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Question 2741

Topic: 6. Spine

A 55-year-old male with a known history of ankylosing spondylitis presents to the emergency department after a low-energy ground-level fall. He complains of moderate neck pain but is neurologically intact. Initial cross-table lateral cervical spine radiographs reveal an ossified anterior longitudinal ligament with a widened C5-C6 disc space. What is the most appropriate next step in management?

. Discharge with a soft cervical collar and outpatient follow-up
. Dynamic flexion-extension radiographs of the cervical spine
. Computed tomography (CT) of the cervical spine only
. Magnetic resonance imaging (MRI) of the cervical spine only
. Computed tomography (CT) of the entire spine

Correct Answer & Explanation

. Computed tomography (CT) of the entire spine


Explanation

Patients with ankylosing spondylitis are highly susceptible to unstable spinal fractures even from minor trauma, and these injuries are often highly unstable. Due to the altered biomechanics of the ankylosed spine, there is a high incidence of non-contiguous secondary fractures (up to 20%). Therefore, the standard of care is to obtain a CT scan of the entire spine (cervical, thoracic, and lumbar) to rule out additional fractures.

Question 2742

Topic: 6. Spine

A 12-year-old male sustains a Chance fracture of L2 while wearing a lap belt during a high-speed motor vehicle collision. Which of the following concomitant injuries is most statistically likely to be found in this patient?

. Aortic transection
. Renal artery avulsion
. Small bowel perforation
. Splenic rupture
. Bladder rupture

Correct Answer & Explanation

. Small bowel perforation


Explanation

Chance fractures are flexion-distraction injuries commonly associated with lap belt use in motor vehicle accidents, particularly in the pediatric population. They carry a very high association (up to 40-50%) with intra-abdominal hollow viscus injuries, most notably small bowel perforations or mesenteric avulsions, due to the corresponding severe localized compression of the abdominal contents against the spine.

Question 2743

Topic: Thoracolumbar Spine & Deformity

A 30-year-old male sustains a fall from a height. Radiographs and CT show an L1 burst fracture. His neurologic examination is completely normal. MRI reveals a complete disruption of the posterior ligamentous complex (PLC). According to the Thoracolumbar Injury Classification and Severity (TLICS) score, what is his total score and the recommended treatment?

. Score 3; non-operative treatment
. Score 4; treatment is at the surgeon's discretion
. Score 5; operative treatment
. Score 6; operative treatment
. Score 7; operative treatment

Correct Answer & Explanation

. Score 5; operative treatment


Explanation

The TLICS score is calculated based on three categories: 1) Morphology: Burst fracture = 2 points. 2) Neurologic status: Intact = 0 points. 3) Posterior ligamentous complex (PLC) integrity: Disrupted = 3 points. Total score = 2 + 0 + 3 = 5. A TLICS score of > 4 indicates instability, and operative intervention is strictly recommended.

Question 2744

Topic: 6. Spine

A 42-year-old female presents to the emergency department after a motor vehicle collision. She is awake, alert, and fully cooperative. She has a right-sided C6 radiculopathy but no long tract signs (no myelopathy). Lateral cervical radiographs reveal a unilateral jumped facet at C5-C6 with 25% anterior translation. What is the most appropriate next step in management?

. Immediate MRI of the cervical spine to assess the intervertebral disc prior to any intervention
. Urgent closed reduction using cranial tongs and progressive traction under continuous neurologic monitoring
. Application of a rigid cervical collar and delayed posterior spinal fusion within 72 hours
. Immediate anterior cervical discectomy and fusion (ACDF) without attempting closed reduction
. Emergent posterior cervical laminectomy and facet reduction

Correct Answer & Explanation

. Urgent closed reduction using cranial tongs and progressive traction under continuous neurologic monitoring


Explanation

According to current spinal trauma guidelines, an awake, alert, and cooperative patient with a cervical facet dislocation can safely undergo immediate closed reduction via skeletal traction with serial neurologic examinations. MRI prior to reduction is not required and may unnecessarily delay spinal cord/nerve root decompression. MRI is mandated prior to reduction ONLY if the patient is unexaminable (e.g., comatose) or fails closed reduction.

Question 2745

Topic: Cervical Spine

An 82-year-old female with multiple medical comorbidities including severe COPD and ischemic heart disease sustains a Type II odontoid fracture with 2 mm of posterior displacement after a mechanical fall. She is neurologically intact. Which of the following is the most appropriate initial management strategy?

. Placement of a halo vest immobilizer for 12 weeks
. Immediate posterior C1-C2 transarticular screw fixation
. Immobilization in a rigid cervical collar
. Anterior odontoid screw fixation
. Immediate suboccipital decompression and occipitocervical fusion

Correct Answer & Explanation

. Immobilization in a rigid cervical collar


Explanation

In elderly patients (>80 years) with significant medical comorbidities, the treatment of Type II odontoid fractures must balance fracture healing with the severe morbidity and mortality of interventions. Halo immobilization in the elderly carries a mortality rate approaching 20-30% due to respiratory complications and falls. Operative fixation also carries high perioperative risks. Current evidence strongly supports that immobilization in a rigid cervical collar is the most appropriate initial treatment. Although the nonunion rate is higher, the majority are stable fibrous nonunions that remain clinically asymptomatic.

Question 2746

Topic: Thoracolumbar Spine & Deformity

A 24-year-old female presents after a high-speed motor vehicle collision. She was wearing a lap-only seatbelt. Imaging reveals a flexion-distraction injury (Chance fracture) at L2. She is neurologically intact. Which of the following is the most commonly associated concomitant injury in this patient population?

. Aortic transection
. Solid organ laceration
. Hollow viscus injury
. Pulmonary contusion
. Pelvic ring disruption

Correct Answer & Explanation

. Hollow viscus injury


Explanation

Chance fractures are flexion-distraction injuries commonly associated with lap seatbelts. Up to 50% of these patients have concomitant intra-abdominal injuries, with hollow viscus (especially small bowel) perforations being the most common.

Question 2747

Topic: 6. Spine

A 68-year-old male with long-standing ankylosing spondylitis presents to the emergency department complaining of new-onset lower cervical pain after a minor bump in his car. Initial standard radiographs of the cervical spine show classic bridging syndesmophytes but no obvious fracture. Neurological exam is intact. What is the most appropriate next step in management?

. Discharge with a soft cervical collar and NSAIDs
. Perform dynamic flexion-extension radiographs
. Obtain a non-contrast CT scan of the cervical spine
. Order an EMG of the upper extremities
. Schedule an outpatient technetium bone scan

Correct Answer & Explanation

. Obtain a non-contrast CT scan of the cervical spine


Explanation

Patients with ankylosing spondylitis are highly susceptible to highly unstable, transdiscal or chalk-stick fractures of the spine even from minor trauma. Standard radiographs are notoriously inadequate for ruling out fractures in this population; a CT scan is mandatory.

Question 2748

Topic: 6. Spine

A 45-year-old male sustains an L1 thoracolumbar burst fracture. He is neurologically intact. When calculating the Thoracolumbar Injury Classification and Severity (TLICS) score to determine operative vs nonoperative management, which of the following MRI findings would add the most points and independently push the total score towards surgical intervention?

. More than 50% loss of anterior vertebral body height
. Retropulsion of bone into the spinal canal causing 40% stenosis
. Disruption of the posterior ligamentous complex (PLC)
. Edema in the adjacent intervertebral disc
. Presence of a sagittal split in the vertebral body

Correct Answer & Explanation

. Disruption of the posterior ligamentous complex (PLC)


Explanation

In the TLICS system, disruption of the posterior ligamentous complex (PLC) is assigned 3 points. When combined with a burst morphology (2 points), the score becomes 5, which strongly favors surgical intervention (score > 4). Canal stenosis without neurologic deficit does not independently add points in TLICS.

Question 2749

Topic: 6. Spine
A 13-year-old girl who is 2 years postmenarche has been referred for management of scoliosis. She denies any history of back pain. Radiographs show a right thoracic curve of 35°. She has a Risser sign of 4 and a bone age of 15.5 years. Management should consist of
. a low-profile spinal orthosis.
. observation and follow-up radiographs in 6 months.
. anterior spinal fusion with instrumentation.
. posterior spinal fusion with instrumentation.
. in situ posterior spinal fusion.

Correct Answer & Explanation

. observation and follow-up radiographs in 6 months.


Explanation

Discussion: Because the patient is skeletally mature with a curve of less than 40°, there is no benefit to bracing and surgery is not indicated. Management should consist of observation and follow-up radiographs in 6 months.

Question 2750

Topic: 6. Spine
When the iliac apophysis starts ossifying in the normal adolescent, growth of the sitting height or trunk height is characterized by
. no appreciable change during the remainder of growth for either boys or girls.
. an increase of 3 to 5 cm in girls and an increase of 5 to 8 cm in boys.
. an increase of 5 to 8 cm in girls and an increase of 3 to 5 cm in boys.
. an increase of 8 to 11 cm in girls and an increase of 11 to 13 cm in boys.
. an increase of 11 to 13 cm in girls and an increase of 8 to 11 cm in boys.

Correct Answer & Explanation

. an increase of 3 to 5 cm in girls and an increase of 5 to 8 cm in boys.


Explanation

Discussion: Studies by Anderson and associates have resulted in a growth-remaining chart for sitting height that shows an increase of 3 to 5 cm in girls and an increase of 5 to 8 cm in boys. Future growth of the spine may impact brace longevity and fit.

Question 2751

Topic: 6. Spine
A 20-year-old professional female jockey who is wearing a helmet is thrown from her horse. What is the most likely location of her injury?
. Face
. Head
. Neck
. Lower back
. Leg

Correct Answer & Explanation

. Head


Explanation

Discussion: The incidence of injury associated with horseback riding is estimated to be one per 350 riding hours to one per 1,000 riding hours. Of these injuries, approximately 15% to 27% are severe enough to warrant hospital admission. Significant and serious injuries in equestrian activities are associated with recreational riders and those not wearing a helmet. Head and spine injuries are more common in recreational and nonhelmeted riders. Extremity injuries are more common in professional and helmeted riders. Professional riders are less likely to be admitted to the hospital than recreational riders, and are about half as likely to be disabled at 6 months after injury as recreational riders.

Question 2752

Topic: 6. Spine
Which of the following palpable bony landmarks is correctly matched with its corresponding vertebral level?
. Angle of the mandible and the C2-C3 interspace
. Hyoid bone and C6
. Carotid tubercle and C6
. Superior portion of the thyroid cartilage and the C3 vertebral body
. Cricoid cartilage and C7-T1

Correct Answer & Explanation

. Carotid tubercle and C6


Explanation

The carotid tubercle is usually located at the level of C6. The angle of the mandible is at C1-C2; the hyoid is at C4; the superior portion of the thyroid cartilage is C4-C5; and the cricoid cartilage is at C6.

Question 2753

Topic: Thoracolumbar Spine & Deformity

A 22-year-old male presents after a high-speed motor vehicle collision where he was wearing a lap belt. Radiographs and CT demonstrate a flexion-distraction injury (Chance fracture) extending through the L2 vertebral body. Which associated injury must be ruled out due to its high incidence in this scenario?

. Aortic transection
. Renal artery thrombosis
. Intra-abdominal hollow viscus injury
. Diaphragmatic rupture
. Splenic laceration

Correct Answer & Explanation

. Intra-abdominal hollow viscus injury


Explanation

Chance fractures (flexion-distraction injuries) commonly occur in lap-belt restrained passengers during severe decelerations. They are highly associated with intra-abdominal injuries (up to 50% incidence), particularly hollow viscus injuries like bowel perforations, necessitating urgent general surgery evaluation.

Question 2754

Topic: 6. Spine

A 62-year-old male requires a THA for end-stage osteoarthritis. He has a history of an instrumented lumbar fusion from L2 to the sacrum. Given the stiffness in his lumbopelvic segment, how does his pelvic dynamics alter his risk profile, and how should the acetabular component positioning be adjusted?

. He will lack normal posterior pelvic tilt when transitioning from standing to sitting; the cup should be placed in more anteversion to prevent anterior impingement and posterior dislocation.
. He will lack normal posterior pelvic tilt when transitioning from standing to sitting; the cup should be placed in less anteversion to prevent anterior impingement and posterior dislocation.
. He will lack normal anterior pelvic tilt when transitioning from sitting to standing; the cup should be placed in more retroversion to prevent posterior impingement and anterior dislocation.
. He will experience exaggerated posterior pelvic tilt when sitting; the cup should be placed with increased inclination to prevent edge loading.
. He will experience exaggerated anterior pelvic tilt when sitting; the cup should be placed in standard "safe zone" parameters as spinal fusion has no effect on hip kinematics.

Correct Answer & Explanation

. He will lack normal posterior pelvic tilt when transitioning from standing to sitting; the cup should be placed in less anteversion to prevent anterior impingement and posterior dislocation.


Explanation

In a patient with a stiff lumbopelvic junction (e.g., L-spine fusion to the sacrum), the pelvis cannot dynamically adjust to position changes. Normally, when moving from a standing to a sitting position, the lumbar spine flexes and the pelvis tilts posteriorly, which functionally increases acetabular anteversion and clears the anterior acetabular rim from the proximal femur. A stiff spine prevents this posterior tilt, leaving the acetabulum functionally retroverted relative to the flexed femur. This leads to anterior impingement and an increased risk of posterior dislocation. To compensate, the surgeon should aim for increased operative anteversion and inclination.

Question 2755

Topic: Thoracolumbar Spine & Deformity

A 65-year-old woman is scheduled for a total hip arthroplasty. Standing and sitting lateral spinopelvic radiographs reveal a stiff lumbar spine with a pelvic tilt change of 5 degrees between standing and sitting, and a significantly decreased standing sacral slope. What is the most appropriate modification in acetabular cup positioning to minimize the risk of dislocation?

. Decrease anteversion and decrease abduction
. Increase anteversion and increase abduction
. Decrease anteversion and increase abduction
. Maintain standard safe zone positioning (15 degrees anteversion, 40 degrees abduction)
. Increase anteversion only while significantly decreasing abduction

Correct Answer & Explanation

. Increase anteversion and increase abduction


Explanation

A stiff lumbar spine (change in pelvic tilt < 10 degrees) combined with a decreased standing sacral slope indicates a 'flatback' deformity where the pelvis is already retroverted and does not retrovert further normally upon sitting. This puts the patient at a high risk for anterior impingement and subsequent posterior dislocation during sitting. To compensate for the lack of dynamic functional pelvic retroversion in flexion, the cup should be placed in more anteversion and slightly more inclination (abduction).

Question 2756

Topic: 6. Spine

A 72-year-old male with a prior T10-to-pelvis fusion for degenerative scoliosis is undergoing a primary total hip arthroplasty. Standing lateral radiographs reveal a stiff spine with decreased lumbar lordosis and a fixed posterior pelvic tilt. To minimize dislocation risk, how should the acetabular component orientation be adjusted relative to the standard Lewinnek safe zone?

. Increase anteversion and increase abduction
. Decrease anteversion and increase abduction
. Increase anteversion and decrease abduction
. Decrease anteversion and decrease abduction
. No adjustment is necessary

Correct Answer & Explanation

. Decrease anteversion and decrease abduction


Explanation

Patients with a stiff spine and a flatback deformity (fixed posterior pelvic tilt) fail to flex their pelvis when sitting, but face a high risk of anterior dislocation in extension. Therefore, the cup should be placed with decreased anteversion and decreased abduction.

Question 2757

Topic: 6. Spine

A 68-year-old male with a long-standing surgical fusion of his lumbar spine (L2-S1) is scheduled for a total hip arthroplasty. Flexion-extension spine radiographs confirm a completely stiff spinopelvic junction with lack of posterior pelvic tilt when sitting. To minimize the risk of dislocation, how should the acetabular cup be positioned relative to the standard safe zone?

. Placed with increased anteversion and increased inclination
. Placed with decreased anteversion and decreased inclination
. Placed with increased anteversion and decreased inclination
. Placed precisely in the standard Lewinnek safe zone
. Placed with decreased anteversion and increased inclination

Correct Answer & Explanation

. Placed with increased anteversion and increased inclination


Explanation

A stiff lumbar spine fails to posteriorly tilt during sitting, preventing the natural increase in functional acetabular anteversion. To prevent anterior impingement and posterior dislocation, the cup should be placed in greater anteversion and inclination.

Question 2758

Topic: 6. Spine
A 30-year-old female is involved in a high-speed motor vehicle collision and sustains a Denis Zone III sacral fracture. Which of the following clinical findings is most likely associated with this specific injury pattern compared to Zone I or Zone II fractures?
. Isolated L5 nerve root palsy
. Bowel and bladder dysfunction
. Unilateral sensory loss over the lateral thigh
. Painless foot drop
. Hyperreflexia in the lower extremities

Correct Answer & Explanation

. Bowel and bladder dysfunction


Explanation

The Denis classification of sacral fractures divides them into Zone I (alar), Zone II (transforaminal), and Zone III (central sacral canal). Zone III injuries carry the highest risk of neurologic deficits (approaching 60%), typically manifesting as cauda equina syndrome, which includes saddle anesthesia, loss of sphincter tone, and bowel/bladder/sexual dysfunction.

Question 2759

Topic: 6. Spine

A 24-year-old motorcyclist sustains a severe closed traction injury to his right brachial plexus. Examination reveals a flail, insensate right upper extremity and a right-sided ptosis and miosis. An MRI of the cervical spine is performed. Which of the following MRI findings is most consistent with the clinical examination and indicates an irreparable lesion at the root level?

. Thickening of the scalene muscles
. Presence of a traumatic pseudomeningocele
. Enlargement of the dorsal root ganglion
. High T2 signal in the spinal cord parenchyma
. Avulsion of the C5 and C6 roots only

Correct Answer & Explanation

. Presence of a traumatic pseudomeningocele


Explanation

The patient has a pan-brachial plexus injury with a Horner syndrome (ptosis, miosis, anhidrosis), indicating involvement of the T1 sympathetic fibers. This suggests a pre-ganglionic root avulsion. The hallmark MRI finding of a pre-ganglionic nerve root avulsion is a traumatic pseudomeningocele, which represents a dural tear with cerebrospinal fluid leakage into the extra-spinal soft tissues. Pre-ganglionic lesions are not amenable to direct nerve repair or grafting and require nerve transfers.

Question 2760

Topic: 6. Spine

A 50-year-old patient presents with right-sided neck pain radiating down the arm, weakness in elbow extension and wrist flexion, and a diminished triceps reflex. Sensation is decreased over the palmar aspect of the middle finger. MRI demonstrates a paracentral disc herniation at the C6-C7 level. Which spinal nerve root is compressed, and where does it normally exit?

. C6 nerve root, exiting below the C6 pedicle
. C6 nerve root, exiting above the C6 pedicle
. C7 nerve root, exiting above the C7 pedicle
. C7 nerve root, exiting below the C7 pedicle
. C8 nerve root, exiting above the T1 pedicle

Correct Answer & Explanation

. C7 nerve root, exiting above the C7 pedicle


Explanation

The clinical presentation (weak triceps, weak wrist flexion, decreased middle finger sensation, diminished triceps reflex) is classic for a C7 radiculopathy. In the cervical spine, there are 8 cervical nerve roots but only 7 cervical vertebrae. Roots C1-C7 exit above their corresponding numbered pedicles. Therefore, the C7 nerve root exits through the C6-C7 neural foramen, which is located above the C7 pedicle.