6. Spine MCQs

A 35-year-old male undergoes a successful primary L4-L5 microdiscectomy for a herniated disc. He asks about the risk of recurrence. What is the generally accepted rate of recurrent disc herniation at the same level following a primary lumbar microdiscectomy?

During a wide lumbar laminectomy and medial facetectomy for severe central and lateral recess stenosis at L4-L5, excessive resection of the pars interarticularis can lead to iatrogenic spondylolisthesis. Biomechanical instability is most likely to occur if the bilateral pars resection exceeds what percentage?

A 65-year-old male with neurogenic claudication is found to have an L4-L5 degenerative spondylolisthesis. Which of the following findings on dynamic flexion-extension radiographs is the most widely accepted threshold to define dynamic instability, thereby strongly supporting the addition of fusion to a surgical decompression?

Dysplastic (Wiltse Type I) spondylolisthesis is characterized by congenital abnormalities of the upper sacrum or the neural arch of L5. Which of the following associated findings is most highly correlated with this specific subtype?

According to the Wiltse classification, Type IV (Traumatic) spondylolisthesis is characterized by an acute fracture involving which specific anatomical structure?

A 45-year-old male presents with left anterior thigh pain and weakness in left knee extension. His left patellar reflex is symmetrically diminished compared to the right. MRI reveals a far-lateral disc herniation. At which lumbar level is this far-lateral herniation most likely located?

A 20-year-old collegiate gymnast complains of isolated, persistent mechanical low back pain. Radiographs and CT show a bilateral L5 pars defect without spondylolisthesis. After 9 months of conservative care, surgery is considered. Which diagnostic test is most appropriate to confirm that the pars defects are the primary pain generators before performing a direct pars repair?

A 14-year-old soccer player presents with a 4-week history of focal lower back pain exacerbated by extension. Plain radiographs (AP, lateral, and obliques) of the lumbar spine are completely normal. Which of the following is the most sensitive imaging modality to detect an early, acute pars interarticularis stress reaction in this patient?

When evaluating a patient with suspected cauda equina syndrome, checking the bulbocavernosus reflex is part of the neurologic exam. Which of the following spinal segments mediates this reflex?

A 55-year-old male presents with progressive bilateral neurogenic claudication, worse on standing and walking, relieved by sitting or leaning forward. MRI shows severe lumbar spinal stenosis at L4/5. Which surgical approach is generally considered the gold standard for this condition if conservative measures fail?

A 65-year-old male presents with progressive clumsiness in his hands and a broad-based gait. MRI reveals multilevel cervical spondylotic myelopathy from C3 to C6 with preserved cervical lordosis. There is no evidence of instability on flexion-extension radiographs. What is the most appropriate surgical intervention?

A 60-year-old male presents with progressive hand clumsiness and broad-based gait. MRI shows severe cervical spinal stenosis at C4-C6. Upright lateral radiographs demonstrate a fixed rigid cervical kyphosis of 20 degrees. What is the most appropriate surgical approach?

A 65-year-old female presents with severe neurogenic claudication. Flexion-extension radiographs reveal an L4-L5 degenerative spondylolisthesis that increases from 3 mm of translation in extension to 8 mm in flexion. Based on standard guidelines for dynamic instability, what is the most appropriate surgical treatment?

A 68-year-old male presents with bilateral hand clumsiness, gait instability, and hyperreflexia. MRI demonstrates severe cervical stenosis with myelomalacia at C4-C5. He has neutral sagittal alignment and denies any neck pain. What is the most appropriate surgical approach?

A 72-year-old female presents with severe neurogenic claudication that improves with leaning forward. MRI shows severe L4-L5 central stenosis with a mobile grade 1 degenerative spondylolisthesis. She has failed 6 months of conservative care. What is the preferred surgical intervention?

A 65-year-old male presents with worsening hand clumsiness, a positive Hoffman's sign, and lower extremity hyperreflexia. MRI shows severe cervical stenosis at C4-C6 with cord signal changes. He undergoes a C4-C6 anterior cervical discectomy and fusion (ACDF). Postoperatively, he exhibits isolated new-onset right deltoid and biceps weakness without sensory deficits. What is the most likely etiology of this new neurological deficit?

A 55-year-old male presents to the emergency department with worsening lower back pain, bilateral lower extremity weakness, and saddle anesthesia. He reports recent episodes of urinary incontinence. Which of the following is the most appropriate immediate step in management?

A 68-year-old female is evaluated for a total hip arthroplasty. Standing and sitting lateral radiographs reveal a stiff lumbar spine with less than 10 degrees of pelvic tilt change between positions. To minimize the risk of posterior dislocation during sitting, how should the acetabular component be positioned?

A 65-year-old male with a history of lumbar spinal fusion (L3-S1) for degenerative scoliosis is undergoing a primary total hip replacement for severe osteoarthritis. Pre-operative planning includes standard AP pelvis and lateral hip radiographs. The surgeon is concerned about optimizing acetabular component positioning to minimize dislocation risk. Given the patient's spinal history, which additional pre-operative imaging and consideration would be most beneficial for surgical planning?

A 68-year-old male with long-standing ankylosing spondylitis presents for a right total hip arthroplasty (THA). Radiographs demonstrate complete autofusion of the lumbar spine and a rigid spinopelvic junction. Compared to a patient with normal spinopelvic mobility, how does this patient's condition affect acetabular mechanics and instability risk?