Menu

6. Spine MCQs

Practice Set 372 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 7421

Topic: 6. Spine

A 55-year-old man with a long-standing history of ankylosing spondylitis presents to the emergency department after a low-energy fall. He complains of severe neck pain but has normal neurology. CT scan reveals a transverse fracture through the C6-C7 disc space extending through the posterior elements. What is the most appropriate management for this injury?

. Rigid cervical collar for 12 weeks
. Halo-vest immobilization
. Anterior cervical discectomy and fusion (ACDF)
. Long-segment posterior cervicothoracic instrumentation and fusion
. Short-segment posterior instrumentation (1 level above and 1 below)

Correct Answer & Explanation

. Long-segment posterior cervicothoracic instrumentation and fusion

Explanation

Spine fractures in ankylosing spondylitis act like long bone fractures and are highly unstable, often involving all three columns. They require long-segment posterior fixation (often 3 levels above and below) to achieve stability and prevent catastrophic neurologic decline.

Question 7422

Topic: 6. Spine

A 60-year-old male with long-standing ankylosing spondylitis presents with localized, severe back pain. Radiographs demonstrate a destructive intervertebral disc lesion with endplate sclerosis and adjacent pseudarthrosis. What is the eponymous term for this lesion?

. Romanus lesion
. Andersson lesion
. Schmorl's node
. Modic change
. Limbus vertebra

Correct Answer & Explanation

. Andersson lesion

Explanation

An Andersson lesion is an inflammatory or traumatic pseudarthrosis of the disc space or fractured vertebra in the ankylosed spine. It is often caused by an unrecognized stress fracture leading to instability and sterile inflammation.

Question 7423

Topic: 6. Spine

A 50-year-old man with ankylosing spondylitis presents with a severe chin-on-chest deformity, preventing forward gaze. He is scheduled for a corrective spinal osteotomy. Which of the following anatomical levels is the safest and most optimal site for a pedicle subtraction osteotomy (PSO) to correct this cervicothoracic kyphosis?

. C3
. C5
. C7
. T3
. T6

Correct Answer & Explanation

. C7

Explanation

C7 is the preferred site for a cervicothoracic osteotomy (like a PSO) in ankylosing spondylitis. The spinal canal is widest at this level, reducing the risk of spinal cord compression, and the vertebral artery typically enters the transverse foramen at C6, avoiding injury at C7.

Question 7424

Topic: 6. Spine

A 65-year-old patient with end-stage ankylosing spondylitis presents with a restrictive pattern on pulmonary function tests. The patient denies any history of smoking or primary pulmonary disease. This restrictive lung physiology is primarily due to ankylosis of which of the following structures?

. Sacroiliac joints
. Costovertebral joints
. Sternoclavicular joints
. Cervicothoracic facet joints
. Glenohumeral joints

Correct Answer & Explanation

. Costovertebral joints

Explanation

Restrictive lung disease in ankylosing spondylitis is primarily caused by the fusion (ankylosis) of the costovertebral joints and thoracic spine. This severely limits chest wall excursion and lung expansion during respiration.

Question 7425

Topic: 6. Spine

A 70-year-old man with ankylosing spondylitis suffers a hyperextension injury to his cervical spine resulting in a fracture.

Due to the altered biomechanics of the ankylosed spine, this patient is at uniquely high risk for which of the following acute complications?

. Spontaneous fusion of the fracture site without intervention
. Epidural hematoma
. Atlantoaxial rotary subluxation
. Vertebral artery aneurysm
. Cerebrospinal fluid leak

Correct Answer & Explanation

. Epidural hematoma

Explanation

Patients with ankylosing spondylitis who sustain spinal fractures are at a highly elevated risk of forming a post-traumatic epidural hematoma. The rigid spine fractures like a long bone, leading to significant bleeding and tearing of epidural vessels.

Question 7426

Topic: 6. Spine

A 45-year-old male with severe ankylosing spondylitis is planning to undergo a corrective spinal osteotomy for rigid cervicothoracic kyphosis.

Which of the following clinical parameters is most useful for calculating the exact amount of sagittal correction required preoperatively?

. Pelvic incidence
. Chin-brow vertical angle
. Sacral slope
. Thoracic kyphosis Cobb angle
. Lumbar lordosis angle

Correct Answer & Explanation

. Chin-brow vertical angle

Explanation

The chin-brow vertical angle (CBVA) is essential for preoperative planning in AS patients with severe kyphosis to ensure horizontal gaze postoperatively. The surgical goal is typically to correct the CBVA to between 10 and 20 degrees.

Question 7427

Topic: 6. Spine

A 62-year-old man with ankylosing spondylitis sustains a seemingly minor cervical spine fracture after a ground-level fall.

He presents with delayed, rapidly progressive quadriparesis 24 hours after admission despite a stable and immobilized fracture pattern. What is the most likely cause?

. Vertebral artery dissection
. Epidural hematoma
. Retropharyngeal abscess
. Syringomyelia
. Missed secondary skip fracture

Correct Answer & Explanation

. Epidural hematoma

Explanation

Epidural hematoma is a well-documented and devastating complication in AS patients following spinal fractures due to altered epidural space dynamics and highly vascularized inflammatory tissue. Delayed neurological decline should prompt immediate MRI evaluation.

Question 7428

Topic: 6. Spine

First-line medical therapy for a patient with severe ankylosing spondylitis who experiences persistent axial symptoms despite continuous, maximized use of NSAIDs involves targeted inhibition of which of the following cytokines?

. Interleukin-1 (IL-1)
. Interleukin-6 (IL-6)
. Tumor necrosis factor-alpha (TNF-alpha)
. Receptor activator of nuclear factor kappa-B ligand (RANKL)
. Transforming growth factor-beta (TGF-beta)

Correct Answer & Explanation

. Tumor necrosis factor-alpha (TNF-alpha)

Explanation

For patients with AS who fail to respond adequately to continuous NSAID therapy, TNF-alpha inhibitors (e.g., etanercept, infliximab, adalimumab) are the recommended first-line biologic therapy. They significantly reduce systemic inflammation and improve spinal mobility.

Question 7429

Topic: 6. Spine

Which of the following clinical or pathologic features best distinguishes primary synovial chondromatosis from secondary synovial chondromatosis?

. Frequent association with advanced osteoarthritis or prior trauma
. The cartilaginous loose bodies are typically of wildly disparate sizes
. The cartilaginous loose bodies are generally numerous and of uniform size
. Typically, fewer than five large loose bodies are present in the joint
. Primary involvement of the spinal intervertebral facet joints

Correct Answer & Explanation

. The cartilaginous loose bodies are generally numerous and of uniform size

Explanation

Primary synovial chondromatosis typically presents with numerous cartilaginous loose bodies of relatively uniform size due to synchronous synovial metaplasia. Secondary synovial chondromatosis (due to OA or trauma) features fewer loose bodies of varying, unequal sizes.

Question 7430

Topic: 6. Spine

A 24-year-old male complains of severe morning stiffness and inflammatory back pain. Plain radiographs of the pelvis are completely negative for sacroiliitis.

Which MRI sequence is most sensitive for detecting the early, active inflammatory phase of sacroiliitis in suspected ankylosing spondylitis?

. T1-weighted without contrast
. T2-weighted gradient-echo
. Short tau inversion recovery (STIR)
. T1-weighted with fat suppression without contrast
. Diffusion tensor imaging (DTI)

Correct Answer & Explanation

. Short tau inversion recovery (STIR)

Explanation

STIR (Short Tau Inversion Recovery) or T2-weighted fat-suppressed MRI sequences are highly sensitive for detecting periarticular bone marrow edema. This edema represents the earliest diagnostic sign of active sacroiliitis in AS before structural radiographic changes appear.

Question 7431

Topic: 6. Spine

Which of the following best describes the typical fracture pattern seen in the cervical spine of a patient with advanced ankylosing spondylitis following a low-energy fall?

. Flexion-compression wedge fracture of the vertebral body
. Hyperflexion teardrop fracture
. Extension-distraction injury through the intervertebral disc space or vertebral body
. Unilateral facet dislocation
. Burst fracture with retropulsed bony fragments

Correct Answer & Explanation

. Extension-distraction injury through the intervertebral disc space or vertebral body

Explanation

In advanced ankylosing spondylitis, the stiff, osteopenic spine acts as a long lever arm. Minor trauma commonly results in highly unstable extension-distraction fractures (chalk stick fractures) typically occurring through the ossified disc space.

Question 7432

Topic: 6. Spine

A 50-year-old male with long-standing ankylosing spondylitis presents with progressive weakness in both lower extremities following a minor ground-level fall. CT of the cervical spine reveals a completely displaced, extension-distraction fracture at C6-C7. Which of the following is the most likely additional complication seen in this demographic?

. Aortic root dilation causing acute dissection
. Cauda equina syndrome
. Spinal epidural hematoma
. Vertebral artery dissection
. Atlantoaxial rotatory subluxation

Correct Answer & Explanation

. Spinal epidural hematoma

Explanation

Patients with ankylosing spondylitis who sustain spinal fractures are at a significantly increased risk for spinal epidural hematomas due to bleeding from the fractured epidural venous plexus or bone. This complication must be considered if neurological deterioration occurs.

Question 7433

Topic: 6. Spine

A 45-year-old male with ankylosing spondylitis presents with a severe fixed, forward-flexed posture. He reports difficulty looking straight ahead. He wishes to undergo surgical deformity correction. What is the most appropriate surgical intervention to correct his sagittal imbalance?

. Multi-level Smith-Petersen osteotomies in the thoracic spine
. Pedicle subtraction osteotomy (PSO) at the lumbar spine (typically L3)
. Anterior lumbar interbody fusion (ALIF) at L4-L5
. Vertebral column resection (VCR) at T4
. Cervical pedicle subtraction osteotomy

Correct Answer & Explanation

. Pedicle subtraction osteotomy (PSO) at the lumbar spine (typically L3)

Explanation

For severe fixed sagittal imbalance in ankylosing spondylitis, a closing-wedge lumbar osteotomy, such as a Pedicle Subtraction Osteotomy (PSO) at L3, provides significant lordotic correction (around 30-40 degrees) without lengthening the anterior column.

Question 7434

Topic: 6. Spine

A patient with undiagnosed ankylosing spondylitis is most likely to present with which of the following extra-articular manifestations prior to definitive spinal fusion?

. Acute angle-closure glaucoma
. Cataract formation
. Acute anterior uveitis
. Retinal detachment
. Optic neuritis

Correct Answer & Explanation

. Acute anterior uveitis

Explanation

Acute anterior uveitis (iritis) is the most common extra-articular manifestation of ankylosing spondylitis, occurring in 25-30% of patients. It typically presents as acute unilateral eye pain, photophobia, and blurred vision.

Question 7435

Topic: 6. Spine

A 60-year-old man with a 30-year history of ankylosing spondylitis presents with localized, progressive thoracolumbar back pain. Radiographs demonstrate an established bamboo spine with a localized, destructive radiolucent cleft at the T11-T12 disc space with sclerotic margins. What is the most appropriate initial management for this specific radiographic finding?

. Intravenous antibiotics and CT-guided biopsy
. Local radiation therapy
. Rigid orthosis or surgical stabilization
. High-dose systemic corticosteroids
. Non-steroidal anti-inflammatory drugs alone

Correct Answer & Explanation

. Rigid orthosis or surgical stabilization

Explanation

The scenario describes an Andersson lesion, a pseudarthrosis occurring in the fused spine of patients with ankylosing spondylitis due to unhealed stress fractures. Treatment focuses on rigid immobilization with an orthosis or surgical stabilization if non-operative measures fail.

Question 7436

Topic: 6. Spine

A 48-year-old man with ankylosing spondylitis presents with a severe chin-on-chest deformity, significantly impairing his horizontal gaze and ability to eat.

A surgical correction is planned. At which anatomic level is an extension osteotomy most safely and effectively performed to correct this specific deformity?

. C1-C2
. C4-C5
. C7-T1
. T4-T5
. T10-T11

Correct Answer & Explanation

. C7-T1

Explanation

The cervicothoracic junction (C7-T1) is the preferred site for an extension osteotomy to correct a chin-on-chest deformity. This level has a relatively wide spinal canal, minimizing spinal cord injury risk, and avoids the vertebral arteries which typically enter the transverse foramen at C6.

Question 7437

Topic: 6. Spine

A 40-year-old male with ankylosing spondylitis presents with localized, worsening back pain and progressive kyphosis. Radiographs reveal a focal destructive discovertebral lesion with surrounding sclerotic margins. What is the most likely diagnosis?

. Pyogenic spondylodiscitis
. Andersson lesion
. Tuberculous spondylitis
. Osteoporotic compression fracture
. Pathologic fracture from metastasis

Correct Answer & Explanation

. Andersson lesion

Explanation

Andersson lesions are aseptic discovertebral pseudarthroses commonly seen in ankylosing spondylitis. They often result from non-union of unrecognized shear fractures and present with focal destruction and sclerosis, sometimes requiring surgical stabilization.

Question 7438

Topic: 6. Spine

A 45-year-old male with severe ankylosing spondylitis presents with a fixed chin-on-chest deformity, severely limiting his forward horizontal gaze and ability to eat. An extension osteotomy is planned for correction. Which anatomical level is generally considered the safest and most effective for this procedure?

. C1-C2 articulation
. C4-C5 level
. L3-L4 level
. C7-T1 cervicothoracic junction
. T4-T5 level

Correct Answer & Explanation

. C7-T1 cervicothoracic junction

Explanation

The cervicothoracic junction (C7-T1) is the preferred and safest site for an extension osteotomy in ankylosing spondylitis. The wider spinal canal at this level accommodates the spinal cord better during the corrective hinge maneuver, minimizing neurologic risk.

Question 7439

Topic: 6. Spine

A 55-year-old male with long-standing ankylosing spondylitis suffers a minor mechanical fall and sustains a transdiscal fracture at the T10-T11 level. Why do spinal fractures in this patient population carry an exceptionally high risk of neurologic compromise?

. The ankylosed spine behaves like a long bone, leading to highly unstable 3-column shear injuries
. They are typically isolated anterior column injuries that rapidly undergo kyphotic collapse
. The densely ossified paraspinal ligaments prevent spontaneous reduction of the fracture
. They typically incite massive epidural hematoma formation without true bone injury
. Associated epidural lipomatosis acts as a space-occupying lesion during injury

Correct Answer & Explanation

. The ankylosed spine behaves like a long bone, leading to highly unstable 3-column shear injuries

Explanation

In ankylosing spondylitis, the multi-level ossification of spinal ligaments and fusion of facet joints create a rigid biomechanical lever. Consequently, fractures behave like long bone fractures traversing all three columns, making them highly unstable and prone to translation.

Question 7440

Topic: 6. Spine

Review the spinal radiograph of a 70-year-old male presenting with severe neurogenic claudication.

Which of the following represents the most likely primary pathomechanism causing his neurologic symptoms?

. Acute osteoporotic wedge compression fracture
. Spinal canal stenosis secondary to bony expansion and overgrowth
. Metastatic destruction of the vertebral body leading to instability
. Epidural abscess formation from hematogenous seeding
. Spondylolysis with isthmic spondylolisthesis

Correct Answer & Explanation

. Spinal canal stenosis secondary to bony expansion and overgrowth

Explanation

The radiograph demonstrates a "picture frame" vertebra, highly characteristic of Paget's disease. Bony overgrowth and expansion of the vertebral body and posterior elements in the sclerotic phase frequently encroach upon the neural elements, leading to severe spinal stenosis.

Test Yourself

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

On this Page