Question 1

Clinical symptoms of lumbar spinal stenosis usually correlate with a canal anteroposterior diameter of less than:

Explanation

The clinical syndrome of lumbar stenosis correlates with a measured anteroposterior diameter of the dural sac of less than 10 mm.

Question 2

Which of the following is the most commonly fractured location along the thoracolumbar axis:

Explanation

Up to 60% of spinal injuries occur between the T11 and L1 segments. The rigid thoracic rib cage and coronal orientation of the facets permit lateral bending and rotation but little flexion and extension. The facet joints then transition caudally to a more sagittal orientation in the lumbar spine, allowing increased flexion/extension but limiting lateral motion. These factors create a stress concentration at the thoracolumbar junction, which is demonstrated by the high incidence of injury at the T11 to L1 segments.

Question 3

A 26-year-old man who was involved in a motor vehicle accident is found to have a T12 compression fracture on plain radiography without evidence of posterior extrusion. The likelihood of finding another fracture in the spinal axis with further evaluation is:

Explanation

A thorough workup in these patients is essential; approximately 10% to 15% of patients will have noncontiguous injuries located elsewhere in the spine.

Question 4

Based on the three-column model of spinal stability, an unstable spinal injury is defined as:

Explanation

The three-column spine consists of the anterior, middle, and posterior columns. In this widely used classification system, the middle column is the key to instability. If the middle column is disrupted, in addition to either the anterior or posterior columns, then instability results.

Question 5

Burst fractures of the vertebral body require prompt evaluation because:

Explanation

When the middle column is involved in a compression injury, it is classified as a burst fracture. This involves axial load on the spine, with or without a flexion component, and retropulsion of the posterosuperior vertebral body into the spinal canal, thus requiring prompt medical attention. Neurologic deficit is variable and is related to the severity of the initial injury and location of the fracture, and only loosely related to the percent of canal compromise.

Question 6

Compression fractures of the spine, although typically considered a one- column injury, can be unstable. Findings at time of presentation suggestive of an unstable fracture include:

Explanation

Compression fractures are inherently stable and may be treated with extension bracing or casting. If, however, the flexion injury is severe enough, damage to the posterior ligaments can result and the injury becomes unstable. Criteria for this instability were developed by McAfee and include more than 20° to 30° of initial kyphosis or more than 50% loss of anterior vertebral height, applicable to both compression and burst fractures.

Question 7

Which of the following is the most important factor responsible for a decreasing proportion of patients with complete paraplegia after sustaining a spinal cord injury today compared with four decades ago:

Explanation

Improvements in the initial triage, resuscitation, and clinical management of spinal cordâ injured patients are likely responsible for a decreasing proportion of patients with complete paraplegia. C urrently, approximately 45% of spinal cordâ injured patients have a complete injury, as opposed to two-thirds four decades ago.

Question 8

Based on the current consensus on treatment of acute spinal cord injury, intravenous steroid treatment is considered to have potential benefit if begun within how many hours of original injury:

Explanation

The results of the National Acute Spinal Cord Injury Study II (NASC IS II) demonstrated significant motor and sensory improvement in patients who were treated within 8 hours of injury with a methylprednisolone bolus of 30 mg/kg, followed by an infusion of 5.4 mg/kg per hour for 24 hours.

Question 9

A 73-year-old woman with a history of cervical stenosis who sustained a fall at home yesterday is now complaining of â clums fingers and weakness in her hands. She denies any difficulty with ambulation or bowel and bladder dysfunction. She most likely has:

Explanation

The most common incomplete spinal cord injury syndrome is most likely central cord syndrome. Central cord syndrome often occurs as a result of a pinching of the spinal cord in elderly patients who have a narrowed spinal canal as the result of degenerative spondylosis. It is a pattern of disproportionately severe upper extremity motor and sensory changes as compared to lower extremity findings.

Question 10

A 27-year-old man was involved in a motor vehicle accident. He was resuscitated at the scene but was noted to have a prolonged hypotensive period. Upon arrival at the medical center, he is noted to be paraplegic but radiographic evaluation does not demonstrate any fracture or soft tissue abnormality. Which of the following is the most likely diagnosis:

Explanation

A watershed zone refers to an area that is supplied purely by end arteries. Therefore, during periods of hypoperfusion, it is the most likely region to sustain an ischemic injury. In the spinal cord, this region lies in the T7-T9 region as it is a watershed zone between the rostral anterior spinal artery distribution and the caudal dominant lumbar segmental artery.

Question 11

The watershed zone of the spinal cord most closely correlates with which region of the spinal cord:

Explanation

A watershed zone refers to an area that is supplied purely by end arteries. Therefore, during periods of hypoperfusion, it is the most likely region to sustain an ischemic injury. In the spinal cord, this region lies in the T7-T9 region as it is a watershed zone between the rostral anterior spinal artery distribution and the caudal dominant lumbar segmental artery.

Question 12

Which of the following is the most common source of infection in vertebral osteomyelitis:

Explanation

Hematogenous seeding from another primary source is the most common causative agent. Hematogenous spread of infections is believed to affect the spine via septic emboli in the endarteriolar circulation of segmental spinal arteries at the vertebral endplates. The majority of cases of pyogenic spondylitis begin in the subchondral, metaphyseal region of the anterior subligamentous portion of the vertebral body â the portion with the greatest arterial supply and the most anastomoses.

Question 13

Which of the following is the most common location of vertebral osteomyelitis along the spinal axis:

Explanation

Lumbar spine is the most common region of the spine affected by hematogenous spread of organisms leading to osteomyelitis followed by the thoracic spine.

Question 14

Which of the following is the most common organism identified in cases of vertebral osteomyelitis:

Explanation

Staphylococcus aureus remains the most common causative organism, but an increasing proportion of cases are due to gramnegative and anaerobic organisms such as Proteus, Escherichia coli and Pseudomonas.

Question 15

Which of the following is the most common presentation of vertebral osteomyelitis:

Explanation

The most common presenting sign of vertebral osteomyelitis is back pain and malaise, often of 3 monthsâ duration or greater. It is often well localized to the affected level and the nature is not unlike most degenerative spinal conditions. A high index of suspicion is essential to make a timely diagnosis. Back pain that awakens a patient at night is a hallmark of infection or tumor. Pain associated with infection tends to be relentless and not related to activity level. Most patients have percussion tenderness over the involved segments. Fevers are noted in fewer than half of patients.

Question 16

Which of the following is the hallmark distinguishing feature of vertebral osteomyelitis when compared to a neoplastic process on imaging:

Explanation

The crossing of the infectious process along the disk space to involve adjacent vertebrae is a hallmark feature of osteomyelitis used to differentiate it from a neoplastic process.

Question 17

Which of the following is the imaging modality of choice with the highest relative sensitivity and specificity in patients with suspected vertebral osteomyelitis:

Explanation

Magnetic resonance imaging (MRI) is the modality of choice for spinal infections. An MRI study provides excellent visualization of the neural elements and can determine whether the inflammatory process extends beyond the margins of disk and bone. MRI also provides excellent regional anatomic information. Scans performed with and without intravenous gadolinium are diagnostic in 90% to 95% of cases.

Question 18

Neurogenic shock is defined as:

Explanation

Neurogenic shock is a unique hemodynamic alteration in patients with spinal cord injuries who have their sympathetic outflow disrupted in addition to the interruption of the motor and sensory pathways. The loss of sympathetic tone to the heart and peripheral vasculature leads to bradycardia and hypotension.

Question 19

The normal range of thoracic kyphosis is:

Explanation

The normal range of thoracic kyphosis is 20° to 50°. The mean in normal adults is 35°. The normal range of lumbar lordosis is 40° to 80°. The mean in normal adults is approximately 60°. The spine is usually straight in the sagittal plane between T10 and L2. The majority of lumbar lordosis occurs between L4 and S1.

Question 20

The normal range of lumbar lordosis is:

Explanation

The normal range of thoracic kyphosis is 20° to 50°. The mean in normal adults is 35°. The normal range of lumbar lordosis is 40° to 80°. The mean in normal adults is approximately 60°. The spine is usually straight in the sagittal plane between T10 and L2. The majority of lumbar lordosis occurs between L4 and S1.

Question 21

A 45-year-old falls from a height and sustains an L1 burst fracture. MRI demonstrates an intact posterior ligamentous complex (PLC) and the patient has no neurologic deficit. According to the Thoracolumbar Injury Classification and Severity (TLICS) score, what is the patient's score and recommended management?

Explanation

The TLICS system assigns 2 points for a burst fracture morphology, 0 points for an intact PLC, and 0 points for an intact neurologic status, totaling 2 points. A score of 3 or less is an indication for non-operative management.

Question 22

A 30-year-old involved in a motor vehicle accident sustains a flexion-distraction injury (Chance fracture) at L2. Which of the following concomitant injuries is most highly associated with this fracture pattern?

Explanation

Chance fractures are caused by a flexion-distraction mechanism, commonly associated with lap seatbelts. They have a high association (up to 40-50%) with intra-abdominal injuries, particularly hollow viscus and mesenteric tears.

Question 23

A 55-year-old man presents with bilateral leg pain and fatigue. During history and physical examination, which of the following findings most reliably differentiates neurogenic claudication from vascular claudication?

Explanation

Neurogenic claudication is hallmark for lumbar spinal stenosis and classically improves with lumbar flexion (e.g., sitting, leaning forward, or cycling). Vascular claudication is related to muscle ischemia during activity and does not improve strictly with postural changes like spine flexion.

Question 24

In evaluating a patient with a suspected L4-L5 posterolateral disc herniation, which of the following physical examination findings is most anticipated?

Explanation

A posterolateral disc herniation at L4-L5 typically compresses the traversing L5 nerve root. L5 radiculopathy is characterized by weakness in extensor hallucis longus (great toe extension) and sensory changes over the dorsum of the foot.

Question 25

A 72-year-old man with long-standing ankylosing spondylitis presents with severe neck pain after a minor fall. Initial plain radiographs of the cervical spine are read as normal. What is the most appropriate next step in management?

Explanation

Patients with ankylosing spondylitis are at an extremely high risk for unstable spinal fractures even after minor trauma. Because osteopenia and altered anatomy can obscure fractures on plain films, a CT scan is mandatory if clinical suspicion exists.

Question 26

Which of the following defines the "middle column" in the Denis three-column classification of the thoracolumbar spine?

Explanation

The Denis middle column consists of the posterior half of the vertebral body, the posterior annulus fibrosus, and the posterior longitudinal ligament (PLL). Disruption of the middle column is the defining feature of a burst fracture.

Question 27

A 40-year-old presents with acute cauda equina syndrome secondary to a massive L5-S1 disc herniation. To maximize the chance of complete neurologic recovery, including bowel and bladder function, surgical decompression should ideally be performed within what timeframe?

Explanation

Surgical decompression for acute cauda equina syndrome should be performed urgently. Evidence suggests that decompression within 48 hours maximizes the potential for neurologic recovery, particularly sphincter function.

Question 28

A 60-year-old man presents with bilateral hand clumsiness, difficulty buttoning his shirts, and a broad-based, unsteady gait. Examination reveals a positive Hoffmann reflex and hyperreflexia in the lower extremities. Which of the following is the most likely diagnosis?

Explanation

The patient exhibits classic upper motor neuron signs (Hoffmann reflex, hyperreflexia, broad-based gait) combined with upper extremity dexterity issues. This constellation of symptoms strongly indicates cervical spondylotic myelopathy.

Question 29

In a patient with traumatic central cord syndrome following a hyperextension injury, which of the following patterns of neurologic deficit is most characteristic?

Explanation

Central cord syndrome typically affects the medially located tracts of the cervical spinal cord. Because the cervical motor tracts serving the upper extremities are located more medially than those serving the lower extremities, patients experience disproportionately greater upper extremity weakness.

Question 30

What is the primary vascular supply to the anterior spinal artery in the lower thoracic and upper lumbar region, which is at particular risk during anterior thoracolumbar surgical approaches?

Explanation

The artery of Adamkiewicz (great anterior radiculomedullary artery) is the major blood supply to the lower two-thirds of the spinal cord. It typically arises on the left side between T8 and L1, and its injury can result in anterior cord syndrome.

Question 31

A 14-year-old competitive gymnast complains of chronic, localized lower back pain that worsens with extension. Radiographs reveal a pars interarticularis defect at L5 without anterior slippage. What is the correct terminology for this condition?

Explanation

Spondylolysis refers specifically to a defect or stress fracture in the pars interarticularis. If anterior translation (slippage) of the vertebral body occurs as a result, it becomes isthmic spondylolisthesis.

Question 32

Diffuse Idiopathic Skeletal Hyperostosis (DISH) is characterized radiographically by flowing ossification along the anterolateral aspect of the vertebral bodies. By Resnick criteria, this flowing ossification must involve at least how many contiguous vertebral bodies?

Explanation

The Resnick and Niwayama radiographic criteria for DISH require the presence of flowing ossification along the anterolateral aspect of at least four contiguous vertebral bodies. It also requires the relative preservation of disc height and absence of sacroiliac joint fusion.

Question 33

A patient arrives in the trauma bay with a severe cervical spine injury. Vital signs demonstrate bradycardia and hypotension. Physical examination shows warm, well-perfused extremities. Which of the following conditions is most likely driving these vital sign abnormalities?

Explanation

Neurogenic shock is a dysautonomia that results from disruption of the descending sympathetic pathways in the cervical or high thoracic spine. It is characterized by loss of sympathetic tone, leading to vasodilation (warm extremities), hypotension, and unopposed vagal tone (bradycardia).

Question 34

A 65-year-old woman with known osteoporosis sustains an acute L1 compression fracture after lifting a box. She is neurologically intact, and her pain is adequately managed with oral analgesics. What is the most appropriate initial treatment?

Explanation

The standard of care for neurologically intact, stable osteoporotic compression fractures is non-operative management. Early mobilization, pain control, and treatment of the underlying osteoporosis are recommended over immediate surgical intervention.

Question 35

During a posterior approach to the lumbar spine, prolonged and aggressive retraction of the paraspinal muscles can lead to denervation and subsequent muscle atrophy. Which nerve is most directly responsible for innervating the multifidus muscle?

Explanation

The medial branch of the dorsal primary ramus provides innervation to the facet joints and the deep paraspinal muscles, particularly the multifidus. Injury to this nerve during excessive retraction leads to multifidus atrophy.

Question 36

An 80-year-old man with advanced cervical spondylosis falls forward, striking his chin. He develops profound weakness in both hands but can still walk, albeit with a spastic gait. MRI confirms a central cord injury without fracture. Which spinal cord tracts are primarily responsible for his upper extremity deficit?

Explanation

The lateral corticospinal tracts carry descending motor fibers. In central cord syndrome, the more medially situated fibers within these tracts (which innervate the cervical/upper extremities) are disproportionately damaged compared to the lateral sacral/lumbar fibers.

Question 37

A 45-year-old male sustains a vertically unstable pelvic ring injury and a concurrent L5 transverse process fracture. Which of the following nerve roots is at highest risk of injury due to its close anatomical relationship to the L5 transverse process?

Explanation

The L5 nerve root courses anteriorly across the sacral ala immediately adjacent to the L5 transverse process. Fractures of the L5 transverse process are highly correlated with L5 nerve root stretch or transection injuries.

Question 38

Which of the following radiographic parameters is the most important biomechanical predictor of adjacent segment disease following a multi-level lumbar fusion?

Explanation

Sagittal imbalance, specifically the failure to restore physiological lumbar lordosis matching the patient's pelvic incidence, significantly increases mechanical stress on adjacent segments. This is a primary driver of adjacent segment degeneration.

Question 39

A 22-year-old man is evaluated after a motor vehicle rollover. Radiographs show a fracture through the pars interarticularis of C2 bilaterally with anterior translation of C2 on C3. This "Hangman's fracture" typically results from which mechanism of injury?

Explanation

Traumatic spondylolisthesis of the axis, commonly referred to as a Hangman's fracture, is classically caused by a forceful hyperextension and distraction mechanism. This pattern was historically seen in judicial hangings and is now common in high-speed MVAs.

Question 40

When examining a patient with suspected degenerative lumbar spinal stenosis, which diagnostic imaging modality is considered the gold standard for defining the cross-sectional area of the dural sac and the degree of soft-tissue neural compression?

Explanation

MRI is the gold standard imaging modality for evaluating lumbar spinal stenosis. It provides superior soft-tissue contrast to visualize thecal sac compression, nerve root impingement, disc herniations, and ligamentum flavum hypertrophy.

Question 41

A 22-year-old male sustains a severe flexion-distraction injury to the thoracolumbar spine (Chance fracture) during a motor vehicle collision. Which of the following is the most commonly associated concomitant injury?

Explanation

Chance fractures are flexion-distraction injuries heavily associated with lap seatbelt wear. They have a high incidence (up to 50%) of concomitant intra-abdominal injuries, particularly hollow viscus injuries like bowel perforations.

Question 42

A 45-year-old man presents with severe right leg pain. Examination reveals weakness in big toe extension and decreased sensation over the dorsal first web space. The Achilles and patellar reflexes are normal. Which nerve root is most likely compressed?

Explanation

A posterolateral disc herniation at the L4-L5 level typically compresses the traversing L5 nerve root. This results in weakness in the extensor hallucis longus (big toe extension) and altered sensation in the first dorsal web space.

Question 43

A 65-year-old man with underlying cervical spondylosis falls forward, striking his chin. He presents with profound bilateral upper extremity weakness but relatively preserved lower extremity strength. What is the most likely diagnosis?

Explanation

Central cord syndrome classically occurs in elderly patients with pre-existing cervical spondylosis following a hyperextension injury. It presents with disproportionate upper extremity weakness compared to the lower extremities.

Question 44

When calculating the Thoracolumbar Injury Classification and Severity (TLICS) score, an incomplete spinal cord injury assigns how many points to the total score?

Explanation

In the TLICS system, neurological status is scored as follows: intact (0), nerve root (2), complete cord (2), incomplete cord (3), and cauda equina (3). An incomplete cord injury assigns 3 points, reflecting its urgency for decompression.

Question 45

A 55-year-old man with longstanding Ankylosing Spondylitis presents with neck pain after a minor fall. Initial plain radiographs are read as normal, but he develops progressive upper extremity weakness. What is the most appropriate next step in management?

Explanation

Patients with ankylosing spondylitis are at high risk for highly unstable, occult cervical spine fractures even after minor trauma. MRI or fine-cut CT is mandatory to rule out a fracture and assess for epidural hematoma.

Question 46

According to the Levine and Edwards classification of traumatic spondylolisthesis of the axis (Hangman's fracture), a Type IIA injury is classically associated with which mechanism and imaging finding?

Explanation

A Type IIA Hangman's fracture is caused by a flexion-distraction injury, resulting in severe angulation but minimal translation. Traction is strictly contraindicated in Type IIA injuries as it will worsen the fracture gap and displacement.

Question 47

Which of the following is an absolute indication for surgical decompression and bullet retrieval in a patient who sustains a gunshot wound to the spine?

Explanation

Most gunshot wounds to the spine are managed non-operatively regardless of the presence of fragments in the canal. Absolute indications for surgery include progressive neurological decline, cauda equina syndrome, or a bullet lodged in the disc space (due to toxicity and migration risk).

Question 48

A patient with a spinal cord injury has preserved motor function below the neurological level, and more than half of the key muscles below the neurological level have a muscle grade of 3 or greater. What is this patient's ASIA impairment scale grade?

Explanation

ASIA D is defined by motor function being preserved below the neurological level, with at least half of the key muscles having a muscle grade of 3 or more. ASIA C requires more than half the muscles to have a grade less than 3.

Question 49

Which of the following clinical findings best distinguishes neurogenic shock from spinal shock?

Explanation

Neurogenic shock is a hemodynamic phenomenon caused by a loss of sympathetic tone, classically characterized by hypotension and bradycardia. Spinal shock is a transient neurological phenomenon defined by the loss of all reflexes and motor function below the injury.

Question 50

According to the Denis three-column model of the spine, the middle column comprises which of the following structures?

Explanation

The Denis middle column consists of the posterior half of the vertebral body, the posterior half of the annulus fibrosus, and the posterior longitudinal ligament (PLL). Failure of the middle column is the defining characteristic of a burst fracture.

Question 51

A 68-year-old man presents with bilateral leg pain that worsens with walking and improves when leaning forward on a shopping cart. MRI shows severe L4-L5 central canal stenosis. Which of the following ligaments is most likely hypertrophied and contributing significantly to the dorsal compression?

Explanation

Lumbar spinal stenosis is typically caused by anterior disc bulging, lateral facet joint hypertrophy, and dorsal ligamentum flavum hypertrophy. The ligamentum flavum buckles and infolds during extension, exacerbating canal compression.

Question 52

The Torg-Pavlov ratio is used to assess cervical spinal stenosis on lateral plain radiographs. A ratio of less than what value is generally considered indicative of developmental cervical stenosis?

Explanation

The Torg-Pavlov ratio compares the sagittal diameter of the spinal canal to the sagittal diameter of the corresponding vertebral body. A ratio of less than 0.8 is a sensitive indicator of developmental cervical spinal stenosis.

Question 53

A 14-year-old gymnast presents with lower back pain. Radiographs reveal a pars interarticularis defect at L5 with 35% forward translation of L5 on S1. According to the Meyerding classification, what grade is this spondylolisthesis?

Explanation

The Meyerding classification grades spondylolisthesis based on the percentage of forward slip: Grade I (0-25%), Grade II (26-50%), Grade III (51-75%), and Grade IV (76-100%). A 35% slip falls into the Grade II category.

Question 54

A 45-year-old intravenous drug user presents with severe, localized back pain, fever, and progressive lower extremity weakness. MRI with contrast demonstrates an epidural abscess at T8. What is the most common causative organism?

Explanation

Staphylococcus aureus is the most common causative organism for spinal epidural abscesses and vertebral osteomyelitis across all patient populations, including intravenous drug users.

Question 55

A patient presents with neck pain radiating down the arm, weakness in wrist flexion and finger extension, and a diminished triceps reflex. Sensation is decreased over the middle finger. Which cervical nerve root is most likely affected?

Explanation

A C7 radiculopathy classically presents with weakness in the triceps, wrist flexors, and finger extensors. Sensory loss typically involves the long (middle) finger, and the triceps reflex is characteristically diminished.

Question 56

When applying a halo vest in an adult, the anterior pins should be placed precisely to avoid neurovascular injury. Which of the following nerves is at greatest risk if the anterior pins are placed too far medially?

Explanation

The anterior pins of a halo ring must be placed in the safe zone, which is 1 cm above the lateral one-third of the eyebrow. Placing the pins medially risks injury to the supraorbital and supratrochlear nerves.

Question 57

A 75-year-old woman sustains an osteoporotic vertebral compression fracture of T12 without neurologic deficit. She is managed conservatively with bracing but continues to have severe, debilitating mechanical pain at 6 weeks. What is the most appropriate next step in management?

Explanation

Percutaneous vertebral augmentation (kyphoplasty or vertebroplasty) is indicated for osteoporotic compression fractures that fail 4-6 weeks of conservative management. It is highly effective for reducing persistent, debilitating mechanical back pain.

Question 58

A unilateral cervical facet dislocation is typically the result of which mechanism of injury?

Explanation

Unilateral facet dislocations typically occur due to a flexion-rotation injury, causing one inferior articular process to jump anterior to the superior articular process below it. Bilateral dislocations are primarily caused by severe flexion-distraction.

Question 59

A 15-year-old male athlete presents with axial lower back pain. Imaging confirms an acute, bilateral L5 pars interarticularis defect (spondylolysis) without spondylolisthesis. What is the initial recommended treatment?

Explanation

Acute, symptomatic spondylolysis in an adolescent athlete is initially managed non-operatively. Treatment consists of rest, restriction from athletic activities, and typically an antilordotic (TLSO) brace until the patient is pain-free.

Question 60

A 25-year-old man sustains a flexion-distraction injury (Chance fracture) of L1 during a motor vehicle collision. What is the most common associated non-orthopedic injury in this setting?

Explanation

Chance fractures, or flexion-distraction injuries, are frequently caused by lap seatbelts and are highly associated with intra-abdominal injuries, particularly hollow viscus and small bowel ruptures. A high index of suspicion and general surgery consultation are essential.

Question 61

A 34-year-old patient has a T12 burst fracture. On evaluation, the patient is neurologically intact, and MRI confirms an intact posterior ligamentous complex (PLC). According to the Thoracolumbar Injury Classification and Severity Score (TLICS), what is the total score and recommended management?

Explanation

The patient scores 2 points for a burst fracture, 0 points for being neurologically intact, and 0 points for an intact PLC, yielding a TLICS score of 2. A score of 3 or less is an indication for nonoperative management, typically with an orthosis.

Question 62

Which of the following clinical features most reliably differentiates neurogenic claudication from vascular claudication in a patient evaluating for lower extremity pain during ambulation?

Explanation

Neurogenic claudication is characteristically relieved by lumbar flexion (such as sitting or leaning on a shopping cart), which increases the spinal canal volume. Vascular claudication is typically relieved simply by resting or standing still, and worsens with increased metabolic demand like walking uphill.

Question 63

According to the Denis three-column theory of the spine, which of the following injury patterns classically defines a burst fracture?

Explanation

A burst fracture involves failure of both the anterior and middle columns under axial compression. This distinguishes it from a simple compression fracture, which involves only the anterior column.

Question 64

A 28-year-old sustains a stab wound to the back resulting in Brown-Séquard syndrome at the T10 level. Which of the following accurately describes the expected neurological deficit below the level of injury?

Explanation

Brown-Séquard syndrome results from spinal cord hemisection. It classically presents with ipsilateral loss of motor function, proprioception, and vibratory sense (corticospinal and dorsal columns), and contralateral loss of pain and temperature sensation (spinothalamic tract).

Question 65

An 82-year-old man with cervical spondylosis sustains a hyperextension injury resulting in central cord syndrome. What is the typical sequence of neurological recovery for this patient?

Explanation

In central cord syndrome, the lower extremities and sacral tracts (located more peripherally in the cord) tend to recover first. Fine motor function of the upper extremities and hands (located more centrally) is typically the last to recover and often remains permanently impaired.

Question 66

In a patient presenting with severe back pain and a large central L4-L5 disc herniation, which of the following findings is the most absolute indication for emergent surgical decompression?

Explanation

Urinary retention with overflow incontinence is a hallmark sign of cauda equina syndrome. This represents an absolute surgical emergency requiring immediate decompression to preserve bowel and bladder function.

Question 67

A 60-year-old diabetic male presents with progressive bilateral leg weakness, fever, and exquisite midline back pain. MRI confirms a spinal epidural abscess. What is the most common causative organism?

Explanation

Staphylococcus aureus is by far the most common organism responsible for spinal epidural abscesses and vertebral osteomyelitis. Prompt recognition, blood cultures, and targeted antibiotic therapy, often combined with surgical decompression, are required.

Question 68

In a pediatric patient with an L5-S1 isthmic spondylolisthesis, which of the following radiographic parameters is considered the strongest predictor of slip progression?

Explanation

A high slip angle (kyphosis at the lumbosacral junction) is the strongest predictor of progression in isthmic spondylolisthesis. It reflects the local destabilizing shear forces acting on the L5-S1 motion segment.

Question 69

A patient involved in a high-speed collision sustains a vertical shear pelvic fracture. CT imaging reveals a sacral fracture extending longitudinally through the neural foramina but not involving the central spinal canal. According to the Denis classification, what zone is this fracture, and what is the approximate rate of associated neurological injury?

Explanation

A Denis Zone II sacral fracture involves the neural foramina but spares the central canal. It carries approximately a 28% risk of neurological injury, typically presenting as unilateral radiculopathy.

Question 70

The resolution of spinal shock in a patient with a complete cervical spinal cord injury is clinically marked by the return of which of the following?

Explanation

Spinal shock is a temporary physiologic state of areflexia and flaccidity below the level of injury. The return of the bulbocavernosus reflex signals the end of spinal shock, allowing for the accurate determination of a complete versus incomplete injury.

Question 71

A Levine-Edwards Type II traumatic spondylolisthesis of the axis (Hangman's fracture) is characterized by a fracture of the pars interarticularis combined with which of the following?

Explanation

A Levine-Edwards Type II Hangman's fracture involves the pars interarticularis with significant translation and kyphotic angulation. It involves disruption of the C2-C3 disc and posterior longitudinal ligament, representing an unstable flexion-rebound extension injury.

Question 72

A 55-year-old male with severe ankylosing spondylitis complains of new-onset back pain after a minor slip. Radiographs suggest a fracture through the T12-L1 disc space. What is the most appropriate next step in management?

Explanation

Patients with ankylosing spondylitis have highly rigid spines that are prone to highly unstable, shear-type fractures even with minimal trauma. Advanced imaging (CT/MRI) of the entire spine is critical to evaluate the fracture extent, rule out non-contiguous fractures, and assess for epidural hematomas.

Question 73

An 84-year-old female sustains a Type II odontoid fracture with 2 mm of posterior displacement following a ground-level fall. She has no neurological deficits. Which of the following is the most appropriate management?

Explanation

In elderly patients with Type II odontoid fractures, rigid cervical collar immobilization is the treatment of choice. Operative intervention and halo vests carry unacceptably high morbidity and mortality rates in this age group.

Question 74

A 45-year-old man presents with sharp pain radiating down his right arm, weakness in triceps extension, and numbness isolated to his middle finger. Which cervical nerve root is most likely compressed?

Explanation

The C7 nerve root supplies the triceps muscle (extension of the elbow), wrist flexors, and provides sensation to the middle finger. A C6-C7 disc herniation typically impinges the C7 root.

Question 75

When evaluating a Jefferson burst fracture of the C1 atlas, which finding on the open-mouth odontoid radiograph best indicates rupture of the transverse atlantal ligament (TAL)?

Explanation

According to Spence's rule, a combined lateral mass overhang of C1 on C2 greater than 6.9 mm on an open-mouth odontoid view implies incompetence or rupture of the transverse atlantal ligament, indicating high instability.

Question 76

In an adult patient with degenerative lumbar scoliosis, which of the following radiographic parameters is the strongest predictor of future curve progression?

Explanation

Risk factors for progression in adult degenerative scoliosis include a Cobb angle > 30 degrees, apical vertebral rotation greater than Grade II, lateral listhesis > 6 mm, and the L5 vertebral body seated above the intercrestal line.

Question 77

A 72-year-old woman sustained an osteoporotic L1 compression fracture 2 months ago. Despite bracing and analgesics, she continues to have severe, mechanical back pain. MRI shows a fluid cleft within the L1 vertebral body (Kümmell disease). What is the most appropriate intervention?

Explanation

Kümmell disease represents avascular necrosis of the vertebral body following a compression fracture, marked by an intravertebral vacuum cleft or fluid sign on MRI. Cement augmentation (kyphoplasty/vertebroplasty) is highly effective for pain relief in these symptomatic non-unions.

Question 78

Which of the following is a classic radiographic diagnostic criterion for Diffuse Idiopathic Skeletal Hyperostosis (DISH)?

Explanation

Resnick criteria for DISH include flowing continuous ossification of the anterolateral aspect of at least four contiguous vertebral bodies, preservation of disc height, and absence of sacroiliac joint erosions or facet ankylosis (which distinguishes it from ankylosing spondylitis).

Question 79

A 40-year-old female presents with progressive myelopathy. MRI reveals a large, calcified, central disc herniation at T8-T9 causing severe cord compression. What is the safest surgical approach for decompression?

Explanation

Approaching a calcified, central thoracic disc via a standard posterior laminectomy carries a very high risk of catastrophic spinal cord injury (paraplegia) due to the need to retract the fragile thoracic cord. An anterior, transthoracic, or lateral extracavitary approach safely allows direct ventral decompression without cord manipulation.

Question 80

A 45-year-old man presents with acute leg pain. MRI reveals a far lateral disc herniation at the L4-L5 level. Which nerve root is most likely compressed, and what is the expected clinical motor deficit?

Explanation

A far lateral disc herniation compresses the exiting nerve root at the same level. At L4-L5, the L4 root is compressed, presenting with quadriceps weakness and a diminished patellar reflex.

Question 81

In sagittal balance evaluation of the spine, the pelvic incidence (PI) is a constant morphological parameter. Which of the following accurately describes the relationship between pelvic incidence, pelvic tilt (PT), and sacral slope (SS)?

Explanation

Pelvic incidence is an anatomical constant for each individual and is defined as the sum of the pelvic tilt and the sacral slope (PI = PT + SS). It dictates the amount of lumbar lordosis required to maintain sagittal balance.

Question 82

According to the Denis three-column classification of the spine, which of the following anatomical structures is considered part of the middle column?

Explanation

The Denis middle column consists of the posterior half of the vertebral body, the posterior annulus fibrosus, and the posterior longitudinal ligament (PLL). The ligamentum flavum and facet joints belong to the posterior column.

Question 83

A 12-year-old boy restrained by a lap belt sustains a flexion-distraction injury (Chance fracture) of L2 during a motor vehicle collision. Which of the following associated injuries has the highest incidence in this scenario?

Explanation

Lap-belt flexion-distraction injuries (Chance fractures) are highly associated with concurrent intra-abdominal injuries, most commonly hollow viscus gastrointestinal tears. Up to 40% of patients with this fracture pattern will have an associated abdominal injury.

Question 84

A 35-year-old female presents with an L1 burst fracture following a fall. She is neurologically intact. MRI demonstrates an intact posterior ligamentous complex (PLC). Based on the Thoracolumbar Injury Classification and Severity (TLICS) score, what is the total score and recommended treatment?

Explanation

In the TLICS system, a burst fracture is scored 2 points for morphology. An intact neurologic status is 0 points, and an intact PLC is 0 points, yielding a total score of 2 which indicates non-operative management.

Question 85

A 55-year-old male presents to the emergency department with acute lower back pain, bilateral sciatica, and saddle anesthesia. Which of the following is the most sensitive early clinical indicator of cauda equina syndrome?

Explanation

Urinary retention is the most sensitive early clinical symptom of cauda equina syndrome. A post-void residual volume greater than 100-200 mL is highly suggestive and should prompt immediate MRI evaluation.

Question 86

A 40-year-old man presents with progressive myelopathy due to a large central T8-T9 disc herniation. What is the most appropriate surgical approach?

Explanation

Central thoracic disc herniations causing myelopathy should be approached anteriorly (e.g., thoracotomy) or anterolaterally. A standard posterior laminectomy carries an unacceptably high risk of catastrophic spinal cord injury due to the need for cord retraction.

Question 87

A 68-year-old man complains of bilateral leg cramping that worsens with walking. Which of the following history findings is most indicative of neurogenic claudication secondary to lumbar spinal stenosis rather than vascular claudication?

Explanation

Neurogenic claudication is typically relieved by lumbar flexion, such as pushing a shopping cart or leaning forward, which increases the spinal canal volume. Walking uphill is also better tolerated than downhill for the same reason.

Orthopedic Prometric MCQs - Chapter 3 Part 1

Orthopedic Prometric MCQs - Chapter 3 Part 32

Orthopedic Prometric MCQs - Chapter 3 Part 32

Chapter Index