Menu

6. Spine MCQs

Practice Set 247 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 4921

Topic: 6. Spine

A 58-year-old man presents with progressive clumsiness in his hands and difficulty with balance. On physical examination, rapidly flicking the nail of his middle finger results in involuntary flexion of the interphalangeal joint of his thumb and the distal interphalangeal joint of his index finger. Which of the following best describes this physical exam finding and its anatomic localizing value?

. Wartenberg sign; indicating ulnar neuropathy at the elbow.
. Hoffmann sign; indicating an upper motor neuron lesion above the level of C5 or C6.
. Babinski reflex; indicating a localized conus medullaris lesion.
. Inverted radial reflex; indicating an upper motor neuron lesion at C7.
. Lhermitte sign; indicating posterior column disease.

Correct Answer & Explanation

. Hoffmann sign; indicating an upper motor neuron lesion above the level of C5 or C6.

Explanation

The Hoffmann sign is elicited by flicking the nail of the middle finger, causing reflex flexion of the thumb and index finger. It indicates an upper motor neuron lesion (corticospinal tract) above the C5 or C6 level, and is a classic finding in cervical spondylotic myelopathy. The inverted radial reflex indicates a lesion specifically at the C5-C6 level, while Lhermitte sign is an electric shock-like sensation down the spine upon neck flexion.

Question 4922

Topic: Thoracolumbar Spine & Deformity

When evaluating a patient for adult spinal deformity correction, achieving a harmonious sagittal profile is a primary goal to improve health-related quality of life. According to the SRS-Schwab classification, which of the following spinopelvic parameter combinations represents the ideal target for postoperative alignment?

. Pelvic Incidence (PI) minus Lumbar Lordosis (LL) < 10 degrees
. Pelvic Tilt (PT) > 25 degrees
. Sagittal Vertical Axis (SVA) > 50 mm
. Thoracic Kyphosis (TK) > Lumbar Lordosis (LL)
. Pelvic Incidence (PI) < Pelvic Tilt (PT)

Correct Answer & Explanation

. Pelvic Incidence (PI) minus Lumbar Lordosis (LL) < 10 degrees

Explanation

The SRS-Schwab classification established threshold values for optimal sagittal alignment in adult spinal deformity: PI - LL < 10 degrees, PT < 20 degrees, and SVA < 50 mm. Failure to achieve these targets strongly correlates with poorer health-related quality of life (HRQOL) scores, persistent pain, and higher rates of revision surgery due to proximal junctional kyphosis or implant failure.

Question 4923

Topic: Thoracolumbar Spine & Deformity

A 35-year-old male falls from a height of 15 feet and sustains a L1 fracture.

Imaging shows a burst fracture with 30% 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 his total score and the recommended management?

. Score 2; conservative management
. Score 4; operative or non-operative management
. Score 5; operative management
. Score 7; operative management
. Score 3; conservative management

Correct Answer & Explanation

. Score 2; conservative management

Explanation

In the Thoracolumbar Injury Classification and Severity (TLICS) system, points are awarded for morphology (Burst = 2 points), neurologic status (Intact = 0 points), and PLC integrity (Intact = 0 points). The total score is 2. A score of 3 or less indicates non-operative management. A score of 4 is indeterminate (surgeon's choice), and 5 or more dictates operative intervention.

Question 4924

Topic: Cervical Spine

A 55-year-old female with a 20-year history of rheumatoid arthritis presents with severe neck pain, suboccipital headaches, and bilateral hand clumsiness. Radiographs show significant basilar invagination.

Which of the following radiographic measurements is the most accurate for diagnosing basilar invagination on a lateral cervical spine radiograph?

. Anterior atlantodens interval (ADI) > 3 mm
. Posterior atlantodens interval (PADI) < 14 mm
. The tip of the odontoid projecting > 4.5 mm above McGregor's line
. Basion-dental interval (BDI) > 12 mm
. Powers ratio > 1.0

Correct Answer & Explanation

. The tip of the odontoid projecting > 4.5 mm above McGregor's line

Explanation

Basilar invagination (cranial settling) in rheumatoid arthritis is classically assessed using McGregor's line (a line drawn from the posterior edge of the hard palate to the most caudal point of the occipital curve). An odontoid tip extending more than 4.5 mm above this line is diagnostic of basilar invagination. ADI and PADI assess atlantoaxial subluxation, while BDI and Powers ratio assess occipitocervical dissociation in trauma.

Question 4925

Topic: 6. Spine

A 24-year-old male rugby player presents with severe neck pain and bilateral upper extremity weakness (deltoids and biceps 3/5, distal muscles 5/5) following a tackling injury. He is awake, alert, and cooperative. Plain films and CT demonstrate a unilateral jumped facet at C5-C6. What is the most appropriate next step in management?

. Immediate MRI of the cervical spine before any reduction maneuver
. Closed reduction via cranial traction in the emergency department
. Immediate anterior cervical discectomy and fusion (ACDF) without prior traction
. High-dose methylprednisolone protocol for 24 hours
. Posterior cervical fusion with laminectomy

Correct Answer & Explanation

. Closed reduction via cranial traction in the emergency department

Explanation

In an awake, alert, and cooperative patient with a cervical facet dislocation and a neurologic deficit, immediate closed reduction with cranial traction (e.g., Gardner-Wells tongs) is indicated to decompress the spinal cord as rapidly as possible. MRI prior to reduction is indicated in patients who are obtunded/unexaminable or those who fail closed reduction, to rule out a herniated disc that could cause secondary cord injury during reduction.

Question 4926

Topic: 6. Spine

A 68-year-old male undergoes a C3-C6 posterior cervical laminectomy and fusion for cervical spondylotic myelopathy. On postoperative day 2, he develops profound weakness in his right deltoid and biceps (1/5), with no other new sensory or motor deficits. What is the most likely etiology of this complication?

. Spinal cord ischemia due to intraoperative hypotension
. Iatrogenic injury to the recurrent laryngeal nerve
. Tethering of the C5 nerve root due to posterior spinal cord drift
. Postoperative epidural hematoma compressing the spinal cord
. Placement of a C6 lateral mass screw into the vertebral artery

Correct Answer & Explanation

. Tethering of the C5 nerve root due to posterior spinal cord drift

Explanation

Postoperative C5 palsy is a well-documented complication of cervical decompression, particularly posterior laminectomy. The most widely accepted mechanism is the posterior drift or shift of the spinal cord following decompression, which puts tension on the relatively short and tethered C5 nerve roots. It presents as isolated deltoid and/or biceps weakness, usually within the first few days post-op, and typically resolves spontaneously over months with supportive care and physical therapy.

Question 4927

Topic: 6. Spine

A 50-year-old diabetic male presents with 2 weeks of worsening back pain, low-grade fevers, new-onset urinary retention, and bilateral leg weakness.

MRI reveals a dorsal spinal epidural abscess at T10-T12 with severe cord compression. Which of the following is the most appropriate definitive management?

. CT-guided aspiration and 6 weeks of IV antibiotics
. Emergent posterior decompressive laminectomy and debridement
. Emergent anterior corpectomy and strut grafting
. High-dose IV dexamethasone and observation
. Empiric IV vancomycin and ceftriaxone alone

Correct Answer & Explanation

. Emergent posterior decompressive laminectomy and debridement

Explanation

The patient has a spinal epidural abscess complicated by progressive neurologic deficits (weakness, urinary retention), indicating cauda equina/conus medullaris or cord compromise. The standard of care for a symptomatic epidural abscess causing neurologic deficit is emergent surgical decompression (usually via laminectomy for dorsal abscesses) and debridement, combined with organism-specific IV antibiotics. Medical management alone is strictly reserved for patients without neurologic deficits or those entirely unfit for surgery.

Question 4928

Topic: 6. Spine

A 42-year-old male presents with severe right-sided anterior thigh pain, weakness in knee extension, and a diminished patellar reflex. MRI of the lumbar spine reveals a far-lateral (extraforaminal) disc herniation. At which lumbar level is this herniation most likely located to produce these specific neurologic findings?

. L2-L3 affecting the L2 nerve root
. L3-L4 affecting the L3 nerve root
. L4-L5 affecting the L4 nerve root
. L5-S1 affecting the L5 nerve root
. L5-S1 affecting the S1 nerve root

Correct Answer & Explanation

. L2-L3 affecting the L2 nerve root

Explanation

A far-lateral (extraforaminal) disc herniation compresses the exiting nerve root at the same level. Therefore, a far-lateral disc herniation at the L4-L5 level compresses the exiting L4 nerve root (unlike a typical paracentral disc herniation at L4-L5, which compresses the traversing L5 nerve root). L4 radiculopathy is classically characterized by anterior thigh pain, quadriceps weakness (knee extension), and an asymmetric or diminished patellar reflex.

Question 4929

Topic: Cervical Spine

An 82-year-old man is evaluated in the emergency department after suffering a ground-level fall. He complains of upper neck pain without radiation. Neurologic examination is completely normal. CT imaging of the cervical spine reveals a Type II odontoid fracture with 2 mm of posterior displacement. Given the patient's age and clinical presentation, what is the most appropriate management strategy?

. Application of a halo vest
. Anterior odontoid screw fixation
. Posterior C1-C2 fusion
. Immobilization in a rigid cervical collar
. Surgical stabilization using C1 lateral mass and C2 pedicle screws

Correct Answer & Explanation

. Immobilization in a rigid cervical collar

Explanation

In the elderly population (especially patients >80 years old), the morbidity and mortality associated with surgical intervention and halo vest immobilization are significantly high. Multiple studies have demonstrated that for mildly displaced Type II odontoid fractures in the elderly, immobilization in a rigid cervical collar is the preferred initial treatment. It offers an acceptable rate of stable nonunion (fibrous union) while avoiding the severe respiratory complications and dysphagia associated with halo vests and surgery.

Question 4930

Topic: 6. Spine

During a posterior spinal fusion for adolescent idiopathic scoliosis, the neuromonitoring team reports a sudden, complete loss of Motor Evoked Potentials (MEPs) in both lower extremities. Somatosensory Evoked Potentials (SSEPs) remain at baseline. Which of the following is the most appropriate initial management step?

. Administer an immediate intravenous bolus of propofol
. Perform a wake-up test immediately
. Increase mean arterial pressure (MAP) to >85 mm Hg
. Administer a bolus of intravenous tranexamic acid
. Proceed with further curve correction to relieve tension

Correct Answer & Explanation

. Increase mean arterial pressure (MAP) to >85 mm Hg

Explanation

A sudden loss of MEPs with intact SSEPs suggests an isolated insult to the anterior corticospinal tracts, commonly due to hypoperfusion of the anterior spinal artery (anterior cord syndrome). The most critical initial step is to optimize spinal cord perfusion by raising the mean arterial pressure (MAP) to greater than 85 mm Hg. Other immediate steps include correcting anemia, reversing any recent corrective maneuvers, and ensuring that anesthetic agents (like volatile gases) are not depressing the signals.

Question 4931

Topic: 6. Spine

A 45-year-old woman presents with severe neck pain radiating down her right arm. Physical examination reveals a diminished triceps reflex, profound weakness in elbow extension and wrist flexion, and decreased sensation over the dorsal aspect of the middle finger. Which of the following cervical disc herniations is most likely responsible for these findings?

. C4-C5
. C5-C6
. C6-C7
. C7-T1
. T1-T2

Correct Answer & Explanation

. C6-C7

Explanation

The patient's findings of triceps weakness, a diminished triceps reflex, and paresthesias in the middle finger are classic for a C7 radiculopathy. In the cervical spine, exiting nerve roots exit above the correspondingly named pedicle (e.g., the C7 root exits at the C6-C7 neural foramen). Therefore, a C6-C7 disc herniation will typically compress the C7 nerve root.

Question 4932

Topic: 6. Spine

A 62-year-old man with a 30-year history of ankylosing spondylitis presents to the emergency department after a low-speed motor vehicle collision. He complains of localized neck pain but has normal motor and sensory function. Plain radiographs of the cervical spine show extensive syndesmophytes and a 'bamboo spine' appearance but no definitive fracture. What is the most appropriate next step in management?

. Discharge with a soft collar and outpatient follow-up in 1 week
. Obtain flexion-extension cervical radiographs to assess stability
. Discharge with a rigid cervical collar and NSAIDs
. Obtain a CT scan of the entire spine
. Perform a diagnostic lumbar puncture

Correct Answer & Explanation

. Obtain a CT scan of the entire spine

Explanation

Patients with ankylosing spondylitis have highly rigid, osteopenic spines that act as long lever arms, making them extremely susceptible to fractures even from minor trauma. These fractures are often highly unstable, most common at the cervicothoracic junction, and easily missed on plain radiographs due to distorted anatomy. The standard of care for an ankylosing spondylitis patient presenting with back or neck pain after trauma is a CT scan of the entire spine (cervical, thoracic, and lumbar) to rule out occult fractures. Flexion-extension views are contraindicated due to the high risk of neurologic injury.

Question 4933

Topic: Thoracolumbar Spine & Deformity
A 65-year-old woman is evaluated for a debilitating flatback deformity and sagittal imbalance. Figure 39 represents a templated standing lateral radiograph. Measurement of her spino-pelvic parameters reveals a pelvic incidence (PI) of 56 degrees and a sacral slope (SS) of 22 degrees. What is her calculated pelvic tilt (PT), and what is the generally accepted target for her postoperative lumbar lordosis (LL)?
. PT = 34 degrees; Target LL = 46-56 degrees
. PT = 78 degrees; Target LL = 46-56 degrees
. PT = 34 degrees; Target LL = 20-30 degrees
. PT = 78 degrees; Target LL = 20-30 degrees
. PT = 22 degrees; Target LL = 66-76 degrees

Correct Answer & Explanation

. PT = 34 degrees; Target LL = 46-56 degrees

Explanation

The formula relating the key pelvic parameters is Pelvic Incidence (PI) = Pelvic Tilt (PT) + Sacral Slope (SS). Given PI = 56 and SS = 22, the PT is 56 - 22 = 34 degrees. For optimal postoperative sagittal alignment and minimization of adjacent segment disease and hardware failure, the target Lumbar Lordosis (LL) should be restored to within 10 degrees of the patient's PI (i.e., PI - LL ≤ 10 degrees). Therefore, an appropriate target LL for this patient is between 46 and 56 degrees.

Question 4934

Topic: 6. Spine

A 55-year-old diabetic intravenous drug user presents with a 1-week history of worsening severe mid-thoracic back pain, fevers, and new-onset bilateral lower extremity weakness (3/5 strength in iliopsoas and quadriceps) along with urinary retention. MRI reveals a large, dorsal spinal epidural abscess compressing the spinal cord at T8. What is the most appropriate definitive management?

. CT-guided needle aspiration and 6 weeks of intravenous antibiotics
. Emergent surgical decompression and culture followed by targeted intravenous antibiotics
. Intravenous broad-spectrum antibiotics alone with hourly neurologic observation
. High-dose intravenous corticosteroids followed by urgent radiotherapy
. Immediate placement of a lumbar drain and intrathecal antibiotics

Correct Answer & Explanation

. Emergent surgical decompression and culture followed by targeted intravenous antibiotics

Explanation

The patient is presenting with a spinal epidural abscess complicated by an acute, progressive neurologic deficit (motor weakness and bowel/bladder dysfunction). In the presence of neurologic compromise, emergent surgical decompression (e.g., laminectomy) and debridement is indicated to relieve cord compression and obtain cultures, followed by targeted prolonged antibiotic therapy. Medical management alone is reserved for patients who are neurologically intact, poor surgical candidates, or have extensive pan-spinal disease without focal compression.

Question 4935

Topic: 6. Spine

A 42-year-old man presents with severe low back pain, bilateral sciatica, perineal numbness, and acute urinary retention. Post-void residual volume is 600 mL. MRI confirms a massive L4-L5 central disc herniation causing cauda equina syndrome. He is scheduled for emergent surgical decompression. Which of the following factors is the most significant predictor of full postoperative recovery of bladder and sphincter function?

. The patient's age
. The precise cross-sectional area of the herniated disc
. The extent of preoperative lower extremity motor weakness
. The time interval from symptom onset to surgical decompression
. The preoperative administration of high-dose dexamethasone

Correct Answer & Explanation

. The time interval from symptom onset to surgical decompression

Explanation

In cauda equina syndrome, the most critical prognostic factor for the recovery of autonomic function (bowel, bladder, and sexual function) is the time elapsed from symptom onset to surgical decompression. Surgery performed within 24 to 48 hours of the onset of symptoms is associated with significantly better neurologic and functional outcomes compared to delayed decompression.

Question 4936

Topic: 6. Spine



A 60-year-old man presents with progressive clumsiness in his hands and a wide-based, unsteady gait. Figure 8 shows his sagittal T2-weighted MRI. Imaging confirms ossification of the posterior longitudinal ligament (OPLL). The K-line is drawn from the mid-canal of C2 to the mid-canal of C7, and the ossified mass crosses the K-line anteriorly (K-line negative). Additionally, the cervical spine demonstrates 15 degrees of kyphosis. Which of the following surgical approaches is most appropriate?

. Posterior cervical laminectomy without fusion
. Posterior cervical laminoplasty
. Anterior cervical corpectomy and fusion
. Isolated C1-C2 posterior instrumented fusion
. Posterior cervical foraminotomies

Correct Answer & Explanation

. Anterior cervical corpectomy and fusion

Explanation

The K-line is a critical concept in planning surgery for cervical OPLL. When the ossified mass crosses the K-line (K-line negative) or there is significant cervical kyphosis, posterior decompression alone (like laminoplasty or laminectomy) is contraindicated. This is because the spinal cord will not sufficiently 'drift back' away from the anterior compressive OPLL mass due to the kyphotic tension. Instead, an anterior approach (such as anterior cervical corpectomy and fusion) or a combined anterior-posterior approach is required for direct decompression.

Question 4937

Topic: 6. Spine

The Spine Patient Outcomes Research Trial (SPORT) evaluated outcomes for patients with symptomatic degenerative spondylolisthesis and lumbar spinal stenosis. At the 4-year follow-up, which of the following conclusions was most strongly supported by the data regarding surgical versus nonoperative management?

. Nonoperative treatment yielded equivalent pain relief and functional outcomes to surgical treatment.
. Surgical treatment was associated with significantly greater improvement in pain and physical function compared to nonoperative treatment.
. Patients who crossed over from the nonoperative group to surgery had worse long-term outcomes than those who remained in the nonoperative group.
. Epidural steroid injections provided superior long-term relief compared to surgical decompression.
. The addition of spinal fusion to decompression yielded no significant improvement in outcomes compared to decompression alone.

Correct Answer & Explanation

. Surgical treatment was associated with significantly greater improvement in pain and physical function compared to nonoperative treatment.

Explanation

The SPORT trial results for degenerative spondylolisthesis demonstrated a clear, statistically significant advantage for surgical intervention (decompression with or without fusion) over nonoperative treatment in terms of pain relief and functional improvement at 4-year follow-up. While there was significant crossover between groups, the 'as-treated' analysis definitively showed the superiority of surgery for this specific pathology.

Question 4938

Topic: 6. Spine

A 65-year-old man presents with progressive gait instability and fine motor clumsiness in his hands. Examination reveals hyperreflexia in the lower extremities, a positive Hoffmann sign bilaterally, and loss of proprioception in his toes.

Which of the following parameters on MRI is most predictive of poor neurological recovery following surgical decompression?

. Increased T2 signal intensity in the spinal cord alone
. Decreased T1 signal intensity in the spinal cord
. Presence of a multi-level anterior osteophyte formation
. Loss of cerebrospinal fluid (CSF) signal at the level of compression
. Modic type 1 changes in the adjacent vertebral bodies

Correct Answer & Explanation

. Decreased T1 signal intensity in the spinal cord

Explanation

In cervical spondylotic myelopathy (CSM), MRI findings that correlate with a poor prognosis for neurologic recovery after surgical decompression include a decreased T1 signal intensity within the spinal cord. This finding often represents permanent spinal cord damage such as cystic changes, necrosis, or severe myelomalacia. Increased T2 signal intensity alone is frequently observed and can represent reversible edema or gliosis, having a more variable or less definitive negative prognostic value compared to decreased T1 signal changes.

Question 4939

Topic: Thoracolumbar Spine & Deformity

A 68-year-old woman presents with severe low back pain, global sagittal imbalance, and difficulty standing upright. Standing full-length lateral radiographs show a pelvic incidence (PI) of 60 degrees, lumbar lordosis (LL) of 30 degrees, and a sagittal vertical axis (SVA) of 12 cm. What is the approximate target lumbar lordosis required to achieve an optimal sagittal balance in this patient if surgical correction is planned?

. 30 degrees
. 40 degrees
. 60 degrees
. 75 degrees
. 90 degrees

Correct Answer & Explanation

. 30 degrees

Explanation

The relationship between pelvic incidence (PI) and lumbar lordosis (LL) is critical in correcting adult spinal deformity. According to the Schwab criteria, normal sagittal balance typically requires the LL to be within 10 degrees of the PI (PI - LL < 10°). In this patient with a PI of 60 degrees, the target LL should be approximately 60 degrees (acceptable range 50-70 degrees). An LL of 30 degrees leaves the patient with a significant PI-LL mismatch of 30 degrees, leading to a positive sagittal vertical axis (SVA) and compensatory mechanisms such as pelvic retroversion and knee flexion.

Question 4940

Topic: Cervical Spine

An 82-year-old man falls from a standing height and presents with neck pain.

Imaging reveals a Type II odontoid fracture with 3 mm of posterior displacement. He is neurologically intact. He has a history of severe chronic obstructive pulmonary disease (COPD) and coronary artery disease. What is the most appropriate initial management?

. Halo vest immobilization
. Rigid cervical collar immobilization
. Anterior odontoid screw fixation
. Posterior C1-C2 fusion
. Occipitocervical fusion

Correct Answer & Explanation

. Rigid cervical collar immobilization

Explanation

In elderly patients with Type II odontoid fractures, rigid cervical collar immobilization is often the preferred initial management, especially in those with significant medical comorbidities (such as COPD and severe coronary artery disease). Halo vest immobilization in the elderly is associated with high morbidity and mortality (including pneumonia, cardiac arrest, and pin site infections) and is generally contraindicated. While surgical intervention (posterior C1-C2 fusion) provides the highest union rate, it carries substantial perioperative risks that must be weighed against the patient's frail health status. Although nonunion is common with a rigid collar, a stable fibrous nonunion frequently results and is well-tolerated by this patient population.

Test Yourself

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

On this Page