6. Spine MCQs

A 14-year-old girl undergoes reduction and instrumented fusion for a high-grade isthmic spondylolisthesis at L5-S1. Postoperatively, she develops new-onset weakness in ankle dorsiflexion and great toe extension. Which nerve root was most likely stretched during the reduction?

An infant with achondroplasia presents with central apnea, profound hypotonia, and hyperreflexia. What is the most critical anatomical abnormality responsible for these symptoms?

A 5-year-old girl presents with torticollis following a mild upper respiratory infection. Radiographs show rotatory subluxation of the atlantoaxial joint. What is the most common underlying mechanism for this specific condition (Grisel's syndrome)?

A 5-year-old child presents to the emergency department after a high-speed motor vehicle collision. Lateral cervical spine radiographs show 3 mm of anterior translation of C2 on C3. Swischuk's line is drawn and passes 1 mm anterior to the posterior arch of C3. What is the correct interpretation?

A 14-year-old female gymnast complains of lower back pain that worsens with extension. Oblique radiographs of the lumbar spine demonstrate a "Scotty dog with a collar" sign. If conservative treatment with rest and bracing fails after 6 months, what is the most appropriate surgical option for a persistent L5 pars defect without spondylolisthesis?

A 7-year-old boy presents with mid-back pain. Lateral spine radiographs demonstrate vertebra plana (a uniformly flattened vertebral body). The adjacent disc spaces are preserved. Biopsy of the lesion would most likely reveal cells positive for which immunohistochemical markers?

A 7-year-old boy presents with mid-back pain. Lateral spine radiographs demonstrate complete collapse of the T8 vertebral body (vertebra plana) with preserved adjacent disc spaces. Biopsy of the lesion reveals a proliferation of mononuclear cells with folded, 'coffee-bean' nuclei and eosinophils. Electron microscopy would classically reveal which of the following structures?

The Spinal Instability Neoplastic Score (SINS) is used to evaluate the need for surgical stabilization in patients with metastatic spine disease. Which of the following components of the SINS criteria carries the highest maximum point value?

A 5-year-old male with Morquio syndrome (Mucopolysaccharidosis Type IV) is scheduled for a bilateral proximal femoral osteotomy. Prior to induction of general anesthesia, which of the following specialized imaging studies is absolutely mandatory to prevent a potentially fatal orthopedic complication?

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

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

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

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

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

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

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

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

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

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

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