Spine

A 6-year-old boy is brought to the clinic due to torticollis that has been present for two weeks. His mother reports the symptoms began a few days after he recovered from a severe streptococcal pharyngitis. He holds his head tilted to the right and rotated to the left. Neurologic examination is entirely normal. A dynamic CT scan demonstrates a fixed C1-C2 rotation. What is the most likely diagnosis?

. Klippel-Feil syndrome
. Grisel syndrome
. Morquio syndrome
. Eosinophilic granuloma of the cervical spine
. Os odontoideum

Correct Answer & Explanation

. Grisel syndrome

Explanation

Grisel syndrome is a non-traumatic atlantoaxial rotatory subluxation (AARS) that occurs secondary to an inflammatory process in the upper respiratory tract or neck, such as pharyngitis, tonsillitis, or retropharyngeal abscess. The inflammation causes hyperemia and laxity of the transverse ligament and adjacent capsular structures, leading to subluxation.

Question 6830

Topic: 6. Spine

A 2-year-old child with achondroplasia presents with hypotonia, motor delay, and newly diagnosed central sleep apnea.

What is the most likely etiology of these neurological findings?

. Atlantoaxial instability
. Foramen magnum stenosis
. Thoracolumbar kyphosis
. Lumbar spinal stenosis
. Syringomyelia

Correct Answer & Explanation

. Foramen magnum stenosis

Explanation

In achondroplasia, foramen magnum stenosis is a critical and potentially life-threatening complication in infants and toddlers. It causes cervicomedullary compression leading to central sleep apnea, hypotonia, quadriparesis, sudden death, and motor delays.

Question 6831

Topic: 6. Spine

A 7-year-old boy with Morquio syndrome (Mucopolysaccharidosis type IV) is evaluated prior to undergoing a corrective osteotomy for severe genu valgum. Which of the following preoperative evaluations is most critical for avoiding a catastrophic perioperative complication?

. Echocardiogram for aortic stenosis
. Flexion-extension cervical spine radiographs
. Pulmonary function testing
. Clotting factor assays
. Renal ultrasound

Correct Answer & Explanation

. Flexion-extension cervical spine radiographs

Explanation

Morquio syndrome is characterized by odontoid hypoplasia and severe ligamentous laxity, which frequently leads to profound atlantoaxial instability (C1-C2). Preoperative flexion-extension cervical spine radiographs (and often an MRI) are critical before any surgery requiring intubation or positioning to prevent cervical spinal cord injury.

Question 6832

Topic: Thoracolumbar Spine & Deformity

A 12-year-old gymnast presents with lower back pain and is diagnosed with an L5-S1 isthmic spondylolisthesis. Her slip is currently measured at 30% (Grade II). Which of the following radiographic parameters indicates the highest risk for progression of the slip?

. Dysplastic sacral dome
. Low pelvic incidence
. Low slip angle
. Spina bifida occulta at L5
. Decreased sacral slope

Correct Answer & Explanation

. Dysplastic sacral dome

Explanation

Risk factors for the progression of a pediatric spondylolisthesis include young age, female sex, high slip grade (>50%), high slip angle (kyphotic L5-S1 angle), a high pelvic incidence, and dysplastic features such as doming of the sacrum or a trapezoidal L5. A dysplastic sacral dome directly decreases the bony restraint to anterior translation.

Question 6833

Topic: Cervical Spine

A 6-year-old boy presents with severe neck pain and torticollis 10 days after a tonsillectomy. He holds his head tilted to the right and rotated to the left. Neurological examination is normal. Radiographs reveal an increased atlantodental interval (ADI) of 4.5 mm. Which of the following is the most likely diagnosis?

. Juvenile idiopathic arthritis
. Os odontoideum
. Klippel-Feil syndrome
. Grisel syndrome
. Retropharyngeal abscess

Correct Answer & Explanation

. Grisel syndrome

Explanation

Grisel syndrome is a non-traumatic atlantoaxial rotatory subluxation (AARS) associated with inflammation of the adjacent head and neck tissues (such as after pharyngitis, tonsillectomy, or upper respiratory tract infections). The inflammatory hyperemia causes laxity of the transverse ligament, leading to subluxation.

Question 6834

Topic: 6. Spine

A 5-year-old girl is referred for evaluation of a high-riding, hypoplastic left scapula that restricts her shoulder abduction. Imaging reveals an omovertebral bone connecting the superior angle of the scapula to the cervical spine. Which of the following conditions is most strongly associated with this deformity?

. Klippel-Feil syndrome
. Ehlers-Danlos syndrome
. Marfan syndrome
. Osteogenesis Imperfecta
. Arthrogryposis Multiplex Congenita

Correct Answer & Explanation

. Klippel-Feil syndrome

Explanation

Sprengel deformity (congenital elevation of the scapula) is frequently associated with an omovertebral bone/band and is most commonly syndromically linked to Klippel-Feil syndrome (cervical spine fusion anomalies).

Question 6835

Topic: Thoracolumbar Spine & Deformity
According to the Wiltse classification, a spondylolisthesis resulting from a stress fracture of the pars interarticularis is classified as which type?
. Type I (Dysplastic)
. Type II (Isthmic)
. Type III (Degenerative)
. Type IV (Traumatic)
. Type V (Pathologic)

Correct Answer & Explanation

. Type II (Isthmic)

Explanation

In the Wiltse classification of spondylolisthesis, Type II is Isthmic, which is caused by a defect in the pars interarticularis (subtype IIA is a stress fracture, IIB is an elongated but intact pars, and IIC is an acute fracture). Type I is dysplastic, Type III is degenerative, Type IV is traumatic (fracture other than pars), and Type V is pathologic.

Question 6836

Topic: 6. Spine
A 65-year-old male presents with progressive clumsiness in his hands, difficulty manipulating small objects, and a broad-based, unsteady gait. Physical examination reveals a positive Hoffmann sign and an inverted radial reflex. What is the most likely diagnosis?
. Cervical radiculopathy
. Degenerative cervical myelopathy
. Amyotrophic lateral sclerosis
. Syringomyelia
. Guillain-Barré syndrome

Correct Answer & Explanation

. Degenerative cervical myelopathy

Explanation

The combination of hand clumsiness, gait disturbance, and upper motor neuron signs (Hoffmann sign, inverted radial reflex, hyperreflexia) is the classic clinical presentation of degenerative cervical myelopathy (cervical spondylotic myelopathy). It results from compression of the spinal cord.

Question 6837

Topic: 6. Spine

A 42-year-old patient presents with severe acute low back pain and bilateral radiculopathy. Which of the following is the most sensitive early clinical symptom of cauda equina syndrome?

. Urinary retention
. Fecal incontinence
. Saddle anesthesia
. Absent Achilles reflexes
. Unilateral foot drop

Correct Answer & Explanation

. Urinary retention

Explanation

Urinary retention is the most consistent and sensitive early symptom of cauda equina syndrome. A normal post-void residual volume (typically <100-200 mL) strongly argues against the diagnosis.

Question 6838

Topic: 6. Spine

A traumatic spondylolisthesis of the axis (Hangman's fracture) classically involves bilateral fractures of the C2 pars interarticularis. What is the predominant mechanism of injury that produces this specific fracture pattern?

. Hyperflexion and distraction
. Hyperextension and axial loading
. Lateral compression
. Direct blow to the occiput
. Rotational shear

Correct Answer & Explanation

. Hyperextension and axial loading

Explanation

A Hangman's fracture typically occurs due to forced hyperextension combined with axial loading of the cervical spine. This mechanism concentrates tremendous stress on the pars interarticularis of C2, leading to bilateral fractures.

Question 6839

Topic: 6. Spine

A 32-year-old male is brought to the emergency department following a diving accident resulting in a complete C5 spinal cord injury. He is hypotensive with a blood pressure of 80/50 mmHg and bradycardic with a heart rate of 48 bpm. What is the primary pathophysiologic mechanism for his hemodynamic state?

. Loss of sympathetic vasomotor tone
. Massive occult hemorrhage
. Complete parasympathetic blockade
. Adrenal insufficiency
. Cardiogenic shock secondary to myocardial contusion

Correct Answer & Explanation

. Loss of sympathetic vasomotor tone

Explanation

This patient is in neurogenic shock, typical of high cervical cord injuries. It is caused by the loss of descending sympathetic tone, leading to profound vasodilation and unopposed vagal (parasympathetic) tone resulting in bradycardia.

Question 6840

Topic: 6. Spine

A 4-year-old child presents with diffuse bone pain, gingival bleeding, and radiographic evidence of a "white line of Frankel" at the metaphyses. This condition is caused by a deficiency in a cofactor required for which specific step in collagen biosynthesis?

. Cleavage of procollagen C-terminal propeptides
. Hydroxylation of proline and lysine residues
. Glycosylation of hydroxylysine residues
. Formation of disulfide bonds in the procollagen molecule
. Extracellular cross-linking by lysyl oxidase

Correct Answer & Explanation

. Hydroxylation of proline and lysine residues

Explanation

The child's presentation is classic for scurvy (Vitamin C deficiency). Vitamin C is an essential cofactor for the enzymes prolyl hydroxylase and lysyl hydroxylase, which are required for the intracellular hydroxylation of proline and lysine residues during collagen synthesis.

Test Yourself

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

On this Page