Menu

6. Spine MCQs

Practice Set 94 of 379

This practice set contains high-yield board review questions covering key concepts in 6. Spine. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 1861

Topic: 6. Spine

A 13-year-old non-ambulatory boy with Duchenne Muscular Dystrophy presents with a progressive 35-degree thoracolumbar scoliosis. He is having increasing difficulty maintaining seating balance. What is the most appropriate surgical recommendation?

. Observation until the curve reaches 50 degrees
. TLSO bracing to halt curve progression
. Posterior spinal fusion from the upper thoracic spine to the pelvis
. Anterior spinal fusion of the lumbar curve only
. Insertion of vertical expandable prosthetic titanium ribs (VEPTR)

Correct Answer & Explanation

. Posterior spinal fusion from the upper thoracic spine to the pelvis

Explanation

Scoliosis in DMD is progressive and does not respond to bracing. Surgical stabilization is typically recommended when curves exceed 20-30 degrees in non-ambulatory patients, usually involving posterior spinal fusion from the upper thoracic spine to the pelvis to correct pelvic obliquity.

Question 1862

Topic: Thoracolumbar Spine & Deformity

In a 10-year-old ambulatory boy with Duchenne Muscular Dystrophy, which of the following functional milestones is the strongest predictor that he will lose independent ambulation within the next 12 to 24 months?

. Development of a 15-degree scoliosis
. 10-meter walk time greater than 9 seconds
. Loss of ability to perform a standing broad jump
. Onset of the Gowers sign
. Elevation of serum creatine phosphokinase (CPK) above 5,000 U/L

Correct Answer & Explanation

. 10-meter walk time greater than 9 seconds

Explanation

A 10-meter walk/run time greater than 9 seconds strongly predicts the loss of independent ambulation within 1 to 2 years in boys with DMD. Other indicators include the inability to rise from the floor or climb stairs.

Question 1863

Topic: 6. Spine

While orthopedic interventions in Duchenne Muscular Dystrophy aim to prolong ambulation and manage spinal deformity, ultimate life expectancy is usually dictated by cardiopulmonary failure. Which of the following cardiac conditions is classically and predominantly associated with DMD?

. Hypertrophic obstructive cardiomyopathy
. Dilated cardiomyopathy
. Restrictive cardiomyopathy
. Severe aortic stenosis
. Myxomatous mitral valve prolapse

Correct Answer & Explanation

. Dilated cardiomyopathy

Explanation

Dilated cardiomyopathy is a hallmark of the advanced stages of Duchenne Muscular Dystrophy, resulting from dystrophin deficiency in cardiac muscle tissue, and is a leading cause of mortality in these patients.

Question 1864

Topic: Thoracolumbar Spine & Deformity

Daily systemic corticosteroid therapy is the gold standard medical management for Duchenne Muscular Dystrophy. What is the primary established orthopedic benefit of long-term glucocorticoid use in this patient population?

. Reversal of established dilated cardiomyopathy
. Increased cortical bone thickness preventing long-bone fractures
. Prolongation of independent ambulation by 2 to 3 years
. Complete prevention of structural scoliosis development
. Elimination of the need for Achilles tendon lengthening procedures

Correct Answer & Explanation

. Prolongation of independent ambulation by 2 to 3 years

Explanation

Corticosteroids (e.g., prednisone, deflazacort) are proven to prolong independent ambulation by an average of 2 to 3 years in DMD patients. They also delay the onset and reduce the severity of scoliosis, though they increase fracture risk due to osteopenia.

Question 1865

Topic: 6. Spine

A 13-year-old boy with Duchenne Muscular Dystrophy has recently lost the ability to ambulate.

Routine radiographic screening reveals a progressive thoracolumbar scoliosis measuring 35 degrees. His Forced Vital Capacity (FVC) is 45% of predicted. What is the most appropriate management for his spinal deformity?

. Posterior spinal fusion from the upper thoracic spine to the pelvis
. Bracing with a custom Thoracolumbosacral Orthosis (TLSO)
. Anterior spinal fusion of the thoracolumbar curve
. Observation until the curve reaches 50 degrees
. Growth-friendly spinal instrumentation (e.g., growing rods)

Correct Answer & Explanation

. Posterior spinal fusion from the upper thoracic spine to the pelvis

Explanation

In non-ambulatory DMD patients, scoliosis progresses rapidly and bracing is ineffective. Posterior spinal fusion to the pelvis is recommended for curves >20-30 degrees to prevent further progression, maintain sitting balance, and protect pulmonary function.

Question 1866

Topic: 6. Spine

A 14-year-old boy with Duchenne Muscular Dystrophy requires posterior spinal fusion for severe scoliosis. Preoperative pulmonary function testing is performed. A Forced Vital Capacity (FVC) strictly below which of the following thresholds indicates an extreme risk for postoperative ventilator dependence?

. 60% of predicted
. 30% of predicted
. 50% of predicted
. 75% of predicted
. 90% of predicted

Correct Answer & Explanation

. 30% of predicted

Explanation

An FVC < 30% of predicted is widely considered a critical threshold in DMD. Patients below this level are at very high risk for prolonged or permanent postoperative mechanical ventilation after major spinal surgery.

Question 1867

Topic: 6. Spine

When performing posterior spinal fusion for scoliosis in a non-ambulatory patient with Duchenne Muscular Dystrophy, extension of the fusion construct to the pelvis is universally recommended. What is the primary functional goal of including the pelvis in the fusion?

. To prevent subsequent hip dislocation
. To provide a rigid anchor that maintains upright seated balance
. To improve active walking endurance
. To correct preexisting fixed knee flexion contractures
. To reverse established restrictive lung disease

Correct Answer & Explanation

. To provide a rigid anchor that maintains upright seated balance

Explanation

Scoliosis in non-ambulatory DMD patients involves significant pelvic obliquity. Extending the fusion to the pelvis levels the spine over the pelvis, maintaining upright sitting balance and preventing pressure ulcers.

Question 1868

Topic: Thoracolumbar Spine & Deformity

Long-term corticosteroid therapy is a standard of care for ambulatory boys with Duchenne Muscular Dystrophy. Which of the following best describes the established orthopedic effect of this systemic treatment?

. Prolongs independent ambulation and delays the onset of severe scoliosis
. Accelerates the development of equinovarus foot contractures
. Promotes earlier fusion of the capital femoral epiphysis
. Increases the peak curve magnitude of early-onset scoliosis
. Reduces the incidence of long bone extremity fractures

Correct Answer & Explanation

. Prolongs independent ambulation and delays the onset of severe scoliosis

Explanation

Corticosteroids (like deflazacort or prednisone) significantly preserve muscle strength in DMD. This prolongs the period of independent ambulation and notably delays both the onset and progression of scoliosis, though it does increase the risk of osteoporotic fractures.

Question 1869

Topic: 6. Spine

A 5-year-old boy uses his hands to walk up his own legs to transition from sitting on the floor to a standing position (Gowers' sign). This classic sign in Duchenne Muscular Dystrophy directly indicates profound weakness in which specific muscle groups?

. Proximal lower extremity muscles (Quadriceps and Gluteals)
. Distal lower extremity muscles (Tibialis anterior and Gastrocnemius)
. Axial spinal musculature (Erector spinae)
. Upper extremity shoulder girdle muscles (Deltoid and Trapezius)
. Abdominal core musculature (Rectus abdominis)

Correct Answer & Explanation

. Proximal lower extremity muscles (Quadriceps and Gluteals)

Explanation

Gowers' sign is a classic maneuver used to compensate for severe weakness in the proximal lower extremity musculature, particularly the gluteus maximus and quadriceps, which are needed for hip and knee extension during rising.

Question 1870

Topic: 6. Spine

In a non-ambulatory 13-year-old boy with Duchenne muscular dystrophy who is not on corticosteroids, at what Cobb angle is posterior spinal fusion generally indicated to prevent progressive deformity and preserve sitting balance?

. 10-15 degrees
. 20-30 degrees
. 45-50 degrees
. 60-70 degrees
. Scoliosis surgery is contraindicated in DMD

Correct Answer & Explanation

. 20-30 degrees

Explanation

In non-ambulatory patients with DMD, spinal fusion is typically recommended early, at a Cobb angle of 20-30 degrees. Early intervention ensures the surgery is performed before pulmonary function declines excessively.

Question 1871

Topic: 6. Spine

A 14-year-old boy with Duchenne muscular dystrophy is being evaluated for posterior spinal fusion. Preoperative pulmonary function testing is obtained. What forced vital capacity (FVC) threshold represents a significantly increased risk for perioperative pulmonary complications?

. FVC less than 80% predicted
. FVC less than 60% predicted
. FVC less than 50% predicted
. FVC less than 30% predicted
. FVC less than 15% predicted

Correct Answer & Explanation

. FVC less than 30% predicted

Explanation

An FVC of less than 30% of predicted is associated with a significantly higher risk of perioperative respiratory complications, prolonged intubation, and failure to wean from the ventilator.

Question 1872

Topic: 6. Spine

A 20-year-old male runner presents with exertional calf pain and paresthesias in the plantar aspect of the foot. Compartment pressures are normal. Ankle-brachial index (ABI) drops significantly with active plantar flexion. What is the most likely diagnosis?

. Medial tibial stress syndrome
. Chronic exertional compartment syndrome
. Popliteal artery entrapment syndrome
. Exertional rhabdomyolysis
. Lumbar radiculopathy

Correct Answer & Explanation

. Popliteal artery entrapment syndrome

Explanation

Popliteal artery entrapment syndrome presents with claudication-like symptoms in young athletes. A drop in ABI with active plantar flexion or passive dorsiflexion is characteristic, distinguishing it from CECS.

Question 1873

Topic: Thoracolumbar Spine & Deformity

Routine use of daily corticosteroids in patients with Duchenne muscular dystrophy has been shown to alter the natural history of the disease. Which of the following is a recognized orthopedic effect of this medical therapy?

. Decreases the risk of long bone fractures
. Increases the incidence of severe scoliosis requiring surgery
. Prolongs independent ambulation by 2 to 3 years
. Accelerates the progression of equinovarus contractures
. Promotes premature closure of the physes preventing limb length discrepancy

Correct Answer & Explanation

. Decreases the risk of long bone fractures

Explanation

Corticosteroid therapy in DMD prolongs independent ambulation, preserves respiratory function, and decreases the incidence of severe scoliosis. However, it increases the risk of vertebral and long bone fragility fractures.

Question 1874

Topic: 6. Spine

When performing posterior spinal fusion for scoliosis in a non-ambulatory patient with Duchenne muscular dystrophy, what is the primary rationale for extending the fusion to the pelvis?

. To correct pre-existing hip flexion contractures
. To prevent the development of pelvic obliquity and preserve sitting balance
. To reduce the risk of crankshaft phenomenon
. To minimize blood loss during the procedure
. To allow for earlier resumption of ambulation

Correct Answer & Explanation

. To prevent the development of pelvic obliquity and preserve sitting balance

Explanation

In DMD, scoliosis fusions are typically extended to the pelvis to correct and prevent future pelvic obliquity. This is critical for maintaining a level, comfortable seated posture and distributing pressure evenly in a wheelchair.

Question 1875

Topic: 6. Spine

During the physical examination of a patient suspected of having cervical spondylotic myelopathy, the examiner firmly flicks the distal phalanx of the middle finger, observing a reflex flexion of the thumb and index finger. This specific physical examination finding is known as:

. Lhermitte sign
. Spurling test
. Hoffmann sign
. Inverted supinator reflex
. Babinski reflex

Correct Answer & Explanation

. Hoffmann sign

Explanation

The Hoffmann sign is elicited by flicking the distal phalanx of the middle finger, leading to reflex flexion of the thumb and index finger. It indicates upper motor neuron dysfunction common in cervical myelopathy.

Question 1876

Topic: 6. Spine

A 65-year-old male presents with bilateral leg cramping and heaviness that worsens after walking two blocks. He notes the pain is completely relieved within a few minutes if he sits down or leans forward over a shopping cart. Examination is normal at rest with palpable pulses. What is the most likely diagnosis?

. Peripheral arterial disease
. Acute lumbar disc herniation
. Lumbar spinal stenosis
. Diabetic polyneuropathy
. Cauda equina syndrome

Correct Answer & Explanation

. Lumbar spinal stenosis

Explanation

The patient's symptoms are classic for neurogenic claudication caused by lumbar spinal stenosis. Relief with lumbar flexion (sitting, leaning over a cart) occurs because flexion increases the cross-sectional area of the spinal canal and neural foramina.

Question 1877

Topic: Cervical Spine

In an adult trauma patient, an atlantodens interval (ADI) greater than 3 mm on lateral cervical spine radiographs most specifically indicates incompetence of which stabilizing structure?

. Alar ligament
. Apical ligament
. Transverse ligament
. Posterior longitudinal ligament
. Ligamentum flavum

Correct Answer & Explanation

. Transverse ligament

Explanation

The transverse ligament is the primary static stabilizer of the atlantoaxial joint. An ADI > 3 mm in an adult suggests transverse ligament rupture, while an ADI > 5 mm implies additional injury to the alar and apical ligaments.

Question 1878

Topic: Thoracolumbar Spine & Deformity

Which of the following intervertebral levels is the most common site for degenerative spondylolisthesis?

. L2-L3
. L3-L4
. L4-L5
. L5-S1
. Cervicothoracic junction

Correct Answer & Explanation

. L4-L5

Explanation

Degenerative spondylolisthesis occurs most frequently at the L4-L5 level, largely due to the sagittal orientation of the facet joints at this level which provides less resistance to forward translation. Isthmic spondylolisthesis, conversely, is most common at L5-S1.

Question 1879

Topic: 6. Spine

A 65-year-old female presents with progressive clumsiness in her hands and difficulty walking. Examination shows a positive Hoffmann sign bilaterally and hyperreflexia. MRI shows severe cervical stenosis at C4-C5 and C5-C6 with T2 signal change in the cord. Which physical exam finding is most specific for cervical myelopathy?

. Decreased grip strength
. Positive Spurling test
. Loss of biceps reflex
. Finger escape sign (Wartenberg sign)
. Shoulder abduction weakness

Correct Answer & Explanation

. Finger escape sign (Wartenberg sign)

Explanation

The finger escape sign, or Wartenberg sign of the ulnar digits, alongside Hoffmann sign and inverted radial reflex, are upper motor neuron signs highly indicative of cervical myelopathy. The Spurling test evaluates cervical radiculopathy, not myelopathy.

Question 1880

Topic: 6. Spine

A 70-year-old male with neurogenic claudication secondary to lumbar spinal stenosis is scheduled for decompression. Which ligament hypertrophies and contributes significantly to the dorsal compression of the thecal sac in this condition?

. Posterior longitudinal ligament
. Anterior longitudinal ligament
. Ligamentum flavum
. Interspinous ligament
. Supraspinous ligament

Correct Answer & Explanation

. Ligamentum flavum

Explanation

The ligamentum flavum typically hypertrophies and buckles into the spinal canal, especially in extension, contributing significantly to the dorsal compression of the thecal sac and nerve roots in degenerative lumbar stenosis.

Test Yourself

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

On this Page