Spine—Thoracic and Lumbar Flashcards
For anterior access to midthoracic spine, why left-sided approach may be preferred?
● A. Heart does not impede access
● B. Mediastinum does not block access
● C. Brachiocephalic vein does not interfere with exposure
● D. It is easier to mobilize aorta
● E. It is easier to mobilize vena cava
D. It is easier to mobilize aorta
Screws for smaller pedicles (usually T1–T4, especially in females) usually require the smallest screw diameter—typically 4.5 mm. What is the typical length?
● A. 5 to 10 mm
● B. 10 to 15 mm
● C. 20 to 25 mm
● D. 30 to 35 mm
● E. 45 to 50 mm
C. 20 to 25 mm
Which of the following is not an advantage of anatomic (“freehand”) thoracic pedicle screw placement technique?
● A. Accuracy as good as or better than other techniques
● B. Avoids the challenges of getting fluoro aligned for each level in a scoliotic spine, especially when a rotational component is present
● C. Releases joints which facilitates reduction of scoliosis
● D. Can be used if anatomy is distorted by previous fusions or congenital anomalies
● E. Not impeded in areas that are difficult to image on fluoroscopy
D. Can be used if anatomy is distorted by previous fusions or congenital anomalies
In freehand thoracic pedicle screw placement technique, pedicle breach rates are highest between which levels?
● A. T1 and T3
● B. T2 and T4
● C. T4 and T6
● D. T6 and T8
● E. T10 and T12
C. T4 and T6
For anterior lumbar interbody fusion (ALIF), what is the usual incision?
● A. Costotransversectomy
● B. Anterolateral
● C. Trans-sternal
● D. Grid iron
● E. Pfannenstiel’s
E. Pfannenstiel’s
What is the medial angle for lumbar pedicle screw at L1?
● A. 5 degrees medially
● B. 10 degrees medially
● C. 15 degrees medially
● D. 20 degrees medially
● E. 25 degrees medially
A. 5 degrees medially
According to Gertzbein classification of pedicle screw medial breach, a breach distance of > 4 mm is what grade?
● A. 0
● B. 1
● C. 2
● D. 3
● E. 4
● F. 5
D. 3
What should be the diameter of lumbosacral pedicle screws in adult lumbar spine?
● A. ≥ 2 mm
● B. ≥ 3 mm
● C. ≥ 4 mm
● D. ≥ 5 mm
● E. ≥ 6 mm
D. ≥ 5 mm
Approach for upper thoracic spine or for cervicothoracic junction is through sternal splitting procedure which can give access up to T3 or from T5 level. For mid or lower thoracic levels, transthoracic or retropleural approach is used. Which of the following is the most appropriate statement about advantages of right-sided thoracotomy over left-sided thoracotomy?
● A. The heart, mediastinum, or brachiocephalic vein do not impede access through right-sided approach
● B. It is easier to make position on the right side as compared to the left side
● C. Aorta is easier to mobilize and retract than vena cava on the right side
● D. There is no impedance of inflow of blood into the heart while using right-sided approach
● E. None of the above
A. The heart, mediastinum, or brachiocephalic vein do not impede access through right-sided approach
Which of the following are the options for thoracic screws placement?
● A. By using intraoperative fluoroscopy
● B. Using anatomic (free hand) thoracic pedicle screw placement method based on anatomic landmarks
● C. Performing small laminotomies and assessing position of the pedicle either by visualization or by palpating medial and superior aspects of pedicles using a dissector
● D. By using image guidance that is fitted with instruments with specialized markers that are tracked in real time by cameras that project the drill or screw location on CT or on X-ray
● E. All of the above
E. All of the above
What is the uniform entry point for free hand pedicle screw placement?
● A. 1 mm inferior to the junction of the lateral edge of the superior facet and the transverse process
● B. 3 mm inferior to the junction of the lateral edge of the superior facet and the transverse process
● C. 4 mm inferior to the junction of the lateral edge of the superior facet and the transverse process
● D. 5 mm inferior to the junction of the lateral edge of the superior facet and the transverse process
● E. 7 mm inferior to the junction of the lateral edge of the superior facet and the transverse process
B. 3 mm inferior to the junction of the lateral edge of the superior facet and the transverse process
Which of the following statements is correct regarding entry points and direction of screw placement in pedicles?
● A. Entry point in the T1, T2, T3, and T12 is even with the middle of the transverse process
● B. Entry point in the T7, T8, and T9 is even with the top of the transverse process
● C. For levels T4, T5, and T6, the entry point gradually move slightly superiorly at each level from mid transverse process at T3 to the top of the transverse process at T7
● D. The mediolateral trajectory is slightly lateral (−5 degree) at T12; at T11 it is 0 degree; from here upward it increases medially at 2 degrees per level up to T1 where it is 27 degrees medially
● E. All of the above
E. All of the above
What is the typical thoracic screw length?
● A. 30 to 35 mm
● B. 35 to 40 mm
● C. 40 to 45 mm
● D. 45 to 50 mm
● E. 50 to 55 mm
B. 35 to 40 mm
Entry point in the lumbar spine for screws is at the base of transverse process at the intersection of the center of the transverse process and the lateral aspect of superior facet. Which of the following statements is correct regarding medial angle of the pedicle screws?
● A. At L1 it is 5 degrees medially
● B. At L2 it is 10 degrees medially
● C. At L3 it is 15 degrees medially
● D. At L4 it is 20 degrees medially
● E. At L5 and S1 it is 25 degrees medially
● F. At S2 it is 40 to 45 degrees laterally
● G. All of the above
G. All of the above
What is the recommended titanium rod diameter for lumbar pedicle screw fixation?
● A. 4.5 mm
● B. 5.5 mm
● C. 6.5 mm
● D. 7.5 mm
● E. 3.5 mm
B. 5.5 mm
