Question 1

A 12-year-old girl presents to the clinic with scoliosis detected by school screening. Her past medical history includes ophthalmologic observation for Lisch nodules of the iris. She has just started her menstrual periods. On physical exam, she has axillary freckles and normal neurological function. Standing radiographs of the spine illustrate a 32° right thoracic curve from T4 to T10 and rib pencilling. In the sagittal plane, she has a thoracic kyphosis of 30°. The most likely diagnosis is:

Explanation

Neurofibromatosis (von Recklinghausen disease) is an autosomal dominant disorder that affects connective tissue. The most common type is NF-1, and is associated with primary skeletal disorders such as scoliosis, cortical thinning and pseudarthrosis of the tibia. It is the result of an abnormality on chromosome 17, and is also associated with: C afÃ au lait spots Neurofibromas Axillary or inguinal freckling Iris hamartomata (Lisch nodules) Scoliosis in NF-1 can occur in 2 patterns. The first is similar to idiopathic scoliosis. The second, or dystrophic type is marked by short, sharper deformities, scalloping of the vertebral bodies, rib pencilling, enlarged foramina and severe apical vertebral body rotation. Some authors have demonstrated that curves characterized as idiopathic in childhood can take on dystrophic characteristics later in life and progress rapidly. Treatment is usually surgical.

Question 2

A 3-year-old boy is referred by the pediatrician for neck stiffness. He has a mild hearing loss, but is otherwise healthy. On examination, his neck is rather short, and he has limitation of lateral rotation and bending, but flexion and extension are normal. There are no palpable bands in his neck. The anteroposterior and lateral cervical spine films ordered by the pediatrician show a congenital fusion of cervical vertebrae. The most likely diagnosis is:

Explanation

The classic findings of Klippel-Feil syndrome include a short neck, low posterior hairline, and decreased neck range of motion, but <50% of patients have all 3 elements of the triad. The neck motion is limited due to congenital fusion of cervical vertebrae, and the severity of cervical spine involvement usually heralds associated manifestations. Facial asymmetry, cranial nerve palsy, deafness, cardiac anomalies, and synkinesia may be detected in the involved child. It is important to differentiate congenital muscular torticollis from Klippel- Feil syndrome, because releasing the sternocleidomastoid muscle will not correct a bony deformity. Static lateral radiographs of the cervical spine may appear normal in young children, as ossification of abnormal levels has not yet occurred. Flexion/extension lateral radiographs are useful to define congenital fusions, and magnetic resonance imaging may further delineate the anatomy. It is also important to test neck motion in all planes, because flexion/extension may be normal if movement occurs through just a few spared levels. Children with Klippel-Feil syndrome rarely develop neurological symptoms as a result of the congenital cervical fusion. Later in life, they may develop neurological impairment as a result of instability or degenerative disk disease.

Question 3

A 10-year-old boy with Down syndrome presents with his parents who have noticed that his endurance for walking seems to have decreased, and he seems clumsier. Your physical examination reveals generalized ligamentous laxity, but no other musculoskeletal abnormalities. His neurological examination is normal. His flexion/extension cervical spine radiographs are abnormal. The most likely pathophysiology is:

Explanation

Children with Down syndrome (trisomy 21) have a higher incidence of hypothroidism, congenital heart disease, leukemia, and slipped capital femoral epiphysis. About 20% of children with Down syndrome develop atlantoaxial instability due to incompetence of the transverse atlantal ligament, and fortunately, most are asymptomatic. Patients with Down syndrome should be screened for atlantoaxial instability with routine flexion/extension lateral cervical radiographs, especially prior to athletic participation. An atlanto-dens interval (ADI) of >5 mm should be treated with activity restriction in the absence of myelopathy. With symptoms of cervical myelopathy or an ADI >7 mm, an atlantoaxial arthrodesis is indicated.

Question 4

A 4-week-old female infant has congenital muscular torticollis. Which of the following is not associated with this condition?

Explanation

Congenital muscular torticollis is the most common cause of torticollis in the infant and young child. Usually, the children have a history of a breech or difficult delivery or primiparous birth. The exact etiology is unknown, but theories center around a compartment syndrome of the sternocleidomastoid muscle as a result of compression of soft tissues around the neck at the time of delivery. This results in fibrosis of the sternocleidomastoid muscle, tilting of the head to the ipsilateral side, and rotation of the head to the opposite side. Congenital muscular torticollis is associated with developmental dysplasia of the hips in up to 20% of children, so a careful examination of hip stability is mandatory, with dynamic ultrasound, if necessary. Plagiocephaly or facial and skull deformities occur in progressive torticollis within the first year of life. The association of metatarsus adductus with congenital muscular torticollis is variable in the literature. Plain radiographs of the cervical spines of children with congenital muscular torticollis are always normal, with the exception of the head tilt and rotation. Treatment initially includes stretching exercises and physical therapy early in life. Surgery (release of the muscle) is recommended if the torticollis persists after 1 year of age.

Question 5

A 13-year old boy presents to the emergency department with back pain of 5 days duration. The pain is exacerbated by sitting or standing. He has a low- grade fever. He has pain on percussion of the lumbar spine. He has no tension signs. White blood cell count is 8000/mm3 and the erythrocyte sedimentation rate is 40 mm/hr. Plain radiographs of the spine demonstrate a narrowed intervertebral space at L3-L4. The most likely diagnosis is:

Explanation

The symptoms of diskitis are often vague and insidious. This hematogenous infection of the disk space acts differently than other musculoskeletal infections. The presentation is often that of a patient with low back pain or refusal to ambulate. Fever is usually low or absent. The white blood cell count is usually normal, but the erythrocyte sedimentation rate or C -reactive protein levels may be elevated. Blood cultures are frequently negative. Radiographs of the spine may be normal initially, but may show intervertebral disk space narrowing or end plate irregularities. Bone scan and magnetic resonance imaging are also helpful in the diagnosis. Treatment is usually conservative, and outcomes are aided by the fact that this condition is usually self-limiting. Rest and immobilization provide symptomatic relief, and many authors favor intravenous antibiotics. After an initial response in 72 hours or less, the patient can be switched to oral antibiotics for 3 to 5 weeks. A biopsy is indicated if the patient does not improve quickly, or if a tumor or abscess formation is suspected. Patients with vertebral osteomyelitis or abscesses are typically more ill- appearing, have high fevers and white blood cell counts, and a markedly elevated erythrocyte sedimentation rate. Furthermore, a patient with an epidural abscess may have neurological symptoms or a positive straight leg raising test, due to nerve root irritation or spinal cord compression.

Question 6

An 11-year-old boy sustains a fall while jumping on a trampoline. He has moderate back pain, an L-5 radiculopathy, and weakness of the right extensor hallucis longus. Radiographs and a computerized tomography scan of the lumbar spine demonstrate a slipped vertebral apophysis. The recommended treatment is:

Explanation

This patient has a slipped vertebral apophysis as a result of trauma. This is analagous to a Salter-Harris type II fracture. A portion of the apophysis and annulus slip posteriorly and may impinge on the exiting nerve root. These usually do not resolve spontaneously or improve with conservative therapy, and excision is indicated. The disk fragments and retropulsed bone must be removed from the canal with a laminectomy for exposure.

Question 7

Appropriate treatment of a nondisplaced Jefferson fracture is:

Explanation

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

Question 8

The American Spinal Injury Association has developed a classification of spinal cord injuries. Using this classification system, an Asia C injury is best described as:

Explanation

Asia C is an incomplete spinal cord injury with reservation of motor function with < grade 3 motor strength.C orrect Answer: Incomplete motor loss with some preservation of motor function with groups with less then grade 3 strength

Question 9

Which of the following incomplete spinal cord injury syndromes has the most potential for recovery:

Explanation

Brown-Sequard syndrome is described as ipsilateral loss of motor function and contralateral loss of pain and temperature sensation. This syndrome is caused by penetrating injuries. Generally < 90% of patient who have this injury will recover ambulation.

Question 10

A 6-year-old boy has neck pain and stiffness following an upper respiratory tract infection. He presented with his head tilted to the right and turned to the left 3 weeks ago, but a soft cervical collar has not been beneficial. There is no known history of trauma. A computerized tomography scan shows rotatory subluxation of C 1 on C 2. The next step in the treatment of this child is:

Explanation

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

Question 11

A 40-year-old victim of a car accident was complaining of anterior chest pain. An x-ray of the chest showed no widening of the mediastinum and absence of pneumothorax. Lateral C XR revealed a fractured sternum with the proximal part of the fracture displaced posteriorly. Which of the following is the next step in the management of this patient?

Explanation

N/AC orrect Answer: Lateral x-ray of the thoracic spine with the patient supine

Question 12

A 42-year-old male has a history of 6 months of pain in the lower thoracic region. Recently, the patient developed weakness in the right lower extremity, bladder and bowel movement. Plain x-rays were normal, but an magnetic resonance imaging (MRI) showed a posterolateral thoracic disk herniation at the level of T10-T11 (Slides 1 and 2). Which of the following is the best suggested treatment?

Explanation

Conservative treatment should be considered for patients without major neurologic deficits. Posterior laminectomy and decompression provides inadequate exposure of the herniated Disk. Vertebractomy, strut bone graft and instrumentation are no necessary. Thoracotomy and costotransversectomy are commonly used for disk herniations at the levels of T4-T12.

Question 13

The patient's clinical diagnosis is degenerative spondylolithesis. In what patient population is this condition most commonly symptomatic?

Explanation

Degenerative spondylolithesis is most frequently symptomatic in the 40- to 70-year-old age range and is six times more common in females than in males. This population appears to have enough disc degeneration and motion to become symptomatic, whereas the older population tend to have acquired enough ankylosis at the level to prevent instability symptoms.

Question 14

The patient was diagnosed with spinal stenosis of the lumbosacral spine. In addition to educating the patient about his condition, the most appropriate initial treatment is:

Explanation

Initial treatment begins with patient education, a physical therapy regime (gentle conditioning exercises), judicious activity change, and sometimes spinal support with a corset or light-weight brace. Anti-inflammatory nonsteroidal drugs provide some relief of symptoms for many patients.

Question 15

The biggest contribution to lumbar lordosis:

Explanation

Most of the lumbar lordosis occurs within the disk spaces and not within the vertebral bodies. Normal lumbar lordosis is between 30°to 50°, increases with age, and is best visualized on a lateral plain radiograph.

Question 16

The superior aspect of the iliac crest often bisects this midline spinal structure:

Explanation

The L4/L5 intervertebral disk space is located by placing your fingers at the top of a patient's iliac crests, while allowing your thumbs to meet at the midline of the spine between the palpable L4 and L5 spinous processes.

Question 17

C ertain physical examination maneuvers attempt to elicit tension signs. When used in the supine position, these maneuvers are designed to apply stretch or tension on the sciatic nerve and any inflamed nerve root against a herniated lumbar disk. Which of the following physical examination tests is not a tension sign maneuver:

Explanation

McMurray sign is used to detect a torn meniscus in the knee and will have minimal effect on the sciatic nerve. Lasegue sign is the classic straight-leg raising test. The bowstring sign is a variation of the straight-leg raising test performed with the knee in a flexed position. Digital pressure is then applied over the popliteal space in an attempt to reproduce the tension sign. The sitting room test is performed with the patient in a sitting position. The hip remains flexed at 90° while the examiner extends the ipsilateral knee. The contralateral straight-leg raising test is performed in the same manner as the straight-leg raising test except the contralateral, or nonpainful, leg is raised.

Question 18

When palpating the sacral triangle in the posterior aspect of a patient's lower back, if gaps are present between the spinous processes or no lumbar or sacral bony prominences are detected, this is suggestive of:

Explanation

When palpating the lumbosacral area (sacral triangle), if palpable gaps are present between the spinous processes or there is an absence of lumbar and/or sacral bony prominences, this is suggestive of spina bifida. A Gibbus deformity is characterized by a sharp kyphosis and is often found in the thoracic spine. Scoliosis is identified by a lateral curvature of the spine A palpable "step-off" of one spinous process relative to the next would be suggestive of a spondylolisthesis. Becs de perroquet is a radiographic feature associated with tuberculosis of the lumbar spine in which bony bridges form across the sides of two adjacent vertebrae.

Question 19

Which of the following is not a routinely used imaging technique for the evaluation of lumbar disk disease:

Explanation

Positron emission tomography (PET) is a technique that measures brain activity through positron emission from radiolabled glucose. Myelography is an invasive procedure with radio-opaque dye placed into subarachnoid space. It aids in the detection of neural compressive lesions. Computer tomography alone offers better visualization of bony lesions, foraminal spinal stenosis, and lateral disk herniations when compared to plain myelography. C omputer tomography is often combined with myelography. Magnetic resonance imaging (MRI) has an advantage over CAT because it detects soft tissue pathologies, including improved spinal cord imaging in the detection of intraspinal tumors. MRI also examines the entire spine. Bone scanning is a nonspecific but sensitive test. It is useful in detecting neoplastic, infectious, traumatic, and/or arthritic problems in the spine.

Question 20

A 28-year-old woman complains of pain and numbness in her lower legs bilaterally for approximately 2 months following strenuous moving of furniture. She now states that she has not voided in the past 48 hours and that her abdomen area is markedly distended. Which is the most likely causative lesion of the patient's symptoms:

Explanation

This patient's symptoms are most consistent with cauda equina syndrome. This surgical emergency can present with bowel or bladder dysfunction, and bilateral lower extremity symptoms are also often present.

Question 21

A 15-year-old boy with achondroplasia presents with progressive bilateral leg pain and weakness that worsens with walking and improves when he bends forward. His neurological exam reveals mild lower extremity weakness and hyperreflexia. Which of the following radiographic findings is most characteristic of the underlying pathophysiology in this patient?

Explanation

Achondroplasia is characterized by a failure of endochondral ossification. In the spine, this classically presents as narrowing of the interpedicular distance from L1 to L5, leading to severe spinal stenosis and neurogenic claudication.

Question 22

A 13-year-old female gymnast presents with progressive lower back pain and a waddling gait. On physical examination, she walks with a peculiar gait with her hips and knees flexed, and she has severe hamstring tightness and a vertical sacrum. Radiographs confirm a high-grade L5-S1 isthmic spondylolisthesis. The gait abnormality described is known as:

Explanation

The Phalen-Dickson sign is characterized by a waddling gait with flexed knees and hips due to severe hamstring tightness and pelvic retroversion (vertical sacrum). It is a classic clinical finding in high-grade spondylolisthesis.

Question 23

A 16-year-old boy presents with a rigid thoracic kyphosis measuring 75 degrees. Radiographs reveal Schmorl's nodes and endplate irregularities. According to Sorensen's criteria, what specific radiographic finding is required to confirm the diagnosis of classic Scheuermann's disease?

Explanation

Scheuermann's kyphosis is formally defined by Sorensen's criteria as anterior wedging of at least 5 degrees in three or more consecutive vertebrae. It is associated with rigid kyphosis and endplate changes such as Schmorl's nodes.

Question 24

An 8-year-old girl is evaluated for a new-onset left cavovarus foot deformity and subtle left leg atrophy. Clinical examination reveals a hairy patch over her lumbosacral spine and hyperreflexia in the lower extremities. Which of the following MRI findings is most likely responsible for her clinical presentation?

Explanation

The patient's clinical presentation (unilateral foot deformity, hairy patch, hyperreflexia) is highly suspicious for tethered cord syndrome. This condition is diagnosed on MRI when the conus medullaris terminates abnormally low, typically below the L2 level.

Question 25

A 10-year-old girl with congenital scoliosis is noted to have a bony septum dividing the spinal cord in the sagittal plane at the T10 level on a recent CT myelogram. She is scheduled to undergo posterior spinal fusion for her progressive scoliosis. What is the critical surgical principle regarding the management of this specific anomaly?

Explanation

Diastematomyelia involves a bony, cartilaginous, or fibrous septum splitting the spinal cord. To prevent catastrophic neurological injury from stretching a tethered cord, the spur must be surgically excised before any corrective maneuvers are applied to the spine.

Question 26

A 2-year-old boy is diagnosed with congenital scoliosis. Based on the natural history of congenital vertebral anomalies, which of the following radiographic patterns carries the worst prognosis for rapid progression of the deformity?

Explanation

The combination of a unilateral unsegmented bar (which prevents growth on the concavity) and a contralateral fully segmented hemivertebra (which actively grows on the convexity) leads to the most rapid and severe progression in congenital scoliosis.

Question 27

A 14-year-old boy with spastic quadriplegic cerebral palsy (GMFCS Level V) has a progressive 75-degree thoracolumbar scoliosis and a 25-degree pelvic obliquity. He is losing sitting balance and has developed ischial pressure sores. When planning surgical correction (posterior spinal fusion), what is the most appropriate distal extent of the fusion?

Explanation

In non-ambulatory patients with severe neuromuscular scoliosis (like GMFCS V CP) and significant pelvic obliquity (>15 degrees), the fusion construct must be extended to the pelvis. This corrects the pelvic obliquity, restores sitting balance, and prevents progressive deformity.

Question 28

A 12-year-old boy with Duchenne Muscular Dystrophy presents with a rapidly progressive 35-degree thoracolumbar scoliosis. His forced vital capacity (FVC) is currently 45% of predicted. What is the most appropriate management of his spinal deformity?

Explanation

Scoliosis in Duchenne Muscular Dystrophy is aggressively progressive and bracing is poorly tolerated and ineffective. Posterior spinal fusion to the pelvis is indicated early (curves >20-30 degrees) before the FVC declines below 30%, which significantly increases perioperative mortality.

Question 29

A 14-year-old male football lineman presents with 4 weeks of localized lower back pain exacerbated by lumbar extension. He denies radicular symptoms. Anteroposterior, lateral, and oblique radiographs of the lumbar spine are completely normal. What is the most appropriate next step in imaging to identify early pars interarticularis stress pathology?

Explanation

MRI of the lumbar spine (specifically utilizing STIR or T2 fat-suppressed sequences) is the preferred initial advanced imaging modality to detect early pars stress edema without exposing the pediatric patient to ionizing radiation (unlike CT or SPECT).

Question 30

A 12-year-old premenarcheal female with adolescent idiopathic scoliosis presents with a right thoracic curve measuring 32 degrees on standing AP radiographs. Her Risser stage is 0. What is the most appropriate evidence-based recommendation for her treatment?

Explanation

This patient has significant remaining growth (premenarcheal, Risser 0) and a curve between 25 and 45 degrees. According to the BRAIST trial, rigid bracing (like a TLSO) for at least 18 hours per day is indicated and highly effective at preventing progression to surgery.

Question 31

According to the Lenke Classification system for Adolescent Idiopathic Scoliosis, what specific radiographic criterion officially defines a 'structural' minor curve on side-bending films?

Explanation

In the Lenke classification system, a minor curve is considered structural if the residual curve on a maximum supine side-bending radiograph remains greater than or equal to 25 degrees, or if the regional kyphosis is +20 degrees or greater.

Question 32

A 16-year-old male with a known diagnosis of Marfan syndrome presents with severe, chronic back pain and intermittent lower extremity radiculopathy. Radiographs show a widened spinal canal and scalloping of the posterior vertebral bodies. Which of the following conditions is the most common spinal manifestation in this population responsible for these findings?

Explanation

Dural ectasia, a ballooning of the dural sac due to connective tissue weakness, is the most common spinal abnormality in Marfan syndrome (present in >60% of patients). It leads to posterior vertebral body scalloping, pedicle thinning, and back/radicular pain.

Question 33

A 6-year-old boy presents with a 3-week history of localized mid-back pain. He is afebrile with no neurological deficits. A lateral radiograph of the thoracic spine demonstrates a complete, uniform collapse of the T8 vertebral body (vertebra plana) with intact posterior elements. What is the most appropriate initial management?

Explanation

Vertebra plana in a young child with no systemic symptoms is classic for Eosinophilic Granuloma (Langerhans cell histiocytosis). The condition is typically benign and self-limiting, with significant spontaneous reconstitution of vertebral height over time; thus, observation is the primary treatment.

Question 34

When evaluating a pediatric patient with an L5-S1 isthmic spondylolisthesis, which of the following combinations of risk factors is most strongly associated with an increased risk of slip progression?

Explanation

Risk factors for progression of a spondylolisthesis include youth (significant growth remaining), a high slip angle (>40-50 degrees), a dysplastic (dome-shaped) sacrum, a trapezoidal L5 body, and high pelvic incidence.

Question 35

A 9-year-old girl with Morquio syndrome (Mucopolysaccharidosis Type IVA) presents for a routine orthopedic evaluation. She has no acute complaints, but you note generalized joint laxity. What critical radiographic screening must be performed in this patient to prevent sudden catastrophic neurological injury?

Explanation

Patients with Morquio syndrome characteristically suffer from severe odontoid hypoplasia and ligamentous laxity. This combination leads to dangerous atlantoaxial (C1-C2) instability, mandating rigorous cervical spine screening to prevent fatal spinal cord compression.

Question 36

A 10-month-old infant is diagnosed with infantile idiopathic scoliosis with a left thoracic curve of 28 degrees. Which of the following radiographic parameters described by Mehta is the most reliable predictor that this curve will progress rather than spontaneously resolve?

Explanation

Mehta's Rib-Vertebra Angle Difference (RVAD) is the critical prognostic factor in infantile idiopathic scoliosis. An RVAD > 20 degrees strongly indicates a progressive curve, whereas an RVAD < 20 degrees typically indicates a resolving curve.

Question 37

A 14-year-old boy presents with a painful right-sided thoracic scoliosis. He reports that the pain is worse at night and dramatically improves when he takes ibuprofen. Neurological examination is normal. Radiographs demonstrate a 15-degree right thoracic scoliosis. If this curve is secondary to an underlying benign tumor, where is the lesion most likely located?

Explanation

The clinical presentation (night pain relieved by NSAIDs) is classic for an osteoid osteoma. In the spine, these lesions typically occur in the posterior elements and cause a painful, rigid scoliosis with the lesion located on the concavity of the curve due to asymmetric muscle spasm.

Question 38

A 1-year-old girl is diagnosed with a congenital scoliosis due to a unilateral unsegmented bar. Because of the high association with other organ system anomalies in the VACTERL association, which two screening tests are mandatory in the routine evaluation of this patient?

Explanation

Congenital scoliosis is frequently associated with VACTERL sequence anomalies (Vertebral, Anorectal, Cardiac, Tracheoesophageal, Renal, Limb). An echocardiogram (cardiac) and a renal ultrasound (renal) are mandatory screenings to rule out life-threatening associated anomalies.

Question 39

A 12-year-old girl with severe, rigid idiopathic scoliosis is undergoing halo-gravity traction prior to definitive spinal fusion. On hospital day 5, she complains of new-onset double vision. On examination, she is unable to abduct her left eye. What is the most likely etiology of her diplopia?

Explanation

The abducens nerve (CN VI) has a long, tortuous intracranial course, making it highly susceptible to stretch injuries during halo-gravity traction. Injury results in a lateral rectus palsy, presenting as diplopia and an inability to abduct the affected eye.

Question 40

A 10-year-old boy with Spinal Muscular Atrophy (SMA) Type 2 presents with a severe, collapsing "parasol" deformity of his ribs and a 90-degree neuromuscular scoliosis. He is non-ambulatory and sits in a custom wheelchair. If a spinal instrumentation and fusion is planned, failure to include the pelvis in the construct will most commonly lead to which of the following complications?

Explanation

In flaccid neuromuscular conditions like Spinal Muscular Atrophy, the spine classically collapses. If the fusion stops short of the pelvis in a non-ambulatory patient, the unbalanced spinal column will progressively tilt, leading to severe pelvic obliquity, skin breakdown, and loss of sitting balance.

Question 41

A 14-year-old boy with a known diagnosis of Neurofibromatosis type 1 presents with a rapidly progressive spinal deformity. Radiographs demonstrate a 50-degree right thoracic curve that is sharply angular, accompanied by severe apical vertebral rotation, rib penciling, and vertebral wedging. Which of the following is the most appropriate surgical management for this patient?

Explanation

Dystrophic curves in NF1 are characterized by rib penciling, vertebral wedging, and sharp angulation. They have a notoriously high rate of progression and pseudoarthrosis, making combined anterior and posterior spinal fusion the gold standard of care.

Question 42

A 5-year-old girl is diagnosed with Klippel-Feil syndrome after presenting with a short neck, low posterior hairline, and restricted cervical motion. Radiographs confirm congenital fusion of C3-C4 and C5-C6. Aside from an echocardiogram and a hearing evaluation, which of the following screening tests is mandatory for this patient?

Explanation

Klippel-Feil syndrome is associated with several systemic anomalies. Up to 30% of these patients have structural renal abnormalities, making a screening renal ultrasound mandatory.

Question 43

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

Explanation

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

Question 44

A 15-year-old boy presents with progressive mid-back pain. Lateral spine radiographs reveal a thoracic kyphosis of 75 degrees. Which of the following radiographic findings confirms the diagnosis of classic Scheuermann's disease?

Explanation

Sorenson's criteria for classic Scheuermann's kyphosis require anterior wedging of greater than or equal to 5 degrees in at least three contiguous vertebrae. Endplate irregularities and Schmorl's nodes are supportive but not diagnostic alone.

Question 45

A 10-month-old infant is diagnosed with a left-sided thoracic idiopathic scoliosis measuring 25 degrees. Which of the following radiographic parameters indicates a high likelihood that the curve will progress rather than resolve spontaneously?

Explanation

The Mehta angle, or rib-vertebra angle difference (RVAD), is crucial for prognosticating infantile idiopathic scoliosis. An RVAD > 20 degrees strongly predicts curve progression requiring intervention.

Question 46

A newborn is noted to have a spinal deformity. Radiographs demonstrate a unilateral unsegmented bar with a contralateral fully segmented hemivertebra in the lower thoracic spine. Due to the high association of concurrent abnormalities, which initial imaging workup is most critical?

Explanation

Congenital scoliosis, especially unsegmented bars and hemivertebrae, is frequently associated with VACTERL anomalies. Screening with a renal ultrasound and echocardiogram is mandatory to rule out life-threatening cardiac and genitourinary defects.

Question 47

A 10-year-old girl with a progressive 40-degree scoliosis is noted to have a cavus deformity of her right foot and a hairy patch over her lumbar spine. An MRI of the spine reveals a bony septum dividing the spinal cord at L2. What is the most appropriate sequence of treatment?

Explanation

This patient has diastematomyelia with a tethering bony spur. To prevent severe neurologic stretch injuries, the tethering structure must be resected prophylactically by neurosurgery before attempting any scoliosis correction.

Question 48

A 4-year-old boy with achondroplasia presents with recent onset of central sleep apnea, hypotonia, and hyperreflexia. Radiographs of the spine show shortened pedicles and a normal cervical alignment. What is the most likely cause of his neurological symptoms?

Explanation

Infants and young children with achondroplasia are at high risk for foramen magnum stenosis due to defective endochondral ossification at the skull base. This can lead to central sleep apnea, myelopathy, and sudden death if not surgically decompressed.

Question 49

A 6-year-old boy with Morquio syndrome (Mucopolysaccharidosis Type IV) presents with progressive weakness and hyperreflexia in all four extremities. Flexion-extension radiographs of the cervical spine will most likely show instability caused by which underlying anomaly?

Explanation

Morquio syndrome classically presents with severe ligamentous laxity and odontoid hypoplasia. This combination results in life-threatening atlantoaxial instability, often requiring prophylactic C1-C2 fusion.

Question 50

A 13-year-old boy with Duchenne Muscular Dystrophy is wheelchair-bound and presents with a 45-degree neuromuscular scoliosis. To minimize perioperative mortality and respiratory complications, spinal fusion is typically indicated before which of the following pulmonary parameters falls below 35%?

Explanation

In Duchenne Muscular Dystrophy, a Forced Vital Capacity (FVC) below 30-35% significantly increases the risk of perioperative pulmonary complications. Surgery is ideally performed before respiratory decline reaches this critical threshold.

Question 51

A 14-year-old non-ambulatory boy with spastic quadriplegic cerebral palsy presents with an 80-degree neuromuscular scoliosis and severe pelvic obliquity causing sitting imbalance and skin breakdown over the ischium. What is the standard surgical approach for this condition?

Explanation

In severe neuromuscular scoliosis due to CP with significant pelvic obliquity, fusion must cross the lumbosacral junction. The standard surgical treatment is posterior spinal fusion from the upper thoracic spine (T2-T3) to the pelvis to restore sitting balance.

Question 52

A 7-year-old boy presents for evaluation of an asymptomatic spinal deformity. Standing radiographs demonstrate a 30-degree left-sided thoracic scoliosis. His neurological exam is entirely normal. Which of the following is the most appropriate next step in management?

Explanation

Atypical curve patterns, such as a left-sided thoracic curve or juvenile onset, carry a high incidence (up to 20%) of intraspinal axis abnormalities like syringomyelia or Chiari malformations. A total spine MRI is strictly indicated.

Question 53

A 12-year-old girl presents with severe lower back pain and radiculopathy. Examination reveals a palpable step-off at the lumbosacral junction. Radiographs show a grade 4 L5-S1 dysplastic spondylolisthesis with a dome-shaped sacrum and a high slip angle. What is the safest and most reliable surgical treatment?

Explanation

High-grade dysplastic spondylolisthesis has a significant risk of L5 or sacral nerve root injury with attempted aggressive anatomic reduction. In situ posterior spinal fusion extending from L4 to S1 is considered a safe and effective definitive treatment.

Question 54

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

Explanation

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

Question 55

A 6-year-old girl presents with torticollis 10 days after undergoing a tonsillectomy. Her head is rotated to the right and tilted to the left. She refuses to move her neck due to pain. Neurologic exam is normal. Which of the following is the most likely diagnosis?

Explanation

Grisel's syndrome is a non-traumatic atlantoaxial rotatory subluxation associated with inflammation of adjacent head and neck tissues. It typically occurs after upper respiratory infections or ENT procedures like tonsillectomy.

Question 56

A 13-year-old pre-menarchal girl presents with a right thoracic adolescent idiopathic scoliosis measuring 32 degrees. Her Risser stage is 0, and her Sanders bone age corresponds to stage 2. What is the most appropriate, evidence-based management strategy?

Explanation

For a skeletally immature patient (Risser 0-2) with a progressive idiopathic curve between 25 and 40 degrees, the BRAIS study demonstrated that TLSO bracing for at least 18 hours a day significantly decreases the risk of progression to surgery.

Question 57

A 12-year-old boy with known Marfan syndrome presents with a 45-degree right thoracic scoliosis. Which of the following statements regarding the behavior and management of scoliosis in Marfan syndrome is most accurate?

Explanation

Scoliosis in Marfan syndrome is known for being rigid, aggressive, and highly resistant to orthotic management. These patients have a high risk of continued progression and frequently require surgical stabilization.

Question 58

An 8-year-old boy presents for evaluation. He has unusually broad shoulders and is able to bring his shoulders together anteriorly at the midline. Radiographs confirm hypoplastic clavicles and delayed skull suture closure. Which of the following pelvic abnormalities is most highly associated with this patient's syndrome?

Explanation

Cleidocranial dysplasia is a skeletal dysplasia caused by a RUNX2 gene mutation. In the lower extremities, it is classically associated with delayed pubic symphysis ossification and developmental coxa vara.

Question 59

An 8-year-old boy with Down syndrome presents with decreasing walking endurance and new-onset clumsiness. Neurological examination reveals hyperreflexia and a positive Babinski sign. Flexion-extension cervical radiographs show atlantoaxial instability. Which of the following radiographic measurements is the most critical threshold indicating the need for surgical stabilization?

Explanation

In children with Down syndrome, the Space Available for the Cord (SAC) is the most reliable predictor of neurological risk. A SAC of less than 14 mm is a strong indication for surgical stabilization to prevent irreversible spinal cord injury.

Question 60

A 10-year-old boy with known neurofibromatosis type 1 (NF1) presents with a 45-degree right thoracic scoliosis. Which of the following radiographic findings is most specifically associated with a high risk for rapid, unrelenting curve progression (dystrophic curve)?

Explanation

Dystrophic curves in NF1 have a high propensity for rapid progression. Radiographic markers include vertebral scalloping (often due to dural ectasia), rib pencilling, spindling of transverse processes, and severe apical rotation.

Question 61

A 6-year-old girl is diagnosed with Klippel-Feil syndrome after radiographs reveal multiple congenital cervical fusions. She has no neurological deficits. As part of her comprehensive initial evaluation, which of the following screening tests is mandatory?

Explanation

Klippel-Feil syndrome is associated with several systemic anomalies, most notably genitourinary defects. A renal ultrasound is mandatory to screen for unilateral renal agenesis or other urologic abnormalities present in up to 30% of patients.

Question 62

A 12-month-old infant with achondroplasia is noted to have a 40-degree thoracolumbar kyphosis on sitting lateral radiographs. The child is neurologically intact and has just started pulling to stand. What is the most appropriate management for this spinal deformity at this time?

Explanation

Thoracolumbar kyphosis is common in infants with achondroplasia and typically resolves spontaneously once the child begins to walk and develops lumbar lordosis. Observation is the standard of care unless the deformity is rigid, severe, or associated with neurological deficit.

Question 63

A 6-year-old boy with Morquio syndrome (Mucopolysaccharidosis Type IV) is evaluated for decreasing ambulatory function and upper extremity weakness. What is the most likely cervical spine pathology responsible for his presentation?

Explanation

Morquio syndrome is classically associated with odontoid hypoplasia and ligamentous laxity, leading to profound C1-C2 instability. This must be monitored closely to prevent cervical myelopathy.

Question 64

A 4-week-old infant is brought to the clinic with a right-sided neck mass and a persistent head tilt to the right with the chin rotated to the left. After diagnosing congenital muscular torticollis and initiating physical therapy, what additional screening is highly recommended?

Explanation

Congenital muscular torticollis is strongly associated with developmental dysplasia of the hip (DDH), occurring in up to 20% of cases. A screening hip ultrasound is recommended to rule out DDH.

Question 65

A newborn is diagnosed with congenital scoliosis secondary to a fully segmented hemivertebra at T8. To evaluate for the most commonly associated concomitant anomalies (VACTERL association), which imaging studies should be ordered?

Explanation

Congenital scoliosis is frequently part of the VACTERL association (Vertebral, Anorectal, Cardiac, Tracheoesophageal, Renal, Limb). An echocardiogram and renal ultrasound are essential for initial screening.

Question 66

A 12-year-old boy presents with back pain and a left-sided thoracic scoliosis. Physical examination reveals absent abdominal reflexes on the left side but normal lower extremity strength. What is the most appropriate next step in management?

Explanation

Atypical scoliosis (left thoracic curve, presence of pain, or abnormal neurological signs like absent abdominal reflexes) raises suspicion for intraspinal anomalies such as syringomyelia or Chiari malformation. A total spine MRI is strictly indicated.

Question 67

A 14-year-old girl with neurofibromatosis type 1 has a sharply angulated, dystrophic thoracic kyphoscoliosis measuring 65 degrees. There are no signs of myelopathy. What is the most reliable surgical strategy to achieve a solid arthrodesis and halt progression?

Explanation

Dystrophic curves in NF1 are highly unstable and prone to pseudarthrosis and curve progression if treated with posterior fusion alone. A combined anterior and posterior spinal fusion is the gold standard for severe dystrophic kyphoscoliosis.

Question 68

An infant presents with multiple large joint dislocations (hips, knees, and elbows) and spatulate thumbs. A diagnosis of Larsen syndrome is suspected. Which of the following evaluations is most critical to perform early to prevent sudden infant death?

Explanation

Larsen syndrome is characterized by multiple joint dislocations and a classic facies. Cervical kyphosis is common and can be rapidly progressive, leading to lethal cervical myelopathy if not identified and stabilized early.

Question 69

A 6-month-old boy is diagnosed with infantile idiopathic scoliosis. Radiographs demonstrate a 35-degree left thoracic curve. Which of the following Rib-Vertebra Angle Difference (RVAD or Mehta's angle) measurements most strongly predicts that the curve will be progressive rather than resolving?

Explanation

Mehta's Rib-Vertebra Angle Difference (RVAD) is critical in predicting the progression of infantile idiopathic scoliosis. An RVAD greater than 20 degrees generally indicates a progressive curve requiring intervention like serial casting.

Question 70

A 15-year-old boy complains of mid-back pain. Lateral spine radiographs demonstrate a rigid thoracic kyphosis of 65 degrees. To formally diagnose classic Scheuermann's disease (type I), the radiographs must show anterior wedging of at least 5 degrees in how many consecutive vertebrae?

Explanation

Sorensen's criteria for classic Scheuermann's kyphosis require anterior wedging of greater than 5 degrees in at least three consecutive vertebrae. It is also associated with Schmorl's nodes and endplate irregularities.

Question 71

A 10-year-old female with congenital scoliosis is found to have diastematomyelia with a bony spur at T10 on MRI. She is scheduled for surgical deformity correction. How should the diastematomyelia be managed in relation to the deformity surgery?

Explanation

In diastematomyelia (split cord malformation), the cord is tethered by a bony or fibrous spur. To prevent acute neurological deficit during deformity correction, the tethering spur must be resected prior to any corrective spinal maneuvers.

Question 72

A 6-month-old child with achondroplasia presents with central sleep apnea, failure to thrive, and lower extremity hyperreflexia. What is the best diagnostic test to identify the source of these symptoms?

Explanation

Infants with achondroplasia are at high risk for foramen magnum stenosis, which can compress the cervicomedullary junction leading to central sleep apnea, hyperreflexia, and even sudden death. MRI is the diagnostic modality of choice.

Question 73

A 7-year-old boy presents with severe neck pain and a persistent torticollis one week after an uncomplicated tonsillectomy. His head is rotated to the right and tilted to the left. He is afebrile with normal inflammatory markers. What is the most likely diagnosis?

Explanation

Grisel's syndrome is an inflammatory non-traumatic atlantoaxial rotatory subluxation that typically follows an upper respiratory infection or head/neck surgery, such as a tonsillectomy.

Question 74

A 13-year-old female with Marfan syndrome presents with a progressive 35-degree thoracic scoliosis. Regarding the management of her spinal deformity, which of the following statements is most accurate?

Explanation

Scoliosis in Marfan syndrome is often more rigid and less responsive to conservative treatment (bracing) than adolescent idiopathic scoliosis (AIS), frequently progressing to require surgical intervention.

Question 75

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

Explanation

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

Question 76

A 16-year-old male presents with a painful structural scoliosis. The pain is worse at night and is dramatically relieved by NSAIDs. Radiographs show a right thoracic curve. If an osteoid osteoma is responsible for this deformity, where is the lesion most likely located?

Explanation

Osteoid osteomas in the spine cause severe muscle spasm on the side of the lesion, pulling the spine toward the tumor. Consequently, the lesion is typically found on the concavity of the scoliotic curve.

Question 77

A 5-year-old girl is evaluated for an elevated left scapula and limited left shoulder abduction. Radiographs reveal a bony connection extending from the cervical spine spinous processes to the superomedial border of the scapula. What is the eponym for this specific anatomical structure?

Explanation

An omovertebral bone is a fibrous, cartilaginous, or osseous connection between the cervical spine and the superior angle of the scapula, classically seen in Sprengel's deformity.

Question 78

A 9-year-old boy presents with delayed closure of cranial sutures, ability to appose his shoulders anteriorly due to absent clavicles, and a wide symphysis pubis on pelvic radiographs. Which of the following gene mutations is responsible for this condition?

Explanation

The clinical presentation is classic for cleidocranial dysplasia. This condition is caused by a mutation in the RUNX2 (formerly CBFA1) gene, which is essential for osteoblast differentiation and intramembranous ossification.

Question 79

A 4-week-old infant presents with a right-sided neck mass and a head tilt to the right with the chin rotated to the left. The mass is firm, mobile, and located within the sternocleidomastoid muscle. Neurological examination is normal. What is the most appropriate initial management?

Explanation

Congenital muscular torticollis typically presents with a sternocleidomastoid mass ('fibromatosis colli') and a characteristic head tilt. Initial management consists of gentle stretching and observation, which resolves the condition in over 90% of cases.

Question 80

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

Explanation

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

Question 81

A 5-year-old child with a mucopolysaccharidosis presents with decreasing exercise tolerance. Examination reveals short stature, knock-knees, and corneal clouding. Which of the following cervical spine abnormalities is most characteristic of this specific syndrome?

Explanation

Morquio syndrome (MPS IV) is highly associated with odontoid hypoplasia and ligamentous laxity, leading to atlantoaxial instability. This requires careful screening with flexion-extension radiographs to prevent catastrophic spinal cord injury.

Question 82

A 6-month-old infant with achondroplasia presents with central apnea, failure to thrive, and hyperreflexia. What is the most likely underlying pathophysiology for these neurological findings?

Explanation

Infants with achondroplasia are at high risk for foramen magnum stenosis, which can compress the cervicomedullary junction. This can present with central apnea, myelopathy, and sudden death, requiring urgent decompression.

Question 83

A 15-year-old boy presents with back pain and a rigid thoracic kyphosis. Lateral standing radiographs demonstrate a thoracic kyphosis of 55 degrees. Which of the following radiographic findings is required to confirm the diagnosis of Scheuermann's disease?

Explanation

The classic Sorensen criteria for Scheuermann kyphosis include anterior wedging of greater than or equal to 5 degrees in three or more consecutive vertebral bodies. Associated findings can include Schmorl nodes and endplate irregularities.

Question 84

A newborn is noted to have a congenital thoracic scoliosis due to a fully segmented hemivertebra. Screening ultrasonography reveals a unilateral absent kidney. Which additional diagnostic test is most routinely indicated for this patient to rule out associated VACTERL anomalies?

Explanation

Congenital scoliosis is frequently associated with VACTERL anomalies (Vertebral, Anorectal, Cardiac, Tracheoesophageal, Renal, and Limb). An echocardiogram and renal ultrasound are essential screening studies.

Question 85

A 6-month-old infant is diagnosed with an infantile idiopathic scoliosis. The curve is left-sided and measures 30 degrees. The rib-vertebra angle difference (RVAD) of Mehta is measured. Which RVAD value most strongly predicts that the curve is progressive rather than resolving?

Explanation

A Mehta Rib-Vertebral Angle Difference (RVAD) of greater than 20 degrees strongly predicts curve progression in infantile idiopathic scoliosis. An RVAD less than 20 degrees is generally associated with spontaneous resolution.

Question 86

A 9-year-old girl with congenital scoliosis presents for preoperative planning before posterior spinal fusion. MRI reveals a split spinal cord separated by a bony spur at T10. What is the most appropriate management regarding the bony spur?

Explanation

Diastematomyelia acts as a spinal cord tether. The bony or cartilaginous spur must be resected and the dura repaired, typically before or concurrently with deformity correction, to prevent neurologic injury during spinal straightening.

Question 87

A 14-year-old boy with Marfan syndrome presents with a 45-degree thoracic scoliotic curve. He is Risser 1. Which of the following best describes the expected response to brace treatment and a common associated spinal anomaly?

Explanation

Patients with Marfan syndrome tend to have a poor response to orthotic management for scoliosis and curves often progress to surgery. They have a high incidence of dural ectasia, which can complicate surgical intervention and cause chronic back pain.

Question 88

A 13-year-old female presents with severe back pain, hamstring tightness, and a waddling gait. Radiographs show a Grade IV isthmic spondylolisthesis of L5 on S1. Which of the following physical examination findings is most characteristic of this condition?

Explanation

High-grade spondylolisthesis typically presents with hamstring tightness, a crouched or waddling gait, pelvic retroversion (a vertical sacrum), and a palpable step-off at the lumbosacral junction.

Question 89

A 12-year-old boy with Duchenne muscular dystrophy has a rapidly progressive scoliosis measuring 40 degrees. He became wheelchair-bound 6 months ago. His forced vital capacity (FVC) is currently 45% of predicted. What is the most appropriate management?

Explanation

In Duchenne muscular dystrophy, once a patient is wheelchair-bound and curves progress beyond 20-30 degrees, posterior spinal fusion to the pelvis is indicated. Surgery should be performed before the FVC drops below 30% to minimize severe pulmonary complications.

Question 90

A 10-year-old girl with Neurofibromatosis type 1 presents with a sharp, angular thoracic kyphoscoliosis (dystrophic curve) and progressive weakness in her hands. MRI shows a solid mass compressing the spinal cord at the apex of the curve. What is the most likely composition of the mass?

Explanation

In NF-1, sharp, dystrophic kyphoscoliotic curves can be complicated by intraspinal pathology. The most common cause of cord compression in this specific scenario is an enlarging neurofibroma or severe angular deformity.

Question 91

A 13-year-old male presents with adolescent idiopathic scoliosis. He has a 40-degree left thoracic curve. Neurological examination is completely normal. Why is a total spine MRI indicated for this patient?

Explanation

Atypical curve patterns, such as a left-sided thoracic curve in adolescent idiopathic scoliosis, carry a higher risk of underlying neural axis abnormalities (e.g., syringomyelia, Chiari malformation). MRI is indicated even with a completely normal neurological exam.

Question 92

A 7-year-old boy with Spinal Muscular Atrophy (SMA) Type 2 presents with a severe, collapsing 70-degree thoracolumbar scoliosis. He is a non-ambulator. What is the most frequent major complication of untreated severe spinal deformity in this patient population?

Explanation

In SMA, collapsing scoliotic deformities lead to severe restrictive lung disease. The combination of respiratory muscle weakness and progressive thoracic deformity frequently leads to respiratory failure and cor pulmonale.

Question 93

A 16-year-old male gymnast presents with a 3-month history of axial low back pain exacerbated by extension. Plain radiographs are normal. What is the most sensitive imaging modality to detect an early, acute stress reaction of the pars interarticularis?

Explanation

MRI with fluid-sensitive sequences (STIR or T2 fat-suppressed) is highly sensitive for detecting marrow edema indicative of an early/acute pars stress reaction. This detects the pathology before a frank fracture line is visible on CT.

Question 94

A 14-year-old boy with spastic quadriplegic cerebral palsy presents with a 70-degree sweeping neuromuscular scoliosis and pelvic obliquity. The right hemipelvis is elevated, and he has a dislocated right hip. If surgical intervention is planned for both the hip and spine, what is the generally accepted staging sequence?

Explanation

Severe pelvic obliquity from neuromuscular scoliosis alters the mechanical alignment of the acetabulum. Spinal fusion to the pelvis to correct obliquity is generally performed first to provide a stable foundation, decreasing the risk of recurrent hip dislocation post-reconstruction.

Question 95

A 6-year-old girl is diagnosed with Klippel-Feil syndrome based on a short neck, low posterior hairline, and fused cervical segments. Which organ system requires urgent screening due to a high incidence of life-threatening or functionally devastating, silent anomalies?

Explanation

Klippel-Feil syndrome has a high association (up to 30%) with renal anomalies, such as unilateral renal agenesis. Renal ultrasound is mandatory to identify these potentially silent but significant abnormalities.

Question 96

A 15-year-old with Osteogenesis Imperfecta Type III presents with progressive headaches, lower cranial nerve dysfunction, and hyperreflexia. Radiographs of the cervical spine demonstrate upward migration of the odontoid process above the Chamberlain line. What is the diagnosis?

Explanation

Basilar invagination is a recognized complication in severe Osteogenesis Imperfecta due to softening of the skull base, leading to upward migration of the odontoid. It can cause brainstem compression and lower cranial nerve palsies.

Question 97

A 4-year-old boy presents with progressive cavovarus foot deformity on the right side and increasing clumsiness. Examination reveals an asymmetric patch of hair over the lumbosacral region and hyperreflexia in the right lower extremity. What is the most appropriate initial diagnostic study?

Explanation

The combination of a progressive foot deformity, a cutaneous lumbosacral stigma (hairy patch), and upper motor neuron signs strongly suggests a tethered cord syndrome. An MRI of the spine is the gold standard diagnostic test.

Orthopedic Prometric MCQs - Chapter 3 Part 1

Orthopedic Prometric MCQs - Chapter 3 Part 22

Orthopedic Prometric MCQs - Chapter 3 Part 22

Chapter Index