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Cervical Spine MCQs

Practice Set 3 of 24

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

Question 41

Topic: Cervical Spine

In a patient with long-standing rheumatoid arthritis, which of the following radiographic findings represents the most critical indication for occipitocervical fusion rather than an isolated C1-C2 fusion?

. Anterior atlantodental interval (ADI) of 4 mm
. Posterior atlantodental interval (PADI) of 15 mm
. Superior migration of the odontoid (cranial settling)
. Subaxial subluxation of 2 mm at C4-C5
. Erosion of the dens

Correct Answer & Explanation

. Superior migration of the odontoid (cranial settling)

Explanation

Cranial settling (basilar invagination or superior migration of the odontoid) indicates vertical instability and typically requires occipitocervical fusion to prevent brainstem compression. An isolated increased ADI without cranial settling may only require a C1-C2 fusion.

Question 42

Topic: Cervical Spine

An 82-year-old male sustains a Type II odontoid fracture with 3 mm of posterior displacement following a ground-level fall. He has severe medical comorbidities. What is the most appropriate management?

. Halo vest immobilization for 12 weeks
. Rigid cervical collar for 8 to 12 weeks
. Anterior odontoid screw fixation
. Posterior C1-C2 transarticular screw fixation
. Posterior C1-C2 Harms technique fusion

Correct Answer & Explanation

. Rigid cervical collar for 8 to 12 weeks

Explanation

In elderly patients with severe medical comorbidities, a rigid cervical collar is often preferred despite a higher nonunion rate, as halo vest immobilization carries a high mortality risk in this population. Surgery is reserved for patients who fail conservative management or can tolerate the procedure.

Question 43

Topic: Cervical Spine

When planning intubation for a patient with severe rheumatoid arthritis, the anesthesiologist should be particularly cautious of atlantoaxial instability. Which ligament's laxity or destruction is the primary cause of this instability?

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

Correct Answer & Explanation

. Transverse ligament

Explanation

The transverse ligament is the primary stabilizer of the atlantoaxial joint. Pannus formation in rheumatoid arthritis often leads to the destruction of this ligament, causing anterior atlantoaxial subluxation.

Question 44

Topic: Cervical Spine

A patient undergoes an anterior cervical discectomy and fusion at C7-T1. Postoperatively, the patient demonstrates a new sensory deficit. If the C8 nerve root is iatrogenically injured, sensation is most likely lost over which of the following areas?

. Lateral aspect of the forearm
. Medial aspect of the forearm and ulnar two digits
. Medial aspect of the arm
. Dorsum of the thumb and index finger
. Volar aspect of the thumb

Correct Answer & Explanation

. Medial aspect of the forearm and ulnar two digits

Explanation

The C8 nerve root provides sensory innervation to the medial aspect of the forearm and the ulnar two digits (ring and little fingers). The lateral forearm is C6, medial arm is T1, and the thumb/index finger typically fall under C6 territory.

Question 45

Topic: Cervical Spine

An open-mouth odontoid radiograph of a trauma patient shows a C1 burst fracture (Jefferson fracture). The sum of the lateral mass overhang of C1 on C2 is measured at 8 mm. According to the Rule of Spence, this finding specifically indicates incompetence of which of the following structures?

. Alar ligament
. Apical ligament
. Transverse ligament
. Posterior longitudinal ligament
. Tectorial membrane

Correct Answer & Explanation

. Transverse ligament

Explanation

The Rule of Spence dictates that if the total overhang of the C1 lateral masses on C2 exceeds 6.9 mm on an AP radiograph, it implies a rupture of the transverse ligament. This indicates an unstable injury requiring rigid immobilization or surgery.

Question 46

Topic: Cervical Spine

A right-sided anterior cervical approach is utilized for a C6-C7 ACDF. The recurrent laryngeal nerve is at risk. What is the anatomic rationale for the right recurrent laryngeal nerve being more susceptible to injury in the lower neck than the left?

. It loops under the aortic arch
. It loops under the right subclavian artery and ascends more obliquely in the neck
. It is located within the carotid sheath on the right
. It crosses anterior to the thyroid gland
. It runs superficial to the platysma

Correct Answer & Explanation

. It loops under the right subclavian artery and ascends more obliquely in the neck

Explanation

The left recurrent laryngeal nerve loops safely under the aortic arch and ascends vertically in the tracheoesophageal groove. The right nerve loops under the right subclavian artery and ascends more obliquely, making it more variable and susceptible to injury during lower cervical approaches.

Question 47

Topic: Cervical Spine

A patient develops severe postoperative dysphagia following a multilevel ACDF. Which of the following intraoperative factors has been most strongly associated with an increased risk of severe prevertebral swelling and chronic dysphagia in this setting?

. Use of an anterior cervical plate
. Use of structural fibular allograft
. Recombinant human bone morphogenetic protein-2 (rhBMP-2) use
. Patient age less than 40 years
. Intraoperative blood loss greater than 100 mL

Correct Answer & Explanation

. Recombinant human bone morphogenetic protein-2 (rhBMP-2) use

Explanation

The use of rhBMP-2 in the anterior cervical spine is notorious for causing robust inflammatory responses leading to severe prevertebral soft tissue swelling, dysphagia, and potentially airway compromise. Its use in ACDF is generally considered off-label and requires extreme caution.

Question 48

Topic: Cervical Spine

An 82-year-old male with severe COPD and coronary artery disease presents after a fall. Imaging reveals a non-displaced Type II odontoid fracture. Which of the following is the most appropriate initial management?

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

Correct Answer & Explanation

. Rigid cervical collar

Explanation

In elderly patients (octogenarians), halo vest placement is associated with a high rate of morbidity and mortality. A rigid cervical collar is the safest initial non-operative treatment for non-displaced or stable patterns in patients with significant comorbidities.

Question 49

Topic: Cervical Spine

In a patient with long-standing rheumatoid arthritis undergoing pre-operative evaluation for a total hip arthroplasty, flexion-extension cervical radiographs are obtained. Which finding would most strongly indicate the need for prophylactic cervical spine stabilization?

. Anterior atlantodental interval (ADI) of 2 mm
. Posterior atlantodental interval (PADI) of 12 mm
. Subaxial subluxation of 2 mm
. Basilar invagination of 1 mm
. C2-C3 facet arthrosis

Correct Answer & Explanation

. Posterior atlantodental interval (PADI) of 12 mm

Explanation

A Posterior Atlantodental Interval (PADI) of 14 mm or less indicates impending cord compression and correlates better with neurologic deficit than ADI. PADI < 14 mm is a critical threshold often prompting surgical intervention in rheumatoid atlantoaxial subluxation.

Question 50

Topic: Cervical Spine

A 75-year-old man sustains a Type II odontoid fracture after a fall. Which of the following factors is most predictive of nonunion if treated conservatively with a halo vest?

. Fracture displacement of 2 mm
. Patient age greater than 50 years
. Anterior displacement of the fracture fragment
. Associated transverse ligament rupture
. Presence of a concomitant C1 ring fracture

Correct Answer & Explanation

. Fracture displacement of 2 mm

Explanation

Risk factors for nonunion of a Type II odontoid fracture include age greater than 50 years, fracture displacement greater than 5 mm, and posterior displacement. Due to poor outcomes with halo immobilization in the elderly, surgical fixation is often preferred.

Question 51

Topic: Cervical Spine

Appropriate treatment of a nondisplaced Jefferson fracture is:

. Hard cervical orthosis
. Halo vest
. Soft collar
. Posterior surgical stabilization
. Nerve treatment necessary

Correct Answer & Explanation

. Hard cervical orthosis

Explanation

Fractures involving the C 1 or atlas are generally caused by axial compression with either a flexion or extension force. Generally, fractures involving the C 1 consist of multiple fragments. The classical Jefferson fracture is a 4-part fracture of the atlas and can be unstable. However, in this situation, a nondisplaced fracture represents a relatively stable injury. An open-mouth odontoid anteroposterior radiograph is frequently useful to evaluate unstable patterns. An unstable fracture typically has displacement of the lateral masses greater than 8 mm. If displacement of this amount occurs, generally, the transverse ligament has been disrupted and should be treated by halo vest immobilization. In this nondisplaced situation, a hard Philadelphia collar is the most appropriate form of treatment.

Question 52

Topic: Cervical Spine
A 6-year-old boy has neck pain and stiffness following an upper respiratory tract infection. He presented with his head tilted to the right and turned to the left 3 weeks ago, but a soft cervical collar has not been beneficial. There is no known history of trauma. A computerized tomography scan shows rotatory subluxation of C1 on C2. The next step in the treatment of this child is:
. Observation
. Open reduction and C1-C2 fusion through an anterior approach
. In situ C1-C2 fusion posteriorly
. Cervical traction
. Hard cervical collar

Correct Answer & Explanation

. Cervical traction

Explanation

This child has torticollis as sequelae of an upper respiratory infection (Grisel syndrome) and rotatory subluxation (fixation) of C1 on C2. Other causes of torticollis include congenital muscular torticollis, neurogenic causes, Sandifer syndrome, Klippel-Feil syndrome, juvenile rheumatoid arthritis, and trauma. The common thread is that all of the etiologies appear to weaken, through inflammation or force, the supporting soft tissue structures of the atlantoaxial articulation. The diagnosis is made by dynamic CT scan. Fielding classified atlantoaxial rotatory subluxation into 4 types: Type I is a simple rotatory displacement without an anterior shift, and is the most common type in children. Type II is rotatory fixation with anterior displacement >3 to 5 mm, and is associated with a deficiency of the transverse ligament and unilateral displacement of one lateral mass of the atlas. Type III rotatory fixation there is anterior displacement >5 mm with bilateral displacement of the lateral mass with one side displaced more than the other. This is caused by a deficiency of both the transverse ligament and secondary ligament. Type IV is rotatory fixation with posterior displacement where the dens allows posterior shift of one or both of the lateral masses, and one shifting more than the other. Types III and IV are rare but have potential for catastrophe and should be recognized to promptly initiate treatment. Children with rotatory fixation of <1 week can be treated with a soft cervical collar and rest for 1 week. Most cases resolve, but close follow-up is necessary. If spontaneous reduction does not occur after 1-2 weeks, aggressive treatment is necessary. Inpatient halter traction with judicious use of muscle relaxants and analgesics is recommended. Halo traction is necessary for reduction of longer standing (2-4 weeks) subluxation. Surgery is indicated in cases of neurological compromise, failure to achieve closed reduction, long-standing deformity (3 months or more), or recurrence following closed treatment. A Gallie-type fusion posteriorly is favored.

Question 53

Topic: Cervical Spine

An 8-year-old girl with Down syndrome presents with a recent history of increasing clumsiness, refusal to walk long distances, and hyperreflexia in her lower extremities. Lateral flexion-extension radiographs of the cervical spine reveal an atlantodens interval (ADI) of 11 mm. What is the most appropriate management?

. Rigid cervical collar for 3 months
. Observation with serial radiographs every 6 months
. Anterior cervical discectomy and fusion
. Posterior C1-C2 fusion
. Suboccipital decompression without fusion

Correct Answer & Explanation

. Posterior C1-C2 fusion

Explanation

Symptomatic atlantoaxial instability or an ADI > 10 mm in children with Down syndrome indicates high risk for severe neurologic injury. Surgical stabilization via posterior C1-C2 fusion is the treatment of choice.

Question 54

Topic: Cervical Spine

A 10-year-old boy presents with neck pain after a minor fall from a trampoline. Lateral cervical spine radiographs show a rounded, corticated bone fragment situated superior to a hypoplastic dens. Flexion-extension views demonstrate 6 mm of anterior translation of C1 on C2. What is the most likely diagnosis?

. Acute Type II odontoid fracture
. Os odontoideum
. Hangman fracture
. Congenital absence of the transverse ligament
. Klippel-Feil anomaly

Correct Answer & Explanation

. Os odontoideum

Explanation

An os odontoideum appears as a smooth, corticated, rounded ossicle separated from a hypoplastic base of the dens, differentiating it from an acute type II fracture which would have irregular, uncorticated margins.

Question 55

Topic: Cervical Spine

A 14-year-old boy is evaluated for neck pain following a minor tackle in football. Cervical radiographs reveal a round, smoothly corticated ossicle with a wide gap separating it from a hypoplastic odontoid peg. The anterior arch of C1 appears hypertrophied. What is the most likely diagnosis?

. Acute Type II odontoid fracture
. Os odontoideum
. Hangman's fracture
. Mach effect
. Persistent terminal ossicle

Correct Answer & Explanation

. Os odontoideum

Explanation

An os odontoideum presents as a smooth, corticated ossicle separate from a hypoplastic dens, often with hypertrophy of the anterior ring of C1. It indicates chronic instability rather than an acute fracture.

Question 56

Topic: Cervical Spine

A 7-year-old boy presents with severe neck pain and a 'cock robin' head tilt one week after undergoing a tonsillectomy. He resists any passive neck movement. Radiographs show a unilateral anterior displacement of the lateral mass of C1 on C2. What is the most likely diagnosis?

. Klippel-Feil syndrome
. Grisel syndrome
. Juvenile idiopathic arthritis
. Odontoid fracture
. Cervical osteomyelitis

Correct Answer & Explanation

. Grisel syndrome

Explanation

Grisel syndrome is a non-traumatic atlantoaxial rotatory subluxation associated with inflammatory conditions of the upper respiratory tract or recent ENT surgery. The 'cock robin' head position is a classic clinical finding.

Question 57

Topic: Cervical Spine

A patient presents after a high-speed collision with severe upper cervical pain. Lateral radiographs show a Basion-Dental Interval (BDI) of 14 mm. What is the most appropriate definitive management?

. Halo vest immobilization for 12 weeks
. Hard cervical collar for 6 weeks
. Occipitocervical fusion
. C1-C2 transarticular screw fixation
. Anterior odontoid screw fixation

Correct Answer & Explanation

. Occipitocervical fusion

Explanation

A BDI greater than 10 mm indicates Atlanto-Occipital Dissociation (AOD), a highly unstable ligamentous injury. Definitive management requires surgical stabilization via occipitocervical fusion.

Question 58

Topic: Cervical Spine

In a patient with a suspected C1 (Jefferson) fracture, an open-mouth odontoid radiograph demonstrates a combined lateral mass overhang of 8 mm on C2. What specific structure is presumed incompetent based on this finding?

. Alar ligament
. Transverse atlantal ligament
. Apical ligament
. Tectorial membrane
. Posterior longitudinal ligament

Correct Answer & Explanation

. Transverse atlantal ligament

Explanation

According to the Rule of Spence, a combined lateral mass overhang of C1 on C2 greater than 6.9 mm on an open-mouth radiograph strongly suggests rupture of the transverse atlantal ligament.

Question 59

Topic: Cervical Spine

What is the primary anatomical and functional advantage of performing an anterior odontoid screw fixation over a posterior C1-C2 fusion for a suitable Type II odontoid fracture?

. Higher union rate in osteoporotic bone
. Preservation of normal C1-C2 atlantoaxial rotation
. No need for postoperative immobilization
. Lower risk of dysphagia
. Better mechanical stability in reverse obliquity fractures

Correct Answer & Explanation

. Preservation of normal C1-C2 atlantoaxial rotation

Explanation

Anterior odontoid screw fixation is a motion-preserving surgery that maintains the roughly 50 degrees of normal cervical rotation that occurs at the C1-C2 atlantoaxial joint, unlike posterior C1-C2 fusion.

Question 60

Topic: Cervical Spine

Which of the following radiographic measurements is most reliable for diagnosing atlanto-occipital dissociation (AOD) on lateral cervical spine imaging in a polytrauma patient?

. Power's ratio greater than 1
. Basion-dental interval (BDI) greater than 10 mm on CT
. Atlanto-dens interval (ADI) greater than 3 mm
. Space available for the cord (SAC) less than 13 mm
. Wackenheim line intersecting the odontoid process

Correct Answer & Explanation

. Basion-dental interval (BDI) greater than 10 mm on CT

Explanation

The Basion-Dental Interval (BDI) and Basion-Axial Interval (BAI), known as the Harris measurements, are the most reliable indicators of AOD. A measurement greater than 10 mm on CT or 12 mm on plain films is diagnostic for atlanto-occipital dissociation.

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