Menu

6. Spine MCQs

Practice Set 114 of 379

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 2261

Topic: 6. Spine
A 20-year-old man sustained an isolated displaced type II odontoid fracture in a motor vehicle accident. He is neurologically intact. Treatment consists of placement in halo traction, and the fracture is reduced. What is the next most appropriate step in treatment?
. Conversion to a halo vest
. Closed reduction and conversion to a halo vest
. Posterior atlantoaxial arthrodesis
. Odontoid screw fixation
. Continued halo immobilization

Correct Answer & Explanation

. Conversion to a halo vest

Explanation

DISCUSSION: The traditional treatment of a reduced type II fracture is a halo vest. A 20-year-old man will tolerate a halo vest better than the elderly or women. Anterior screw fixation has gained increasing support; however, it too has risks and requires a significant learning curve. More recently, C1 lateral mass screws have become more popular. The long-term results and benefits have not yet been determined.

Question 2262

Topic: 6. Spine

A 42-year-old woman reports neck stiffness, upper extremity pain, clumsiness, weakness, and instability of gait. Examination reveals 4+ of 5 strength in the upper extremities and 3+ biceps, brachioradialis, and patellar reflexes with a positive Hoffman sign bilaterally. MRI and CT scans are shown in Figures 10a and 10b. Based on the history and imaging findings, what is the most likely diagnosis? Review Topic

. Diffuse idiopathic skeletal hyperostosis
. Ankylosing spondylitis
. Ossification of the posterior longitudinal ligament
. Rheumatoid arthritis
. Degenerative cervical stenosis

Correct Answer & Explanation

. Diffuse idiopathic skeletal hyperostosis

Explanation

The sagittal T2-weighted MRI scan shows moderate-severe multilevel cervical stenosis. The cord compression is noted to be not only at the disk levels but also at the midvertebral body levels, and the posterior longitudinal ligament appears to be thickened. The CT scan confirms that the posterior longitudinal ligament is indeed thickened and ossified, compatible with a diagnosis of ossification of the posterior longitudinal ligament. This diagnosis is most common in individuals of Japanese descent and has a genetic linkage. The anterior osteophytes are smaller than those seen in diffuse idiopathic skeletal hyperostosis and are not syndesmotic. Patients with ankylosing spondylitis typically have non-marginal syndesmophytes. Patients with rheumatoid arthritis may have evidence of instability at C1-C2 on flexion-extension radiographs and subaxial subluxations.

Question 2263

Topic: 6. Spine

What is a known risk factor for wound infection after spinal fusion for neuromuscular scoliosis? Review Topic

. Number of levels fused
. Blood loss
. Serum albumin level <3.5 g/dL
. Preoperative curve magnitude

Correct Answer & Explanation

. Number of levels fused

Explanation

The risk for wound infection after spinal fusion for neuromuscular scoliosis ranges from 4% to 14% and is higher than risk after spinal fusion in idiopathic scoliosis. A recent study of a database of 151 patients with neuromuscular scoliosis found the presence of ventriculoperitoneal shunt to be associated with an increased risk for wound infection. Age, preoperative major curve magnitude, number of vertebral levels fused, length of surgery, blood loss, and transfusion requirements were not associated with increased risk. A previous study found that poor nutritional status as measured by serum albumin <3.5 g/dL (reference range, 3.5-5.0 g/dL) or lymphocytes<1500 cells/ยตL (reference range, 1000-4800/ยตL) has been associated with increased postoperative wound infections.

Question 2264

Topic: 6. Spine

Figures 169a through 169c show the radiograph and MRI scans of a 74-year-old woman who has had back and bilateral leg pain for the past 6 months. Nonsurgical management has failed to provide relief. What is the best option for surgical treatment? Review Topic

. Posterior decompression
. Posterior interbody arthrodesis
. Posterior decompression and in situ arthrodesis
. Posterior decompression and instrumented arthrodesis
. Anterior and posterior arthrodesis

Correct Answer & Explanation

. Posterior decompression and instrumented arthrodesis

Explanation

The patient has symptoms of lumbar spinal stenosis and radiographic evidence of a grade I degenerative spondylolisthesis at L4-5. Surgical treatment has been shown to provide better clinical outcomes than nonsurgical management. Treatment for spondylolisthesis remains somewhat controversial but posterior lumbar instrumented arthrodesis is best supported in the literature. Decompression alone places the patient at risk for recurrent stenosis and progression of deformity. Noninstrumented arthrodesis for this condition results in high rates of nonunion and worsened longterm outcomes. There is insufficient evidence to support the role for interbody arthrodesis (either through an anterior or posterior approach) compared with posterior decompression and arthrodesis.

Question 2265

Topic: 6. Spine
The image depicts the radiograph obtained from a woman who began having more right than left hip pain during a recent pregnancy. Physical examination reveals increased range of motion with positive flexion-abduction-external rotation (FADIR) and flexion-adduction-internal rotation (FADIR) tests, as well as pain with external logroll. Assessment of the image reveals:
. Classic dysplasia with volume-deficient acetabula.
. Acetabular retroversion with positive crossover signs and ischial spine signs.
. No substantial dysplasia, with normal acetabular volume and anteversion.
. Inadequate radiographic evidence to assess for hip dysplasia.

Correct Answer & Explanation

. No substantial dysplasia, with normal acetabular volume and anteversion.

Explanation

Studies have demonstrated that pelvic inclination can dramatically affect the interpretation of radiographs in the dysplastic hip, with 9ยฐ of increased pelvic inclination leading to the presence of crossover signs and posterior wall signs. A distance of 30 mm to 50 mm from the sacrococcygeal junction to the pubis is often used to assess the adequacy of pelvic inclination on radiographs, although Siebenrock and associates determined the mean difference to be 32 mm in men and 47 mm in women. In this patient, the pelvic inclination is dramatically increased, leading to overestimation of acetabular retroversion.

Question 2266

Topic: 6. Spine
Figures 59a and 59b show the plain radiographs, and Figures 59c and 59d show the CT scan of a 77-year-old woman who has had pain in her back and both buttocks for the past 6 months. She reports that the pain radiates down her right thigh and leg when she is standing. What is the most likely diagnosis?
. Lumbar spinal stenosis
. Metastatic disease of the spine
. Rheumatoid lumbar spondylitis
. Isthmic spondylolisthesis
. Degenerative spondylolisthesis at L4-5 and L5-S1

Correct Answer & Explanation

. Lumbar spinal stenosis

Explanation

Plain radiographs of this patient's lumbar spine show degenerative changes. The CT scan shows narrowing of the spinal canal, and the patient's symptoms are consistent with lumbar stenosis. Measuring the AP diameter of the osseous canal by CT yields a correct diagnosis only 20% of the time, whereas measurements of the cross-sectional area of the dural sac by CT or of the AP diameter of the canal by myelography should lead to a correct diagnosis in 83% of patients.

Question 2267

Topic: 6. Spine
A number of potential complications are associated with the direct lateral approach to the lumbar spine; which complication is most common?
. Infection
. Iliopsoas weakness
. Injury to the aorta
. Foot drop

Correct Answer & Explanation

. Iliopsoas weakness

Explanation

DISCUSSION: Sofianos and associates examined the cases of 45 patients who underwent the lateral transpsoas approach and found that 18 of 45 patients (40%) experienced at least 1 complication. The most common complication was postsurgical weakness of the iliopsoas, which was an issue for 10 of 45 patients (22.2%). The second-most-common complication in this series was anterior thigh hypoesthesia. This occurred in 8 of 45 patients (17.8%). A series of 600 patients by Rodgers and associates noted that thigh pain and psoas weakness following a direct lateral approach to the lumbar spine were both "nearly universal" but almost "always transient."

Question 2268

Topic: 6. Spine
A 42-year-old man sustained a burst fracture at L2 in a motor vehicle accident. Examination reveals that he is neurologically intact. Figure 18 shows a cross-sectional CT scan through the fracture. If the fracture is managed nonsurgically for the next 2 years, the retained fragments can be expected to
. gradually resorb and widen the spinal canal.
. result in neurologic deterioration.
. remain essentially unchanged in size.
. potentially migrate within the spinal canal.
. increase the risk of further injury to the adjacent dural sac.

Correct Answer & Explanation

. gradually resorb and widen the spinal canal.

Explanation

DISCUSSION: Numerous articles have reported that both surgical and nonsurgical management of burst fractures are associated with resolution of impingement at long-term follow-up. If the patient is neurologically intact and appropriately treated at the time of injury, neurologic deterioration is not expected nor is there a risk of injury to the dural sac. The retained fragments can be expected to gradually resorb and widen the spinal canal. REFERENCES: Mumford J, Weinstein JN, Spratt KF, et al: Thoracolumbar burst fractures: The clinical efficacy and outcome of nonoperative management. Spine 1993;18:955-970. Wood KB, Butterman G, Mehbod A, et al: Operative compared with nonoperative treatment of a thoracolumbar burst fracture without neurologic deficit: A prospective, randomized study. J Bone Joint Surg Am 2003;85:773-781.

Question 2269

Topic: 6. Spine

273 In an athlete who has full, painless range of motion and a normal neurological examination, which of the following is considered an absolute contraindication to participation in a collision sport such as football?

. A history of c4-C5 anterior discectomy and fusion
. A history of spinal cord neurapraxia with transient quadriparesis that has now resolved
. Os odontoideum
. Congenital C5-C6 fusion
. Congenital Stenosis
. back ย  answerQuestion 03.273

Correct Answer & Explanation

. Os odontoideum

Explanation

The combination of congenital stenosis withinstability, disk disease (bulge or herniation), degenerative change (osteophytes), MR imaging evidence of cord abnormality, neurologic findings lasting longer than 36 hours, or more than one recurrence is considered an absolute contraindication to sports participation. Congenital stenosis (Pavlov ratio less than 0.8) without instability is not considered a contraindication to play. Congenital anomalies of the upper cervical spine are an absolute contraindication to participation in all contact sports. This includes os odontoideum, odontoid hypoplasia or aplasia, and atlantooccipital fusion, even if asymptomatic. During play, if neurological symptoms resolve quickly and the neurologic examination is normal with full motor strength, the patient may return to the game. Persistence of symptoms or lack of a pain-free range of motion requires further evaluation, including cervical spine radiographs. Players should be restricted from further play until they have recovered full muscle strength. Cervical disk herniations can have serious permanent neurologic complications. A disk bulge without herniation as demonstrated by MR imaging, can be treated conservatively with activity modification. Return to play may occur when pain-free full range of motion is demonstrated and radicular symptoms are completely resolved. Symptomatic disk herniation with cord or root impingement may require anterior diskectomy with interbody fusion. A limited fusion (one or two levels) of the subaxial cervical spine is not considered a contraindication to future play if the segments above and below the fusion are normal. A return to play cannot be recommended until there is radiographic evidence that the graft is well incorporated, the symptoms are completely resolved, and the player demonstrates a painless range of motion and full motor strength. With the exception of spear tackler ร•s spine, there is no evidence that transient neurapraxia of the cord predisposes an individual to subsequent permanent quadriplegia or quadriparesis.Thomas BE, et al. Cervical spine injuries in football players. J AM Acad Orthop Surg 1999;7:338-347Torg JS et al: Neurapraxia of the cervical spinal with transientquadriplegia. JBJS Am 1986:68:1354-

Question 2270

Topic: 6. Spine
Surgical treatment for symptomatic disk herniations is associated with which of the following?
. Substantial rate of nerve root injury
. Early relief of pain sustained out to 2 years
. Recurrent herniation rate of 35%
. Outcomes that are substantially worse than nonsurgical management
. 10% rate of infectious diskitis

Correct Answer & Explanation

. Early relief of pain sustained out to 2 years

Explanation

DISCUSSION: The recently published SPORT trial verifies that surgical treatment of symptomatic disk herniations is associated with early and sustained pain relief. The trial also verifies that nonsurgical management is associated with improved symptoms as well. Nerve root injury, recurrent herniation, and diskitis are known complications of surgery, but all are less common than described above. REFERENCE: Weinstein JN, Lurie JD, Tosteson TD, et al: Surgical vs nonoperative treatment for lumbar disk herniation: The Spine Patient Outcomes Research Trial (SPORT) observational cohort. JAMA 2006;296:2451-2459.

Question 2271

Topic: 6. Spine
An elderly patient falls and sustains an extension injury to the neck that results in upper extremity weakness, spared perianal sensation, and lower extremity spasticity. These findings best describe what syndrome?
. Brown-Sequard
. Cauda equina
. Anterior cord
. Posterior cord
. Central cord

Correct Answer & Explanation

. Central cord

Explanation

DISCUSSION: These findings indicate central cord syndrome, an injury that is more common in the older population who have some degree of spondylosis. The physiologic insult can be a central spinal hematoma with resultant hematomyelia. Bowel and bladder functional return has a good prognosis, unlike the upper extremity motor loss. Cauda equina syndrome generally involves injury at the lumbar levels, with some degree of lower extremity motor loss. Posterior cord syndrome is characterized by preservation of motor function below the level of injury and position/vibratory sensory loss. Brown-Sequard syndrome, which is often produced by a penetrating injury, results in contralateral hypalgesia and ipsilateral weakness. Anterior cord syndrome has a poor prognosis for functional return; lower extremity findings include loss of light touch, sharp/dull, and temperature sensations below the level of injury, as well as motor function. REFERENCES: Apple DF Jr: Spinal cord injury rehabilitation, in Rothman RH, Simeone FA (eds): The Spine, ed 3. Philadelphia, PA, WB Saunders, 1992, Chapter 31. Leventhal MR: Fractures, dislocations and fracture-dislocations of spine, in Crenshaw AH (ed): Campbellโ€™s Operative Orthopaedics, ed 8. St. Louis, MO, Mosby, 1992.

Question 2272

Topic: 6. Spine

Which of the following is a relative contraindication to performing laminoplasty in a patient with cervical myelopathy? Review Topic

. Ossification of the posterior longitudinal ligament (OPLL)
. Cervical kyphosis measuring 20 degrees
. 30 degrees of sagittal mobility on flexion-extension views
. Multilevel canal stenosis
. Patient age older than 55 years

Correct Answer & Explanation

. Ossification of the posterior longitudinal ligament (OPLL)

Explanation

Laminoplasty is one of the surgical options for decompressing the spinal cord in patients with cervical myelopathy. An ideal candidate is a patient with preserved cervical lordosis, as expansion of the canal relies on posterior drift of the spinal cord to achieve decompression. Posterior decompression, such as laminectomy and laminoplasty, are ideal for multilevel canal stenosis. Developed in Japan, laminoplasty is commonly performed in patients with OPLL as it avoids the dangers of working around the ossified posterior ligament. There is no age criterion for this procedure. As it is a motion-preserving procedure, 30 degrees of flexion-extension is not considered a contraindication.

Question 2273

Topic: 6. Spine
A 42-year-old woman who underwent surgery for lumbar scoliosis 2 years ago now has fixed sagittal plane imbalance and severe back pain. Which of the following is considered a contraindication to isolated pedicle subtraction osteotomy for the treatment of iatrogenic flatback syndrome in this patient?
. Anterior pseudarthrosis
. Prior laminectomy at the osteotomy level
. Sagittal decompensation of more than 20 cm on standing lateral radiographs
. Kyphosis at the thoracolumbar junction
. Vascular calcification at the osteotomy site

Correct Answer & Explanation

. Anterior pseudarthrosis

Explanation

Pedicle subtraction osteotomy is the preferred osteotomy technique for the treatment of many patients with iatrogenic flatback syndrome. In the presence of an anterior pseudarthrosis, however, it must be done in conjunction with an anterior procedure. Prior laminectomy is not a contraindication. Significant correction, usually averaging about 30ยฐ, can be obtained through each osteotomy. Osteotomies should be performed at L2 or below in the presence of kyphosis at the thoracolumbar junction. The pedicle subtraction technique is preferred with vascular calcifications because it does not lengthen the anterior column, which could risk vascular injury.

Question 2274

Topic: 6. Spine
  • A 25-yo man sustains the injury shown in Figures 29a and 29b as a result of high-speed trauma. Examination reveals diffuse weakness in the lower extremities that is slightly worse on the right side, and decreased rectal tone and sensation. A CT scan is shown in figures 29c and 29d. Definitive treatment of the injury to the spine is delayed because of a severe pulmonary contusion. At 15 days after the injury, the patientโ€™s neurological status remains unchanged. Management should now consist of
. Posterior fusion at T10-L3 with segmental instrumentation
. Laminectomy and fusion of T12-L2 with segmental instrumentation
. Bed rest in a hyperextension brace
. L1 vertebrectomy and anterior decompression with strut graft fusion and instrumentation
. Progressive ambulation as tolerated in a custom-molded thoracolumbosacral orthosis

Correct Answer & Explanation

. L1 vertebrectomy and anterior decompression with strut graft fusion and instrumentation

Explanation

Anterior decompression is preferred for patients who have incomplete neurologic injury with a compression or burst fracture, if the posterior ligament complex has not been disrupted. Progressive ambulation with a TLSO may be indicated for a simple wedge compression fracture. If the compression is greater than 40% and no neural deficit, then posterior stabilization may be indicated to prevent further collapse and neural deficit. Wedge compression with subluxation or dislocation indicates disruption of posterior ligament complex requiring posterior instrumentation and fusion. Compression and distraction injuries of the middle complex should be treated by Harrington or C-D distraction and compression instrumentation. (Bohlman: The Spine, 1992 pp1047-1056)

Question 2275

Topic: 6. Spine
A 14-year-old patient with an L3 myelomeningocele underwent anterior and posterior spinal fusion for a curve of 50ยฐ. Follow-up examination 1 week after the procedure now reveals persistent drainage from the posterior wound. Results of laboratory cultures show Streptococcus viridans, Staphylococcus aureus, and Enterococcus. In addition to IV antibiotics, surgical irrigation, and debridement, management should include
. removal of all hardware.
. temporary placement of antibiotic beads.
. wound closure over drains.
. bedside dressing changes.
. a RAST test for latex allergy.

Correct Answer & Explanation

. wound closure over drains.

Explanation

DISCUSSION: The rate of wound infections has dramatically decreased with the routine use of prophylactic antibiotics. Factors known to increase the risk of infection include instrumentation, prolonged surgical time, excessive blood loss, poor perioperative nutritional status, a history of surgery, and a history of infection. The use of allograft does not result in an increased rate of infection. Adequate treatment requires early diagnosis and intervention. Temperature elevation and persistent wound drainage are highly suspicious for infection. An erythrocyte sedimentation rate and a WBC are not useful in diagnosis unless serial examinations show rising levels. Patients should be taken to the operating room where the entire wound can be reopened, irrigated, and debrided. Bone graft can be washed and replaced. Hardware should not be removed. The wound should be closed over suction drains. IV antibiotics should be given for a period of at least 10 days, followed by 6 weeks orally. Leaving the wound open to granulate with dressing changes results in prolonged hospitalization, inadequate treatment of the infection, and a poor cosmetic result.

Question 2276

Topic: 6. Spine
A 7-year-old girl with spinal muscular atrophy (SMA) type II has popping of the left hip. Examination reveals painless subluxation of the joint in adduction with palpable reduction in abduction. Radiographs show coxa valga, subluxation of the left hip, and pelvic obliquity with elevation of the left hemipelvis. Treatment should consist of
. observation.
. bilateral adductor and iliopsoas releases, with nighttime abduction bracing.
. proximal femoral varus osteotomy with internal fixation.
. proximal femoral varus osteotomy with volume-reducing periacetabular osteotomy.
. proximal femoral varus osteotomy with shelf acetabular augmentation.

Correct Answer & Explanation

. observation.

Explanation

DISCUSSION: Observation is the treatment of choice. Hip subluxation and dislocation are not uncommon in patients with SMA type II who are unlikely to be ambulatory. Scoliosis occurs in these patients 100% of the time and frequently creates pelvic obliquity. However, in long-term follow-up, patients with SMA type II and hip dislocations had little associated pain or functional limitations because of hip instability. In addition, recurrent hip subluxation after surgical treatment has been documented. Given the rarity of symptoms from hip instability in long-term follow-up, and the possibility of recurrent dislocation, surgical intervention for hip instability may expose SMA type II patients to undue surgical risk for minimal if any functional gain.

Question 2277

Topic: 6. Spine

Figures 82a through 82c show the radiograph and 3-dimensional (3-D) CT scans of a 2-year-old boy whose scoliosis has progressed 15 degrees during the past year. The child is clinically healthy. He has been walking since 11 months of age. An MRI scan of the entire spine revealed no other anomalies. What additional study is indicated? Review Topic

. Renal ultrasound
. Blood cultures
. Flexion-extension cervical spine radiographs
. Platelet count

Correct Answer & Explanation

. Renal ultrasound

Explanation

Renal anomalies are found in as many as one-third of patients with congenital scoliosis, so a renal ultrasound should be obtained. There may be other anomalies, including cardiac. There are no other anomalies on MRI, so flexion-extension cervical spine radiographs are not indicated. There is no associated marrow or platelet problem with hemivertebra. There is no indication for blood cultures because this is a noninfection disorder. The radiographs and 3-D CT scans show a hemivertebra scoliosis already beyond 45 degrees. Resection of the hemivertebra with stabilization is the indicated treatment. The scoliosis will get worse with observation and bracing. Fusion posteriorly can only minimally correct and not stop progression of the scoliosis.

Question 2278

Topic: 6. Spine
A 27-year-old woman has a bilateral C5-C6 facet dislocation and quadriparesis after being involved in a motor vehicle accident. Initial management consisted of reduction with traction, but she remains a Frankel A quadriplegic. To facilitate rehabilitation, surgical stabilization and fusion is planned. From a biomechanical point of view, which of the following techniques is the least stable method of fixation?
. Anterior cervical plating with interbody bone graft
. Posterior cervical plating with lateral mass screw fixation
. Posterior sublaminar wiring
. Simple posterior interspinous wiring
. Bohlman interspinous wiring

Correct Answer & Explanation

. Anterior cervical plating with interbody bone graft

Explanation

In two different biomechanical studies performed in both bovine and human cadaveric spines, all posterior techniques of stabilization were found to be superior to anterior plating in flexion-distraction injuries of the cervical spine. These injuries usually have an intact anterior longitudinal ligament that allows posterior fixation to function as a tension band. Anterior plating with grafting destroys this last remaining stabilizing structure and does not allow for a tension band effect because all of the posterior stabilizing structures have been destroyed with the injury. In clinical practice, however, anterior plating can be effective in the treatment of this injury with appropriate postoperative orthotic management.

Question 2279

Topic: 6. Spine
Figures 92a through 92c are the radiographs of a 34-year-old man with low-back pain and an inability to walk upright. What is the appropriate surgical treatment?
. Smith-Peterson osteotomies at T12-L1, L1-L2 and L2-3.
. Vertebral column resection through a posterior approach
. Anterior-posterior osteotomy
. Pedicle subtraction osteotomy at L3

Correct Answer & Explanation

. Pedicle subtraction osteotomy at L3

Explanation

This patient has a marked fixed sagittal imbalance and a mild coronal imbalance. His fused sacroiliac joints indicate ankylosing spondylitis. Sufficient correction likely can be achieved with a pedicle subtraction osteotomy in the midlumbar spine. Smith-Petersen osteotomies necessitate flexibility of the anterior column, which is not associated with this diagnosis. Also, osteoclasis can result in vascular injuries. Vertebral column resection should not be needed in this case.

Question 2280

Topic: 6. Spine

A patient who underwent an L5-S1 hemilaminotomy and partial diskectomy for radiculopathy 3 weeks ago now reports increasing leg and back pain with radicular signs. An axial T2-weighted MRI scan is shown in Figure 97a, an axial T1-weighted MRI scan is shown in Figure 97b, and a contrast enhanced T1-weighted MRI scan is shown in Figure 97c. What is the most appropriate management for the patient's symptoms? Review Topic

. Irrigation and debridement of deep wound infection
. CT-guided needle biopsy and IV antibiotics
. Revision laminotomy and diskectomy
. L4-L5 anterior debridement and fusion
. Open repair of the L4-L5 pseudomeningocele

Correct Answer & Explanation

. Irrigation and debridement of deep wound infection

Explanation

The MRI scans show a recurrent disk herniation. There is no increase fluid signal or enhancement to suggest infection or any other pathologic process. There is no infection; therefore, IV antibiotics and debridement are not indicated. Similarly, a pseudomeningocele is not present. In addition, with progressive weakness, physical therapy is not appropriate. A revision diskectomy is useful for recurrent radiculopathy.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page