This practice set contains high-yield board review questions covering key concepts in Thoracolumbar Spine & Deformity. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 761
Topic: Thoracolumbar Spine & Deformity
In a 65-year-old female undergoing spinal deformity correction for adult degenerative scoliosis, achieving which of the following spinopelvic parameters is most strongly correlated with favorable postoperative health-related quality of life (HRQOL) outcomes?
In adult spinal deformity, sagittal balance is the primary driver of patient-reported outcomes. Restoring the lumbar lordosis to within 10 degrees of the patient's fixed pelvic incidence (PI-LL < 10 degrees) is critical for optimal clinical results.
Question 762
Topic: Thoracolumbar Spine & Deformity
A newborn presents with rhizomelic short stature, bilateral clubfeet, "hitchhiker" thumbs, and cystic swelling of the pinnae. Mutations in the SLC26A2 gene are suspected. Which of the following spinal deformities is most characteristic of this condition?
Correct Answer & Explanation
. Progressive cervical kyphosis
Explanation
The patient has diastrophic dysplasia (SLC26A2 mutation). A hallmark and potentially life-threatening complication of this condition is progressive cervical kyphosis, which can cause neurologic compromise.
Question 763
Topic: Thoracolumbar Spine & Deformity
A 30-year-old female presents with atypical scoliosis and weakness in her intrinsic hand muscles. Neurological exam demonstrates diminished pinprick sensation over her shoulders. Imaging confirms a cervical syrinx. What cranial anomaly is most frequently associated with this condition?
Correct Answer & Explanation
. Chiari I malformation
Explanation
Syringomyelia is strongly associated with Chiari I malformations. Herniation of the cerebellar tonsils through the foramen magnum disrupts normal cerebrospinal fluid flow, leading to central cord cavitation.
Question 764
Topic: Thoracolumbar Spine & Deformity
According to the Thoracolumbar Injury Classification and Severity (TLICS) score, which of the following posterior ligamentous complex (PLC) statuses contributes the highest number of points to the total score?
Correct Answer & Explanation
. Disrupted
Explanation
In the TLICS scoring system, the Posterior Ligamentous Complex (PLC) status is scored as follows: Intact = 0 points, Suspected/Indeterminate = 2 points, Disrupted = 3 points. A total score of >4 generally indicates surgical management.
Question 765
Topic: Thoracolumbar Spine & Deformity
A 65-year-old male presents with severe intractable low back pain and progressive stooped posture, limiting his ability to ambulate. Radiographs reveal a scoliotic curve of 45 degrees, sagittal vertical axis (SVA) of +10 cm, pelvic incidence (PI) of 60 degrees, and lumbar lordosis (LL) of 20 degrees. His pelvic tilt (PT) is 35 degrees. What is the primary surgical goal in correcting his sagittal imbalance?
Correct Answer & Explanation
. Match lumbar lordosis (LL) to pelvic incidence (PI) within 9 degrees.
Explanation
This patient presents with significant adult spinal deformity, particularly sagittal imbalance, characterized by a large positive sagittal vertical axis (SVA), reduced lumbar lordosis (LL 20°) relative to pelvic incidence (PI 60°), and a high pelvic tilt (PT 35°). For adult spinal deformity, particularly regarding sagittal balance, a key surgical goal is to restore the PI-LL mismatch to within a specific range (ideally PI ≈ LL, or PI-LL < 10 degrees). A PI-LL mismatch of 40 degrees (60-20) is severe and contributes significantly to his symptoms and imbalance. While reducing SVA to <5 cm and achieving PT <25 degrees are desired outcomes and indicators of successful sagittal correction, matching lumbar lordosis to pelvic incidence (PI-LL < 9 degrees) is the primary target for reconstructing the lumbar spine's lordosis to achieve a stable and balanced sagittal profile, which subsequently helps in normalizing SVA and PT. Coronal plane correction is important but often secondary to sagittal balance in symptomatic adults. Kyphoplasty addresses specific fractures, not global deformity.
Question 766
Topic: Thoracolumbar Spine & Deformity
A 35-year-old presents with a T12 burst fracture with 60% canal compromise and an incomplete neurological deficit (ASIA D). The patient also has significant kyphotic deformity (30 degrees) at the fracture site. What is the most appropriate surgical approach to address both the neurological deficit and the spinal stability and deformity?
Correct Answer & Explanation
. Combined anterior-posterior approach.
Explanation
For a T12 burst fracture with significant canal compromise (60%), an incomplete neurological deficit (ASIA D), and substantial kyphotic deformity (30 degrees), a combined anterior-posterior approach is often considered the most appropriate. The anterior approach allows for direct decompression of the neural elements by removing retropulsed bone fragments and reconstruction of the anterior column, which is crucial for restoring sagittal balance and stability. The posterior approach provides rigid segmental fixation and allows for better kyphosis correction through pedicle screw instrumentation, offering a comprehensive treatment of stability, deformity, and neurological compromise. While posterior-only approaches can be used, they often struggle with direct anterior decompression and severe kyphosis correction.
Question 767
Topic: Thoracolumbar Spine & Deformity
A 30-year-old male sustains a T12 burst fracture after a fall from height. He has 50% canal compromise and a neurological deficit with grade 3/5 motor strength in both lower extremities (ASIA D). There is no significant kyphosis on initial imaging. What is the most appropriate surgical approach and strategy?
Correct Answer & Explanation
. Posterior reduction, decompression via transpedicular or costotransversectomy approach, and long-segment pedicle screw fixation (T10-L2).
Explanation
The patient has a T12 burst fracture with significant canal compromise and a neurological deficit (ASIA D). Non-operative management (D) is inappropriate. Posterior laminectomy alone (A) is generally contraindicated for burst fractures, especially with neurological deficits, as it can worsen kyphosis and instability without effectively decompressing anteriorly displaced fragments. Anterior corpectomy and reconstruction (B) effectively decompresses the cord and reconstructs the anterior column, but it may not be sufficient for severe posterior element injuries or provide enough stability alone. Immediate anterior and posterior combined approach (E) is very aggressive and reserved for highly unstable or complex deformities. The most appropriate strategy, which allows for robust decompression and stabilization from a single approach, isposterior reduction, decompression via a transpedicular or costotransversectomy approach, and long-segment pedicle screw fixation (T10-L2)(C). This approach allows for indirect and often direct decompression of the spinal canal, provides excellent stabilization, corrects kyphosis, and minimizes morbidity compared to combined approaches. Long-segment fixation (typically two levels above and two below) is generally preferred for burst fractures with neurological deficit to ensure adequate stability and load sharing.
Question 768
Topic: Thoracolumbar Spine & Deformity
A 35-year-old male sustains a T12 burst fracture after a fall, resulting in an incomplete neurological deficit (ASIA D). Imaging shows significant canal compromise (>50%) and 30 degrees of kyphosis. The TLICS score is calculated as 8. What is the most appropriate surgical management for this patient?
Correct Answer & Explanation
. Posterior spinal fusion and instrumentation from T10 to L2.
Explanation
The patient has an unstable thoracolumbar burst fracture (morphology 3 points) with neurological involvement (incomplete, 3 points) and disruption of the posterior ligamentous complex (PLC is likely disrupted with 30 degrees kyphosis, 2 points). This gives a TLICS score of 3+3+2 = 8. A TLICS score of >=5 indicates a strong recommendation for surgical management. Given the significant canal compromise, kyphosis, and incomplete neurological deficit, posterior decompression (indirect via ligamentotaxis or direct via laminectomy) and fusion with long-segment instrumentation (T10-L2) is the most appropriate approach to restore stability, indirectly decompress the canal, and prevent further neurological deterioration. Anterior decompression is an option but often combined with posterior fusion or used for specific anterior column reconstruction, and less common as a standalone initial approach for burst fractures with posterior instability. Vertebroplasty is for pain relief in stable compression fractures, not unstable burst fractures with neurological deficit. Short-segment posterior instrumentation without decompression may not be sufficient for significant canal compromise and neurological deficit.
Question 769
Topic: Thoracolumbar Spine & Deformity
A 68-year-old female presents with severe debilitating low back pain, radiating into both legs, worse with standing. She has a progressive adult degenerative scoliosis with a coronal Cobb angle of 35 degrees and a sagittal vertical axis (SVA) of +8 cm. She has failed extensive conservative management. Surgical planning for this patient should primarily address:
Correct Answer & Explanation
. Restoration of sagittal balance with long-segment fusion
Explanation
In adult degenerative scoliosis, especially with a significant positive sagittal vertical axis (SVA > 5 cm), sagittal imbalance is a major contributor to pain and disability. The primary goal of surgical intervention is to restore sagittal balance and decompress neural elements. This typically requires long-segment fusion to achieve stable correction and often involves osteotomies to restore lumbar lordosis. Isolated decompression addresses symptoms but not the underlying instability or deformity. Short-segment fusion may lead to junctional kyphosis or continued imbalance. Anterior column support alone is insufficient without posterior fixation. Posterior column osteotomy alone may not provide adequate correction for substantial sagittal imbalance.
Question 770
Topic: Thoracolumbar Spine & Deformity
A 72-year-old female presents with severe, chronic low back pain radiating into both legs, worse with standing and ambulation, and significantly improved with sitting. Radiographs show a long-segment degenerative lumbar scoliosis (40 degrees) with a positive sagittal vertical axis (SVA) of 8 cm. Conservative management has failed. What is the primary goal of surgical correction for this patient?
Correct Answer & Explanation
. Restoration of sagittal balance and achieving a neutral or slightly negative SVA.
Explanation
This patient presents with adult degenerative scoliosis with severe symptoms and a positive sagittal vertical axis (SVA) of 8 cm, indicating significant sagittal imbalance. While decompression and coronal correction are components, the primary goal of surgical correction in adult spinal deformity, especially with a positive SVA, is the restoration of sagittal balance. Sagittal imbalance is strongly correlated with pain and functional disability. Correcting the positive SVA (ideally to a slightly negative or neutral range, -2 to +2 cm) by restoring lumbar lordosis and harmonizing pelvic parameters is crucial for long-term functional improvement and pain relief. Simply decompressing or correcting the coronal curve without addressing sagittal balance often leads to suboptimal outcomes or 'flatback syndrome.'
Question 771
Topic: Thoracolumbar Spine & Deformity
A 14-year-old female gymnast presents with chronic lower back pain. Lateral lumbar radiographs demonstrate a Grade II isthmic spondylolisthesis at L5-S1. The pelvic incidence (PI) is measured at 75 degrees. Which of the following statements regarding her spinopelvic parameters is most accurate?
Correct Answer & Explanation
. High pelvic incidence increases shear forces at the lumbosacral junction, predisposing to slip progression
Explanation
Pelvic incidence (PI) is a fixed morphologic parameter (PI = Pelvic Tilt + Sacral Slope) that does not change with posture. A high PI (>60 degrees) correlates with a high sacral slope, which increases the shear forces across the pars interarticularis at the L5-S1 junction. This strongly predisposes patients to the development and progression of isthmic spondylolisthesis. A high PI requires a compensatoryincreasein lumbar lordosis.
Question 772
Topic: Thoracolumbar Spine & Deformity
A 3-month-old infant presents with severe shortening of all limbs, hitchhiker thumbs, and cystic swelling of the external ears. Radiographs reveal short, thick tubular bones and a characteristic cleft palate. Which of the following spinal deformities poses the most critical risk of severe neurological compromise in the natural history of this disorder?
Correct Answer & Explanation
. Cervical kyphosis
Explanation
This patient has diastrophic dysplasia (SLC26A2 mutation). Severe cervical kyphosis is common and, while it can resolve spontaneously, it may rapidly progress and cause lethal or severe neurological compromise, requiring close monitoring.
Question 773
Topic: Thoracolumbar Spine & Deformity
A 14-year-old female presents with scoliosis. On physical exam, stroking the skin around the umbilicus fails to elicit an umbilical deviation toward the stimulus on the left side. What is the significance of this finding in the context of adolescent idiopathic scoliosis?
Correct Answer & Explanation
. It suggests an underlying syrinx or neuroaxis abnormality, warranting an MRI
Explanation
Asymmetric or absent abdominal reflexes are an objective 'hard' neurological sign in a patient with scoliosis. This finding strongly suggests an underlying intraspinal anomaly, such as syringomyelia, and mandates an MRI of the entire neuroaxis.
Question 774
Topic: Thoracolumbar Spine & Deformity
A 12-year-old girl with syringomyelia and an associated Chiari I malformation presents with a 60-degree progressive thoracic scoliosis. Which of the following describes the recommended sequence of surgical interventions?
Correct Answer & Explanation
. Suboccipital decompression/syrinx decompression prior to scoliosis correction
Explanation
To minimize the risk of devastating neurological complications during deformity correction, neurosurgical intervention (suboccipital decompression) for the Chiari malformation/syrinx must be performed before addressing the scoliosis.
Question 775
Topic: Thoracolumbar Spine & Deformity
A 6-year-old is evaluated for short-trunk short stature, scoliosis, and generalized joint laxity. Radiographs demonstrate platyspondyly, delayed epiphyseal ossification, and irregular, flared metaphyses. A mutation in the TRPV4 gene is identified. This gene encodes for an ion channel primarily permeable to which of the following?
Correct Answer & Explanation
. Calcium
Explanation
Spondyloepimetaphyseal dysplasia (SEMD), Maroteaux type, is caused by mutations in the TRPV4 gene. TRPV4 functions as a calcium-permeable, non-selective cation channel essential for normal chondrocyte function.
Question 776
Topic: Thoracolumbar Spine & Deformity
A newborn presents with short limbs, severe rigid clubfeet, a "hitchhiker" thumb, and cystic swelling of the pinnae. Cervical kyphosis is noted on radiographs. What is the underlying defective mechanism?
Correct Answer & Explanation
. Defect in a sulfate transport protein
Explanation
Diastrophic dysplasia is caused by a mutation in the SLC26A2 gene, resulting in defective intracellular sulfate transport. Clinical hallmarks include hitchhiker thumbs, severe clubfeet, and cauliflower ears.
Question 777
Topic: Thoracolumbar Spine & Deformity
A 2-year-old child presents with coarse facial features, severe thoracolumbar kyphosis (gibbus deformity), corneal clouding, and hepatosplenomegaly. Urine analysis shows elevated levels of both dermatan sulfate and heparan sulfate. Which enzyme is deficient in this patient?
Correct Answer & Explanation
. Alpha-L-iduronidase
Explanation
Hurler Syndrome (Mucopolysaccharidosis Type I) is caused by a deficiency in alpha-L-iduronidase, leading to the accumulation of dermatan and heparan sulfate. Clinically, it is differentiated from Hunter syndrome (MPS II) by the presence of corneal clouding.
Question 778
Topic: Thoracolumbar Spine & Deformity
A newborn presents with short-limbed dwarfism, hitchhiker thumbs, cauliflower ears, and severe rigid clubfeet. What is the most critical orthopedic complication that must be monitored closely during early infancy in this condition?
Correct Answer & Explanation
. Progressive cervical kyphosis
Explanation
The patient has diastrophic dysplasia (SLC26A2 mutation). Cervical kyphosis is common and can progress to severe spinal cord compression or resolve spontaneously, making close monitoring critical.
Question 779
Topic: Thoracolumbar Spine & Deformity
A 17-year-old boy with spondyloepiphyseal dysplasia congenita presents with worsening back deformity. Based on the typical progression of this disease and the provided radiograph, what is the most likely spinal deformity?
Correct Answer & Explanation
. Progressive dorsolumbar kyphosis with platyspondyly
Explanation
Correct Answer: Progressive dorsolumbar kyphosis with platyspondylyPatients with spondyloepiphyseal dysplasia congenita typically develop progressive dorsolumbar kyphosis with platyspondyly and deformed vertebrae, as demonstrated in the radiograph.
Question 780
Topic: Thoracolumbar Spine & Deformity
In the context of adult spinal deformity, which of the following radiographic parameters is most strongly correlated with health-related quality of life (HRQOL) and patient-reported outcomes?
Correct Answer & Explanation
. Sagittal vertical axis (SVA)
Explanation
Sagittal vertical axis (SVA), which measures the plumb line from C7 relative to the sacral promontory, is widely considered the most important radiographic parameter correlating with health-related quality of life (HRQOL) and patient-reported outcomes in adult spinal deformity. Patients with positive sagittal imbalance (forward lean) tend to have significantly worse pain and functional scores. While Cobb angle, PI, and PT are also important, SVA directly reflects global sagittal balance and its impact on energy expenditure and posture.
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