Menu

Thoracolumbar Spine & Deformity MCQs

Practice Set 44 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 861

Topic: Thoracolumbar Spine & Deformity

A 15-year-old competitive gymnast presents with intractable mechanical low back pain for 9 months. She has failed intensive physical therapy and bracing. Radiographs show a Grade II L5-S1 isthmic spondylolisthesis. She has no radicular symptoms. What is the gold-standard surgical intervention for this patient?

. Direct repair of the pars interarticularis (Buck technique)
. L5-S1 in situ posterolateral fusion
. L5-S1 complete reduction and interbody fusion
. L4-S1 anterior lumbar interbody fusion (ALIF)
. Laminectomy of L5 without fusion

Correct Answer & Explanation

. L5-S1 in situ posterolateral fusion

Explanation

For adolescents with symptomatic low-grade (Grade I or II) isthmic spondylolisthesis who fail conservative care, an in situ L5-S1 posterolateral fusion is the established gold standard. Attempting complete anatomic reduction increases the risk of an L5 nerve root stretch injury.

Question 862

Topic: Thoracolumbar Spine & Deformity

A 22-year-old female sustains a seatbelt-type injury in a motor vehicle accident. CT demonstrates an L2 flexion-distraction (Chance) fracture strictly confined to the bone, with avulsion of the posterior spinous process and widening of the pedicles. Neurologic exam is normal. What is the most appropriate primary treatment?

. Extension thoracolumbosacral orthosis (TLSO)
. Anterior L2 corpectomy and plating
. L2 laminectomy without fusion
. Posterior interspinous wiring
. Percutaneous pedicle screw fixation without fusion

Correct Answer & Explanation

. Extension thoracolumbosacral orthosis (TLSO)

Explanation

A purely bony Chance fracture (flexion-distraction injury) without neurologic compromise has excellent healing potential due to the large cancellous bone surfaces involved. It is typically managed successfully with closed reduction and an extension orthosis (TLSO).

Question 863

Topic: Thoracolumbar Spine & Deformity

A 22-year-old male is involved in a high-speed motor vehicle accident while wearing a lap belt. Radiographs show a flexion-distraction injury (Chance fracture) at the T12 level. Which of the following associated injuries must be urgently ruled out?

. Diaphragmatic rupture
. Aortic transection
. Intra-abdominal hollow viscus injury
. Pulmonary contusion
. Pelvic ring disruption

Correct Answer & Explanation

. Intra-abdominal hollow viscus injury

Explanation

Chance fractures (flexion-distraction injuries) are highly associated with lap seatbelt injuries. There is a strong association (up to 50%) with intra-abdominal injuries, particularly hollow viscus injuries (e.g., bowel perforation), which require urgent general surgery evaluation.

Question 864

Topic: Thoracolumbar Spine & Deformity

A 15-year-old female gymnast complains of chronic low back pain and radiating left leg pain. Radiographs reveal a Grade II isthmic spondylolisthesis at L5-S1. If this patient is experiencing single-root radicular symptoms, which specific nerve root is most likely compressed by the pathoanatomy of this condition?

. L3
. L4
. L5
. S1
. S2

Correct Answer & Explanation

. L5

Explanation

In L5-S1 isthmic spondylolisthesis, the L5 exiting nerve root is most commonly compressed within the neural foramen. This compression is typically caused by the hypertrophic fibrocartilaginous tissue attempting to heal the pars interarticularis defect (the "pars mass").

Question 865

Topic: Thoracolumbar Spine & Deformity
In evaluating a patient for an adult spinal deformity correction, achieving sagittal balance is critical to prevent adjacent segment disease. According to the Schwab-SRS classification, the mismatch between Pelvic Incidence (PI) and Lumbar Lordosis (LL) should ideally be maintained within what range?
. PI - LL < 10 degrees
. PI - LL < 20 degrees
. PI - LL > 15 degrees
. PI - LL = 0 to -10 degrees
. PI - LL > 25 degrees

Correct Answer & Explanation

. PI - LL < 10 degrees

Explanation

In sagittal plane deformity correction, optimal outcomes and decreased risk of adjacent segment disease are correlated with achieving a Pelvic Incidence (PI) minus Lumbar Lordosis (LL) mismatch of less than 10 degrees (ideally PI ≈ LL ± 9 degrees). A mismatch greater than 10 degrees indicates residual flatback deformity.

Question 866

Topic: Thoracolumbar Spine & Deformity
A 14-year-old gymnast presents with progressive low back pain exacerbated by extension. Lateral radiographs of the lumbar spine reveal a pars interarticularis defect at L5 with a 30% anterior translation of L5 on S1. According to the Meyerding classification, what grade of spondylolisthesis does this patient have?
. Grade I
. Grade II
. Grade III
. Grade IV
. Grade V (Spondyloptosis)

Correct Answer & Explanation

. Grade II

Explanation

The Meyerding classification grades the severity of spondylolisthesis based on the percentage of anterior translation of the superior vertebral body over the inferior one. Grade I: < 25%; Grade II: 25-50%; Grade III: 50-75%; Grade IV: 75-100%; Grade V (Spondyloptosis): > 100% (complete slippage). A 30% slip falls into the Grade II category.

Question 867

Topic: Thoracolumbar Spine & Deformity

A 35-year-old male falls from a roof and sustains a T12 burst fracture. He is neurologically intact. MRI demonstrates definitive disruption of the posterior ligamentous complex (PLC). According to the Thoracolumbar Injury Classification and Severity (TLICS) score, what is his score and the recommended management?

. TLICS score 2, non-operative management
. TLICS score 3, non-operative management
. TLICS score 4, surgeon's choice of operative or non-operative
. TLICS score 5, operative management
. TLICS score 7, operative management

Correct Answer & Explanation

. TLICS score 5, operative management

Explanation

The TLICS score is calculated based on three categories: injury morphology, integrity of the PLC, and neurologic status. Burst fracture = 2 points. Intact neurology = 0 points. Disrupted PLC = 3 points. Total score = 5. A TLICS score >= 5 is an indication for operative management. A score of 4 can be managed operatively or non-operatively based on the surgeon's clinical judgment.

Question 868

Topic: Thoracolumbar Spine & Deformity

A 68-year-old female presents with severe back pain and forward-leaning posture. Standing 36-inch radiographs demonstrate adult spinal deformity. Her pelvic incidence (PI) is measured at 55 degrees, pelvic tilt (PT) is 30 degrees, and lumbar lordosis (LL) is 25 degrees. What is her PI-LL mismatch, and what is the generally accepted surgical target for this parameter?

. Mismatch is 15 degrees; target is < 30 degrees
. Mismatch is 25 degrees; target is < 20 degrees
. Mismatch is 30 degrees; target is within 10 degrees
. Mismatch is 55 degrees; target is within 15 degrees
. Mismatch is 85 degrees; target is > 40 degrees

Correct Answer & Explanation

. Mismatch is 30 degrees; target is within 10 degrees

Explanation

The Pelvic Incidence minus Lumbar Lordosis (PI - LL) mismatch is a critical parameter in adult spinal deformity correction. In this patient, PI (55) - LL (25) = 30 degrees. The SRS-Schwab classification defines the ideal target for surgical correction as a PI-LL mismatch of within 10 degrees (ideally < 9 degrees) to optimize sagittal balance, reduce adjacent segment disease, and improve patient-reported outcomes.

Question 869

Topic: Thoracolumbar Spine & Deformity

A 22-year-old male is a restrained driver (lap belt only) in a high-speed MVC. He presents with a transverse ecchymosis across his abdomen. Radiographs and CT show a horizontal fracture line passing through the spinous process, pedicles, and vertebral body of L2. What associated injury is classically most critical to rule out in this specific fracture pattern?

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

Correct Answer & Explanation

. Hollow viscus (gastrointestinal) injury

Explanation

The patient has sustained a Chance fracture, which is a flexion-distraction injury often caused by a lap-belt acting as a fulcrum during rapid deceleration. This injury mechanism causes significant anterior compression and massive posterior column distraction. Chance fractures are highly associated with intra-abdominal injuries, particularly hollow viscus injuries (bowel rupture/ischemia), which occur in up to 30-50% of cases and require urgent general surgery evaluation.

Question 870

Topic: Thoracolumbar Spine & Deformity
A 34-year-old female sustains a T12 burst fracture following a motor vehicle collision. She has normal strength and sensation in bilateral lower extremities (ASIA E). MRI demonstrates definitive disruption of the posterior ligamentous complex (PLC). According to the Thoracolumbar Injury Classification and Severity Score (TLICS), what is her total score and the recommended management?
. Score of 3; non-operative management with a TLSO brace
. Score of 4; surgeon's discretion regarding operative versus non-operative management
. Score of 5; operative stabilization
. Score of 6; operative stabilization
. Score of 7; operative stabilization

Correct Answer & Explanation

. Score of 5; operative stabilization

Explanation

The TLICS score is calculated based on three categories. 1. Morphology: Burst fracture = 2 points. 2. Neurologic status: Intact = 0 points. 3. Posterior Ligamentous Complex (PLC): Definitively disrupted = 3 points. Total score = 5 points. A score of ≤3 suggests non-operative treatment, 4 is indeterminate (surgeon's choice), and ≥5 indicates surgical stabilization.

Question 871

Topic: Thoracolumbar Spine & Deformity
In the surgical planning for a 62-year-old female with adult spinal deformity, achieving optimal sagittal balance is critical to prevent adjacent segment disease and mechanical failure. Which of the following defines the ideal relationship between Pelvic Incidence (PI) and Lumbar Lordosis (LL)?
. PI and LL should be inversely proportional
. PI - LL should be ≤ 10 degrees
. LL should exceed PI by at least 20 degrees
. PI should be exactly half of the LL
. PI + LL should equal Pelvic Tilt (PT)

Correct Answer & Explanation

. PI - LL should be ≤ 10 degrees

Explanation

Pelvic incidence (PI) is a fixed morphologic parameter of the pelvis, while lumbar lordosis (LL) is a dynamic postural parameter. The goal of adult spinal deformity surgery is to restore harmonious spinopelvic alignment. Schwab's criteria for successful realignment indicate that the mismatch between PI and LL should be ≤ 10 degrees (PI - LL ≤ 10°). Pelvic Tilt (PT) should ideally be < 20°, and the Sagittal Vertical Axis (SVA) < 5 cm.

Question 872

Topic: Thoracolumbar Spine & Deformity

Which of the following is the most classic demographic and anatomical presentation for degenerative spondylolisthesis versus isthmic spondylolisthesis?

. Degenerative: Teenage gymnast at L5-S1. Isthmic: 60-year-old female at L4-L5.
. Degenerative: 60-year-old female at L4-L5. Isthmic: Teenage gymnast at L5-S1.
. Degenerative: 40-year-old male at L3-L4. Isthmic: 60-year-old male at L4-L5.
. Degenerative: 60-year-old male at L5-S1. Isthmic: 20-year-old female at L3-L4.
. Degenerative and Isthmic most commonly both occur at L5-S1 in adult males.

Correct Answer & Explanation

. Degenerative: 60-year-old female at L4-L5. Isthmic: Teenage gymnast at L5-S1.

Explanation

Degenerative spondylolisthesis classically occurs in older females (e.g., >50 years old), most frequently at the L4-L5 level, due to facet joint osteoarthritis and ligamentum flavum hypertrophy. Isthmic spondylolisthesis (secondary to a pars interarticularis defect) most classically presents in adolescents or young adults (frequently athletes involving repetitive hyperextension, like gymnasts), predominantly at the L5-S1 level.

Question 873

Topic: Thoracolumbar Spine & Deformity

A 14-year-old female gymnast complains of chronic low back pain. Radiographs demonstrate a Grade II L5-S1 isthmic spondylolisthesis. After 6 months of failed physical therapy and bracing, what is the most appropriate surgical treatment?

. L5-S1 anterior lumbar interbody fusion (ALIF) alone
. L5 pars repair (Buck technique)
. L5-S1 posterolateral fusion in situ
. L4-S1 posterior instrumented fusion with full reduction
. L5 laminectomy without fusion

Correct Answer & Explanation

. L5-S1 posterolateral fusion in situ

Explanation

For a symptomatic Grade II isthmic spondylolisthesis in an adolescent that has failed conservative care, an L5-S1 posterolateral fusion in situ is the standard of care. Pars repair is typically reserved for L4 or higher and only for Grade 0-I slips.

Question 874

Topic: Thoracolumbar Spine & Deformity

In the surgical management of Adult Spinal Deformity, restoring sagittal balance is a primary goal. Which of the following pelvic parameters is a fixed, position-independent morphological measurement of the pelvis?

. Pelvic Tilt (PT)
. Sacral Slope (SS)
. Pelvic Incidence (PI)
. Lumbar Lordosis (LL)
. Sagittal Vertical Axis (SVA)

Correct Answer & Explanation

. Pelvic Incidence (PI)

Explanation

Pelvic incidence is a fixed morphological parameter that dictates the necessary amount of lumbar lordosis (LL = PI ± 9 degrees). Pelvic tilt and sacral slope are dynamic parameters that change with patient positioning.

Question 875

Topic: Thoracolumbar Spine & Deformity

In evaluating a patient with adult spinal deformity, achieving appropriate sagittal balance is a primary surgical goal. Which of the following spinopelvic parameters is morphological and remains fixed regardless of patient positioning?

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

Correct Answer & Explanation

. Pelvic incidence (PI)

Explanation

Pelvic incidence (PI) is a fixed morphological parameter unique to each individual's pelvic anatomy. As the pelvis retroverts or anteverts to compensate for deformity, pelvic tilt and sacral slope change, but PI remains constant.

Question 876

Topic: Thoracolumbar Spine & Deformity

Which factor is most strongly associated with progression of a low-grade (Grade I or II) spondylolisthesis in children?

. Presence of sacral dome rounding
. Age greater than 15 years
. Female gender
. Participation in non-contact sports
. Development of hamstring tightness

Correct Answer & Explanation

. Presence of sacral dome rounding

Explanation

Sacral dome rounding (or dome-shaped sacrum) is a key morphological risk factor associated with the progression of spondylolisthesis, especially in the setting of Type I dysplastic slips, as it indicates a less stable articulation. While hamstring tightness is a symptom, and other factors may play minor roles, sacral morphology is a strong radiological predictor of progression.

Question 877

Topic: Thoracolumbar Spine & Deformity
Which of the following describes a 'high-grade' spondylolisthesis?
. A slip of less than 25% (Meyerding Grade I)
. A slip of 25-50% (Meyerding Grade II)
. A slip of greater than 50% (Meyerding Grade III-V)
. Any symptomatic spondylolisthesis
. A spondylolisthesis with associated spinal stenosis

Correct Answer & Explanation

. A slip of greater than 50% (Meyerding Grade III-V)

Explanation

High-grade spondylolisthesis refers to a slip of greater than 50% (Meyerding Grades III, IV, and V). These slips are often associated with more severe symptoms, lumbosacral kyphosis, and a higher risk of complications with surgical reduction compared to low-grade slips (Grades I and II).

Question 878

Topic: Thoracolumbar Spine & Deformity

What is the typical angle measured on a lateral radiograph to assess the severity of lumbosacral kyphosis associated with high-grade spondylolisthesis?

. Lumbar Lordosis (LL)
. Sacral Slope (SS)
. Pelvic Incidence (PI)
. Lumbosacral Angle (LSA) or Slip Angle (Dubousset's Angle)
. T1 Pelvic Angle (TPA)

Correct Answer & Explanation

. Lumbosacral Angle (LSA) or Slip Angle (Dubousset's Angle)

Explanation

The Lumbosacral Angle (also known as the Slip Angle or Dubousset's Angle) is specifically used to quantify lumbosacral kyphosis in spondylolisthesis. It is formed by the intersection of a line drawn along the inferior endplate of L5 and a line drawn along the superior endplate of S1. Increased kyphosis (a negative angle) is a sign of instability and often correlates with higher-grade slips. Other angles like LL, SS, PI, TPA are measures of overall sagittal balance but not specific to L5-S1 kyphosis due to slip.

Question 879

Topic: Thoracolumbar Spine & Deformity

In the context of degenerative spondylolisthesis, which level is most commonly affected?

. L2-L3
. L3-L4
. L4-L5
. L5-S1
. T12-L1

Correct Answer & Explanation

. L4-L5

Explanation

Degenerative spondylolisthesis most commonly occurs at the L4-L5 level. This is thought to be due to the orientation of the L4-L5 facet joints, which are more sagittally oriented and thus less resistant to anterior shear forces, combined with the greater mobility and stress at this segment.

Question 880

Topic: Thoracolumbar Spine & Deformity

What is the main concern with surgical reduction of high-grade spondylolisthesis in terms of achieving optimal spinal balance?

. Increased risk of non-union
. Difficulty in achieving adequate decompression
. Potential for pelvic retroversion
. Overcorrection leading to flatback syndrome
. Difficulty in achieving correct sacral slope

Correct Answer & Explanation

. Overcorrection leading to flatback syndrome

Explanation

A significant concern with aggressive reduction of high-grade spondylolisthesis, particularly in patients with compensatory hyperlordosis above the slip, is the potential for overcorrection of the lumbosacral kyphosis. This can lead to a 'flatback syndrome' or sagittal imbalance if the overall lumbar lordosis is excessively restored without considering the patient's global sagittal alignment. It's often more about restoring a balanced sagittal alignment than just maximal reduction of the slip.

Test Yourself

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

On this Page