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Thoracolumbar Spine & Deformity MCQs

Practice Set 29 of 49

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

Question 561

Topic: Thoracolumbar Spine & Deformity

In the evaluation of a thoracolumbar burst fracture, disruption of the middle column is the defining characteristic. Which of the following anatomical structures forms the middle column according to the Denis three-column theory?

. Anterior half of the vertebral body, anterior annulus, and anterior longitudinal ligament (ALL)
. Posterior half of the vertebral body, posterior annulus, and posterior longitudinal ligament (PLL)
. Pedicles, facet joints, and ligamentum flavum
. Spinous processes, interspinous ligaments, and supraspinous ligaments
. Transverse processes and intertransverse ligaments

Correct Answer & Explanation

. Anterior half of the vertebral body, anterior annulus, and anterior longitudinal ligament (ALL)

Explanation

The Denis middle column consists of the posterior half of the vertebral body, the posterior aspect of the annulus fibrosus, and the posterior longitudinal ligament (PLL).

Question 562

Topic: Thoracolumbar Spine & Deformity

A 45-year-old man falls from a roof and sustains an L1 burst fracture with 60% canal compromise and an intact neurologic examination. MRI demonstrates that the posterior ligamentous complex is intact. Which management strategy is most appropriate?

. Thoracolumbosacral orthosis (TLSO)
. Anterior corpectomy and fusion
. Posterior short-segment pedicle screw fixation
. Laminectomy alone
. Percutaneous vertebroplasty

Correct Answer & Explanation

. Thoracolumbosacral orthosis (TLSO)

Explanation

Neurologically intact patients with a thoracolumbar burst fracture and an intact posterior ligamentous complex (TLICS score < 4) can be successfully managed nonoperatively with a TLSO. Surgery is generally reserved for neurologic deficits or ligamentous instability.

Question 563

Topic: Thoracolumbar Spine & Deformity

In the evaluation of adult spinal deformity, which of the following radiographic parameters correlates most closely with poor health-related quality of life (HRQOL) scores?

. Coronal Cobb angle greater than 40 degrees
. Sagittal vertical axis (SVA) greater than 5 cm
. Lumbar lordosis equal to pelvic incidence
. Sacral slope less than 20 degrees
. Thoracic kyphosis greater than 50 degrees

Correct Answer & Explanation

. Coronal Cobb angle greater than 40 degrees

Explanation

A positive Sagittal Vertical Axis (SVA) greater than 5 cm is the radiographic parameter most strongly correlated with adverse health-related quality of life outcomes and pain in adult spinal deformity.

Question 564

Topic: Thoracolumbar Spine & Deformity

A 22-year-old woman involved in a high-speed motor vehicle collision while wearing a lap seatbelt sustains a flexion-distraction injury of T12.

What associated injury must be most highly suspected and ruled out?

. Aortic dissection
. Intra-abdominal hollow viscus injury
. Diaphragmatic rupture
. Renal artery avulsion
. Sternoclavicular dislocation

Correct Answer & Explanation

. Aortic dissection

Explanation

Chance fractures (flexion-distraction injuries) are highly associated with intra-abdominal injuries. Hollow viscus injuries, such as bowel rupture, occur in up to 50% of these patients.

Question 565

Topic: Thoracolumbar Spine & Deformity

When planning surgical correction for a 65-year-old woman with adult degenerative scoliosis, the surgeon aims to restore sagittal balance. The patient has a pelvic incidence of 55 degrees. What is the optimal target lumbar lordosis?

. 25 degrees
. 35 degrees
. 45 degrees
. 55 degrees
. 65 degrees

Correct Answer & Explanation

. 25 degrees

Explanation

To achieve optimal sagittal balance, the lumbar lordosis (LL) should be matched to within 9 degrees of the pelvic incidence (PI). Therefore, a target LL of approximately 55 degrees is appropriate.

Question 566

Topic: Thoracolumbar Spine & Deformity

In a 70-year-old patient undergoing multi-level decompression and fusion for adult degenerative scoliosis, which of the following is an accepted indication for extending the fusion to the pelvis?

. L5-S1 disc degeneration with an intact L5-S1 facet joint
. L5 spondylolysis
. Apex of the curve at L2
. Lumbar lordosis of 45 degrees with pelvic incidence of 45 degrees
. Severe fractional curve at L4-S1 with coronal imbalance

Correct Answer & Explanation

. L5-S1 disc degeneration with an intact L5-S1 facet joint

Explanation

Extending a long fusion to the pelvis in adult deformity is indicated when there is significant L5-S1 pathology, a severe fractional curve causing coronal imbalance at the lumbosacral junction, or previous wide laminectomy at L5-S1.

Question 567

Topic: Thoracolumbar Spine & Deformity

A 65-year-old woman presents with severe mechanical back pain and an inability to stand up straight. When evaluating her sagittal spinopelvic alignment, which of the following formulas correctly describes the relationship between pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS)?

. PI = PT - SS
. PI = PT + SS
. PT = PI + SS
. SS = PI + PT
. PI = (PT + SS) / 2

Correct Answer & Explanation

. PI = PT - SS

Explanation

Pelvic incidence is a fixed morphological parameter defined as the sum of pelvic tilt and sacral slope (PI = PT + SS). It dictates the amount of lumbar lordosis required to maintain global sagittal balance.

Question 568

Topic: Thoracolumbar Spine & Deformity

A 35-year-old man falls from a ladder. Examination reveals intact motor and sensory function. CT shows an L1 burst fracture with 40% canal compromise. MRI reveals an intact posterior ligamentous complex (PLC). What is his Thoracolumbar Injury Classification and Severity (TLICS) score, and the recommended treatment?

. Score 2, nonoperative management
. Score 4, operative management
. Score 5, operative management
. Score 2, operative management
. Score 4, nonoperative management

Correct Answer & Explanation

. Score 2, nonoperative management

Explanation

The TLICS score is 2: 1 point for a burst fracture mechanism, 0 points for intact neurology, and 0 points for an intact PLC. A score of 3 or less is typically treated nonoperatively with a brace or early mobilization.

Question 569

Topic: Thoracolumbar Spine & Deformity

In adult spinal deformity, which of the following radiographic parameters correlates most strongly with poor health-related quality of life (HRQOL) scores?

. Thoracic kyphosis > 40 degrees
. Coronal Cobb angle > 50 degrees
. Positive sagittal vertical axis (SVA) > 5 cm
. Pelvic tilt < 10 degrees
. Lumbar lordosis > 60 degrees

Correct Answer & Explanation

. Thoracic kyphosis > 40 degrees

Explanation

A positive sagittal vertical axis (SVA) greater than 5 cm is the radiographic parameter most highly correlated with adverse health-related quality of life outcomes in adult spinal deformity patients. Restoration of sagittal balance is the primary goal of reconstructive surgery.

Question 570

Topic: Thoracolumbar Spine & Deformity

A patient with severe adult degenerative scoliosis and a profound loss of lumbar lordosis develops a progressive positive sagittal vertical axis.

What are the expected primary compensatory mechanisms utilized by the patient to maintain an upright posture and horizontal gaze?

. Pelvic anteversion and knee extension
. Pelvic retroversion and knee flexion
. Pelvic anteversion and hip extension
. Decreased thoracic kyphosis and knee extension
. Increased sacral slope and hip flexion

Correct Answer & Explanation

. Pelvic anteversion and knee extension

Explanation

To compensate for a positive sagittal balance (forward pitch), patients will characteristically retrovert the pelvis (increasing pelvic tilt) and flex their knees. This biomechanically shifts the center of gravity posteriorly.

Question 571

Topic: Thoracolumbar Spine & Deformity

A 65-year-old woman presents with severe low back pain and difficulty standing upright. Radiographs reveal adult degenerative scoliosis. Which of the following radiographic parameters correlates most closely with poor health-related quality of life (HRQOL) scores in this patient?

. Coronal Cobb angle > 30 degrees
. Pelvic tilt > 10 degrees
. Sagittal vertical axis (SVA) > 5 cm
. Lumbar lordosis greater than pelvic incidence
. Sacral slope < 20 degrees

Correct Answer & Explanation

. Coronal Cobb angle > 30 degrees

Explanation

In adult spinal deformity, positive sagittal balance (SVA > 5 cm) has been shown to be the most reliable radiographic predictor of poor clinical outcomes and decreased health-related quality of life (HRQOL) scores.

Question 572

Topic: Thoracolumbar Spine & Deformity

A 45-year-old man falls from a height and sustains an L1 burst fracture. Exam shows normal neurologic function. CT shows 40% loss of vertebral height and retropulsion, with an intact posterior ligamentous complex (PLC) confirmed on MRI. What is his Thoracolumbar Injury Classification and Severity (TLICS) score and the recommended treatment?

. 2 points, nonoperative
. 4 points, operative
. 5 points, operative
. 2 points, operative
. 4 points, nonoperative

Correct Answer & Explanation

. 2 points, nonoperative

Explanation

The TLICS score is 2: morphology is burst (2 points), neurology is intact (0 points), and PLC is intact (0 points). A score of less than 4 generally indicates nonoperative management.

Question 573

Topic: Thoracolumbar Spine & Deformity

A 24-year-old woman is involved in a high-speed motor vehicle collision while wearing a lap belt. She sustains a T12 Chance fracture.

Which of the following associated injuries must be most highly suspected and ruled out?

. Aortic dissection
. Hollow viscus injury
. Diaphragmatic rupture
. Splenic laceration
. Renal artery thrombosis

Correct Answer & Explanation

. Aortic dissection

Explanation

Chance fractures (flexion-distraction injuries) are frequently associated with lap seatbelt use and have a high incidence (up to 40-50%) of concomitant intra-abdominal injuries, particularly hollow viscus ruptures.

Question 574

Topic: Thoracolumbar Spine & Deformity

A 55-year-old woman who underwent a T10 to L5 posterior spinal fusion 10 years ago now complains of progressive forward posture and thigh pain when walking. Her pelvic incidence is 55 degrees and her lumbar lordosis is 25 degrees. What is the primary cause of her symptoms?

. Adjacent segment disease at L5-S1
. Pseudarthrosis at L4-L5
. Iatrogenic flatback syndrome with PI-LL mismatch
. Proximal junctional kyphosis
. Degenerative hip osteoarthritis

Correct Answer & Explanation

. Adjacent segment disease at L5-S1

Explanation

The patient has a pelvic incidence to lumbar lordosis (PI-LL) mismatch of 30 degrees (normal target is within 10 degrees). Previous lumbar fusions failing to restore lordosis often result in iatrogenic flatback syndrome and compensatory mechanisms.

Question 575

Topic: Thoracolumbar Spine & Deformity

A 40-year-old man is scheduled for an L5-S1 anterior lumbar interbody fusion (ALIF) for isthmic spondylolisthesis. During the approach, which structure is at highest risk of injury leading to retrograde ejaculation?

. Superior hypogastric plexus
. Ilioinguinal nerve
. Sympathetic trunk
. Parasympathetic pelvic splanchnic nerves
. Genitofemoral nerve

Correct Answer & Explanation

. Superior hypogastric plexus

Explanation

The superior hypogastric plexus lies anterior to the L5-S1 disc space. Injury to these sympathetic fibers during an anterior approach to L5-S1 can result in retrograde ejaculation in males.

Question 576

Topic: Thoracolumbar Spine & Deformity

A 45-year-old man falls from a height and sustains a thoracolumbar burst fracture at L1. He is neurologically intact. Radiographs show 20 degrees of kyphosis and 40% loss of vertebral body height. MRI shows an intact posterior ligamentous complex (PLC). According to the Thoracolumbar Injury Classification and Severity Score (TLICS), what is the most appropriate management?

. Posterior spinal fusion
. Anterior corpectomy and fusion
. Thoracolumbosacral orthosis (TLSO)
. Short segment pedicle screw fixation
. Percutaneous vertebroplasty

Correct Answer & Explanation

. Posterior spinal fusion

Explanation

The TLICS score for this patient is 2 (burst fracture = 2, neurologically intact = 0, PLC intact = 0). A score of 3 or less implies nonoperative management is indicated, typically with a TLSO or hyperextension brace.

Question 577

Topic: Thoracolumbar Spine & Deformity

In the evaluation of adult spinal deformity, which of the following spinopelvic parameters is considered a fixed, position-independent morphologic measurement?

. Pelvic tilt (PT)
. Sacral slope (SS)
. Lumbar lordosis (LL)
. Pelvic incidence (PI)
. Sagittal vertical axis (SVA)

Correct Answer & Explanation

. Pelvic tilt (PT)

Explanation

Pelvic incidence is a fixed anatomic parameter defined by the angle between a perpendicular line to the sacral plate and a line connecting the midpoint of the sacral plate to the bicoxofemoral axis. Unlike pelvic tilt and sacral slope, it does not change with patient positioning.

Question 578

Topic: Thoracolumbar Spine & Deformity

A 65-year-old woman presents with adult degenerative scoliosis and severe mechanical back pain. Preoperative assessment reveals a Pelvic Incidence (PI) of 55 degrees. To optimize her postoperative sagittal alignment and minimize the risk of disability, what should be her target postoperative Lumbar Lordosis (LL)?

. 25 degrees
. 35 degrees
. 55 degrees
. 75 degrees
. 85 degrees

Correct Answer & Explanation

. 25 degrees

Explanation

To achieve optimal sagittal balance in adult spinal deformity, the lumbar lordosis (LL) should be restored to within 9 to 10 degrees of the patient's pelvic incidence (PI). Since her PI is 55 degrees, a target LL of approximately 55 degrees minimizes the PI-LL mismatch.

Question 579

Topic: Thoracolumbar Spine & Deformity

A 22-year-old man involved in a high-speed motor vehicle collision sustains a flexion-distraction injury (Chance fracture) of L2. Which of the following associated injuries must be highly suspected and ruled out?

. Aortic dissection
. Pulmonary contusion
. Hollow viscus injury
. Diaphragmatic rupture
. Renal artery thrombosis

Correct Answer & Explanation

. Aortic dissection

Explanation

Chance fractures are flexion-distraction injuries commonly caused by lap seatbelts during motor vehicle accidents. They are highly associated with intra-abdominal injuries, particularly to hollow organs such as the bowel, occurring in up to 50% of cases.

Question 580

Topic: Thoracolumbar Spine & Deformity



A 30-year-old construction worker falls off a ladder and sustains an L1 burst fracture. CT scan reveals a vertically oriented fracture of the lamina. What is the most critical implication of this specific posterior element fracture pattern?

. It increases the risk of a persistent cerebrospinal fluid leak post-healing
. It indicates an increased likelihood of dural tear and nerve root entrapment
. It requires anterior-only surgical stabilization
. It decreases the risk of post-traumatic kyphosis
. It guarantees the patient will develop conus medullaris syndrome

Correct Answer & Explanation

. It increases the risk of a persistent cerebrospinal fluid leak post-healing

Explanation

A vertical laminar fracture associated with a thoracolumbar burst fracture is highly predictive of a dural tear. During surgery, care must be taken to avoid over-distraction, which could lead to nerve roots being pulled into the fracture site and entrapped.

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