The ANSWERS! for July Quiz

Thank you very much for participating. If you played, you are a winner in my book. Congratulations to Dr. Andrews for the top score and Drs Dey, Aggarwal and Bonney for a tie at 2nd place! There will be multiple more chances to take away the lead in the coming months. Below are the answers with some explanation.

1. D. Per the article on uncommon manifestations of intervertebral disc pathologic conditions -  "Massive lumbar herniations have been defined by some authors as lumbar disk herniations occupying greater than 50% of the spinal canal at axial imaging... the findings in the literature suggest that size alone is not a rational surgical indication, particularly if the symptoms are limited to sciatica or are improving... massive disk herniations have been shown to decrease in size to a greater degree than smaller herniations" 

2. B. Per the above article - "A discal cyst, also referred to as a disk cyst, is a rare condition defined as the communication of an intraspinal extradural cyst with an intervertebral disk"

3. C. Per the above article - These giant thoracic disk herniations are often densely calcified (∼95%) and tend to erode the dura...For symptomatic thoracic disk herniations, women in the 3rd to 5th decades are most often affected...Two-thirds of symptomatic thoracic disk herniations that require surgery are located between T8 and T11

4. D. Per the above article - These giant thoracic disk herniations are often densely calcified (∼95%) and tend to erode the dura...Formation of an intradural disk herniation requires a perforation of the anulus, the posterior longitudinal ligament, and the dura...A calcified disk remnant or osteophytic spur can cause a dural defect, the resultant CSF leak, and the clinical manifestations of CSF hypotension

5. B. Per the article Imaging Characteristics of Bone Graft Materials - Osteoinduction is the process through which pluripotential mesenchymal cells are recruited from the surrounding tissue and differentiate into osteoblasts. 

6. C. Per the above article - Allografts (cadaveric bone transplants) are popular substitutes for autografts but provide mainly an osteoconductive matrix that lacks osteoinductive properties

7. A. Per the above article - In the immediate postoperative period, allo-grafts have signal hypointensity on both T1- and T2-weighted MR images. 

8. A. Per the above article - Graft combinations are often used to obtain both osteoconductive and osteoinductive properties. Allografts may be mixed with autologous platelet-rich plasma, a concentration of human platelets in a small volume of plasma, which encourages osteoinduction by supplying fundamental growth proteins that are secreted by the platelets and that initiate wound healing.

9. A. Per the article - Acute Shoulder Trauma: What the Surgeon Wants to Know - All fractures not meeting the numeric criteria for displacement or angulation are classified as one-part fractures, regardless of the actual number of fracture fragments or the degree of comminution. 

10. D. Per the above article - the risk increases further when the spur of bone derived from the medial metaphyseal cortex that remains attached to the anatomic head (the medial metaphyseal segment) is shorter than 8 mm or displaced more than 2 mm, implying that the medial periosteum is disrupted. The combination of anatomic neck fracture with a short and displaced medial metaphyseal segment yields a positive predictive value of 97% for ischemia

11. C. Per the above article - concomitant rotator cuff tears are more common in elderly individuals... Although rotator cuff tear is less common in young patients...

12. C.  Per the above article - Type VI fractures are often not reconstructible and are treated nonsurgically to preserve the remaining soft-tissue supports.

Bonus: C. This is tricky - but the key is "according to no one but the test giver". D is automatically out as it is not about NYC at all. A and B are commonly found in many people's lists of best songs about NY - google and see. But I can't find C on any of these lists including wikipedia's rather exhaustive list of songs about NY. Balloon man makes references to 6th Ave, Bryant Park, jumping of the Empire State etc. I tried to help by putting a rick roll in the New York New York link.