Question 1

A 72-year-old man with acute onset low back pain with increased severity during the night should be evaluated by:

Explanation

An elderly patient with unsolicited low back pain is suggestive of a primary malignancy or metastatic disease of the lumbar spine. A thorough history and physical examination are indicated, as well as imaging to evaluate the lumbar spinal axis and the neural elements.

Question 2

An otherwise healthy 56-year-old patient with suspected spinal stenosis after history and physical examination undergoes plain radiography that is unremarkable for spondylolisthesis. The next feasible imaging modality that is indicated in aiding the diagnosis is:

Explanation

Although a computed tomography myelogram is slightly more specific and sensitive than magnetic resonance imaging (MRI) in evaluating lumbar stenosis, MRI is almost as sensitive and it is noninvasive. Therefore, in an otherwise healthy patient without contraindications, an MRI should be considered as the next imaging modality.

Question 3

Untreated low back pain most commonly:

Explanation

Generally, patients diagnosed with low back pain should undergo 4 weeks of conservative treatment with an accepted prognosis of predominantly spontaneous improvement over a 4-week period, regardless of treatment.

Question 4

Which of the following is NOT a routinely used imaging modality for evaluation of spinal pathology:

Explanation

Diskography is a diagnostic technique that has been used since the 1950â s. The study involves injection of dye into an intervertebral disk space. A positive study is one in which the injected dye is not contained within the disk space or in which the injection reproduces the characteristic distribution of the patientâ s pain. The current role of diskography remains undefined and, at this time, diskography is not a first-line diagnostic study in the evaluation of patients with low back pain.

Question 5

Which of the following is the most common type of spondylolisthesis seen in the adult population:

Explanation

The prevalence of degenerative spondylolisthesis is 2% to 5%; the prevalence increases with age. Symptomatic patients usually present in the fourth decade of life or later. The disease is five times more common in the female sex. The African American population, diabetics, and patients with sacralization of the L5 vertebrae are also at increased risk for developing symptomatic spondylolisthesis.

Question 6

Which of the following is the most common location of adult degenerative spondylolisthesis:

Explanation

The L4-L5 interspace is the most common location of adult degenerative spondylolisthesis.

Question 7

Which of the following statements is true regarding the initial diagnostic radiographic evaluation of patients with spondylolisthesis:

Explanation

Plain radiographs should be performed in a standing position as some cases of spondylolisthesis can be missed if x-rays are taken in a supine position. Forward displacement of L4 on L5 and more rarely L5 on S1 or L3 on L4, without a pars interarticularis defect is often demonstrated. Other radiologic findings of osteophyte formation, such as disk-space narrowing, endplate sclerosis, vacuum disk sign, facet sclerosis and hypertrophy, are consistent with long-standing degenerative disease. Hemisacralization of L5 may be revealed. Flexion, extension, and lateral bending films often reveal hypermobility.

Question 8

Initial nonoperative management of adult degenerative spondylolisthesis includes all of the following except:

Explanation

Conservative treatment for degenerative spondylolisthesis is consistent with the conservative care of most degenerative spinal disorders. It includes modified activity, physical therapy (conditioning exercises emphasizing lumbar flexion and progression to aerobic conditioning), anti-inflammatory medication, and sometimes spinal support with a corset or light-weight brace.

Question 9

Which of the following statements is true regarding lumbar degenerative scoliosis:

Explanation

Degenerative lumbar scoliosis occurs in approximately the same number of women as men. Lumbar curves are generally smaller than those in idiopathic scoliosis and are more evenly distributed between left and right, also in contrast to idiopathic curves that occur predominantly to the left.

Question 10

Which of the following is the most common complaint in patients with degenerative lumbar scoliosis:

Explanation

Patients with degenerative lumbar scoliosis typically complain of symptoms related to the associated spinal stenosis. These symptoms commonly include (with approximate incidence rates): low back pain (100%), reduced tolerance for standing and walking (85% to 100%), neurogenic claudication (50%), and radicular or pseudoradicular pain radiating into the buttocks or thighs (40% to 60%).

Question 11

Bony contribution to the lumbar lordotic curvature is provided by:

Explanation

The anterior portion of each body has a slightly increased height that contributes to the sagittal lumbar lordosis. The posterior vertebral arch consists of the paired pedicles, laminae, and a midline dorsal spinal process.

Question 12

Superior articulating facets in the lumbosacral spine differ from those in the thoracic spine because facets in the lumbosacral spine:

Explanation

The paired superior articular facets are directed dorsomedially with their corresponding inferior articular processes directed ventrolaterally. These diarthrodial articulations possess thin, lax joint capsules capable of a limited gliding articulation between adjoining vertebrae. They permit flexion, lateral bending and extension, but resist rotation due to both size and facet orientation. The facets alone can bear up to 18% of the compressive load.

Question 13

Limitation of hyperextension in the lumbosacral spine is controlled by the:

Explanation

More flexion-extension motion occurs in the caudal segments of the lumbar spine than in the upper and middle levels. The welldeveloped anterior longitudinal ligament and the anterior portion of the annulus fibrosus are important inhibitors of hyperextension.

Question 14

Which of the following is the primitive remnant of the nucleus pulposus:

Explanation

The nucleus pulposus is derived from the primitive notochord. It consists predominantly of hydrated proteoglycans with a minor component of a random network of type I and type II collagen.

Question 15

Which of the following is the most common region of the spine affected by metastatic disease:

Explanation

The thoracic spine is the most common site of metastatic disease. This has been attributed to the watershed zone being located in the low thoracic region.

Question 16

Which of the following is the most common complaint at time of presentation in patients with metastatic spine disease:

Explanation

The most common manifestation of metastatic disease is persistent pain. Pain is most marked at night and aggravated by movement. History of trauma is usually absent. Pain is followed by weakness of the lower extremities, sensory loss, and bladder and bowel changes.

Question 17

Which of the following methods is the standard in diagnosing vertebral metastatic disease:

Explanation

The only definitive method of determining the presence and nature of metastatic tumor is vertebral biopsy. Computed tomography-guided biopsy of the spine provides an accurate access to the lesion. Open biopsy is indicated when image guided biopsy is not feasible or non-diagnostic. Differential diagnosis mainly involves spinal infections, osteoporosis, disk disease, and multiple myeloma.

Question 18

Which of the following is NOT an indication for surgical intervention in metastatic vertebral disease:

Explanation

In patients with metastatic vertebral disease, indications for surgery include progressive neurologic deficit, instability of the spine, uncontrollable pain, and failure of radiation therapy. Surgical intervention can add significant morbidity while providing marginal improvement in longevity of a patient with an already poor prognosis.

Question 19

Which of the following is the most common cause of lumbar stenosis:

Explanation

Degenerative lumbar stenosis is the most common cause of lumbar stenosis. With normal aging of the disk, the water-binding capacity of the nucleus pulposus is dissipated, diminishing its ability to withstand normal compressive and rotational forces. With progressive degeneration of the disk, collapse occurs. This collapse results in overriding of the facet joints and relative lengthening of adjacent capsular and ligamentous structures. Continued instability, which may be multidirectional, results in hypertrophic changes about the periphery of the vertebral body at its annular attachments. Radiographically, these are seen as traction osteophytes. Similarly, osteophytes form about the facet joints, which lead to compromise of the neural canal. With disease progression, hypertrophic changes predominate, leading to ankylosis and auto stabilization. In patients with less than optimal canal configurations or dimensions or those with excessive hypertrophic degenerative changes, narrowing of the spinal canal, lateral recesses, and neural foramina may result in neurogenic signs and symptoms.

Question 20

Which of the following is the most common presentation of a patient with lumbar stenosis:

Explanation

The most common complaint in patients with spinal stenosis is chronic low back pain with worsening and lower extremity weakness after ambulation (claudication). Symptoms are often resolved by rest and/or leaning forward.

Question 21

A 45-year-old male presents to the emergency department with acute onset saddle anesthesia, bowel and bladder incontinence, and bilateral lower extremity weakness. MRI demonstrates a massive extruded L4-L5 disc herniation compressing the thecal sac. What is the most appropriate management to maximize the potential for neurological recovery?

Explanation

This patient presents with acute cauda equina syndrome, which is a surgical emergency. Emergent surgical decompression is mandatory, ideally within 24 to 48 hours of symptom onset, to maximize the recovery of bowel, bladder, and lower extremity motor function.

Question 22

A 38-year-old woman presents with a 4-week history of severe right-sided sciatica. She is neurologically intact. MRI demonstrates a large, sequestered L5-S1 disc herniation. If managed conservatively, what is the most likely natural history of the extruded disc material?

Explanation

Large, sequestered disc herniations have the highest rate of spontaneous resorption among disc herniation types. The extruded nucleus pulposus is recognized as foreign material, triggering a macrophage-mediated inflammatory response that typically leads to clinical improvement and radiographic resorption.

Question 23

Which of the following clinical features is most reliable for differentiating neurogenic claudication caused by lumbar spinal stenosis from vascular claudication?

Explanation

Neurogenic claudication is characteristically relieved by lumbar flexion (e.g., leaning on a shopping cart or sitting), which increases the cross-sectional area of the spinal canal. Vascular claudication is strictly exertion-related and relieved by simply resting (standing still) without postural changes.

Question 24

A 55-year-old male with long-standing ankylosing spondylitis presents after a ground-level fall. He complains of severe neck pain but remains neurologically intact. Initial standard anteroposterior and lateral cervical radiographs are interpreted as unremarkable. What is the most appropriate next step in his management?

Explanation

Patients with ankylosing spondylitis are at extremely high risk for occult, highly unstable extension-type fractures (chalk stick fractures) even after low-energy trauma. A CT scan of the entire cervical spine is mandatory, as plain radiographs often miss these fractures due to altered anatomy and osteopenia.

Question 25

During a posterior lumbar instrumented fusion, the surgeon prepares to place a pedicle screw at the L4 level. What is the standard anatomical starting point for the insertion of an L4 pedicle screw?

Explanation

The standard starting point for a lumbar pedicle screw is at the intersection of a horizontal line bisecting the transverse process and a vertical line corresponding to the lateral border of the superior articular process.

Question 26

A 62-year-old diabetic male presents with a 5-day history of severe localized back pain, fever, and progressive lower extremity weakness. Laboratory markers show elevated ESR and CRP. An MRI reveals a spinal epidural abscess. What is the most likely causative organism?

Explanation

Staphylococcus aureus is the most common causative organism in spinal epidural abscesses. The classic clinical triad of an epidural abscess consists of back pain, fever, and neurological deficits.

Question 27

A 72-year-old man with pre-existing cervical spondylosis sustains a hyperextension injury to his neck in a motor vehicle collision. On examination, he demonstrates significant weakness in his upper extremities, particularly the hands, with relatively preserved motor strength in his lower extremities. What is the most likely diagnosis?

Explanation

Central cord syndrome is the most common incomplete spinal cord injury, typically occurring after hyperextension injuries in older patients with cervical spondylosis. It is characterized by disproportionately greater motor impairment in the upper extremities compared to the lower extremities.

Question 28

During the neurological examination of a 60-year-old patient with suspected cervical spondylotic myelopathy, you rapidly flick the distal phalanx of the middle finger downward, eliciting a reflexive flexion of the thumb and index finger. What is the name of this upper motor neuron sign?

Explanation

The Hoffmann sign is elicited by flicking the distal phalanx of the middle finger, which causes reflexive flexion of the thumb and index finger. It indicates upper motor neuron dysfunction, commonly seen in cervical myelopathy.

Question 29

A 14-year-old female gymnast presents with severe chronic low back pain limiting her participation in sports. Radiographs demonstrate a Grade II L5-S1 isthmic spondylolisthesis. After 6 months of supervised physical therapy, bracing, and NSAIDs, her severe pain persists. What is the most appropriate surgical intervention?

Explanation

Symptomatic Grade II isthmic spondylolisthesis at L5-S1 that fails conservative management is best treated with an L5-S1 spinal fusion. Direct pars repair (e.g., Buck's procedure) is generally reserved for isolated pars defects or Grade I slips at higher lumbar levels (L1-L4) without significant disc degeneration.

Question 30

A 25-year-old male is involved in a high-speed collision wearing only a lap belt. Radiographs reveal a severe flexion-distraction injury (Chance fracture) at L1. Which of the following associated injuries must be most carefully excluded in this patient?

Explanation

Chance fractures (flexion-distraction injuries) are highly associated with lap-belt mechanisms and carry a very high incidence (up to 50%) of concomitant intra-abdominal injuries, particularly hollow viscus ruptures.

Question 31

A 68-year-old male with a history of prostate cancer presents with progressive back pain. An anteroposterior (AP) radiograph of the lumbar spine reveals the absence of the cortical outline of the right L3 pedicle. What is this radiographic finding commonly termed?

Explanation

The missing pedicle on an AP radiograph of the spine is known as the "winking owl sign." It is highly suggestive of metastatic disease involving the vertebral pedicle.

Question 32

When evaluating the sagittal alignment of an adult patient with spinal deformity, which of the following spinopelvic parameters is considered a fixed morphological feature that remains constant regardless of patient positioning?

Explanation

Pelvic incidence is a fixed morphological parameter defined after skeletal maturity and does not change with posture. It is calculated mathematically as the sum of pelvic tilt and sacral slope (PI = PT + SS).

Question 33

Which of the following factors is most strongly associated with an increased risk of non-union in a Type II odontoid fracture treated with non-operative management?

Explanation

Initial fracture displacement greater than 5 mm is a major risk factor for non-union in Type II odontoid fractures. Other significant risk factors include patient age greater than 50 years and posterior displacement.

Question 34

A trauma patient arrives at the emergency department with a complete T4 spinal cord injury. Vital signs reveal profound hypotension and bradycardia, and his extremities are warm and flushed. This clinical presentation is most characteristic of:

Explanation

Neurogenic shock results from the loss of sympathetic autonomic tone following severe cervical or upper thoracic cord injury, leading to unchecked vagal tone, bradycardia, and profound hypotension with warm extremities. Spinal shock, by contrast, refers to the temporary loss of spinal reflexes below the injury level.

Question 35

A 65-year-old male presents with global spine stiffness but minimal pain. Radiographs reveal flowing ossification along the anterolateral aspect of five contiguous vertebral bodies in the thoracic spine, with relative preservation of intervertebral disc height and normal sacroiliac joints. What is the most likely diagnosis?

Explanation

DISH is characterized by flowing anterolateral osteophytes involving at least four contiguous vertebral bodies, preserved disc height, and the absence of sacroiliac joint erosion. It is distinct from ankylosing spondylitis, which classically involves the sacroiliac joints.

Question 36

A 16-year-old male football lineman complains of localized low back pain exacerbating with spinal extension. Plain radiographs are normal. Which imaging modality is currently preferred to definitively detect an early, acute pars interarticularis stress reaction (marrow edema) without exposing the patient to ionizing radiation?

Explanation

MRI, specifically utilizing STIR or T2 fat-suppressed sequences, is highly sensitive for detecting bone marrow edema indicative of an acute pars stress reaction. It is preferred over SPECT or CT because it avoids radiation exposure in the adolescent population.

Question 37

A 32-year-old intravenous drug user presents with progressive, unrelenting back pain. MRI confirms hematogenous pyogenic discitis-osteomyelitis at the L3-L4 level. Based on the vascular anatomy of the adult spine, which region of the spinal segment is typically the initial site of bacterial seeding?

Explanation

In adults, the intervertebral disc is avascular. Hematogenous infection initially seeds the highly vascularized subchondral bone of the vertebral endplate, subsequently destroying the endplate and spreading into the adjacent avascular disc.

Question 38

A patient presents with severe right-sided neck pain radiating down the arm. Examination reveals weakness in right wrist extension, an absent brachioradialis reflex, and decreased sensation over the dorsal aspect of the thumb and index finger. Which cervical nerve root is most likely compressed?

Explanation

A C6 radiculopathy classically presents with weakness in wrist extension, sensory deficits over the thumb and index finger, and a diminished brachioradialis reflex. C5 affects the deltoid/biceps, while C7 primarily affects triceps and wrist flexion.

Question 39

A 50-year-old female presents with progressive myelopathy due to a large, centrally located, calcified thoracic disc herniation at T8-T9. Which of the following surgical approaches is generally CONTRAINDICATED due to the unacceptably high risk of catastrophic spinal cord injury?

Explanation

A simple posterior laminectomy is contraindicated for a central thoracic disc herniation due to the need to retract the delicate thoracic spinal cord to access the disc, resulting in an unacceptably high risk of permanent paraplegia. Anterior or posterolateral approaches are required.

Question 40

A traumatic spondylolisthesis of the axis, historically termed a 'Hangman's fracture', classically involves bilateral fractures passing through which anatomical structure of the C2 vertebra?

Explanation

A Hangman's fracture is defined as bilateral fractures through the pars interarticularis of the C2 vertebra. It is typically caused by a hyperextension and axial loading mechanism.

Question 41

A 45-year-old male presents with right leg pain radiating down the lateral calf to the dorsum of the foot. Examination reveals 3/5 strength in the extensor hallucis longus and decreased sensation over the first dorsal web space. Which nerve root is most likely compressed?

Explanation

A posterolateral disc herniation at L4-L5 typically compresses the traversing L5 nerve root. This presents with weakness in the EHL and sensory deficits over the first dorsal web space.

Question 42

A 65-year-old female with known degenerative spondylolisthesis at L4-L5 presents with worsening back and leg pain. She reports a new onset of urinary incontinence. Post-void residual bladder volume is 400 mL. The most appropriate immediate management is:

Explanation

The patient exhibits classic signs of cauda equina syndrome, including urinary retention/incontinence and a high post-void residual. Emergent MRI and surgical decompression are indicated to prevent permanent neurological deficits.

Question 43

An 11-year-old gymnast presents with persistent lower back pain exacerbated by extension. Oblique lumbar radiographs demonstrate a "collar on the Scotty dog." What is the most appropriate initial management?

Explanation

The radiograph finding indicates a pars interarticularis defect (spondylolysis). Initial management for symptomatic pediatric spondylolysis without significant slip is non-operative, primarily consisting of activity restriction and bracing.

Question 44

In evaluating a patient with cervical spondylotic myelopathy, which of the following physical exam findings is considered the earliest clinical sign of disease progression?

Explanation

Subtle loss of hand dexterity (e.g., difficulty buttoning shirts) and upper motor neuron signs like the Hoffman sign are often the earliest clinical indicators of cervical myelopathy.

Question 45

A 55-year-old male with long-standing ankylosing spondylitis presents to the emergency department after a low-energy fall. He complains of severe lower neck pain but has a normal neurologic exam. Plain radiographs of the cervical spine are difficult to interpret due to marked deformity. What is the most critical next step in imaging?

Explanation

Patients with ankylosing spondylitis are at high risk for highly unstable "chalk-stick" fractures even from minor trauma. A CT scan of the affected spinal region is critical as plain radiographs often miss these fractures.

Question 46

A 70-year-old man presents with neurogenic claudication. He reports his bilateral leg pain improves when leaning forward on a shopping cart. This postural relief is primarily due to:

Explanation

Flexion of the lumbar spine increases the cross-sectional area of the spinal canal and neural foramina. This relieves the dynamic compression on the nerve roots, characteristic of lumbar spinal stenosis.

Question 47

A 60-year-old woman is undergoing a lumbar laminectomy for spinal stenosis. During the procedure, an incidental durotomy occurs. What is the most appropriate management?

Explanation

Incidental durotomies should be repaired primarily with a watertight closure to prevent cerebrospinal fluid leaks. Placing a subfascial drain on suction is generally contraindicated as it can exacerbate the leak.

Question 48

A 45-year-old intravenous drug user presents with severe, unrelenting back pain and low-grade fever. MRI reveals fluid in the L3-L4 disc space with endplate destruction and bone marrow edema. The patient is neurologically intact. What is the most appropriate next step in management?

Explanation

In a hemodynamically stable patient without neurologic deficits, a tissue diagnosis via CT-guided biopsy should be obtained prior to initiating antibiotics to ensure directed therapy for vertebral osteomyelitis/discitis.

Question 49

Which of the following Modic changes on MRI of the lumbar spine is characterized by high signal intensity on T1-weighted images and intermediate-to-high signal intensity on T2-weighted images?

Explanation

Modic Type 2 changes represent fatty replacement of the red marrow adjacent to the endplates. Fat shows high signal intensity on T1 and intermediate-high signal on T2.

Question 50

A 68-year-old man with a history of prostate cancer presents with mid-thoracic back pain. AP radiograph shows an absent left pedicle at T8 (the "winking owl" sign). Which of the following is the most likely diagnosis?

Explanation

The "winking owl" sign indicates pedicle destruction, which is a classic radiographic sign of metastatic spine disease. Prostate cancer is a common primary source for blastic or lytic spinal metastases.

Question 51

A 24-year-old male is involved in a motor vehicle collision and sustains a hyper-flexion injury to the cervical spine. MRI shows a unilateral facet dislocation at C5-C6. He has right-sided upper extremity weakness. What is the sequence of management?

Explanation

In an awake, cooperative patient with a cervical facet dislocation, rapid closed reduction using cranial traction is safe and effective. An MRI is required if the patient fails reduction or develops worsening neurologic symptoms.

Question 52

During a posterolateral approach to the lower lumbar spine, a surgeon encounters excessive bleeding from a venous plexus located within the spinal canal. This bleeding is most likely originating from the:

Explanation

Batson's venous plexus is a valveless network of veins located in the epidural space of the spinal canal. It is frequently encountered and can be a source of significant bleeding during spinal surgery.

Question 53

A 75-year-old woman is evaluated for a recent osteoporotic compression fracture of the L1 vertebral body resulting in 20% loss of anterior height. She is neurologically intact. What is the most appropriate initial treatment?

Explanation

The majority of single-level osteoporotic compression fractures without neurologic deficit or severe deformity are managed successfully with conservative care, including bracing (TLSO) and pain management.

Question 54

In evaluating a patient with a traumatic spinal cord injury, the physical exam reveals loss of motor function and proprioception on the right side of the lower body, and loss of pain and temperature sensation on the left side. This presentation is characteristic of:

Explanation

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

Question 55

A 35-year-old male presents with severe mid-thoracic back pain and myelopathy. Imaging reveals a massive, calcified central disc herniation at T7-T8 compressing the spinal cord. What is the safest surgical approach for decompression?

Explanation

A standard posterior laminectomy for a central thoracic disc herniation is highly contraindicated due to the risk of spinal cord traction and paraplegia. Anterior or lateral approaches (e.g., costotransversectomy or transthoracic) are required to safely remove the disc without retracting the cord.

Question 56

An 80-year-old male sustains a Type II odontoid fracture after a ground-level fall. The fracture is displaced 6 mm posteriorly. Non-operative management is chosen. He is at highest risk for which of the following complications?

Explanation

Type II odontoid fractures in the elderly, particularly with displacement >5 mm, have a very high risk of non-union due to limited vascularity at the fracture site and difficulties with rigid immobilization.

Question 57

Degenerative spondylolisthesis most commonly occurs at which level, and is largely attributed to the sagittal orientation of the facet joints?

Explanation

Degenerative spondylolisthesis most frequently occurs at the L4-L5 level. It is commonly associated with a more sagittal orientation of the facet joints, which provides less resistance to anterior shear forces.

Question 58

A patient sustains an unstable burst fracture of T12 with 50% canal compromise but remains neurologically intact. The decision is made to perform a posterior short-segment pedicle screw fixation. To minimize the risk of construct failure, which biomechanical principle is most critical?

Explanation

In severe burst fractures with significant anterior column comminution, posterior short-segment fixation alone has a high rate of hardware failure. Providing anterior column support (via structural graft or cage) or extending the fusion levels helps offload the posterior construct.

Question 59

A 16-year-old female is diagnosed with adolescent idiopathic scoliosis. Her Cobb angle is 35 degrees, and she is pre-menarchal with a Risser stage of 1. What is the most appropriate management?

Explanation

Bracing is indicated in growing adolescents (Risser 0-2) with progressive curves or curves measuring 25 to 45 degrees. A TLSO aims to halt curve progression during the remaining growth spurt.

Question 60

The "danger space" in the cervical spine is a potential space that allows for the spread of infection from the neck directly into the mediastinum. It is located between the:

Explanation

The danger space is located between the alar fascia anteriorly and the prevertebral fascia posteriorly. It extends from the skull base down to the diaphragm, serving as a conduit for infections to spread into the posterior mediastinum.

Question 61

A 45-year-old man presents with right leg pain radiating to the lateral aspect of his foot. Physical examination reveals a diminished ankle jerk reflex and 3/5 weakness in ankle plantar flexion. Sensation is decreased over the lateral border of the foot. Which nerve root is most likely affected?

Explanation

The S1 nerve root controls ankle plantar flexion, provides sensation to the lateral aspect of the foot, and mediates the Achilles reflex. This is most commonly compressed by a posterolateral L5-S1 disc herniation.

Question 62

A 32-year-old woman presents with severe back pain, bilateral sciatica, saddle anesthesia, and urinary retention. MRI confirms a massive L4-L5 disc herniation compressing the thecal sac. For optimal prognostic neurologic recovery, emergent surgical decompression should ideally be performed within:

Explanation

Cauda equina syndrome is a surgical emergency. Decompression performed within 48 hours is associated with a significantly higher rate of resolution of sensory and motor deficits, as well as bladder and bowel dysfunction.

Question 63

A 60-year-old man with neurogenic claudication finds significant relief of his leg pain when leaning forward on a shopping cart. This postural relief is anatomically explained by:

Explanation

Flexion of the lumbar spine stretches the ligamentum flavum (making it thinner) and opens the interlaminar space, thereby increasing the cross-sectional area of the spinal canal and relieving pressure on the nerve roots.

Question 64

In a patient with a suspected far lateral (extraforaminal) disc herniation at the L4-L5 level, which nerve root is most directly compressed?

Explanation

A far lateral (extraforaminal) disc herniation impinges the exiting nerve root at that level. At L4-L5, the exiting root is L4, whereas a standard posterolateral herniation at L4-L5 would impinge the traversing L5 root.

Question 65

An 80-year-old man with a history of prostate cancer presents with severe, unremitting low back pain that is worse at night. Anteroposterior plain radiographs reveal an absent right pedicle at L3. This radiographic finding is classically referred to as the:

Explanation

The "winking owl" sign occurs on an AP radiograph when one pedicle is destroyed (often by lytic metastatic disease), leaving only the contralateral pedicle visible, resembling a winking owl.

Question 66

A 55-year-old poorly controlled diabetic male presents with fevers, severe localized back pain, and an elevated CRP. MRI reveals fluid in the L3-L4 disc space and adjacent vertebral body edema. What is the most common causative organism for this condition?

Explanation

Staphylococcus aureus is the most common organism responsible for pyogenic vertebral osteomyelitis and discitis. While Pseudomonas is a notable risk in IV drug users, S. aureus remains the most common overall.

Question 67

A 65-year-old patient with long-standing ankylosing spondylitis sustains a minor fall. He complains of new-onset mechanical neck pain but exhibits no neurologic deficits. Plain radiographs of the cervical spine are obscured by the shoulders and appear unremarkable. The most appropriate next step in management is:

Explanation

Patients with ankylosing spondylitis have a highly rigid spine, making them highly susceptible to unstable fractures even from minor trauma. A CT scan is mandatory as plain radiographs often miss these fractures.

Question 68

A 50-year-old woman presents with worsening clumsiness in her hands and difficulty maintaining balance while walking. Examination reveals a positive Hoffman's sign, hyperreflexia in the lower extremities, and a broad-based gait. The most likely diagnosis is:

Explanation

The triad of upper extremity clumsiness, gait instability, and upper motor neuron signs (Hoffman's, hyperreflexia) is the classic presentation of cervical spondylotic myelopathy.

Question 69

The Rule of Spence is utilized to evaluate the integrity of the transverse ligament in C1 ring (Jefferson) fractures. A ruptured transverse ligament is indicated if the combined lateral mass overhang on an open-mouth odontoid radiograph exceeds:

Explanation

According to the Rule of Spence, a combined overhang of the lateral masses of C1 on C2 of more than 6.9 mm indicates a rupture of the transverse alar ligament, signifying instability.

Question 70

A 72-year-old woman falls and strikes her chin, forcing her neck into severe hyperextension. She develops profound motor weakness in her arms and hands, but retains relatively preserved motor strength in her legs. Which incomplete spinal cord syndrome does this represent?

Explanation

Central cord syndrome typically occurs after a hyperextension injury in patients with preexisting cervical stenosis. It predominantly affects the centrally located cervical tracts, causing upper extremity weakness out of proportion to the lower extremities.

Question 71

Which classification of odontoid fractures relies entirely on the fracture line location, and which specific type carries the historically highest rate of nonunion requiring surgical stabilization?

Explanation

Anderson and D'Alonzo Type II odontoid fractures occur at the base of the dens. They have a high rate of nonunion due to a tenuous blood supply and relative mechanical instability.

Question 72

A 25-year-old male presents with severe mechanical back pain. Standing lateral lumbar radiographs reveal a pars interarticularis defect with a 35% anterior translation of L5 on S1. According to the Meyerding classification, this represents:

Explanation

The Meyerding classification grades the percentage of slip: Grade I (0-25%), Grade II (26-50%), Grade III (51-75%), Grade IV (76-100%), and Grade V (>100%, spondyloptosis). A 35% slip is Grade II.

Question 73

A 40-year-old male sustains a stab wound to the right side of his thoracic spine. He subsequently exhibits loss of ipsilateral motor function and proprioception, and loss of contralateral pain and temperature sensation below the lesion level. This presentation is characteristic of:

Explanation

Brown-Sequard syndrome results from spinal cord hemisection. It features ipsilateral loss of motor function (corticospinal tract) and dorsal column function (proprioception), with contralateral loss of spinothalamic function (pain/temperature).

Question 74

In a patient suffering from central lumbar spinal stenosis, the hypertrophy of which specific posterior ligament significantly contributes to the dorsal narrowing of the spinal canal?

Explanation

The ligamentum flavum lines the posterior aspect of the spinal canal. Its hypertrophy and buckling with age, along with facet arthropathy, are primary contributors to acquired degenerative central spinal stenosis.

Question 75

A patient presenting with an acute posterolateral disc herniation at the C5-C6 level will most likely exhibit weakness in which of the following actions?

Explanation

A C5-C6 disc herniation compresses the exiting C6 nerve root. The C6 root supplies the extensor carpi radialis longus and brevis (wrist extension) and the biceps/brachioradialis (elbow flexion).

Question 76

A 75-year-old female presents with acute severe back pain. Plain radiographs reveal a wedge compression fracture at T12. To best differentiate between an acute osteoporotic compression fracture and a chronic deformity, the optimal imaging sequence is:

Explanation

MRI with STIR or T2 fat-suppressed sequences is highly sensitive for detecting bone marrow edema, which differentiates an acute/subacute compression fracture from a chronic, healed deformity.

Question 77

A 60-year-old male with metastatic lung cancer presents with a rapid 24-hour onset of bilateral leg weakness and bowel incontinence. MRI shows a large epidural tumor mass compressing the thoracic spinal cord. According to the Patchell trial criteria, the preferred immediate management is:

Explanation

For solid tumors causing acute malignant epidural spinal cord compression with progressing neurologic deficits, direct surgical decompression and stabilization provides superior functional preservation compared to radiation therapy alone.

Question 78

Which of the following physical examination maneuvers is considered a Waddell sign, indicating a non-organic component to a patient's low back pain presentation?

Explanation

Waddell signs test for non-organic (psychological or exaggerated) pain. Simulated axial loading of the skull causing lower back pain is a classic non-organic sign, as this maneuver does not physiologically load the lumbar spine.

Question 79

A 14-year-old female gymnast presents with persistent, activity-related lower back pain. Oblique lumbar radiographs reveal a "collared Scotty dog" appearance. This radiographic sign specifically indicates:

Explanation

The "collared Scotty dog" sign seen on oblique lumbar radiographs represents a defect or fracture in the pars interarticularis, which is the definition of spondylolysis.

Question 80

Following a motor vehicle collision, a 30-year-old man sustains a burst fracture of L1. According to the Denis three-column concept of spinal stability, the middle column comprises the:

Explanation

In the Denis three-column theory, the middle column consists of the posterior half of the vertebral body, the posterior portion of the annulus fibrosus, and the posterior longitudinal ligament. Disruption of this column characterizes a burst fracture.

Question 81

A 55-year-old man presents with progressive clumsiness in his hands, frequent dropping of objects, and a wide-based gait. Examination reveals hyperreflexia in the lower extremities and a positive Hoffmann sign bilaterally. Which of the following is the most appropriate initial diagnostic imaging modality?

Explanation

The patient's symptoms and signs (clumsiness, wide-based gait, hyperreflexia, positive Hoffmann sign) are classic for cervical spondylotic myelopathy. MRI of the cervical spine is the gold standard for evaluating spinal cord compression.

Question 82

A 45-year-old man develops acute right leg pain radiating to the anterior thigh following heavy lifting. Physical examination demonstrates weakness in knee extension and a diminished patellar tendon reflex. An MRI of the lumbar spine reveals a far lateral disc herniation at the L4-L5 level. Which nerve root is most likely compressed?

Explanation

In the lumbar spine, a far lateral (extraforaminal) disc herniation compresses the exiting nerve root at that level. Therefore, a far lateral disc at L4-L5 compresses the L4 nerve root, leading to anterior thigh pain, quadriceps weakness, and a decreased patellar reflex.

Question 83

A 14-year-old female gymnast presents with progressive low back pain. Examination reveals a palpable step-off at the lumbosacral junction. Radiographs demonstrate a Grade 2 isthmic spondylolisthesis at L5-S1. Neurological examination is normal. What is the most appropriate initial management?

Explanation

Initial management of low-grade (Grade 1 and 2) isthmic spondylolisthesis without neurological deficits in an adolescent is conservative. This involves activity modification, physical therapy emphasizing core stabilization, and potentially bracing.

Question 84

A 60-year-old man presents to the emergency department with severe acute lower back pain, bilateral sciatica, and perineal numbness. Which of the following clinical findings is the most sensitive indicator of cauda equina syndrome?

Explanation

Urinary retention is the most consistent and sensitive finding in cauda equina syndrome. A normal post-void residual bladder volume effectively rules out the diagnosis in most cases.

Question 85

A 35-year-old intravenous drug user presents with fever, severe focal mid-back pain, and elevated inflammatory markers. MRI reveals an anterior epidural abscess at T8. The empirical antibiotic regimen should primarily target which of the following microorganisms?

Explanation

Staphylococcus aureus is the most common causative organism in spinal epidural abscesses and vertebral osteomyelitis, particularly in intravenous drug users. Empirical coverage must include MRSA along with gram-negative coverage until cultures are finalized.

Question 86

A 65-year-old man with a history of prostate cancer complains of progressive bilateral leg weakness and hyperreflexia. Plain radiographs show diffuse osteoblastic lesions in the thoracic spine. What is the most critical next step in management?

Explanation

The patient presents with signs of myelopathy (leg weakness, hyperreflexia) in the setting of known metastatic prostate cancer. An urgent whole-spine MRI is required to rule out and evaluate impending or actual spinal cord compression.

Question 87

A 25-year-old man falls from a 10-foot ladder. CT reveals an L1 burst fracture with 30% canal compromise. He is neurologically intact, and the posterior ligamentous complex is intact (TLICS score = 2). Which of the following is the most appropriate treatment?

Explanation

According to the Thoracolumbar Injury Classification and Severity (TLICS) score, a score of 3 or less is an indication for non-operative management. A neurologically intact burst fracture with an intact posterior ligamentous complex is safely treated with a TLSO brace.

Question 88

A 70-year-old man with long-standing ankylosing spondylitis presents with severe neck pain after a minor low-energy fall. Initial standard cervical radiographs appear negative. What is the most appropriate next step in his evaluation?

Explanation

Patients with ankylosing spondylitis have rigid, osteoporotic spines making them highly susceptible to fractures from minor trauma. Standard radiographs can miss up to 30% of these fractures; therefore, a CT scan is mandatory for any patient with AS complaining of post-traumatic spinal pain.

Question 89

A 50-year-old man of Japanese descent presents with progressive upper extremity numbness, clumsy hands, and a spastic gait. CT imaging demonstrates a dense, continuous osseous mass posterior to the vertebral bodies from C3 to C6. What is the primary pathophysiology?

Explanation

The presentation and CT findings are pathognomonic for OPLL, which frequently causes cervical myelopathy. It has a high prevalence in Asian populations and is characterized by the ossification of the ligament directly posterior to the vertebral bodies.

Question 90

In the evaluation of a patient with adult spinal deformity, which of the following spinopelvic parameters is considered a fixed, morphologic parameter that does not change with patient positioning?

Explanation

Pelvic incidence (PI) is an anatomical parameter defined by the relationship of the sacrum to the femoral heads and remains constant after skeletal maturity. It mathematically equals the sum of pelvic tilt and sacral slope (PI = PT + SS).

Question 91

A 22-year-old man is involved in a high-speed motor vehicle collision while wearing a lap belt only. He sustains a flexion-distraction (Chance) fracture of L2. What is the most frequently associated concomitant injury?

Explanation

Chance fractures are caused by flexion-distraction forces, classically seen with lap-belt injuries. They have a high rate (up to 50%) of associated intra-abdominal injuries, particularly hollow viscus (bowel) injuries.

Question 92

An 80-year-old man presents with bilateral upper extremity weakness and numbness following a fall in which he struck his forehead, causing hyperextension of the neck. His lower extremities have near-normal strength. What is the most likely diagnosis?

Explanation

Central cord syndrome typically occurs after a hyperextension injury in older individuals with pre-existing cervical spondylosis. It characteristically produces motor weakness in the upper extremities that is disproportionately greater than in the lower extremities.

Question 93

A 40-year-old man complains of neck pain radiating down his arm to his middle finger. Examination reveals weakness in elbow extension (triceps) and wrist flexion, with an absent triceps reflex. Which cervical nerve root is most likely affected?

Explanation

A C7 radiculopathy presents with pain radiating to the middle finger, weakness in the triceps and wrist flexors, and a diminished or absent triceps reflex. C6 typically affects wrist extension and the brachioradialis reflex.

Orthopedic Prometric MCQs - Chapter 3 Part 1

Orthopedic Prometric MCQs - Chapter 3 Part 31

Orthopedic Prometric MCQs - Chapter 3 Part 31

Chapter Index