neurospine2

Question 1

31. A 65-year-old man presents 6 months after a motor vehide collision complaining of severe disabling neck pain. Cervical CT reveals a non-united type II odontold fraclure. The MOST appropriate management is:
    A. Posterior C1-C2 arthrodesis
    B. B. Halo immobilization
    C. Hard cervical collar
    D. Anterior odontoid screw fixation

Answer 1

A. Posterior C1-C2 arthrodesis

Posterior C1-C2 fixation/arthrodesis immobilizes the entire C1-C2 complex, and is the treatment of choice in this condition. Generally, a fracture older than 3 months Is considered a chronic fracture. Acute type II odontoid fractures do not respond well to external orthrosis (hard collar or halo), and healing rates are even poorer for chronic fractures. Published clinical series have reported <50% healing rates for anterior odontoid screw fixation in chronic fractures. Low healing rates are generally ascribed to pannus formation at the fracture site.

Question 2

32. A 65-year-old woman presents with severe, progressive back pain is found to have degenerative, thoracolumbar scoliosis as depicted in the pigures. Which radiographic parameter has the greatest impact on physical function and disability?
    A. Abnormal coronal balance
    B. Presence of apical rotation
    C. Scoliosis curbe magnitude
    D. Positive sagittal balance
    E. Presence of single curve

Answer 2

D. Positive sagittal balance

of the choices provided, the radiographic parameter that has been shown to have the greatest impact on health status measures is positive sagittal balance (measured from C7 to the posterior margin of the sacrum). Glassman and colleagues assessed the impact of multiple radiographic parameters on health status measures based on a large population of adult deformity patients. Patients with a positive sagittal balance had significantly greater pain, decreased physical function, worse self image, and poorer social function. This underscores the important of achieving sagittal balance when surgically addressing spinal deformity. This also underscores the importance of ensuring that an adequate degree of lordosis is provide when performing instrumented lumbar fusions in order to prevent development of “flat back”

Question 3

33. A 66-years-old white male present after a witnessed fall down six steps complaining of pain and weakness, worse in arms than legs. Plain radiographs, CT and MRI of the cervical spine are shown in the pigures. What underlying medical condition does this patient have:
    A. Severe Cervical Spondylosis
    B. Ankylosing Spondylitis
    C. Osteoporosis
    D. Diffuse Idiopathic Skeletal Hyperostosis

Answer 3

D. Diffuse Idiopathic Skeletal Hyperostosis

the answer is Diffuse Idiopathic Skeletal Hyperostosis (DISH). DISH is a common condition characterized by abundant ossification throughout the body. It occurs most often in the spine with the anterior longitudinal ligament being most often affected. It affect males predominantly and may occur in 20% of the population. For the diagnosis, there should be flowing calcification or ossification of at least four condiguous vertebral bodies in addition to preservation of disc height in the involved areas and absence of sclerosis of fusion of the SI joints. Other differentiating factors from ankylosing spondylitis (AS) include syndesmophytes and calcification of the annulus fibrosis and nucleus pulposus in AS. Among others complications, patiens with DISH are predisposed to spine injures from minor otherwise trivial mechanisms. Most fractures are of the spine seen in DISH are characterized as distraction extension injuries. Often there is a transverse shift of the fractured segment as opposed to the compression fracture, probably due to limited or absent dissipations.

Question 4

34. A 68 years-old male with a history of prostatic cancer present with low-grade fever and severe low back pain progressing to include lower extremity numbness. Thoracic CT shows extensive destruction of the T11 and T12 vertebral bodies with relative sparing of the T11-12 disc space, as well as a large paraspinous abscess with calcification. Thoracic MRI shows a kyphotic deformity with enhancing soft tissue and bone extending into the anterior spinal canal and resulting in moderate stenosis and spinal cord compresion. The MOST likely pathologic process is:
    A. Osteoporotic Compression Fracture
    B. Discitis – Staph Aureus
    C. Pott’s Disease – Tubercolosis
    D. Pathologic Fracture – Metastatic Tumor
    E. Discitis – Staph Apidermidis

Answer 4

C. Pott’s Disease – Tubercolosis

the answer is Pott’s Disease, resulting from tuberculosis. The radiographic description is classic for Pott’s Disease. Staphylococcal infection is unlikely due to the fact that discitis centered on the disc space and generally spares the vertebral bodies (opposite to the imaging appearance described in this case). Pathological fracture due to metastasis is would not explain the presence of a paraspinous abscess. Osteoporotic compression fracture would not presence with extensive, enhancing epidural soft tissue extension.

Question 5

35. A 68 years-old woman presents with progressive myelopathy with MRI shown. An isolated posterior approach is contraindicated in this patient in the presence of:
    A. Fixed kyphotic deformity
    B. Posterior ligamentous hypertrophy
    C. Subluxation at C3/4 and C4/5
    D. Ventral compressive pathology
    E. Compressive pathology across multiple levels

Answer 5

A. Fixed kyphotic deformity

an isolated posterior approach is contraindicated due the fixed kyphotic deformity. Among the listed factors, appropriate assessment of the cervical alignment is most important when determining if a posterior approach is appropriate. The posterior approach is ideally suited for patiens demonstrating a degree of lordosis. The presence of a straight or kyphotic alignment will limit dorsal migration of the spinal cord and potentially cause the spinal cord and nerve roots to drape across ventral pathology, leading to further neurologic compromise

Question 6

36. A 70 years-old male with a type II dens fracture has non-union of the dens despite 6 month of halo fixation. His new cervical CT scan demonstrates non-union of the dens with 6 mm of posterior displacement. Cervical x-rays reveal that anatomic reduction of the fracture is not possibble. No other associated fractures are identified. He is otherwise neurologically intact and is in good medical condition. What is the most appropriate treatment option at this time?
    A. Continued halo management for an additional 3 months
    B. Management in a hard cervical collar for 3 month
    C. Removal of halo fixation and observation
    D. Anterior odontoid screw fixation
    E. Posterior C1-2 instrumented arthrodesis

Answer 6

E. Posterior C1-2 instrumented arthrodesis

the most appropriate management would be to perform posterior C1-2 instrumented arthrosis. The reported rate of chronic nonunion fractures of the dens after halo fixation in the elderly is around 28%. A posterior fixation would provide the best rate of fusion as compared to an anterior odontoid screw fixation in the setting of chronic nonunion of dens. The reported rate of fusion from a posterior C1-2 arthrodesis is approximately 85%. Contraindications to anterior odontoid screw fixation include: disruption of the transverse ligament, concomitant atlantoaxial joint injuries, fracture line parallel to screw trajectory, cervical kyphosis, barrel chest habitus, obesity that would make the screw trajectory not possible. Anterior screw fixation should not be used in patient with nonunion fractures in which fractures healing and/or fixation will be impaired. Furthermore, the 6 mm of posterior displacement would make the posterior approach superior to an odontoid screw.

Question 7

37. A 72 years old woman has been diagnosed with osteoporosis, with a T-score of -2.6 on a recent central DXA scan. She has recently been started on supplemental calcium (1500 mg daily) and bisphosphonate. Which one of the following would be the most appropriate next step in management of her osteoporosis?
    a. Screening urinary calcium levels
    b. Doubling the calcium supplement
    c. Repeating bone density testing in 2 years
    d. Measuring hormonal levels
    e. Obtaining x-rays of the lumbar spine

Answer 7

c. Repeating bone density testing in 2 years

in asymptomatic postmenopausal women with osteoporosis, many physicians monitor changes in bone mineral density (BMD) by central DXA every year or two during pharmacologic therapy for osteoporosis. It is important to note that drugs may decrease a patient’s risk of fracture even when there in no apparent increase in BMD. As with most test, BMD has some precision error. Therefore, changes of less than 2 to 4% in the vertebra and 3 to 6% at the hip from test to test can be due to the precision error of the method. Repeat bone density measurements for monitoring disease progression in response to therapy should generally be performed after 1 or 2 years. Two years is consistent with guidlines developed by the Centers for Medicare & Medicaid Services (CMS).

Question 8

38. A C1-2 transarticular screw is most likely to result in injury to the vertebral artery when misdirected:
    A. Medially
    B. Caudally
    C. Laterally
    D. Anteriorly
    E. Cranially

Answer 8

B. Caudally

the vertebral artery is most vulnerable to injury during C1-2 transarticular screw placement due to drill misdirection caudally. The vertebral foramen lies caudal to the pars of C2, and anatomic variations of the foramen can place the vertebral artery at risk during placement of a transarticular screw. Cranial misdirection of the screw could possibly affect the occiput-C1 joint altough this occurrence is extremely uncummon. Medial placement of a transarticular screw could result in dural laceration, with or without spinal cord injury. Placement of a transarticular screw too far anteriorly has been reported to cause hypoglosal nerve dysfunction in few case reports.

Question 9

39. A 54 years old male presents with a three day history of bladder problems. He states that he does not feel his bladder filling, and that urine sometimes leaks out. Neurologic exam is normal with the exception of hypoactive reflexes. His CT myelogram is displayed below. What is the most appropriate treatment for this patient?
    A. Endovascular therapy with particulate embolic agents
    B. A ventral approach, carpectomy and recection of the lesion
    C. A posterior approach, laminectomy, durotomy, and ligation of draining vein
    D. Continued observation, physical therapy and lumbal strenghtening
    E. Endovascular embolization followed by radiosurgery

Answer 9

C. A posterior approach, laminectomy, durotomy, and ligation of draining vein

the patient has a Type I spinal malformation, or a spinal arteriovenous fistula. The fistula lies within the dura and is an abnormal connection between the radicular vein and artery lying dorsally on the spinal cord making a posterior approach preferable. His problem is caused by venous engorgement in the spinal cord from backflow of venous blood through the radicular draining vein into the coronal venous system on the dorsal aspect of the spinal cord. An arterial steal phenomenon may also be contributing to the problem, altough this is likely less significant

Question 10

40. A normal intraoperative electromyographic study during lumbar fusion surgery has been shown to the BEST corelate with:
    A. Improved fusion rates
    B. Improved patient outcomes
    C. Lack of a neurological injury
    D. Pedicle fractures

Answer 10

C. Lack of a neurological injury

intraoperative electrophysiological monitoring during pedicle screw placement is useful as a diagnostic test, as a normal evoked EMG response is highly predictive of intrapedicular screw placement in the pedicle adjacent to the monitored root. The use of such monitoring has, however, never been shown to devrease the incidence of pedicle breach during screw placement, decrease the incidence of neurological injury, or improve patient outcomes. An abnormal EMG response, moreover, is not highly predictive of a neurological injury (because of a high false-positive rate of EMG abnormalities of this setting)

Question 11

41. A patient awakens from left-sided costotransversectomy at T10 for resection of a ventral metastatic tumor with complete paraplegia and loss of pain and temperature sensation. His sensation to light touch in the lower extremities is spared. Post operative MRI reveals no evidence of spinal cord compression or hematoma. What the most likely diagnosis?
    A. Posterior cord syndrome
    B. Anterior cord syndrome
    C. Central cord syndrome
    D. Brown-Sequard Syndrome

Answer 11

B. Anterior cord syndrome

the most likely diagnosis is anterior cord syndrome. The sacrifice of the left T10 nerve root likely compromised the artery of Adamkiewicz. This artery supplies the anterior 2/the most likely diagnosis is anterior cord syndrome. The sacrifice of the left T10 nerve root likely compromised the artery of Adamkiewicz. This artery supplies the anterior 2/3 of the spinal cord. It commonly arises at T10 on the left but may arise anywhere from T7-L4. It may be seen on the right in 17% of patients. When planning o posterolateral approach for ventral access to the spinal cord, a spinal angiogram may be helpful in identifying the artery of Adamkiewicz to prevent a vascular insult to the cord when sacrifying a nerve root.

Question 12

42. A patient present with a classic Type II odontoid fracture. A MRI and Flexion-Extension Dynamic Radiographs of the cervical spine are consistent with disruption of the transverse ligament. The MOST appropriate treatment is:
    A. Anterior odontoid screw fixation
    B. Halo immobilization
    C. Occipital-cervical fusion
    D. Hard cervical collar
    E. Posterior C1-2 fixation

Answer 12

E. Posterior C1-2 fixation

Disruption of the transverse ligament indicates an unstable C1-2 complex, requiring C1-2 fixation. Because the instability is ligamentous is nature. Treatment must be based on functionaly fusing the unstable segment. Hard cullar and halo treatment immobilize bony fractures for healing but are inadequate to address ligamentous instability. Anterior odontoid screw fixation simply reapproximates the fractured odontoid peg to the C2 body and is inadequate to address an unstable C1-2 segment. Occipital-cervical fusion sacrifies adjacent motion segments needlessly, including the occiput-C1 motion segment which is functionally critical.

Question 13

43. A patient present with bilateral nondisplaced fractures through the C2 pars interarticularis (hangman’s fracture). Flexion-extension dynamic cervical radiographs show < 2mm motion and no significant deformity. The most appropriate treatment modality is:
    A. Anterior C2-3 discectomy and fusion
    B. Posterior C1-2 fixation
    C. Posterior C1-3 fixation
    D. External immobilization
    E. Occipito-cervical fixation

Answer 13

D. External immobilization

the majority of hangman’s fractures are considered stable fractures. The literature consistently reports exellent healing rates with external orthosis, both hard collar and halo immobilization. Operative fixation is reserved for unstable fractures (i.e > 5 mm displacement or gross malalignment)

Question 14

44. A spinal cord injured patient’s examination reveals the presence of voluntary but non-functional strenght in the lower extremities (more than half of the muscles have less than antigravity strenght). Sensation to pain, temperature, and proprioception is markedly diminished distal to the injury. The patient’s american spinal injury association (ASIA) impairment scale grade is:
    A. E
    B. C
    C. A
    D. D
    E. B

Answer 14

B. C

the ASIA grading system was developed to standardizet the reporting of spinal cord injuries. It is a modification of the Frankle scale. Grades range from A to E. A lessions are characterized by no motor or sensory function detected below the level of the lession, including the sacral segment. Grade B is characterized by no motor function detected below the level of the lession and some preserved sensory function below the level of the lession. Grade C patients characteristically have some voluntary motor function preserved below the level of the lession, but this function is too weak to serve any useful purpose (define as more than half of key muscle having a strenght grade of 3 or less). Sensation may or may not be preserved. Grade D patients have functionally useful voluntary motor function below the level of the injury. While grade E patients have normal strength and sensation, altough abnormal reflexes may persist based upon the above grading scheme, this patiens injury would be catagorized as grade C

Question 15

45. A thirty six years old female presents to the emergency room with a two day history of difficulty with urination, anterior tibialis weakness and diminished rectal tone. Her MRI is attached. What is the most important surgical goal?
    A. Instrumented stabilization and fusion
    B. Generous posterior decompression
    C. Lysis of adhesions in the cauda equina
    D. Resection of the mass
    E. Sectioning of the filum terminale

Answer 15

E. Sectioning of the filum terminale
the patient has a terminal lipoma of the conus and filum terminale that is tethering the spinal cord. The lession is not malignant, nor is it likely to grow significantly. The patient’s symptoms are most likely related to spinal cord tethering. Her best chance of improvement and prevention of further neurological deterioration is to completely untether the cord, including section the filum terminale and detachment of the lipoma from adjacent dura. Some of the lipoma may need to be removed to accomplish an untethering, but it does not require resection. Attempts at comprete resection puts the patient at risk for neurologic deficit as it is likely adherent to the neural elements.

Question 16

46. A twenty four years old woman present with right arm and leg weakness and left cranial nerve VI palsy following a high-speed motor vehicle accident. Her lateral cervical spine x-ray shows upper cervical prevertebral soft tissue swelling and a basion-dental interval of 16 mm. Her head CT is negative for intracranial hemorrhage. What is the recommended treatment of this injury?
    A. In situ arthrodesis and immobilization in a 4-poster brace
    B. Traction followed by immobilization in a halo
    C. Immobilization in a hard collar
    D. Internal fixation and arthrodesis
    E. Emmobilization in a halo

Answer 16

D. Internal fixation and arthrodesis

the most appropriate treatment option is internal fixation and arthrodesis. Traumatic atlanto-occipital dislocation frequently results in death at the time of injury. Surviving patients may present with a normal neurological exam, but often present with hemiparesis or quadriparesis. Cranial nerve palsies may be seen. This injury is extremely unstable and patients frequently deteroriate without timely occipitocervical instrumentation.

Question 17

47. According to the BEST medical evidence available regarding lumbar fusion, the addition of pedicle screw fixation to a single or double level posterolateral fusion performed for chronic low back pain due to degenerative disease without deformity or neurological deficit is associated with which of the following outcomes:
    A. Unchanged complication rate
    B. Higher fusion rate
    C. Lower overall cost
    D. Shorter hospital stay
    E. Improved patient outcomes

Answer 17

B. Higher fusion rate

according to the best medical evidence available, the placement of pedicle screws as an adjunct to posterolateral fusion performed for low back pain in patiens without deformity or radiographic instability improves fusion rates, but does not improve patient outcomes. There is compelling evidence that the addition of pedicle screws increase cost and complications.

Question 18

48. According to the guidlines for the Performance of Fusion Procedures for Degenerative Disease of the Lumbar Spine, the literature supports the use of fusion in lumbar decompression surgery for degenerative stenosis when associated with:
    A. Conjoined nerve root
    B. Focal disc herniation
    C. Spondylolisthesis
    D. Spina bifida
    E. Congenital stenosis

Answer 18

C. Spondylolisthesis

medical evidence does not support the addition of fusion to decompressive surgery in patient with degenerative lumbar stenosis unless there are additional structural problems such as spondylolithesis, for which there is Class I evidece. Some Class III evidence supports the addition of fusion in patients with no deformity but with instability demonstrated on flexion and extention x-rays and on patiens undergoing wide laminectomies (with significant facet disruption). There is no substansial evidence available on the addition of fusion to decompression for patients with stenosis and congenital stenosis, spina bifida, conjoined root, or focal disc herniation.

Question 19

49. According to the guidlines for surgical management of degenerative spinal disease, the short and long term economic impact of lumbar fusion surgery for degeneratve spinal disease is:
    A. Positive in the short term and negative in the long term
    B. Negligible in the short term and positive in the long term
    C. Negative in the short term and negative in the long term
    D. Negative in the short term but positive in the long term
    E. Positive in the short term and positive in the long term

Answer 19

D. Negative in the short term but positive in the long term

the economic impact of lumbar fusion surgery is negative in the short-term, partiqularly if instrumentation is involved. In the long term, however, there are beneficial economic effects, partiqularly with respect to return to employment data. The impact is not negligible. It is quite costly up front but often has a significant long term beneficial impact. In a carefully selected patient pool the initial negative impact of fusion surgery is outwighed by the beneficial effects over time.

Question 20

50. After a type II odontoid fracture, the function of which ligament/membrane most strongly influences treatment options:
    A. Alar
    B. Tectorial
    C. Apical
    D. Transverse
    E. Anterior longitudinal

Answer 20

D. Transverse

rupture of the transverse ligament (also known as the cruciate ligament) allows translation of C1 on C2, evidenced by an increase in the anterior dental interval. Incompetence of this ligament is a contraindication to odontoid screw fixation and is associated with delayed instability. Incompetence may be diagnosed based on either increase in the anterior dental interval (>3mm in adults is considered abnormal) or MRI findings. The other ligaments (alar, apical, interspinous and anterior longitudinal) are important in determining the degree of stability, need for bracing or internal fixation, prognosis for healing and other factors, but individually are less determinative of the spesific operative approach, in particular the need for C1-2 bony fusion.

Question 21

51. An eleven years old boy is brought to clinic by his parents with a one week history of neck pain. On questioning, the boy denies any falls or other accidents. He has no significant past medical history. A review of system is non-contributory. On physical exam, he is well-develoved, well-nourishd young male with a normal posture. He is slightly tender to midline palpation of the servical spine. Cervical range of motion is somewhat limited. His neurological exam is normal. His vital signs are normal, and he is afebrile. An MRI of the servical spine was obtaine by the boy’s pediatrician. The lateral view is displayed. What is the most likely diagnosis?
    A. Paget’s disease
    B. Metastatic cancer
    C. Hurler’s syndrome
    D. Pott’s disease
    E. Eosinophilic granuloma

Answer 21

E. Eosinophilic granuloma

Eosinophilic Granuloma is the spine is a benign, non-infectious disease process which typically present as a solitary lession, restricted to the vertebral body without involvement of the disc space and/or posterior elements. A systemic workup of such patients is generally advisable.

Question 22

52. Based on published medical evidence review, discography may BEST be used as a diagnostic test for which clinical purpose?
    A. Functional Imaging relevant to patient selection for lumbar fusion
    B. Repair of annular tears
    C. Visualization of clinically relevant disc space abnormalities
    D. Prediction of outcome following lumbar interbody fusion
    E. Diagnosis of discogenic low back pain

Answer 22

A. Functional Imaging relevant to patient selection for lumbar fusion

discography does not have adequate sensitivity or spesificity as an independent predictor of outcome following lumbar fusion surgery. Discography does not allow visualization of clinically relevant disc abnormalities not visualized by non-invasive axial imaging techniques. When employed using concordant pain response as an outcome measure, however discography may serve as a functional study of the lumbar spine relevant to the identification of pain arising from individual degenerative discs.

Question 23

53. Class I medical evidence supports the use of lumbar fusion in patients with degenerative low back pain, without stenosis or spondylolisthesis, under which of the following circumstances:
54. Acute severe axial back pain
55. Protracted pain responding to medical management
56. Protracted pain arising from 3 or more levels
57. Acute pain refractory to epidural injections
58. Protracted pain refractory to multi-modality medical management

Answer 23

5. Protracted pain refractory to multi-modality medical management

Class I medical evidence supports the use of fusion surgery in the treatment of patients with degenerative spine disease who have been carefully selected and who have had pain that has been refractory to the best medical management. Such patients do better with surgery than do patients treated with conservative therapy. Stenosis or spondylolisthesis need not be a component of the disorder. Precise definition of selection criteria remains elusive. Degenerative disc disease is ubiquitous. Multi-level changes make designation of the pain-generator problematic. Patients may respond to conservative measures despite profound multi-level degenerative changes on radiographic studies.

Question 24

54. During a retroperitoneal approach to the lumbar spine, what structure runs along the medial aspect ot the psoas muscle ang lateral aspect of the spine?
55. Ilioinguinal nerve
56. Ureter
57. Sympathetic trunk
58. Genitofemoral nerve
59. Aorta

Answer 24

3. Sympathetic trunk
   the sympathetic trunk runs medially along the medial border of the psoas. The ilioinguinal nerve emerges along the upper lateral border of the psoas to the quadratus lumborum. The genitofemoral nerve travels more laterally along the psoas. The ureter is usually adherent to the posterior peritoneum and generally falls away from the psoas and spine during the dissection and exposure, as does the aorta.

Question 25

55. Following anterior cervical discectomy and fusion (ACDF), which of the following complications is the most common?
56. Dyshagia
57. Homer’s syndrome
58. Thoracic duct injury
59. New radiculopathy
60. Hoarsness

Answer 25

1. Dyshagia

Temporary or persistent dysphagia can occur in up to 80% of post-operative ACDF patients. Improvement may take many months. Dysphagia appears to be secondary to local response to traction and manipulation rather than locking plate profile (this was not an uncommon complication of anterior cervical surgery prior to the employment of locking plate system). An overly proud construct conformity certainly add to the syndrome. Other complication and syndrome are thankfully more rare altough overall morbidity for the procedure can approach 25%. Esophageal injury occurs in less than 1% of cases as does Homer’s syndrome, vertebral artery injury, and thoracic duct injury. New neurologic deficits can occur in up to 2% of cases. Recurrent laryngeal nerve injuries (resulting in hoarseness) occur in 1-2% of cases.

Question 26

56. Harrington distraction rods were commonly used for the correction and stabilization of scoliosis. At which of the following locations is a harington rod most likely to fracture:
57. The upper hook/rod (point A)
58. The middle of the shaft (point B)
59. The lower hook/rod (point E)
60. The middle ratchet (point D)
61. The proximal ratchet (point C)

Answer 26

5. The proximal ratchet (point C)

the proximal ratchet (point C) is the point of maximum stress application. Stress application is defined by the bending moment and strength of the rod, which is proportional to the cube of the diameter of the rod. The proximal ratchet (point C) is a transition point from the diameter of the shaft to the smaller diameter of the ratchet. Because the strength is define by the cube diameter, even a small changes in the diameter will significantly affect the strength of the rod. The bending moment at either end of the rod are too short to define a large enough stress to fracture the rod. The rod would be unlikely to fracture at mid-shaft due to the fact that it’s diameter is much greater than the proximal ratchet.

Question 27

57. In the spine, which tumor is most commonly located in an intradural/extremedullary location:
58. Astrocytoma
59. Hemangioblastoma
60. Ependymoma
61. Adenocarcinoma
62. Schwannoma

Answer 27

5. Schwannoma

the most common intradural/extremedullary neoplasm are the schwannomas and neurofibroma. Schwannomas are composed of neoplastic Schwann cells, whereas neurofibromas are composed of a mixture of neoplastic Schwann cells, fibroblasts, and perineural cells. Other less common intradural/extremedullary spinnal lesions include meningiomas, and ependymomas are most commonly intramedullary lesions. Carcinomas are most commonly extradural spinal column lesions.

Question 28

58. The first priority in the overall assessment of a trauma patient with an acute cervical spine fracture is:
59. Ongoing hemorrhage
60. Neurological deficit
61. Spinal instability
62. Blood pressure
63. Airway integrityd

Answer 28

5. Airway integrityd

altough spinal instability, neurological deficit, and control of hemorrhage certainly are important issues in the management of an acute cervical spine fracture, ATLS protocol dictates that assessment of airway patency takes precedence. This is followed by assessment of circulation/control of hemorrhage, and performance of a brief neurological examination. During initial management of the trauma, it should always be presumed that the patient harbors an unstable spinal injury. Assessment of spinal stability and acquisition of additional studies should occur after the secondary survey has been performed.

Question 29

59. The most likely cause of decreased fusion rates in smokers undergoing lumbar spinal arthrodesis is:
60. Decreased overall nutritional health
61. Cardiopulmonary complication from COPD
62. Peripheral vascular disease
63. Inhibition of bone formation by nicotine
64. Greater noncompliance with postoperative treatment recomendations

Answer 29

4. Inhibition of bone formation by nicotine

a number of clinical studies have reported lower fusion rates in smokers. Animal studies have demonstrated the effect of nicotine on lower rates of fusion. While the other choices listed may contribute to the failure of successful arthrodesis in patients, nicotine appears to be the primary factor involved

Question 30

60. The right vertebral artery is injured during posterior C1-2 transarticular screw fixation, while placing the first screw. The MOST appropriate surgical management strategy is:
    A. Place the left screw
    B. Remove the right screw
    C. Extend the fusion to the occiput
    D. Use only right sided instrumentation

Answer 30

D. Use only right sided instrumentation

Unilateral vertebral artery injury may be tolerated, whereas bilateral injury is generally fatal. If bleeding can be controlled at the time of surgery, the screw on the side of vertebral artery injury can be placed or left in place. Postoperative arteriography is recomended to evaluate for propagating thrombus or dissection. If interventional techniques are available and thrombus or dissection is identified, temporary and then permanent baloon oclusion may prevent embolic complications. Once a single vertebral artery is compromised, no attempt should be made to place to contralateral screw and potentially endanger the contralateral vertebral artery. There are reports in the literature of fatality occurring as a result of brainstem infarction after bilateral vertebral artery compromise during C1-2 transarticular screw placement.

Question 31

61. The use of recombinant bone morphogenetic protein in the performace of a lumbar fusion is currently supported by randomized controlled clinical trials for which fusion approach/type:
    A. Posterior lumbar interbody fusion procedures
    B. Anterior lumbar interbody fusion procedures
    C. Non-instrumented posterolateral lumbar fusion procedures
    D. Instrumented posterolateral lumbar fusion procedures

Answer 31

B. Anterior lumbar interbody fusion procedures

a randomized, controlled clinical trial comparing recombinant human BMP2 to autograft has been performed in the context of anterior lumbar interbody fusion procedures employing a threaded titanium cage. The use of rhBMP2 was associated with fusion rates and clinical outcomes at least as good as those obtained with autograft. There have been no published randomized trials and very few cohort studies describing the use of BMP’s with other fusion techniques. All such uses are considered off-label uses.

Question 32

62. What are the current evidence-based guidelines regarding posterolateral lumbar fusion for patient with radiculopathy due to intervertebral disc herniation?
    A. Recomended in patient with recurrent disc herniation without evidence of instability, deformity, or chronic low back pain.
    B. Not recomended because interbody fusions are associated with better outcomes.
    C. Recomended for patients with large para-central disc herniation.
    D. Do not recomended because simple decompression is associated with better outcomes.
    E. Recomended for patient who fail to improve with six to eight weeks of conservative management.

Answer 32

D. Do not recomended because simple decompression is associated with better outcomes.

patients with radiqulopathy due to disc herniation who do not improve with measures are good candidates for decompressive surgery. However, the outcome of lumbar disc surgery for radiculopathy is not improved by the addition of a posterolateral fusion in the vast majority of patients. Therefore, the routine use of posterolateral fusion is not recommended as a primary treatment for patients with radiculopathy.

Question 33

What grade of spondylolithesis is depicted by the x-rays:
A. V
B. IV
C. III
D. II
E. I

Answer 33

D. II

the lesion depicted in figures 1 and 2 is most consistent with a grade II isthmic spondylolisthesis. Isthmic spondylolisthesis occurs as a result of bilateral fractures of the pars interarticularis. Radiography shows 25% to 50% anterior listhesis of L5 on S1. That classifies this lesion as a Meyerding grade II. The meyerding grading system (reference meyerding HW. Spondylolisthesis. Surg Gynecol Obstet 54:371-377, 1932) is widely used and denotes the grade of slippage in 25% increments. Therefore, a 0 to 25% slip is a grade I, a 25% to 50% slip is a grade II, etc. Isthmic spondylolisthesis rarely produces central spinal stenosis because the bony roof of the spinal canal remain dorsally situated because of either elongation or frank fracture of the pars interarticularis, essentially disconnecting it from the vertebral body. The nerve root exiting at the level of the malalignment is most prequently affected. In this case, the L5 nerve root, exiting below the L5 pedicle and the body of sacrum. Therefore, L5 radiculophaty and/or low back pain would be common findings.

Question 34

64. What is the most common adverse event following laminoplasty for cervical spondylotic myelophaty?
    A. Loss of cervical range of motion
    B. C5 root palsy
    C. Inadequate cord decompression
    D. Progressive cervical kyphosis
    E. Accelerated adjacent level deterioration

Answer 34

A. Loss of cervical range of motion

laminoplasty has been advocated over laminectomy as a means of achieving adequate dorsal decompression in the cervical spine, while decreasing the risk of progressive kyphosis in patients with lordotic or straight cervical spines. However, the literature reports a range of 30%-50% loss of cervical range of motion postoperatively in selectes series. While C5 root palsy is a noted phenomenon occuring in cervical decompression for CSM and OPLL, it’s pathophysiology is poorly understood and the rate of occurence has been reported in the range of 10-15% in selected series.

Question 35

65. What is the recomended insertion torque for halo pins in adults?
    A. 8 inch pounds
    B. 6 inch pounds
    C. 4 inch pounds
    D. 10 inch pounds
    E. 12 inch pounds

Answer 35

A. 8 inch pounds

halo pins inserted with 8 in-lb insertional torque demonstrate significantly less loosening and pin site infection with cynical loading than pins with 6 in-lb.

Question 36

66. What radiographic finding is a contraindication to cervical laminoplasty?
    A. Spinal cord signal change
    B. Ossified posterior longitudinal ligament (OPPLL)
    C. Multilevel cervical spondylosis
    D. Cervical kyphosis
    E. Congenital cervical stenosis

Answer 36

D. Cervical kyphosis

A contracindication to performing a cervical laminoplasty is a patient with cervical kyphosis. The concern for kyphotic patients after laminoplasty is worsening of the kyphosis. Moreover, in kyphosis, a laminoplasty will not allow the cord to migrate posteriorly due to the bow-stringing effect of the kyphotic deformity. Cervical laminoplasty is appropriate for patient with multilevel cervical spondylosis and can be used in patients with spinal cord signal change. The procedure is indicated as a possible treatment option for patient with OPLL and congenital cervical stenosis. The ideal candidate will have a good cervical lordosis and be free of axial neck pain. Patients with straightening of the cervical spine may also be candidates for laminoplasty.

Question 37

67. Which of the following is considered a major risk factor for osteoporosis by the National Osteoporosis Foundation?
    A. Prior falls
    B. High body mass index (BMI)
    C. Current smoking
    D. Use of NSAIDs
    E. Alcohol use of 1 drink per day

Answer 37

C. Current smoking

According to the National Osteoporosis foundation, the major risk factors for osteoporosis (and related fractures) in Caucasian postmenopause women are:

• personal history of fracture as an adult
• history of fragility fracture in a first-degree relative
• low body weight (<about 127 lbs)

Question 38

68. Which of the following is the most caudal level(s) effectively immobilized by a standard thoracolumbosacral orthosis (TLSO)?
    A. T9-10
    B. L1-2
    C. T11-12
    D. L3-4
    E. L5-S1

Answer 38

D. L3-4

Without more distal immobilization, such as a tigh extension, the lower two lumbar segmentss generally show the same or more mobility with a TLSO. Furthermore, studies have demonstrated more notable reductions in motion at L3-4 than at L4-5 without the use of a thigh extender with a TLSO.

Question 39

69. Which of the following most accurately defines, from a biomechanical perspective, the location of rod fracture as depicted in figure 1? The point of:
    A. Maximum stress application
    B. 3-point bending
    C. Narrowest diameter
    D. Greates flexibility
    E. Maximum strain application

Answer 39

stress is a measurement of force per unit area and in this case defined mathematically as the bending moment (torque) divided by the strength of the rod. Strength is a measurement of a material’s ability to resist stress and is proportional to the cube of the diameter of a rod. The point of maximum stress application, typically located at the middle of a long construct, is the usual fracture point. This rod has a constant diameter. If it tapered, or had a transition point, this would likely be a point of fracture for a constant stress application.