Figure 8 shows the AP radiograph of a 33-year-old woman who sustained a midshaft clavicle fracture from a motorcycle accident 15 months ago. She continues to have significant pain with activities of daily living. Management should consist of

open reduction and internal fixation with a dynamic compression plate placed superiorly and autogenous bone grafting.

5 units PRBCs. The estimated blood loss was 1276cc and not affected by the fracture pattern or high/low energy pattern. They concluded that preoperative hemorrhage contributed to transfusion needs more than intraoperative blood loss.

Figures A and B are the AP radiographs of the left and right atypical femur fractures with characteristic cortical thickening, transverse fracture pattern with medial beaking, and lateral stress reaction at the site of the fracture.

A 38-year-old woman has persistent elbow pain but is unable to recall a specific traumatic event. Examination reveals that the patient exhibits apprehension when the elbow is placed in valgus with forearm supination and axial loading. Because of chro

Free tendon graft reconstruction with capsuloligamentous plication

A 43-year-old man who works as a plumber has a painful stiff elbow in his dominant arm. He notes that while he recalls no single event of injury, he thinks the many years of pulling wrenches and soldering pipes have resulted in his problem. He report

Osteophyte resection and capsular release

Orthopedic Spine Review MCQs & Answers | Dr Hutaif

Question 1

A 55-year-old Asian male with progressive hand clumsiness and hyperreflexia undergoes a multi-level cervical laminoplasty for Ossification of the Posterior Longitudinal Ligament (OPLL). On post-operative day 2, he develops profound weakness in bilateral shoulder abduction and external rotation, but maintains normal lower extremity motor function and normal sensation. What is the most likely etiology of this post-operative complication?

Explanation

C5 palsy is a well-known complication after cervical decompressive surgery, particularly laminectomy and laminoplasty, occurring in roughly 5-10% of cases. It typically presents as deltoid and biceps weakness (shoulder abduction and elbow flexion) without sensory deficits or long tract signs. The prevailing theory is that posterior decompression allows the spinal cord to drift posteriorly, tethering or stretching the short C5 nerve roots.

Question 2

A 32-year-old male is brought to the trauma bay after a high-speed motor vehicle collision. He has severe neck pain. A lateral cervical radiograph demonstrates 60% anterior translation of the C4 vertebral body over C5. What is the primary mechanism of injury leading to this specific radiologic finding?

Explanation

Anterior translation of a cervical vertebral body greater than 50% over the body below is pathognomonic for bilateral facet dislocation. According to the Allen-Ferguson classification, the mechanism of injury for bilateral facet dislocations is hyperflexion-distraction. This results in tearing of the posterior ligamentous complex, facet capsules, and often the intervertebral disc and posterior longitudinal ligament.

Question 3

A 45-year-old male presents with acute onset of severe, burning right anterior thigh pain and weakness with knee extension. Bowel and bladder functions are intact. An MRI of the lumbar spine reveals a far lateral (extraforaminal) disc herniation at the L3-L4 level on the right side. Which nerve root is most likely compressed by this lesion?

Explanation

In the lumbar spine, a far lateral (extraforaminal) disc herniation compresses the exiting nerve root at the level of the herniation. Therefore, an L3-L4 far lateral disc compresses the L3 nerve root. A paracentral disc herniation at the same L3-L4 level would compress the traversing L4 nerve root.

Question 4

A 22-year-old male falls from a roof and sustains an L1 vertebral fracture. Neurological examination is completely normal. CT and MRI show an L1 burst fracture with 15 degrees of kyphosis, retropulsion of the posterosuperior body fragment by 2 mm, and an intact posterior ligamentous complex. According to the Thoracolumbar Injury Classification and Severity (TLICS) score, what is the most appropriate management?

Explanation

The TLICS score for this patient is calculated as follows: Morphology is Burst (2 points); Neurologic status is Intact (0 points); Posterior Ligamentous Complex (PLC) is Intact (0 points). The total TLICS score is 2. A score of 3 or less indicates non-operative management, typically with TLSO bracing. A score of 4 is indeterminate, and 5 or more dictates operative intervention.

Question 5

A 10-year-old girl who was a restrained rear-seat passenger in a severe head-on collision presents with a transverse ecchymosis across her lower abdomen. Lumbar spine radiographs reveal a transverse fracture through the spinous process, pedicles, and posterior aspect of the L2 vertebral body. Given this specific spinal fracture pattern, what is the most common associated visceral injury?

Explanation

The patient has a Chance fracture (a flexion-distraction injury) commonly associated with lap seatbelt use. This mechanism causes a distraction force through the posterior and middle columns. Up to 40-50% of pediatric patients with seatbelt signs and Chance fractures have associated intra-abdominal injuries, most commonly hollow viscus (small bowel) injuries.

Question 6

A 70-year-old male with metastatic prostate cancer presents with progressive back pain and difficulty walking. MRI reveals an epidural tumor at T8 causing high-grade spinal cord compression. His Spinal Instability Neoplastic Score (SINS) is 10. He has good overall performance status and an estimated survival of > 1 year. Which of the following is the most appropriate next step in management?

Explanation

According to the Neurologic, Oncologic, Mechanical, and Systemic (NOMS) framework, a SINS score of >= 7 indicates indeterminate or frank mechanical instability. Mechanical instability is an absolute indication for surgical stabilization regardless of tumor histology or radiosensitivity. Because the patient has high-grade epidural cord compression, instability, and a good prognosis, surgical decompression and stabilization followed by radiotherapy is indicated.

Question 7

A 14-year-old female gymnast presents with refractory lower back pain. Radiographs reveal a Grade II isthmic spondylolisthesis at L5-S1. Her pelvic parameters are measured. Which of the following statements correctly describes the relationship between pelvic incidence (PI) and isthmic spondylolisthesis?

Explanation

Pelvic incidence (PI) is an anatomical parameter that is constant in an adult. High pelvic incidence results in a steeper sacral slope and higher shear forces at the lumbosacral junction. It is strongly correlated with both the development and progression of isthmic spondylolisthesis at L5-S1.

Question 8

A 62-year-old male with long-standing ankylosing spondylitis presents to the emergency department with neck pain after a ground-level fall. He is neurologically intact. Standard anteroposterior and lateral cervical spine plain radiographs are interpreted as "unremarkable." What is the most appropriate next step in management?

Explanation

Patients with ankylosing spondylitis have a highly rigid and osteopenic spine, functioning mechanically like a long bone. They are exceptionally susceptible to highly unstable fractures even from minor trauma. Due to distorted anatomy and osteopenia, plain radiographs often miss fractures in these patients. A CT scan of the entire cervical spine is the mandatory standard of care for any AS patient with neck pain following trauma.

Question 9

A 35-year-old male is involved in a severe motor vehicle collision. Radiographs demonstrate a Levine-Edwards Type IIA traumatic spondylolisthesis of the axis (Hangman's fracture), characterized by severe angulation with minimal anterior translation. Which of the following statements regarding the mechanism of injury and its initial management is correct?

Explanation

A Levine-Edwards Type IIA Hangman's fracture is characterized by significant angulation but minimal translation, differing from the classic Type II. The injury mechanism is flexion-distraction. Application of cervical traction is absolutely contraindicated, as it will exacerbate the distraction and deformity. Initial treatment typically involves application of a halo vest in slight extension and compression.

Question 10

An adult patient is undergoing planning for complex corrective surgery to address severe symptomatic degenerative lumbar scoliosis and sagittal imbalance. Measurement of the patient's pelvic incidence (PI) yields a value of 55 degrees. To achieve optimal post-operative global sagittal balance, what is the approximate target value for the post-operative lumbar lordosis (LL)?

Explanation

In the sagittal plane, a harmonious spinopelvic relationship is achieved when the lumbar lordosis (LL) roughly matches the pelvic incidence (PI). The widely accepted formula proposed by Schwab and the SRS-Schwab adult spinal deformity classification states that the target PI minus LL (PI-LL mismatch) should be within 9-10 degrees (ideally < 10 degrees). Therefore, if PI is 55 degrees, the target LL should be approximately 55 degrees.

Question 11

An 80-year-old male presents with neck pain after a fall from standing. A CT scan reveals a Type II odontoid fracture with 2 mm of posterior displacement. Which of the following factors places this patient at the highest risk for developing a nonunion?

Explanation

Risk factors for nonunion of a Type II odontoid fracture include patient age greater than 50-65 years, displacement greater than 5 mm, angulation greater than 10 degrees, delayed diagnosis, and posterior displacement > 5 mm. While this fracture has posterior displacement, it is only 2 mm (displacement < 5 mm is a lower risk). The patient's advanced age (80 years) is the most significant independent risk factor for nonunion presented.

Question 12

A 40-year-old male presents with acute saddle anesthesia, bilateral lower extremity weakness, and an inability to void. An MRI confirms a massive central disc herniation at L4-L5 causing cauda equina syndrome. If urodynamic testing were performed during this acute early phase, which of the following bladder profiles would most characteristically be seen?

Explanation

Acute cauda equina syndrome causes a lower motor neuron (LMN) injury to the parasympathetic nerves innervating the bladder (S2-S4). This typically results in an acontractile (areflexic) bladder with loss of sensation, leading to urinary retention, large bladder capacity, increased post-void residual volume, and ultimately overflow incontinence.

Question 13

A 30-year-old intravenous drug user presents with severe lower back pain, high fevers, and progressive paraparesis. MRI reveals L2-L3 pyogenic spondylodiscitis with severe endplate destruction and a large anterior epidural abscess causing severe thecal sac compression. What is the most appropriate surgical approach for this patient?

Explanation

For anterior spinal infections (spondylodiscitis) accompanied by vertebral body destruction and an anterior epidural abscess, an anterior surgical approach (corpectomy and structural grafting) is most appropriate. It directly addresses the anterior pathology, allows for thorough debridement, and provides mechanical support to the anterior column. Laminectomy is contraindicated as it destabilizes the spine, particularly when the anterior column is already compromised, leading to progressive kyphosis and neurologic deterioration.

Question 14

A 4-year-old boy presents to the emergency department with neck stiffness after a minor fall. A lateral cervical spine radiograph shows 3 mm of anterior displacement of C2 on C3. To determine if this is a physiologic pseudosubluxation or a true ligamentous injury, Swischuk's line is drawn. Which of the following describes a finding that supports a diagnosis of physiologic pseudosubluxation?

Explanation

Pseudosubluxation of C2 on C3 is common in children under 8 years due to horizontal facet joints and ligamentous laxity. It is differentiated from a true cervical spine injury by using Swischuk's line, which is drawn from the anterior aspect of the posterior arch of C1 to the anterior aspect of the posterior arch of C3. If the anterior aspect of the posterior arch of C2 lies within 1.5 to 2 mm of this line, the subluxation is physiologic.

Question 15

A 35-year-old recent immigrant presents with progressive thoracic back pain, fevers, and an increasing kyphotic deformity. Imaging demonstrates destruction of the T8 and T9 vertebral bodies with large paraspinal fluid collections. Which of the following findings is more characteristic of spinal tuberculosis (Pott's disease) compared to pyogenic spondylodiscitis?

Explanation

Mycobacterium tuberculosis infection of the spine (Pott's disease) primarily affects the anterior portion of the vertebral bodies. The infection tends to spread beneath the anterior longitudinal ligament to adjacent vertebrae. Unlike pyogenic infections, which rapidly destroy cartilage and the intervertebral disc through proteolytic enzymes, M. tuberculosis lacks these enzymes, leading to characteristically late sparing of the intervertebral disc spaces.

Question 16

A 70-year-old male with a history of cervical spondylosis falls forward, striking his chin. He develops severe weakness in his upper extremities, but is relatively able to walk. The disproportionate weakness in the upper extremities compared to the lower extremities is due to the anatomical arrangement of which specific spinal cord tract?

Explanation

This patient has Central Cord Syndrome. The disproportionate weakness in the upper extremities occurs because the motor fibers innervating the cervical region (arms/hands) are located more centrally/medially within the lateral corticospinal tract. Fibers innervating the trunk, legs, and sacral region are layered progressively more peripherally (laterally), sparing them in central cord injuries.

Question 17

Recombinant human Bone Morphogenetic Protein-2 (rhBMP-2) is utilized as a potent osteoinductive agent in spinal fusion surgery. Upon binding to its surface receptors, through which primary intracellular signaling pathway does rhBMP-2 mediate its osteoinductive effect?

Explanation

Bone Morphogenetic Proteins (BMPs), members of the TGF-beta superfamily, initiate bone formation by binding to serine/threonine kinase receptors. This receptor activation results in the phosphorylation of receptor-regulated SMAD proteins (specifically SMAD 1, 5, and 8). These form a complex with the co-SMAD (SMAD 4), which then translocates to the nucleus to regulate the transcription of osteogenic genes like Runx2.

Question 18

A 50-year-old female presents with severe neck pain radiating down her lateral forearm and into her thumb. On physical examination, she demonstrates 4/5 strength in wrist extension and elbow flexion. Which of her deep tendon reflexes is most likely to be diminished?

Explanation

The patient's clinical presentation is classic for a C6 radiculopathy. C6 compression causes sensory changes in the lateral forearm and thumb (C6 dermatome), weakness in wrist extension (extensor carpi radialis longus/brevis) and elbow flexion (biceps/brachialis), and a diminished or absent brachioradialis reflex. A diminished triceps reflex would point to C7.

Question 19

A 25-year-old male is evaluated following a crushing pelvic injury. CT imaging reveals a vertical fracture of the sacrum that extends through the central sacral canal. According to the Denis classification of sacral fractures, this is a Zone III injury. Which of the following clinical deficits is most highly associated with this specific injury zone?

Explanation

The Denis classification of sacral fractures divides them into three zones based on their relationship to the sacral foramina. Zone I (alar) is lateral to the foramina. Zone II (foraminal) involves the foramina and frequently causes sciatica/radiculopathy. Zone III (central canal) involves the central sacral spinal canal and carries the highest rate of neurologic injury (up to 57%), characteristically presenting as cauda equina syndrome with bowel, bladder, and sexual dysfunction.

Question 20

An orthopedic resident is applying a halo vest to an adult patient with a high cervical spine fracture. To ensure safe placement of the anterior pins, what is the appropriate anatomical location and application torque to minimize the risk of neurovascular injury and pin failure?

Explanation

The anterior "safe zone" for halo pin placement is approximately 1 cm superior to the orbital rim, centered over the lateral two-thirds of the orbit (lateral to the supraorbital notch). Placing the pins medial to this notch risks injuring the supraorbital and supratrochlear nerves. The standard application torque for a rigid halo in adults is 8 in-lb. In pediatric patients, multiple pins and a lower torque (e.g., 2-4 in-lb) are used depending on bone age.

Question 21

A 65-year-old male with long-standing ankylosing spondylitis presents to the emergency department after a mechanical ground-level fall. He complains of severe lower neck pain. Neurological examination is intact. Lateral cervical spine radiographs show no obvious fracture. What is the most appropriate next step in management?

Explanation

Patients with ankylosing spondylitis (AS) have a highly rigid, osteopenic spine that acts like a long bone, making it highly susceptible to fractures even from low-energy trauma (e.g., ground-level falls). The cervicothoracic junction is the most common site. Plain radiographs often miss these fractures due to altered anatomy, osteopenia, and superimposed shoulder shadows. A non-contrast CT scan is the gold standard and strictly required in any AS patient with neck/back pain following trauma, regardless of normal initial plain films. Flexion-extension views are contraindicated due to the risk of iatrogenic spinal cord injury.

Question 22

A 55-year-old male presents with deep, persistent sacral pain and mild bowel dysfunction. Imaging reveals a large, destructive midline sacral mass extending to the S2 level. Histopathology demonstrates lobules of large cells with prominent intracytoplasmic vacuoles. Which of the following is the most appropriate definitive management for this lesion?

Explanation

The clinical presentation and histology (physaliferous cells with large intracytoplasmic vacuoles) are pathognomonic for chordoma. Chordomas are slow-growing but locally aggressive, malignant primary bone tumors derived from notochord remnants. They are notoriously radioresistant and chemoresistant. The mainstay of treatment for sacral chordomas is en bloc wide surgical resection with negative margins, as intralesional resection inevitably leads to high local recurrence rates.

Question 23

Which of the following is a strict diagnostic criterion for Diffuse Idiopathic Skeletal Hyperostosis (DISH) according to Resnick and Niwayama?

Explanation

The Resnick and Niwayama criteria for DISH include: 1) Flowing ossification along the anterolateral aspect of at least four contiguous vertebral bodies. 2) Relative preservation of intervertebral disc height in the involved segments and absence of extensive radiographic changes of degenerative disc disease (no vacuum phenomenon or marginal sclerosis). 3) Absence of apophyseal joint bony ankylosis and sacroiliac joint erosion, sclerosis, or intra-articular osseous fusion (which critically distinguishes it from Ankylosing Spondylitis). DISH is not associated with HLA-B27.

Question 24

An 8-year-old girl presents with painful torticollis one week after recovering from an upper respiratory tract infection. Radiographs demonstrate an atlantoaxial rotatory subluxation. According to the Fielding and Hawkins classification, a Type II injury is characterized by:

Explanation

Fielding and Hawkins classified atlantoaxial rotatory subluxation (AARS) into four types. Type I: Rotatory fixation with no anterior displacement (ADI < 3 mm); transverse ligament intact. Type II: Rotatory fixation with anterior displacement of 3 to 5 mm; indicates transverse ligament deficiency. Type III: Rotatory fixation with anterior displacement > 5 mm; indicates deficiency of both the transverse and alar ligaments. Type IV: Posterior rotatory fixation. The scenario describes Grisel's syndrome (AARS secondary to head/neck infection/inflammation).

Question 25

A 30-year-old male sustains a T12 burst fracture after a fall. On examination, he is neurologically intact. MRI demonstrates definitive 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 management?

Explanation

The TLICS system evaluates three categories: morphology, neurologic status, and posterior ligamentous complex (PLC) integrity. This patient has a burst fracture morphology (2 points), intact neurologic status (0 points), and a definitively disrupted PLC (3 points). Total score = 2 + 0 + 3 = 5. A TLICS score <= 3 suggests non-operative management, a score of 4 is indeterminate (surgeon's choice), and a score >= 5 is a strong indication for surgical management.

Question 26

A 6-year-old girl is diagnosed with Klippel-Feil syndrome based on the classic clinical triad and cervical spine radiographs showing multiple congenitally fused segments. As part of her comprehensive evaluation, which of the following screening tests is most critical to perform?

Explanation

Klippel-Feil syndrome is a congenital disorder characterized by the failure of segmentation of two or more cervical vertebrae. The classic triad includes a short neck, low posterior hairline, and limited neck range of motion. It is highly associated with other visceral and skeletal anomalies. Up to 30-40% of patients have congenital genitourinary anomalies (e.g., unilateral renal agenesis, horseshoe kidney). Therefore, a renal ultrasound is a critical screening tool. Other associated conditions include congenital heart defects (e.g., VSD, not specifically aortic root dilation), Sprengel deformity, and hearing loss.

Question 27

A 68-year-old man presents to the emergency department after a hyperextension injury to his neck during a motor vehicle collision. He exhibits severe motor weakness in his hands and arms, with relatively preserved strength in his legs. Perianal sensation and sphincter tone are intact. Which of the following anatomical structures is primarily damaged in this syndrome?

Explanation

The patient is presenting with Central Cord Syndrome, the most common incomplete spinal cord injury, typically occurring in elderly patients with pre-existing cervical spondylosis who sustain a hyperextension injury. The pathognomonic finding is disproportionately greater motor impairment in the upper extremities compared to the lower extremities. The pathophysiology involves injury to the central gray matter and the medial aspect of the lateral corticospinal tracts (which carry motor fibers for the cervical segments/upper extremities, whereas lumbar/sacral fibers are located more laterally).

Question 28

A 45-year-old intravenous drug user presents with a two-week history of worsening back pain, fever, and new-onset urinary retention. MRI of the lumbar spine confirms a ventral epidural abscess at L3-L4 compressing the cauda equina. Which of the following dictates the urgent need for surgical decompression rather than isolated medical management?

Explanation

Spinal epidural abscesses can often be managed with culture-directed antibiotics alone if the patient is neurologically intact. However, the development of a neurological deficit (such as urinary retention, indicating cauda equina syndrome, or progressing motor weakness) is an absolute indication for urgent surgical decompression to prevent irreversible neurological damage. Factors like location (ventral vs dorsal), inflammatory marker levels, and etiology guide the broader treatment plan but do not single-handedly dictate the need for emergent surgery over neurological status.

Question 29

A 15-year-old boy presents with progressive thoracic curvature and mid-back pain. Radiographs reveal a severe thoracic kyphosis. According to Sorensen's criteria, a definitive diagnosis of Scheuermann's kyphosis requires which of the following radiographic findings?

Explanation

Scheuermann's kyphosis is a structural deformity of the thoracic or thoracolumbar spine occurring during adolescence. According to Sorensen's criteria, the diagnosis is radiographically confirmed by the presence of anterior wedging of at least 5 degrees in three or more contiguous vertebral bodies. Other associated but non-diagnostic findings include Schmorl's nodes, endplate irregularities, and intervertebral disc space narrowing.

Question 30

A 14-year-old female presents with severe mechanical lower back pain and a 'waddling' gait. Radiographs reveal a Meyerding Grade IV isthmic spondylolisthesis at L5-S1. The slip angle is measured at 55 degrees. What is the most critical pelvic parameter that determines the overall sagittal balance and risk of progression in this patient?

Explanation

Pelvic Incidence (PI) is a fixed morphological parameter unique to each individual and is defined as the sum of Pelvic Tilt (PT) and Sacral Slope (SS) (PI = PT + SS). In high-grade spondylolisthesis (Meyerding Grade III-V), patients typically have a high Pelvic Incidence, which predisposes them to greater shear forces at the lumbosacral junction. A high slip angle (>45-50 degrees) combined with high PI strongly correlates with an increased risk of further progression and poor functional outcomes, often necessitating surgical reduction and stabilization.

Question 31

A 72-year-old woman sustains an Anderson and D'Alonzo Type II odontoid fracture after a fall. Which of the following factors is most strongly associated with an increased risk of nonunion if this fracture is treated non-operatively with a hard cervical collar?

Explanation

Anderson and D'Alonzo Type II odontoid fractures (fractures through the base of the dens) have a notoriously high rate of nonunion due to watershed vascularity. Recognized risk factors for nonunion with conservative management include age > 50 years, initial displacement > 5 mm, posterior displacement, angulation > 10 degrees, and a delay in diagnosis/treatment. Therefore, age > 50 years is a major predictor of nonunion, and surgical stabilization is often recommended in this demographic.

Question 32

A 25-year-old male sustains a gunshot wound to the abdomen. The bullet traversed the descending colon and lodged in the L3 vertebral body. The patient has 4/5 weakness in right hip flexion and knee extension. The abdomen is explored, and a bowel repair is performed. Regarding the spinal injury, what is the most appropriate management?

Explanation

In the management of spinal gunshot wounds, routine bullet removal is generally not indicated unless the bullet is within the spinal canal causing a progressive neurologic deficit, or if it is located within the thecal sac. In cases where a bullet traverses a hollow viscus (e.g., colon) before lodging in the spine, the primary treatment is broad-spectrum intravenous antibiotics (covering anaerobes and gram-negatives for 7-14 days) to prevent osteomyelitis/discitis. Stable or non-progressive incomplete deficits are usually observed. Steroids are contraindicated in penetrating spinal cord injuries.

Question 33

A 60-year-old Asian male presents with progressive clumsiness in his hands and a wide-based gait. CT of the cervical spine shows severe Ossification of the Posterior Longitudinal Ligament (OPLL) from C3 to C6, occupying 60% of the spinal canal. The 'double-layer sign' is present on the axial CT. What does this sign indicate?

Explanation

The 'double-layer sign' on a CT scan in a patient with OPLL represents a hyperdense ossified PLL and a hyperdense ossified dura mater separated by a hypodense central layer. This radiographic finding is highly specific for dural ossification. Surgeons must be aware of this, as attempting an anterior resection of the OPLL mass carries a very high risk of dural tearing and subsequent CSF leak. In such cases, posterior decompression or a modified anterior approach (leaving the ossified dura/OPLL 'floating') is typically preferred.

Question 34

A 58-year-old woman with a history of breast cancer presents with mechanical back pain localized to T8. She is neurologically intact. According to the Spinal Instability Neoplastic Score (SINS), which of the following clinical or radiographic features contributes the maximum number of points toward the total score?

Explanation

The Spinal Instability Neoplastic Score (SINS) is used to assess spinal stability in neoplastic disease. Severe mechanical pain (pain with movement/loading, relieved by recumbency) is a hallmark of instability and scores the maximum 3 points in the pain category. T8 is considered a semi-rigid location (1 point). Blastic lesions imply stability and score 0 points. Mechanical pain heavily influences the decision for surgical stabilization.

Question 35

A 35-year-old male arrives at the trauma bay comatose (GCS 6) following a high-speed motorcycle crash. Lateral cervical spine radiographs show a C5-C6 bilateral facet dislocation with 50% anterior translation of C5 on C6. What is the most appropriate next step in the management of his cervical spine injury?

Explanation

In a patient with a cervical facet dislocation, closed reduction via cranial traction can be performed safely in an awake, alert, and cooperative patient who can provide continuous neurological feedback. However, in an obtunded or unexaminable patient (like this comatose male), closed reduction is contraindicated due to the inability to assess for neurological worsening. An emergent MRI must be obtained first to rule out a herniated disc behind the vertebral body prior to any closed or open reduction attempt.

Question 36

A 3-year-old boy presents with a limp, refusal to walk, and low-grade fever for 4 days. Inflammatory markers (ESR, CRP) are elevated. An MRI reveals fluid and enhancement in the L4-L5 disc space with adjacent vertebral body endplate edema. Which of the following statements best explains the pathophysiology of this condition in this age group?

Explanation

Pediatric discitis typically affects children under the age of 5. The primary pathophysiological mechanism is hematogenous seeding of bacteria (most commonly Staphylococcus aureus). Unlike adults, children have a rich vascular supply to the intervertebral disc via vessels that penetrate the cartilaginous endplates. These vascular channels typically obliterate by around age 7 or 8. Treatment involves blood cultures, immobilization, and appropriate intravenous antibiotics.

Question 37

A 28-year-old male suffers a stab wound to the right side of his neck at the C6 level, resulting in a Brown-Sequard syndrome. Based on the anatomical pathways of the spinal cord, which of the following physical examination findings is expected?

Explanation

Brown-Sequard syndrome (spinal cord hemisection) results in: 1) Ipsilateral loss of motor function (corticospinal tract). 2) Ipsilateral loss of proprioception, vibration, and fine touch (dorsal columns). 3) Contralateral loss of pain and temperature sensation (spinothalamic tract). Because the spinothalamic fibers enter the cord and ascend 1-2 levels before crossing over via the anterior white commissure, the contralateral loss of pain and temperature begins 1-2 levels below the site of the injury.

Question 38

In the evaluation of adult spinal deformity, which of the following radiographic parameters has been most strongly and consistently correlated with poor Health-Related Quality of Life (HRQOL) scores?

Explanation

In adult spinal deformity, sagittal plane alignment is the primary driver of clinical symptoms and poor Health-Related Quality of Life (HRQOL) scores. A positive Sagittal Vertical Axis (SVA) > 50 mm (measured as the horizontal distance from a plumb line dropped from the center of the C7 vertebral body to the posterior superior corner of the S1 endplate) correlates strongly with increased pain and decreased function. While a PI-LL mismatch > 10 degrees is also a crucial predictor, the option provided incorrectly stated 'less than 10 degrees'.

Question 39

A 40-year-old male presents with severe acute low back pain radiating to both legs, saddle anesthesia, and urinary incontinence. An MRI reveals a massive central L4-L5 disc herniation. The pathophysiology of his urinary incontinence is most accurately described as:

Explanation

Cauda Equina Syndrome (CES) represents a lower motor neuron (LMN) injury caused by compression of the lumbosacral nerve roots below the conus medullaris. The parasympathetic fibers originating from S2-S4 mediate bladder contraction. Compression of these roots leads to an areflexic, flaccid bladder (detrusor areflexia). As the bladder fills beyond its capacity without the ability to contract, the intravesical pressure overcomes sphincter resistance, resulting in overflow incontinence. Post-void residual volume (PVR) is typically elevated.

Question 40

Recombinant human Bone Morphogenetic Protein-2 (rhBMP-2) is utilized in spinal fusion surgery to enhance arthrodesis. At the cellular level, through which of the following intracellular signaling pathways does rhBMP-2 primarily exert its osteoinductive effect?

Explanation

BMPs are members of the Transforming Growth Factor-beta (TGF-beta) superfamily. rhBMP-2 binds to serine/threonine kinase receptors on the cell surface of mesenchymal stem cells. This binding phosphorylates and activates the intracellular Smad 1, 5, and 8 proteins. These activated Smads then form a complex with the co-Smad (Smad 4), translocate into the nucleus, and regulate the transcription of target osteogenic genes (e.g., Runx2, Osterix), thereby promoting differentiation into osteoblasts.

Question 41

A 72-year-old male with pre-existing cervical stenosis experiences a hyperextension injury during a fall. He presents with profound bilateral upper extremity motor weakness but is still able to ambulate with only mild lower extremity clumsiness. Proprioception and vibratory sensation are preserved. What is the primary pathophysiologic mechanism for this specific neurologic deficit?

Explanation

This patient presents with Central Cord Syndrome, typical of hyperextension injuries in stenotic cervical spines. The pathophysiology involves central grey matter hemorrhage and edema, which disproportionately affects the medially located cervical motor tracts compared to the peripheral sacral/lumbar tracts.

Question 42

An 80-year-old female presents after a ground-level fall with severe neck pain. CT scan reveals a Type II odontoid fracture with 6 mm of posterior displacement. She has a history of severe COPD and ischemic heart disease. What is the most appropriate definitive management?

Explanation

In elderly patients, Type II odontoid fractures have a high nonunion rate, and halo vests are associated with high morbidity and mortality. Posterior C1-C2 fusion is the treatment of choice for displaced fractures in this demographic to achieve stability and avoid the risks of conservative bracing.

Question 43

A 55-year-old male with a 20-year history of ankylosing spondylitis presents with severe neck pain after a low-speed motor vehicle collision. Neurologic exam is intact. Radiographs and CT show a transverse fracture through the C5-C6 disc space extending through the posterior elements. What is the most appropriate surgical treatment?

Explanation

Fractures in ankylosing spondylitis are highly unstable "chalk-stick" fractures that involve all three spinal columns. They typically require long-segment posterior instrumentation (often 3 levels above and below) because anterior-only or short-segment constructs have unacceptably high failure rates.

Question 44

A 35-year-old male is evaluated after a fall from a ladder. CT imaging demonstrates an L1 burst fracture with 15 degrees of kyphosis and 30% canal compromise. The posterior ligamentous complex (PLC) is completely intact on MRI. Neurologic examination is entirely normal. According to the Thoracolumbar Injury Classification and Severity (TLICS) score, what is the most appropriate management?

Explanation

This patient has a TLICS score of 2 (Morphology: Burst = 2; Neuro: Intact = 0; PLC: Intact = 0). A score of less than 4 indicates non-operative management, making a TLSO brace or early mobilization the most appropriate choice.

Question 45

A 14-year-old girl with Adolescent Idiopathic Scoliosis is evaluated for surgery. Her standing radiographs show a main thoracic curve of 55 degrees and a lumbar curve of 35 degrees. On side-bending radiographs, her lumbar curve reduces to 15 degrees, and her proximal thoracic curve reduces to 10 degrees. How is her curve pattern classified according to the Lenke system?

Explanation

A Lenke Type 1 curve involves a structural main thoracic curve with non-structural proximal thoracic and lumbar curves. Because the lumbar curve bends out to less than 25 degrees, it is considered non-structural.

Question 46

During a posterior spinal fusion for an L4-L5 degenerative spondylolisthesis, the neuromonitoring technician reports a sudden 80% decrease in transcranial motor evoked potentials (MEPs) in the right lower extremity. Somatosensory evoked potentials (SSEPs) remain at baseline. What is the most appropriate immediate first step?

Explanation

The initial step for an isolated loss of MEPs is to rule out systemic or anesthetic causes such as hypotension, hypoxia, or the recent administration of paralytic agents. Prompt communication with the anesthesia team is crucial before altering the surgical field.

Question 47

A 42-year-old intravenous drug user presents with 2 weeks of worsening back pain, low-grade fevers, and new-onset bilateral leg weakness (3/5) starting 12 hours ago. Inflammatory markers are markedly elevated. MRI reveals a massive L2-L4 dorsal epidural abscess. What is the most appropriate next step in management?

Explanation

A spinal epidural abscess presenting with an acute, progressive neurologic deficit is a surgical emergency. Urgent surgical decompression must be performed immediately to prevent irreversible paralysis, taking precedence over isolated antibiotic therapy or percutaneous biopsy.

Question 48

A 15-year-old competitive gymnast presents with intractable mechanical low back pain for 9 months. She has failed intensive physical therapy and bracing. Radiographs show a Grade II L5-S1 isthmic spondylolisthesis. She has no radicular symptoms. What is the gold-standard surgical intervention for this patient?

Explanation

For adolescents with symptomatic low-grade (Grade I or II) isthmic spondylolisthesis who fail conservative care, an in situ L5-S1 posterolateral fusion is the established gold standard. Attempting complete anatomic reduction increases the risk of an L5 nerve root stretch injury.

Question 49

A 62-year-old female with long-standing rheumatoid arthritis presents with worsening neck pain and myelopathy. Lateral flexion-extension radiographs show an Atlantodental Interval (ADI) of 8 mm. The posterior Space Available for the Cord (SAC) is 12 mm. What is the most appropriate management?

Explanation

In the rheumatoid cervical spine, a Space Available for the Cord (SAC) of less than 14 mm or an ADI greater than 9 mm correlates strongly with neurologic injury. Because her SAC is 12 mm and she is myelopathic, a posterior C1-C2 fusion is strictly indicated.

Question 50

In a 12-year-old patient with a Grade IV L5-S1 dysplastic spondylolisthesis, radiographic evaluation demonstrates a significantly elevated "slip angle". What does an increased slip angle primarily indicate in this clinical scenario?

Explanation

The slip angle measures lumbosacral kyphosis. A high slip angle in high-grade spondylolisthesis is one of the strongest biomechanical predictors for continued slip progression and deformity, heavily favoring surgical stabilization.

Question 51

A 60-year-old male with metastatic renal cell carcinoma presents with acute T8 paraparesis. MRI shows a T8 metastatic lesion causing high-grade epidural spinal cord compression. Based on the Neurologic, Oncologic, Mechanical, and Systemic (NOMS) framework, what is the optimal treatment strategy?

Explanation

Renal cell carcinoma is traditionally radioresistant. For radioresistant tumors causing high-grade cord compression, the NOMS framework recommends "separation surgery" to decompress the cord and create a safe margin, followed by high-dose Stereotactic Radiosurgery (SRS).

Question 52

A 45-year-old male presents to the emergency department with sudden onset perineal numbness, bilateral sciatica, and inability to void. Bladder scan reveals 700 mL of retained urine. MRI shows a massive central disc extrusion at L4-L5. What is the critical time window for definitive intervention to maximize functional recovery?

Explanation

Cauda equina syndrome is an absolute surgical emergency. Literature supports that urgent surgical decompression, ideally performed within 24 to 48 hours of symptom onset, maximizes the chance of recovering bladder, bowel, and sexual function.

Question 53

A 22-year-old female sustains a seatbelt-type injury in a motor vehicle accident. CT demonstrates an L2 flexion-distraction (Chance) fracture strictly confined to the bone, with avulsion of the posterior spinous process and widening of the pedicles. Neurologic exam is normal. What is the most appropriate primary treatment?

Explanation

A purely bony Chance fracture (flexion-distraction injury) without neurologic compromise has excellent healing potential due to the large cancellous bone surfaces involved. It is typically managed successfully with closed reduction and an extension orthosis (TLSO).

Question 54

A 30-year-old male presents after a diving accident. Radiographs reveal a fracture through the pars interarticularis of C2 with 4 mm of anterior translation and 12 degrees of angulation of C2 on C3 (Levine-Edwards Type II Hangman's fracture). What is the recommended initial management?

Explanation

A Type II Hangman's fracture involves significant angulation and translation due to disruption of the C2-C3 disc and posterior longitudinal ligament. It is best managed initially with gentle axial traction for reduction, followed by definitive immobilization in a halo vest.

Question 55

A 50-year-old male complains of radiating neck pain into his right arm, specifically accompanied by numbness in his middle finger. On exam, he has 3/5 weakness in right elbow extension and an absent right triceps reflex. Which cervical disc herniation level is the most likely cause of these findings?

Explanation

The clinical presentation describes a C7 radiculopathy (triceps weakness, absent triceps reflex, and middle finger numbness). In the cervical spine, the exiting nerve root is named for the lower vertebral segment, so the C7 nerve root is compressed at the C6-C7 disc level.

Question 56

A 2-year-old boy is diagnosed with congenital scoliosis secondary to a fully unsegmented unilateral bar with a contralateral hemivertebra at T8. Prior to any planned surgical intervention, which diagnostic modality is absolutely mandatory?

Explanation

Congenital scoliosis has a high association (up to 40%) with intraspinal anomalies such as tethered cord, diastematomyelia, and syringomyelia. Therefore, an MRI of the entire neuroaxis is mandatory before any corrective surgery to prevent iatrogenic neurologic injury.

Question 57

A 48-year-old female undergoes a right-sided anterior cervical discectomy and fusion (ACDF) at C6-C7. Post-operatively, she complains of significant hoarseness. Direct laryngoscopy confirms a unilateral paralyzed vocal cord. Injury to which of the following structures is most likely responsible?

Explanation

The recurrent laryngeal nerve (RLN) supplies the intrinsic muscles of the larynx. It is highly vulnerable during lower anterior cervical approaches (C6-T1), particularly on the right side where its anatomical course is more variable and non-recurrent.

Question 58

A 72-year-old male sustains a Type II odontoid fracture after a fall from standing. Which of the following is the most significant risk factor for nonunion if treated non-operatively with a rigid cervical collar?

Explanation

Risk factors for nonunion of Type II odontoid fractures include age > 50 years, initial displacement > 5 mm, posterior displacement, and delay in treatment. Non-operative management in elderly patients often leads to fibrous nonunion, requiring careful consideration of surgical morbidity.

Question 59

A 30-year-old male sustains an axial load injury to the cervical spine. An open-mouth odontoid radiograph reveals a combined lateral overhang of the C1 lateral masses on C2 of 8.5 mm. Which of the following is the most appropriate next step in management?

Explanation

A combined lateral overhang of the C1 lateral masses on C2 of >6.9 mm (Spence's rule) strongly suggests a rupture of the transverse atlantal ligament. MRI is indicated to directly evaluate the integrity of the ligament, which dictates whether treatment should be a halo vest or C1-C2 fusion.

Question 60

A 65-year-old male 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 no neurologic deficits. CT scan reveals a non-displaced, highly unstable extension-type fracture through the C6-C7 disc space. What is the most devastating and relatively common early complication associated with this specific injury pattern?

Explanation

Patients with ankylosing spondylitis are prone to unstable, sheer-type spinal fractures even from minor trauma due to altered biomechanics. They have a significantly increased risk of post-traumatic epidural hematomas, which can cause sudden and devastating neurologic deterioration.

Question 61

A 70-year-old male with pre-existing cervical spondylosis presents with severe bilateral arm weakness, particularly in his hands, and relatively preserved lower extremity strength after a hyperextension injury. Perianal sensation is intact. What is the anatomic rationale for this specific pattern of neurologic deficit?

Explanation

Central cord syndrome typically occurs after hyperextension injuries in patients with pre-existing spondylosis. The upper extremity motor tracts are located more medially within the corticospinal tract, making them more susceptible to central cord damage than the laterally situated lower extremity tracts.

Question 62

A 22-year-old male is involved in a high-speed motor vehicle accident while wearing a lap belt. Radiographs show a flexion-distraction injury (Chance fracture) at the T12 level. Which of the following associated injuries must be urgently ruled out?

Explanation

Chance fractures (flexion-distraction injuries) are highly associated with lap seatbelt injuries. There is a strong association (up to 50%) with intra-abdominal injuries, particularly hollow viscus injuries (e.g., bowel perforation), which require urgent general surgery evaluation.

Question 63

During an anterior cervical discectomy and fusion (ACDF) at C5-C6 using a right-sided approach, the patient develops postoperative hoarseness. Which anatomical feature explains why the recurrent laryngeal nerve is more susceptible to injury on the right side compared to the left during this approach?

Explanation

The right recurrent laryngeal nerve loops around the right subclavian artery and crosses the surgical field more transversely and aberrantly compared to the left. The left recurrent laryngeal nerve loops under the aortic arch and ascends predictably in the tracheoesophageal groove, making it less prone to injury.

Question 64

A 68-year-old female presents with severe neurogenic claudication. Imaging reveals a Grade 1 degenerative spondylolisthesis at L4-L5 with significant lateral recess stenosis. If a single nerve root is primarily compressed in the lateral recess at this level, which physical exam finding is most likely?

Explanation

In L4-L5 degenerative spondylolisthesis, the stenosis most commonly affects the lateral recess, leading to compression of the traversing L5 nerve root. L5 radiculopathy typically presents with weakness in the extensor hallucis longus (EHL) and altered sensation over the first dorsal web space.

Question 65

A 7-year-old child presents with torticollis and severe neck stiffness one week after undergoing a routine tonsillectomy. The child holds their head tilted to the right and rotated to the left. Cervical spine radiographs and a subsequent CT scan demonstrate anterior displacement and rotation of the atlas on the axis without evidence of trauma. What is the most likely diagnosis?

Explanation

Grisel's syndrome is a non-traumatic atlantoaxial rotatory subluxation associated with inflammatory conditions of the head and neck, such as tonsillitis or post-tonsillectomy. Regional inflammation leads to hyperemia and subsequent laxity of the transverse ligament.

Question 66

A 24-year-old female is involved in a high-speed motor vehicle collision while wearing a rear-seat lap belt. Radiographs reveal a transverse fracture propagating through the spinous process, pedicles, and vertebral body of L1. Which of the following concomitant injuries is most highly associated with this specific fracture pattern?

Explanation

A Chance fracture is a flexion-distraction injury strongly associated with lap-belt use in motor vehicle collisions. It has a high association (up to 50%) with intra-abdominal hollow viscus injuries, such as small bowel perforations.

Question 67

An 80-year-old male sustains a Type II odontoid fracture after a ground-level fall. He is neurologically intact. If this patient is treated conservatively with a rigid cervical orthosis (hard collar), which of the following factors represents the greatest independent risk for fracture nonunion?

Explanation

Risk factors for nonunion of Type II odontoid fractures include patient age > 50 years, initial displacement > 5 mm, posterior displacement, and angulation > 10 degrees. Advanced age is a highly significant, independent predictor of nonunion.

Question 68

A 70-year-old male with pre-existing multi-level cervical spondylosis sustains a hyperextension injury to his neck during a fall. He presents with severe motor weakness in his upper extremities, but retains relatively preserved functional motor strength in his lower extremities. Which spinal cord tract's anatomical somatotopic arrangement explains this specific pattern of neurological deficit?

Explanation

Central cord syndrome typically results from hyperextension injuries in stenotic cervical spines. Within the lateral corticospinal tract, the cervical motor fibers are located medially while the lumbar/sacral fibers are lateral, explaining the disproportionate upper extremity weakness.

Question 69

A 28-year-old male suffers a stab wound to the right side of his back at the T10 level. Upon examination, he exhibits loss of motor function and proprioception on the right side of his lower extremities, and loss of pain and temperature sensation on the left side. Which of the following best describes this classic neurological presentation?

Explanation

Brown-Sequard syndrome results from a functional hemisection of the spinal cord. It presents with ipsilateral loss of motor function (corticospinal tract) and proprioception (dorsal columns), and contralateral loss of pain and temperature sensation (spinothalamic tract).

Question 70

A 65-year-old male with a 30-year history of advanced ankylosing spondylitis presents to the emergency department with severe, localized thoracic back pain after a minor fall from standing. Initial plain radiographs of the thoracic spine are reported as negative for acute fracture. What is the most appropriate next step in management?

Explanation

Patients with ankylosing spondylitis have rigidly fused, osteoporotic spines and are at exceptionally high risk for highly unstable, occult fractures even from low-energy trauma. A CT or MRI of the entire spine is mandatory to rule out life-threatening fractures or epidural hematomas.

Question 71

A 15-year-old female gymnast complains of chronic low back pain and radiating left leg pain. Radiographs reveal a Grade II isthmic spondylolisthesis at L5-S1. If this patient is experiencing single-root radicular symptoms, which specific nerve root is most likely compressed by the pathoanatomy of this condition?

Explanation

In L5-S1 isthmic spondylolisthesis, the L5 exiting nerve root is most commonly compressed within the neural foramen. This compression is typically caused by the hypertrophic fibrocartilaginous tissue attempting to heal the pars interarticularis defect (the "pars mass").

Question 72

A 12-year-old pre-menarchal female presents for a routine scoliosis screening. Full-length standing radiographs demonstrate a right thoracic Cobb angle of 32 degrees. Her Risser stage is 0. According to current guidelines, what is the most appropriate primary management strategy?

Explanation

Full-time TLSO bracing (at least 16-18 hours/day) is indicated for Adolescent Idiopathic Scoliosis in skeletally immature patients (Risser 0-2, pre-menarchal) with a Cobb angle between 25 and 44 degrees to prevent further curve progression.

Question 73

A 45-year-old male presents with right-sided neck pain radiating down his arm. Physical exam reveals notable weakness in wrist extension, sensory deficit over the thumb and index finger, and a symmetrically diminished brachioradialis reflex. Which cervical disc herniation level is most likely responsible for these objective findings?

Explanation

The clinical findings of weakness in wrist extension, diminished brachioradialis reflex, and altered sensation in the radial digits are classic for a C6 radiculopathy. In the cervical spine, this is most commonly caused by a herniation at the C5-C6 disc space compressing the exiting C6 nerve root.

Question 74

A 50-year-old active intravenous drug user presents with progressive back pain, fever, and markedly elevated CRP and ESR. MRI reveals T1 hypointensity and T2 hyperintensity in the L3-L4 disc space with destruction of the adjacent vertebral endplates. The patient is neurologically intact and hemodynamically stable. What is the most appropriate immediate next step in management?

Explanation

In a hemodynamically stable patient with pyogenic spondylodiscitis and no neurological deficits, it is critical to establish a microbiological diagnosis via image-guided biopsy before initiating antibiotic therapy. Empiric antibiotics should be withheld to avoid falsely negative cultures.

Question 75

A 35-year-old male dives into a shallow pool and sustains an axial loading injury to his neck. AP open-mouth odontoid radiographs reveal a combined lateral mass overhang of C1 on C2 measuring 8.5 mm. According to the Rule of Spence, this specific radiographic finding suggests rupture of which ligamentous structure?

Explanation

The Rule of Spence dictates that a combined lateral mass overhang of C1 on C2 measuring 6.9 mm or greater on an AP open-mouth radiograph indicates a highly likely rupture of the transverse ligament. This renders a Jefferson (C1 burst) fracture highly unstable.

Question 76

A traumatic spondylolisthesis of the axis (Hangman's fracture) is characterized by bilateral fractures through the pars interarticularis of C2. What is the classic primary mechanism of injury responsible for this fracture pattern?

Explanation

A Hangman's fracture is classically caused by a mechanism of hyperextension combined with axial loading. In modern scenarios, this is most commonly seen in motor vehicle collisions where the patient's unrestrained chin strikes the dashboard.

Master Orthopedic Spine Cases: Sharpen Your Diagnostic Skills

Orthopedic With Answer Spine Review | Dr Hutaif Spine S -...

Key Takeaway

Orthopedic With Answer Spine Review | Dr Hutaif Spine S -...

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