This practice set contains high-yield board review questions covering key concepts in 6. Spine. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 1381
Topic: 6. Spine
Which of the following is the most common concern regarding anesthesia for a patient with juvenile rheumatoid arthritis:
Correct Answer & Explanation
. Small, stiff jaw
Explanation
Stiffness and mandibular hypoplasia are fairly common in juvenile rheumatoid arthritis (JRA) due to inflammation of the temporomandibular joint that affects the growth plates of the mandibles. Basilar invagination is rare in JRA. Rotatory subluxation of C 1-C 2 is rare in JRA. Subaxial subluxation is rare in JRA. Cervical stenosis is not a clinical problem in JRA.
Question 1382
Topic: 6. Spine
A 4-year-old boy is brought to a clinic because he has been fussy, febrile, and unable to bend over for the past 4 days. In the office, his temperature is 38.2° C and his neurologic examination is normal. His lumbar lordosis is flattened and he resists flexion or extension. He has normal range of hip motion. Plain films of the lumbar spine are normal. The next imaging study should be:
Correct Answer & Explanation
. Magnetic resonance imaging of the spine
Explanation
Magnetic resonance imaging should be the next step to rule out pyogenic spondylitis. Ultrasound has not been proven effective in evaluation of anterior spinal pathology. Computed tomograms do not have a greater sensitivity than plain films in early diagnosis of infection. An indium labeled scan may yield diagnostic information but would not be the preferred test because of the time needed and inability to provide other diagnostic information. Hip arthrogram would not be the next step because the hip range of motion is normal. Even if hip pathology were suspected, the next step would be a plain film and an ultrasound.
Question 1383
Topic: 6. Spine
The most common region of the spine affected by tuberculosis is:
Correct Answer & Explanation
. Lower thoracic-upper lumbar
Explanation
The lower thoracic-upper lumbar spine is most commonly affected by tuberculosis. Multiple vertebrae are often involved in tuberculosis spondylitis.
Question 1384
Topic: Cervical Spine
A 6-year-old child with normal intelligence presents with short stature, corneal clouding, and severe genu valgum. Radiographs reveal atlantoaxial instability and platyspondyly with central anterior beaking of the vertebral bodies. What accumulated substance is expected in the urine?
Correct Answer & Explanation
. Keratan sulfate
Explanation
Morquio syndrome (MPS IV) is characterized by the accumulation of keratan sulfate. Orthopedic manifestations include severe genu valgum, odontoid hypoplasia, and platyspondyly with central anterior beaking.
Question 1385
Topic: 6. Spine
A newborn presents with bilateral knee dislocations, hip dislocations, and bilateral clubfeet. Physical examination reveals a depressed nasal bridge, prominent forehead, and spatulate thumbs. What spine abnormality is most critically associated with this condition?
Correct Answer & Explanation
. Cervical kyphosis
Explanation
Larsen syndrome (FLNB mutation) is characterized by multiple large joint dislocations and classic facial features. Cervical kyphosis is the most critical spinal abnormality and can lead to severe myelopathy if not stabilized.
Question 1386
Topic: Cervical Spine
A 5-year-old child with normal intelligence presents with short trunk dwarfism, severe genu valgum, and a barrel chest. Radiographs reveal severe platyspondyly with anterior central beaking of the vertebrae and marked hypoplasia of the odontoid. What enzyme is most likely deficient in this patient?
Correct Answer & Explanation
. N-acetylgalactosamine-6-sulfatase
Explanation
The patient has Morquio syndrome (Mucopolysaccharidosis Type IV), characterized by normal intelligence, severe skeletal dysplasia, and potentially lethal atlantoaxial instability due to odontoid hypoplasia. It is caused by a deficiency in N-acetylgalactosamine-6-sulfatase (Type IVA) or beta-galactosidase (Type IVB).
Question 1387
Topic: 6. Spine
A 10-year-old boy with a history of multiple fractures, blue sclerae, and dentinogenesis imperfecta presents with progressive weakness in his upper extremities, hyperreflexia, and gait instability. What is the most likely cause of his new neurologic symptoms?
Correct Answer & Explanation
. Basilar invagination
Explanation
Patients with Osteogenesis Imperfecta (OI) have softened cranial bones that can lead to basilar invagination (settling of the skull onto the cervical spine). This can compress the brainstem and upper cervical cord, causing upper motor neuron signs, weakness, and cranial nerve deficits.
Question 1388
Topic: 6. Spine
A 14-year-old boy with end-stage renal disease complains of generalized, severe bone pain. Radiographs of the spine show dense bands of sclerosis at the superior and inferior endplates of the vertebral bodies, producing a "rugger jersey" appearance. What laboratory profile is most consistent with his condition?
Correct Answer & Explanation
. Low calcium, high phosphate, high PTH
Explanation
Renal osteodystrophy is driven by secondary hyperparathyroidism due to renal failure. Failing kidneys cannot excrete phosphate or produce sufficient 1,25-dihydroxyvitamin D, leading to hyperphosphatemia, hypocalcemia, and a compensatory marked elevation in parathyroid hormone (PTH).
Question 1389
Topic: 6. Spine
A 4-year-old boy with Morquio syndrome (Mucopolysaccharidosis Type IV) presents for orthopedic evaluation. Which of the following spinal abnormalities is the most critical and potentially life-threatening complication associated with this disorder?
Correct Answer & Explanation
. Atlantoaxial instability due to odontoid hypoplasia
Explanation
Morquio syndrome is frequently associated with profound odontoid hypoplasia and ligamentous laxity, leading to severe atlantoaxial instability. This represents the most critical orthopedic complication, often requiring early cervical fusion to prevent lethal myelopathy.
Question 1390
Topic: 6. Spine
A 10-year-old girl with neurofibromatosis type 1 (NF1) presents with a severe scoliotic curve. Radiographs demonstrate a sharp, short-segmented structural kyphoscoliosis in the thoracic spine with marked vertebral wedging and "penciling" of the ribs. What is the most appropriate management?
Correct Answer & Explanation
. Combined anterior and posterior spinal fusion
Explanation
Dystrophic scoliosis in NF1 is characterized by short, sharp curves, vertebral wedging, and a high risk of pseudoarthrosis and curve progression. Given the aggressive nature and high failure rate of single-approach procedures, combined anterior and posterior spinal fusion is the treatment of choice.
Question 1391
Topic: 6. Spine
The mean amount of growth height occurring in each vertbra per year during later childhood and early adolescence is:
Correct Answer & Explanation
. 0.7 mm
Explanation
The mean growth is 0.7 mm per vertebra per year. This measurement is averaged across all of the thoracic and lumbar vertebrae.
Question 1392
Topic: Thoracolumbar Spine & Deformity
Which of the following features is true of congenital scoliosis but not infantile idiopathic scoliosis:
Correct Answer & Explanation
. Vertebrae are abnormally formed from birth.
Explanation
In congenital scoliosis, the vertebrae are abnormally formed from birth. The vertebrae are normal at birth in infantile idiopathic scoliosis. Age of onset is before age 3 in both types of scoliosis. The thoracic curve may be convex to the left slide or the right side in either curve type. In infantile idiopathic scoliosis, it is most commonly convex to the left. The rib-vertebral angle difference (angle between the apical vertebral endplate and the rib on the convexity minus the rib on the concavity) greater than 20° predicts an increased risk of worsening in infantile idiopathic scoliosis but not in congenital scoliosis. Bracing has not been shown to affect infantile idiopathic scoliosis.
Question 1393
Topic: 6. Spine
A 6-year-old girl is wearing a seatbelt but no shoulder harness when the car she is occupying strikes another car. She suffers an abdominal contusion as well as a spine injury. The facets of L1 and L2 are spread apart as is the disk between them. The angle between the two vertebrae is 35°. The neurologic exam is within normal limits. Recommended treatment includes:
Correct Answer & Explanation
. Open reduction, instrumentation, and fusion L1-L2
Explanation
Open reduction and 2-level fusion is the simplest way of handling this injury. Immobilization in a hyperextension cast is likely to exacerbate the abdominal injury. An orthosis is not likely to reduce the deformity. Traction would not be a good mechanism to reduce the deformity. In situ fusion would be insufficient without instrumentation.
Question 1394
Topic: 6. Spine
Which of the following is the most common concern regarding anesthesia for a patient with juvenile rheumatoid arthritis:
Correct Answer & Explanation
. Small, stiff jaw
Explanation
Stiffness and mandibular hypoplasia are fairly common in juvenile rheumatoid arthritis (JRA) due to inflammation of the temporomandibular joint that affects the growth plates of the mandibles. Basilar invagination is rare in JRA. Rotatory subluxation of C1-C2 is rare in JRA. Subaxial subluxation is rare in JRA. Cervical stenosis is not a clinical problem in JRA.
Question 1395
Topic: 6. Spine
A 4-year-old boy is brought to a clinic because he has been fussy, febrile, and unable to bend over for the past 4 days. In the office, his temperature is 38.2° C and his neurologic examination is normal. His lumbar lordosis is flattened and he resists flexion or extension. He has normal range of hip motion. Plain films of the lumbar spine are normal. The next imaging study should be:
Correct Answer & Explanation
. Magnetic resonance imaging of the spine
Explanation
Magnetic resonance imaging should be the next step to rule out pyogenic spondylitis. Ultrasound has not been proven effective in evaluation of anterior spinal pathology. Computed tomograms do not have a greater sensitivity than plain films in early diagnosis of infection. An indium labeled scan may yield diagnostic information but would not be the preferred test because of the time needed and inability to provide other diagnostic information. Hip arthrogram would not be the next step because the hip range of motion is normal. Even if hip pathology were suspected, the next step would be a plain film and an ultrasound.
Question 1396
Topic: 6. Spine
A 5-year-old girl comes into the clinic with back pain. Her family has just moved to the United States from southeastern Asia. A lateral radiograph shows destruction of T11, T12, and L1. Magnetic resonance imaging shows a moderate posterior soft tissue mass. A neurological exam is normal. Biopsy confirms tuberculosis. For treatment of the girl's spinal problem, recommended treatment includes:
Correct Answer & Explanation
. Anterior debridement, strut graft, and posterior fusion with instrumentation
Explanation
Anterior debridement, strut graft, and posterior fusion with instrumentation provide the patient with the best chance of a positive result. This procedure minimizes graft dislodgement and posterior overgrowth. A two-drug therapy for at least 6 months leaves the patient at a significant risk of progressive kyphosis and neurologic deficit. A two-drug therapy for at least 6 months along with a body cast also leaves the patient with significant risk of progressive kyphosis and neurologic deficit. The lack of anterior support from a two-drug therapy and posterior spinal fusion to prevent deformity leaves the patient with significant risk of kyphosis. Even with an anterior spinal debridement and a rib strut graft, there is a risk of graft dislodgment over this large defect and of posterior growth into kyphosis.
Question 1397
Topic: Thoracolumbar Spine & Deformity
Scoliosis in Marfan syndrome, as compared to idiopathic scoliosis, is characterized by which of the following:
Correct Answer & Explanation
. Scoliosis curves are more likely to begin in the juvenile period.
Explanation
Scoliosis curves are much more likely to begin in the juvenile period than idiopathic scoliosis. There is no significant difference in the likelihood of left thoracic curves in Marfan syndrome. Brace treatment is less likely to be successful in Marfan syndrome than in idiopathic scoliosis. Marfan patients with scoliosis are more likely to have back pain. Marfan curves are more likely to progress in adulthood.
Question 1398
Topic: 6. Spine
A 16-year-old boy with type I Ehlers-Danlos syndrome has a spinal curvature that has progressed 18° in the past year. The curve is a double major type with a Cobb angle of 60° in each curve. There is no associated kyphosis. The following treatment is recommended:
Correct Answer & Explanation
. Posterior fusion and instrumentation
Explanation
Posterior fusion and instrumentation is the best-documented treatment. Although this form of treatment is followed by an increased incidence of wound healing problems, the problems can be treated. Observation is not recommended because the curve is highly likely to increase and cause a decrease in pulmonary function. Bracing has no role in large curves, and it is not known if bracing is successful at all in Ehlers-Danlos syndrome. Anterior fusion with instrumentation would be difficult with a double curve. Anterior fusion carries an increased risk due to vascular fragility. It is not necessary because there is no increased risk of crankshaft or pseudarthrosis. There is no particular reason for adding an anterior procedure in this situation in view of the vascular risk.
Question 1399
Topic: Thoracolumbar Spine & Deformity
Scoliosis in osteogenesis imperfecta is characterized by which of the following:
Correct Answer & Explanation
. Scoliosis is due primarily to ligamentous laxity.
Explanation
Scoliosis in osteogenesis imperfecta (OI) is due primarily to ligamentous laxity. Scoliosis in OI is due primarily to ligamentous laxity, not bony fractures. There is no association between brainstem impression and scoliosis. Scoliosis in OI rarely responds to brace treatment. Scoliosis, when present in OI, is a major impairment of quality of life.
Question 1400
Topic: 6. Spine
A 65-year-old woman with advanced rheumatoid arthritis presents with neck pain and mild myelopathy. Flexion-extension radiographs demonstrate 9 mm of atlantoaxial subluxation. What primary anatomic structure is compromised, leading to this instability?
Correct Answer & Explanation
. Transverse ligament
Explanation
The transverse ligament is the primary restraint to anterior translation of the atlas on the axis. Its attenuation or rupture due to inflammatory pannus in rheumatoid arthritis leads to atlantoaxial subluxation.
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