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Thoracolumbar Spine & Deformity MCQs

Practice Set 4 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 61

Topic: Thoracolumbar Spine & Deformity

During a posterior lumbar instrumented fusion, the surgeon prepares to place a pedicle screw at the L4 level. What is the standard anatomical starting point for the insertion of an L4 pedicle screw?

. The medial border of the superior articular process at the base of the lamina
. The intersection of the middle of the transverse process and the lateral border of the superior articular process
. The inferior tip of the spinous process and medial border of the pars interarticularis
. The superior articular process perfectly centered between the superior and inferior facets
. The exact center of the lumbar lamina

Correct Answer & Explanation

. The intersection of the middle of the transverse process and the lateral border of the superior articular process

Explanation

The standard starting point for a lumbar pedicle screw is at the intersection of a horizontal line bisecting the transverse process and a vertical line corresponding to the lateral border of the superior articular process.

Question 62

Topic: Thoracolumbar Spine & Deformity

A 14-year-old female gymnast presents with severe chronic low back pain limiting her participation in sports. Radiographs demonstrate a Grade II L5-S1 isthmic spondylolisthesis. After 6 months of supervised physical therapy, bracing, and NSAIDs, her severe pain persists. What is the most appropriate surgical intervention?

. L5 laminectomy without fusion
. Direct pars interarticularis repair (Buck's procedure)
. L5-S1 posterior spinal fusion
. L4-L5 microdiscectomy
. Sacral laminectomy

Correct Answer & Explanation

. L5-S1 posterior spinal fusion

Explanation

Symptomatic Grade II isthmic spondylolisthesis at L5-S1 that fails conservative management is best treated with an L5-S1 spinal fusion. Direct pars repair (e.g., Buck's procedure) is generally reserved for isolated pars defects or Grade I slips at higher lumbar levels (L1-L4) without significant disc degeneration.

Question 63

Topic: Thoracolumbar Spine & Deformity

A 25-year-old male is involved in a high-speed collision wearing only a lap belt. Radiographs reveal a severe flexion-distraction injury (Chance fracture) at L1. Which of the following associated injuries must be most carefully excluded in this patient?

. Aortic transection
. Intra-abdominal visceral injury
. Pelvic ring disruption
. Diaphragmatic rupture
. Cervical facet dislocation

Correct Answer & Explanation

. Intra-abdominal visceral injury

Explanation

Chance fractures (flexion-distraction injuries) are highly associated with lap-belt mechanisms and carry a very high incidence (up to 50%) of concomitant intra-abdominal injuries, particularly hollow viscus ruptures.

Question 64

Topic: Thoracolumbar Spine & Deformity

When evaluating the sagittal alignment of an adult patient with spinal deformity, which of the following spinopelvic parameters is considered a fixed morphological feature that remains constant regardless of patient positioning?

. Pelvic tilt
. Sacral slope
. Pelvic incidence
. Lumbar lordosis
. Sagittal vertical axis

Correct Answer & Explanation

. Pelvic incidence

Explanation

Pelvic incidence is a fixed morphological parameter defined after skeletal maturity and does not change with posture. It is calculated mathematically as the sum of pelvic tilt and sacral slope (PI = PT + SS).

Question 65

Topic: Thoracolumbar Spine & Deformity

An 11-year-old gymnast presents with persistent lower back pain exacerbated by extension. Oblique lumbar radiographs demonstrate a "collar on the Scotty dog." What is the most appropriate initial management?

. Immediate in-situ posterolateral fusion
. Activity modification and rigid bracing
. Translaminar screw fixation
. Corticosteroid injections
. Laminectomy

Correct Answer & Explanation

. Activity modification and rigid bracing

Explanation

The radiograph finding indicates a pars interarticularis defect (spondylolysis). Initial management for symptomatic pediatric spondylolysis without significant slip is non-operative, primarily consisting of activity restriction and bracing.

Question 66

Topic: Thoracolumbar Spine & Deformity

Degenerative spondylolisthesis most commonly occurs at which level, and is largely attributed to the sagittal orientation of the facet joints?

. L2-L3
. L3-L4
. L4-L5
. L5-S1
. C5-C6

Correct Answer & Explanation

. L4-L5

Explanation

Degenerative spondylolisthesis most frequently occurs at the L4-L5 level. It is commonly associated with a more sagittal orientation of the facet joints, which provides less resistance to anterior shear forces.

Question 67

Topic: Thoracolumbar Spine & Deformity
A 25-year-old male presents with severe mechanical back pain. Standing lateral lumbar radiographs reveal a pars interarticularis defect with a 35% anterior translation of L5 on S1. According to the Meyerding classification, this represents:
. Grade I spondylolisthesis
. Grade II spondylolisthesis
. Grade III spondylolisthesis
. Grade IV spondylolisthesis
. Spondyloptosis

Correct Answer & Explanation

. Grade II spondylolisthesis

Explanation

The Meyerding classification grades the percentage of slip: Grade I (0-25%), Grade II (26-50%), Grade III (51-75%), Grade IV (76-100%), and Grade V (>100%, spondyloptosis). A 35% slip is Grade II.

Question 68

Topic: Thoracolumbar Spine & Deformity

A 14-year-old female gymnast presents with persistent, activity-related lower back pain. Oblique lumbar radiographs reveal a "collared Scotty dog" appearance. This radiographic sign specifically indicates:

. Spondylolisthesis
. Spondylolysis
. Herniated nucleus pulposus
. Facet arthropathy
. Discitis

Correct Answer & Explanation

. Spondylolysis

Explanation

The "collared Scotty dog" sign seen on oblique lumbar radiographs represents a defect or fracture in the pars interarticularis, which is the definition of spondylolysis.

Question 69

Topic: Thoracolumbar Spine & Deformity

Following a motor vehicle collision, a 30-year-old man sustains a burst fracture of L1. According to the Denis three-column concept of spinal stability, the middle column comprises the:

. Anterior longitudinal ligament and anterior half of the vertebral body
. Posterior half of the vertebral body, posterior annulus, and posterior longitudinal ligament
. Pedicles, facets, and pars interarticularis
. Spinous processes and supraspinous ligament
. Ligamentum flavum and neural arch

Correct Answer & Explanation

. Posterior half of the vertebral body, posterior annulus, and posterior longitudinal ligament

Explanation

In the Denis three-column theory, the middle column consists of the posterior half of the vertebral body, the posterior portion of the annulus fibrosus, and the posterior longitudinal ligament. Disruption of this column characterizes a burst fracture.

Question 70

Topic: Thoracolumbar Spine & Deformity

A 14-year-old female gymnast presents with progressive low back pain. Examination reveals a palpable step-off at the lumbosacral junction. Radiographs demonstrate a Grade 2 isthmic spondylolisthesis at L5-S1. Neurological examination is normal. What is the most appropriate initial management?

. In situ posterolateral fusion of L5-S1
. Reduction and pedicle screw fixation
. Activity modification, physical therapy, and bracing
. Laminectomy of L5
. Epidural steroid injection

Correct Answer & Explanation

. Activity modification, physical therapy, and bracing

Explanation

Initial management of low-grade (Grade 1 and 2) isthmic spondylolisthesis without neurological deficits in an adolescent is conservative. This involves activity modification, physical therapy emphasizing core stabilization, and potentially bracing.

Question 71

Topic: Thoracolumbar Spine & Deformity

A 25-year-old man falls from a 10-foot ladder. CT reveals an L1 burst fracture with 30% canal compromise. He is neurologically intact, and the posterior ligamentous complex is intact (TLICS score = 2). Which of the following is the most appropriate treatment?

. Short-segment posterior instrumentation and fusion
. Anterior corpectomy and strut grafting
. Thoracolumbosacral orthosis (TLSO) bracing and early mobilization
. Strict bed rest for 6 weeks
. Percutaneous vertebroplasty

Correct Answer & Explanation

. Thoracolumbosacral orthosis (TLSO) bracing and early mobilization

Explanation

According to the Thoracolumbar Injury Classification and Severity (TLICS) score, a score of 3 or less is an indication for non-operative management. A neurologically intact burst fracture with an intact posterior ligamentous complex is safely treated with a TLSO brace.

Question 72

Topic: Thoracolumbar Spine & Deformity

In the evaluation of a patient with adult spinal deformity, which of the following spinopelvic parameters is considered a fixed, morphologic parameter that does not change with patient positioning?

. 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 (PI) is an anatomical parameter defined by the relationship of the sacrum to the femoral heads and remains constant after skeletal maturity. It mathematically equals the sum of pelvic tilt and sacral slope (PI = PT + SS).

Question 73

Topic: Thoracolumbar Spine & Deformity

Normal sagittal thoracic alignment is:

. 5° to 10° of kyphosis due to the adjacent lordotic cervical and lumbar segments
. Straight because of the rib cage
. Lordotic to support the body weight anteriorly
. 20° to 50° of kyphosis between T1 and T10
. 60° to 80° of kyphosis between T1 and T10

Correct Answer & Explanation

. 20° to 50° of kyphosis between T1 and T10

Explanation

Thoracic kyphosis has contributions from the trapezoidal shapes of the thoracic vertebrae, from the intevertebral disk positions, and from the stiffness of the ribs and sternum. The reported normal values range from 20° to 50°.

Question 74

Topic: Thoracolumbar Spine & Deformity

A 75-year-old female presents with multiple severe thoracic osteoporotic compression fractures. Which of the following physiologic consequences is most likely to be found on her clinical evaluation?

. Cervical kyphosis compensation
. Decreased forced vital capacity
. Radicular pain radiating down the posterior thighs
. Upper motor neuron signs in the lower extremities
. Enhanced diaphragmatic excursion

Correct Answer & Explanation

. Decreased forced vital capacity

Explanation

Severe progressive thoracic kyphosis from multiple compression fractures reduces the volume of the thoracic cavity. This characteristically leads to restrictive lung disease, demonstrating decreased forced vital capacity on pulmonary function testing.

Question 75

Topic: Thoracolumbar Spine & Deformity

A 65-year-old female with osteoporosis is being treated conservatively for a T12 compression fracture. What is the expected role of orthotic bracing (e.g., TLSO or Jewett brace) in this patient?

. It prevents progression of kyphotic deformity
. It provides long-term improvement in forced vital capacity
. It is proven to reduce mortality at 1 year
. It provides early pain relief but does not significantly prevent kyphosis
. It accelerates bone healing on serial radiographs

Correct Answer & Explanation

. It provides early pain relief but does not significantly prevent kyphosis

Explanation

Current literature indicates that orthotic bracing for osteoporotic compression fractures aids in early pain control and allows for earlier mobilization. However, it does not significantly prevent long-term progressive kyphosis or accelerate fracture union.

Question 76

Topic: Thoracolumbar Spine & Deformity

Which of the following associated injuries has the highest incidence in patients diagnosed with a bony Chance fracture of the thoracolumbar junction?

. Aortic dissection
. Hollow viscus intestinal injuries
. Renal artery avulsion
. Splenic rupture
. Diaphragmatic hernia

Correct Answer & Explanation

. Hollow viscus intestinal injuries

Explanation

Chance fractures (flexion-distraction injuries) are highly associated with intra-abdominal injuries, particularly hollow viscus injuries (e.g., bowel ruptures). A high index of suspicion and prompt general surgery evaluation are essential.

Question 77

Topic: Thoracolumbar Spine & Deformity

Regarding the Thoracolumbar Injury Classification and Severity Score (TLICS), a patient presents with a T11-T12 burst fracture, indeterminate posterior ligamentous complex (PLC) status on MRI, and intact neurologic function. What is the total TLICS score and the recommended management?

. Score 2, non-operative management
. Score 3, non-operative management
. Score 4, either operative or non-operative
. Score 5, operative management
. Score 6, operative management

Correct Answer & Explanation

. Score 4, either operative or non-operative

Explanation

TLICS calculates morphology (burst = 2), PLC status (indeterminate = 2), and neurologic status (intact = 0) for a total of 4. A score of 4 means the treatment can be either operative or non-operative based on the surgeon's clinical judgment.

Question 78

Topic: Thoracolumbar Spine & Deformity

A 12-year-old restrained passenger in a motor vehicle collision presents with a lap-belt injury. Radiographs show a fracture extending horizontally through the spinous process, pedicles, and vertebral body of L2. What associated injury must be specifically ruled out?

. Aortic tear
. Intra-abdominal hollow viscus injury
. Diaphragmatic rupture
. Renal artery thrombosis

Correct Answer & Explanation

. Aortic tear

Explanation

This describes a Chance fracture (flexion-distraction injury), highly associated with lap-belt use. Up to 50% of these patients have concurrent intra-abdominal injuries, most commonly involving hollow viscus organs (bowel perforation).

Question 79

Topic: Thoracolumbar Spine & Deformity
A lateral lumbar radiograph of a 14-year-old gymnast shows forward slippage of L5 on S1 by 60%. According to the Meyerding classification, what grade of spondylolisthesis does this represent?
. Grade II
. Grade III
. Grade IV
. Grade V

Correct Answer & Explanation

. Grade III

Explanation

The Meyerding classification grades spondylolisthesis based on the percentage of slip: Grade I (0-25%), Grade II (26-50%), Grade III (51-75%), Grade IV (76-100%), and Grade V (>100%, spondyloptosis). A 60% slip is Grade III.

Question 80

Topic: Thoracolumbar Spine & Deformity

Which of the following patients is not at increased risk for isthmic spondylolisthesis:

. Football lineman
. Gymnast
. Eskimo
. Nonambulatory patient
. Weight lifter

Correct Answer & Explanation

. Nonambulatory patient

Explanation

Isthmic spondylolisthesis is most common in white men and least common in black women. It is thought to arise from repetitive hyperextension of the lumbar spine causing a stress fracture of the pars intra-articularis. Sports such as weight lifting, gymnastics, football, and javelin throwing have a particularly high incidence of this condition. Isthmic spondylolisthesis is never present at birth and is rare in nonambulatory patients.

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