August Quiz Answers

1. This structure covers the bone surface except at joints and contributes to bone production and remodeling:

a. Apophysis
b. Trabecula
c. Periosteum (1 pt)
d. Metaphysis

2. The patient has a fracture of the base of the 5th metatarsal with a small fragment retracted from the base. This would represent what type of force of trauma?

a. Shear
b. Distraction
c. Compression
d. Tension (1 pt)

3. What is a Die-Punch fragment? Articular surface fragment that is driven into the epiphysis or metahysis. Where does it most commonly occur? Tibial plateau fx (2 pts)

4. What is an osteochondral fracture? Compression or shear fracture of subchondral bone and overlying cartilage that is confined to the peripheral portion of the epiphysis (1 pt)

5. What is an insufficiency fracture? Fracture caused by normal stresses are placed on bone that is weakened by a generalized process such as osteoporosis (1 pt)

6. What is a pathologic fracture? Fracture caused normal stresses to an abnormal bone - like a benign or malignant tumor (1 pt)

7. An intraarticular fracture that has significantly increased risk of developing post traumatic osteoarthritis? fx with step-off or diastasis of greater than 2 mm (1 Pt)

8. What are the 2 types of nonunion? Hypertrophic (sclerotic and associated with excess bone deposition) and atrophic (associated with demineralization) (2 pt)

9. What are 3 common types of causes of orthopedic hardware failure? Inadequate reduction, inadequate hardware, noncompliant patients (3 pt)

10. What is impingement? Abnormal tissue compression (1 pt)

11. What is anisotropic? Not the same in every direction (1 pt)

12. What is the magic angle? Normal ligament or tendon will have intermediate or bright signal when oriented 55 degrees relative to the bore of the magnet on short TE sequences such as GRE, T1 (1pt)

13. How to avoid magic angle? use longer TE such as T2 (1 pt)

14. What are tendons most prone to subluxation? Extensor carpi ulnaris, peroneus brevis and longus, tibialis posterior (3 pt)

15. If you think there is fatty infiltration of a muscle, which sequence will you look at?

a. T2FS
b. T1 (1 pt)
c. STIR
d. GRE

16. What are the 3 grades of muscle strain? Grade 1 - edema between muscle fibers usually along myotendinous junction; 2 - extensive edema and fluid collections; 3 - disruption of the musculotendinous junction with loss of function (3 pt)

17. What is the finding at about 4 weeks after denervation on MRI? Edema in the muscle (high signal on STIR and T2)  What about after several months? muscle wasting with fatty infiltration best seen on T1 (2 pt with 1 for each answer)

18. What is an osteochonral defect? A cartilage defect that involves both cartilage and subchondral bone (1 pt)

19. What is the feared complication of physeal injury? growth arrest (1 pt)

20. What is the 1st finding in osteochondritis dissecans on MRI? Subchondral marrow edema (1 pt)

21. Anatomic neck fracture of the humerus is worrisome, why? Blood supply to head is disrupted causing poor healing, avn, and secondary osteoarthritis. (1 pt)

22. Fractures of what parts of the scapula are treated with surgical reduction and fixation? Glenoid, scapular neck, and coracoid (3 pts)

23. Other than AC separation, what are other causes of widened AC joint? Erosion of distal clavicle in RA, hyperparathyroidism, infection, traumatic osteolysis (weightlifters) (4 pt)

24. AC joint is normally how wide with what difference between sides? 5 mm (I don't call widened until 7-8 mm) with no more than 2-3 mm difference between sides (2 pt)

25. Coracoclavicular distance is usually what with what difference between sides? no wider than 11-13 mm with no more than 5 mm difference (2 pt)

26. Which rotator cuff tendon attaches to the lesser tuberosity? Subscapularis (1 pt)

27. If the biceps tendon is dislocated - you should assume there is a tear in what tendon? Subscapularis (1 pt)

28. Denervation of the posterior deltoid and teres minor is associated with fibrous bands in what space? Quadrilateral space with impingement on the axillary nerve (1 pt)

29. Acromioplasty is performed for what? Surgical decompression of the subacromial space in the setting of rotator cuff impingement (this is currently an issue of debate) (1 pt)

30. If you see fluid filled cysts within a muscle belly, you should look for what? Tendon delamination (intrasubstance tears) (1 pt)

31. Where is the critical zone in the rotator cuff and what is it? 1 cm proximal to the distal insertion of the rotator cuff. It is the watershed area between humeral head and muscular blood supply (2 pt)

32. Where does one find a Hill-Sachs lesion on the humerus? Wedge shaped defect in the lateral posterosuperior aspect of the humeral head at or above the coracoid process. (1 pt)

49 points total