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Thoracolumbar Spine & Deformity MCQs

Practice Set 13 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 241

Topic: Thoracolumbar Spine & Deformity

A 55-year-old female presents with severe thigh pain and an inability to stand upright. She had a Harrington rod fusion from T10 to L4 at age 16 for idiopathic scoliosis. Radiographs demonstrate a pelvic tilt of 35 degrees and a sagittal vertical axis (SVA) of +12 cm.

What is the primary cause of her symptoms?

. Pseudarthrosis at T12-L1
. Iatrogenic flatback syndrome due to loss of lumbar lordosis
. Adjacent segment degeneration with dynamic listhesis
. Late-onset surgical site infection
. Hardware failure of the Harrington rod

Correct Answer & Explanation

. Iatrogenic flatback syndrome due to loss of lumbar lordosis

Explanation

Harrington rods utilized distraction forces, which inherently flattened the normal lumbar lordosis. Over time, patients develop 'flatback syndrome' characterized by a positive SVA and compensatory high pelvic retroversion (increased PT), leading to severe back and leg pain.

Question 242

Topic: Thoracolumbar Spine & Deformity

The Gaines procedure is a salvage operation reserved for severe cases of spondyloptosis (Grade V spondylolisthesis). Which of the following best describes the surgical sequence of the Gaines procedure?

. Posterior in situ fusion from L4 to the pelvis with fibular strut grafts
. Anterior release of L5-S1 followed by posterior pedicle screw reduction
. Anterior L5 corpectomy followed by posterior reduction and fusion of L4 onto S1
. Posterior laminectomy of L5 followed by anterior interbody fusion at L4-L5
. Sacral dome osteotomy followed by L5 transvertebral screw fixation

Correct Answer & Explanation

. Anterior L5 corpectomy followed by posterior reduction and fusion of L4 onto S1

Explanation

The Gaines procedure is a two-stage technique for spondyloptosis. It involves an anterior L5 vertebrectomy (corpectomy), followed by a posterior procedure to resect the posterior elements of L5 and reduce/fuse L4 directly onto S1.

Question 243

Topic: Thoracolumbar Spine & Deformity

A 16-year-old female presents with progressive scoliosis, exhibiting a 55-degree thoracic curve (T5-T12). Her pulmonary function tests show a forced vital capacity (FVC) of 60% of predicted. What is the primary concern regarding her respiratory function in the long term without intervention?

. Increased risk of asthma attacks.
. Diaphragmatic paralysis.
. Restrictive lung disease and respiratory insufficiency.
. Obstructive lung disease.
. Development of pulmonary hypertension and cor pulmonale.

Correct Answer & Explanation

. Restrictive lung disease and respiratory insufficiency.

Explanation

Correct Answer: CSevere scoliosis, particularly thoracic curves exceeding 50-60 degrees, can significantly restrict chest wall and lung expansion. This leads to a restrictive ventilatory defect, characterized by reduced lung volumes (like FVC). Over time, this can progress to chronic respiratory insufficiency and, in severe cases, pulmonary hypertension and cor pulmonale (right heart failure due to lung disease). While pulmonary hypertension can be a late complication, restrictive lung disease is the primary and direct impact on lung function. Asthma is not directly caused by scoliosis. Diaphragmatic paralysis is unrelated. Obstructive lung disease involves airflow limitation, which is not the primary issue in scoliosis.

Question 244

Topic: Thoracolumbar Spine & Deformity

A 45-year-old male presents after a fall from a ladder, sustaining a T10 compression fracture. Imaging reveals a wedge compression fracture with 30% loss of anterior vertebral body height, no posterior wall involvement, and an intact posterior ligamentous complex. Neurological examination is completely normal. Using the Thoracolumbar Injury Classification System (TLICS), what is the most appropriate management recommendation?

. Surgical stabilization due to high TLICS score.
. Conservative management with bracing and early mobilization.
. Anterior decompression and fusion.
. Vertebroplasty or kyphoplasty.
. Immediate halo vest immobilization.

Correct Answer & Explanation

. Conservative management with bracing and early mobilization.

Explanation

Correct Answer: BRationale:The Thoracolumbar Injury Classification System (TLICS) assigns points based on three main categories: morphology of the injury, integrity of the posterior ligamentous complex (PLC), and neurological status. A score of 3 or less typically indicates non-operative management, while a score of 5 or more suggests surgical intervention. A score of 4 is equivocal and often depends on surgeon preference or other patient factors.Morphology:Compression fracture = 1 point.Posterior Ligamentous Complex (PLC) Integrity:Intact = 0 points.Neurological Status:Intact = 0 points.Total TLICS score = 1 + 0 + 0 = 1 point. A score of 1 strongly indicates conservative management with bracing and early mobilization.Why other options are incorrect:A) Surgical stabilization due to high TLICS score:The TLICS score is 1, which is low and indicates non-operative management.C) Anterior decompression and fusion:This is indicated for significant anterior canal compromise, which is not present here, or for specific fracture patterns not seen in a simple compression fracture.D) Vertebroplasty or kyphoplasty:These procedures are primarily for pain relief in osteoporotic compression fractures, not typically for traumatic compression fractures in a 45-year-old, especially when conservative management is indicated by TLICS.E) Immediate halo vest immobilization:Halo vests are used for cervical spine injuries, not thoracolumbar fractures.

Question 245

Topic: Thoracolumbar Spine & Deformity

A 25-year-old female presents after a fall from 10 feet. CT reveals an L1 burst fracture with 15 degrees of focal kyphosis and 30% canal compromise. She has normal neurological function, and MRI confirms the posterior ligamentous complex (PLC) is completely intact. According to the Thoracolumbar Injury Classification and Severity (TLICS) score, what is the most appropriate management?

. Immediate operative decompression and fusion
. Treatment with a Thoracolumbosacral orthosis (TLSO)
. Percutaneous short-segment pedicle screw fixation
. Anterior corpectomy and cage placement
. Bed rest for 6 weeks without orthosis

Correct Answer & Explanation

. Treatment with a Thoracolumbosacral orthosis (TLSO)

Explanation

This patient has a TLICS score of 2 (Burst morphology = 2; Neuro intact = 0; PLC intact = 0). A score of 3 or less is an indication for non-operative management, typically with a TLSO brace and early mobilization.

Question 246

Topic: Thoracolumbar Spine & Deformity

A 30-year-old male falls from a ladder, sustaining an L1 burst fracture. CT shows 40% canal compromise. He is neurologically intact. MRI demonstrates an intact posterior ligamentous complex (PLC). According to the Thoracolumbar Injury Classification and Severity (TLICS) score, what is the most appropriate management?

. Posterior spinal fusion from T11 to L3
. Anterior corpectomy and fusion
. Thoracolumbosacral orthosis (TLSO) brace
. Laminectomy and short-segment fixation
. Bed rest for 6 weeks followed by physical therapy

Correct Answer & Explanation

. Thoracolumbosacral orthosis (TLSO) brace

Explanation

The TLICS score is 2 (1 point for compression mechanism, +1 point for burst component, 0 for intact PLC, 0 for intact neurologic status). A TLICS score of 3 or less is an indication for non-operative management, such as a TLSO brace.

Question 247

Topic: Thoracolumbar Spine & Deformity

A 22-year-old male falls from a height and sustains an L1 burst fracture. He is neurologically intact. MRI demonstrates definitive rupture of the posterior ligamentous complex (PLC). According to the Thoracolumbar Injury Classification and Severity (TLICS) score, what is his total score and recommended management?

. Score 2; nonoperative management in a TLSO
. Score 4; operative or nonoperative management
. Score 5; operative management
. Score 7; operative management
. Score 3; nonoperative management

Correct Answer & Explanation

. Score 5; operative management

Explanation

The TLICS score is calculated as follows: Burst fracture morphology (2 points), intact neurologic status (0 points), and ruptured PLC (3 points) for a total of 5 points. A score of 5 or greater indicates surgical stabilization is recommended.

Question 248

Topic: Thoracolumbar Spine & Deformity

A 16-year-old male is brought to the emergency department after a high-speed motor vehicle collision where he was a restrained rear-seat passenger wearing a lap belt. Radiographs and CT imaging reveal a flexion-distraction injury of the lumbar spine (Chance fracture).

Which of the following associated injuries must be most aggressively ruled out in this patient?

. Aortic transection
. Intra-abdominal hollow viscus injury
. Diaphragmatic rupture
. Renal artery thrombosis
. Pelvic ring disruption

Correct Answer & Explanation

. Intra-abdominal hollow viscus injury

Explanation

Chance fractures (flexion-distraction injuries) sustained via a lap belt mechanism are highly associated with intra-abdominal pathology, particularly hollow viscus injuries (e.g., bowel perforation). These occur in up to 50% of cases and demand careful general surgery evaluation.

Question 249

Topic: Thoracolumbar Spine & Deformity
Which type of spondylolisthesis is most commonly associated with a sacral spina bifida occulta and a trapezoidal L5 vertebral body?
. Type I Dysplastic
. Type II Isthmic
. Type III Degenerative
. Type IV Traumatic
. Type V Pathologic

Correct Answer & Explanation

. Type I Dysplastic

Explanation

Type I, or Dysplastic Spondylolisthesis, is a congenital anomaly characterized by malformed sacral facets, an elongated pars, and a trapezoidal L5 vertebral body, often associated with sacral spina bifida occulta. This morphology leads to an inherent instability that predisposes to anterior slippage. The other types have different underlying etiologies.

Question 250

Topic: Thoracolumbar Spine & Deformity

What is the primary role of an oblique radiograph in the workup of spondylolisthesis?

. To assess overall spinal alignment and balance
. To visualize the pars interarticularis for a defect
. To measure the percentage of vertebral slip
. To evaluate disc height and endplate sclerosis
. To identify facet joint arthrosis

Correct Answer & Explanation

. To visualize the pars interarticularis for a defect

Explanation

Correct Answer: BOblique radiographs are specifically used to visualize the pars interarticularis, which appears as the 'neck' of the 'Scottie dog.' A defect or fracture in the pars ('collar on the Scottie dog') is indicative of an isthmic spondylolysis or spondylolisthesis. Other views (AP/Lateral) are better for alignment, slip percentage, and disc space evaluation.

Question 251

Topic: Thoracolumbar Spine & Deformity

A 62-year-old female presents with neurogenic claudication. Radiographs demonstrate an L4-L5 Grade I degenerative spondylolisthesis. Which of the following anatomic characteristics is most strongly associated with the development of this condition?

. Coronal orientation of the L4-L5 facet joints
. Sagittal orientation of the L4-L5 facet joints
. Decreased pelvic incidence
. Decreased lumbar lordosis
. A pre-existing defect in the pars interarticularis

Correct Answer & Explanation

. Sagittal orientation of the L4-L5 facet joints

Explanation

Sagittal orientation of the facet joints is a major anatomic risk factor for degenerative spondylolisthesis, as it provides less resistance to anterior shear forces. Increased pelvic incidence and female sex are also well-documented risk factors.

Question 252

Topic: Thoracolumbar Spine & Deformity

An 11-year-old girl is diagnosed with a high-grade dysplastic spondylolisthesis at L5-S1. Which of the following radiographic parameters is the most reliable predictor for further slip progression?

. Sacral slope
. Pelvic tilt
. Slip angle
. Lumbar lordosis
. Intervertebral disc height

Correct Answer & Explanation

. Slip angle

Explanation

A high slip angle (typically > 45-50 degrees) is the most predictive radiographic parameter for the progression of a high-grade spondylolisthesis. It reflects the local kyphosis at the lumbosacral junction.

Question 253

Topic: Thoracolumbar Spine & Deformity

A 16-year-old male with a high-grade L5-S1 isthmic spondylolisthesis is evaluated for surgical intervention. Radiographic assessment reveals a high pelvic incidence (PI). Which of the following accurately describes the relationship between pelvic incidence and high-grade spondylolisthesis?

. Pelvic incidence decreases as the severity of the slip increases.
. High pelvic incidence implies a more vertical sacrum, increasing shear forces.
. Pelvic incidence is a dynamic parameter that normalizes after successful in situ fusion.
. High pelvic incidence correlates with increased sacral slope and higher shear forces at the lumbosacral junction.
. Pelvic incidence has no established correlation with the risk of slip progression.

Correct Answer & Explanation

. High pelvic incidence correlates with increased sacral slope and higher shear forces at the lumbosacral junction.

Explanation

Pelvic incidence (PI) is a fixed morphologic parameter (PI = Pelvic Tilt + Sacral Slope). High PI is strongly associated with high-grade isthmic spondylolisthesis because it results in a higher sacral slope, which increases the anterior shear forces across the L5-S1 disc space.

Question 254

Topic: Thoracolumbar Spine & Deformity

According to the Wiltse classification of spondylolisthesis, which of the following mechanisms correctly defines a Type IV (Traumatic) spondylolisthesis?

. Congenital dysplasia of the L5-S1 facet joints
. A stress fracture of the pars interarticularis
. An acute fracture of the posterior arch elements other than the pars interarticularis
. Long-standing segmental instability leading to facet remodeling
. Iatrogenic excessive resection of the pars during decompression

Correct Answer & Explanation

. An acute fracture of the posterior arch elements other than the pars interarticularis

Explanation

Wiltse Type IV (Traumatic) spondylolisthesis is caused by an acute fracture of the posterior bony elements, such as the pedicle, lamina, or facets, but strictly excludes fractures of the pars interarticularis (which define Type II, Isthmic).

Question 255

Topic: Thoracolumbar Spine & Deformity

A 55-year-old female presents with neurogenic claudication. Review the provided representative imaging.

In classical degenerative spondylolisthesis at this typical level, which of the following anatomic factors is most strongly predictive of progression?

. Coronal orientation of the facet joints
. Sagittal orientation of the facet joints
. Presence of an occult pars defect
. Decreased pelvic incidence
. Sacral kyphosis

Correct Answer & Explanation

. Sagittal orientation of the facet joints

Explanation

Degenerative spondylolisthesis most commonly occurs at L4-L5. A sagittal orientation of the facet joints (>45 degrees relative to the coronal plane) provides less resistance to anterior translational forces and is a strong predictor of slip progression.

Question 256

Topic: Thoracolumbar Spine & Deformity
A 13-year-old male with a known Grade III L5-S1 isthmic spondylolisthesis presents with an altered gait. On examination, he walks with a characteristic waddling motion, maintaining his hips and knees in flexion with a flattened lumbar lordosis. This classic clinical presentation is referred to as:
. Gowers sign
. Phalen-Dickson sign
. Lasègue sign
. Waddell sign
. Hoover sign

Correct Answer & Explanation

. Phalen-Dickson sign

Explanation

The Phalen-Dickson sign is a classic physical examination finding in high-grade pediatric isthmic spondylolisthesis. It consists of a waddling gait with knee and hip flexion, driven by severe hamstring spasticity and a retroverted pelvis.

Question 257

Topic: Thoracolumbar Spine & Deformity

A 65-year-old female undergoes a decompressive laminectomy for L4-L5 degenerative spondylolisthesis. During the procedure, an incidental durotomy occurs. The surgeon successfully achieves a primary, watertight suture repair. What is the most appropriate postoperative management regarding mobilization?

. Strict flat bed rest for 5 to 7 days
. Immediate placement of a lumbar subarachnoid drain
. Early mobilization without mandatory bed rest
. Placement of high-suction subfascial drains
. Revision surgery within 24 hours to apply a fascial patch

Correct Answer & Explanation

. Early mobilization without mandatory bed rest

Explanation

Recent literature and current guidelines support early mobilization following a successful primary, watertight repair of an incidental durotomy. Prolonged bed rest increases the risk of deep vein thrombosis and pneumonia without significantly reducing the rate of cerebrospinal fluid leaks.

Question 258

Topic: Thoracolumbar Spine & Deformity

An 18-year-old gymnast complains of chronic low back pain exacerbated by extension. Radiographs show a Grade I isthmic spondylolisthesis at L5-S1. The slip angle is measured to assess the risk of progression. How is the slip angle (sagittal roll) correctly measured on a lateral radiograph?

. The angle between the superior endplate of L5 and the superior endplate of S1.
. The angle between the inferior endplate of L5 and a line perpendicular to the posterior cortex of the S1 body.
. The angle between the anterior cortex of L5 and the anterior cortex of S1.
. The angle formed by the intersection of lines drawn along the posterior margins of the L4 and S1 bodies.
. The angle between the superior endplate of L5 and the inferior endplate of S1.

Correct Answer & Explanation

. The angle between the inferior endplate of L5 and a line perpendicular to the posterior cortex of the S1 body.

Explanation

The slip angle (sagittal roll or kyphotic angle) in spondylolisthesis is measured between a line drawn parallel to the inferior endplate of L5 and a line drawn perpendicular to the posterior cortex of the first sacral vertebral body.

Question 259

Topic: Thoracolumbar Spine & Deformity

A 60-year-old male undergoes a bilateral L4-L5 laminectomy and medial facetectomy for central stenosis. Postoperatively, he develops progressive mechanical back pain, and a repeat radiograph at 6 months reveals a new Grade II forward slip of L4 on L5. To minimize the risk of this iatrogenic (Wiltse Type VI) spondylolisthesis, resection of the pars interarticularis should not exceed what percentage?

. 10%
. 25%
. 50%
. 75%
. 100%

Correct Answer & Explanation

. 50%

Explanation

Iatrogenic spondylolisthesis (Wiltse Type VI) is a known complication of lumbar decompression. Biomechanical studies indicate that preserving at least 50% of the bilateral pars interarticularis and facet joints is critical to maintain segmental stability and prevent post-surgical slip.

Question 260

Topic: Thoracolumbar Spine & Deformity

A 22-year-old male presents with back pain and is diagnosed with an L5-S1 isthmic spondylolisthesis. Which spinopelvic parameter is typically abnormally increased in this population, predisposing them to elevated lumbosacral shear forces?

. Pelvic tilt
. Sacral slope
. Pelvic incidence
. Lumbar lordosis
. Thoracic kyphosis

Correct Answer & Explanation

. Pelvic incidence

Explanation

Pelvic incidence is a fixed morphological parameter that is significantly increased in patients with isthmic spondylolisthesis compared to the normal population. A high pelvic incidence increases shear forces at the lumbosacral junction, predisposing to listhesis.

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