Ch67 Lumbar and thoracic intervertebral disc herniation/radiculopathy

Question 1

Why are most disc prolapses paramedian or in the subarticular zone?

Answer 1

PLL is strongest in the midline

Posterolateral annulus bears a disproportionate portion of the load exerted

Question 2

What is a limbus fracture?

Answer 2

traumatic separation of a segment of bone from the edge of the vertebral ring apophysis at the site of anular attachment.

Question 3

What is Lasegues’s sign?

Answer 3

Straight leg raise test

patient supine, raise afflicted limb by the ankle until pain is elicited

(should occur at < 60°, tension in nerve increases little above this angle). A positive test consists of leg pain or paresthesias in the distribution of pain (back pain alone does not qualify).

Question 4

What is Fajersztajn’s sign?

Answer 4

SLR on the painless leg causes contralateral limb pain (a greater degree of elevation is usually required than the painful side). More specific but less sensitive than SLR (97% of patients undergoing surgery with this sign have confirmed HLD).

Question 5

How would you clinically differentiate between hip joint pain and nerve root compression?

Answer 5

FABER or Patricks sign

Flexion, abduction, and external rotation of hip, place lateral maueolus on contralateral knee and push down on the knee of the ipsilateral leg. Should induce hip pain but not nerve root compression.

Question 6

What is Hoover’s sign?

Answer 6

to distinguish unilateral functional weakness of iliopsoas from organic weakness using synergistic contraction of the contralateral gluteus medius. The supine patient is asked to lift one leg off the bed against resistance from the examiner’s hand. The examiner simultaneously places the palm of his/her other hand under the heel of the unlifted leg and gently lifts.

Question 7

What proportion of disc herniations are in the thoracic spine?

Answer 7

0.25-0.75%

Question 8

Which side is the Artery of Adamkiewicz normally found?

Answer 8

Left in 80%