Anatomy and Basic Sciences (2008-2019)

Question 1

1. 5 components of the SSSC (2012)

Answer 1

• Glenoid
• Coracoid
• Coracoclavicular ligament
• Distal Clavicle
• Acromioclavicular ligament
• Acromion

Question 2

2. List the boundaries of the Quadrangular space. List TWO contents of the Quadrangular space. (2011, 2016)

Answer 2

Netter’s Orthopedics:

• Borders: Medial border of humerus, Long head of triceps, Teres Major, Teres Minor
• Contents: Axillary Nerve, Posterior Circumflex artery, humeral artery

Question 3

3. List 5 nerves coming off the posterior cord of the brachial plexus. (2015)

Answer 3

• Radial
• Axillary
• Thoracodorsal
• Upper subscapularis
• Lower subscapularis

Question 4

4. Name the 2 muscles innervated by the lower subscapular nerve (2016)

Answer 4

• Subscapularis
• Teres Major

Question 5

5. What 2 muscles surround the radial nerve at the distal humerus as it pierces the intermuscular septum. (2013)

Answer 5

• Brachialis
• Brachioradialis

Question 6

6. Give 3 physical findings (besides pain) associated with a trendelenberg gait. (2014)

Answer 6

• Abduction weakness
• Weak EHL
• ? Leg Length Discrepancy
• ?Trendelenberg Lurch
• ?Inability to maintain level pelvis when lifting contralateral leg of weak abductors

Question 7

7. What is Hunter’s canal?

Answer 7

• The Hunter’s canal (subsartorial, adductor canal) is an aponeurotic tunnel in the middle third of the thigh, extending from the apex of the femoral triangle to the opening in the adductor magnus, the adductor hiatus.

Question 8

8. 4 components of the PLC (2012)

Answer 8

• Lateral Collateral Ligament
• Popliteofibular Ligament
• Popliteus tendon
• Less Consistently Described:
  
  • Biceps Femoris
  • IT Band
  • Arcuate ligament complex
  • Lateral Joint Capsule
  • Fabellofibular ligament
  • Lateral Head of Gastroc

Question 9

9. List in order from weakest to strongest the tensile loads to failure of the knee ligaments (medial, lateral, posterior cruciate and anterior cruciate). (2013)

Answer 9

Miller’s Orthopedics (p.289)

• LCL 750N
• ACL 2200-2500N
• PCL 2500-3000N
• MCL 5000N

Question 10

10. 4 nerves to block for ankle block (2012)

Answer 10

• Tibial Nerve
• Superficial Peroneal Nerve
• Deep Peroneal Nerve
• Sural Nerve
• Saphrenous Nerve

Question 11

11. List 4 components of the syndesmosis (2013)

Answer 11

• Anterior inferior tibfib ligament
• Posterior inferior tibfib ligament
• Interosseous Ligament
• Inferior Transverse Ligament

Question 12

12. Given a histologic diagram of the physeal zones and asked to identify and label all 5. (2015, 2016)

Answer 12

• Reserve zone
• Proliferating zone
• Hypertrophic zone
  
  • Maturation zone
  • Degenerative zone
  • Zone of provisional calcification
• Metaphysis
  
  • Primary spongiosa
  • Secondary spongiosa

Question 13

13. Label the 19 structures in this cross-section of the proximal leg (it was this cross-section exactly). (5 points)

Answer 13

1. Fibula
2. Tibia
3. Tibial Tubercle
4. Patellar Tendon
5. Tib Ant
6. EDL
7. Common Peroneal Nerve
8. Lateral Gastroc
9. Soleus
10. Tibial Posterior (Popliteus?)
11. Popliteal Artery
12. Tibial Nerve
13. Medial Gastroc
14. Lesser Saphrenous Vein
15. Semi-tendinosis
16. Greater Saphrenous Vein
17. Semi-membranosus (?MCL)
18. Gracilis
19. Sartorius

Question 14

14. What is the order of the physeal zones from Metaphysis to Epiphysis?
15. Reserve zone, Proliferative zone, Hypertrophic zone
16. Proliferative zone, Hypertrophic zone, Reserve zone
17. Hypertrophic zone, Reserve zone, Proliferative zone
18. Hypertrophic zone, Proliferative zone, Reserve zone

Answer 14

ANSWER: D

2011, 2013

Hypertrophic zone, Proliferative zone, Reserve zone

Question 15

 15. What is the last physis to fuse in the body?

1. Medial clavicle
2. Lateral clavicle
3. Distal femoral physis
4. Olecranon

Answer 15

a. Medial clavicle

2012

Question 16

16. What is the last bone to ossify in the foot:
17. Cuboid
18. Medial cuneiform
19. Navicular
20. Base of 5th phalanx

Answer 16

ANSWER: C (Navicular)

• 2011, 2015
• Netter’s Orthopedics:
  
  • Fetal - Talus, Primary Calc, Primary MT/phalanges
  • Birth - Cuboid
  • 1yr - Lateral Cuneiform
  • 2-3 yrs - medial cuneiform, phalanges secondary
  • 4yr - navicular, intermediate cuneiform
  • 5-9yrs - 1st MT secondary, calcaneal secondary

Question 17

17 . Within the foot and ankle, where do accessory ossicles NOT occur and are subsequently indicative of a fracture at that site?

1. Tip of fibula
2. Posterior talus
3. FHL insertion
4. Insertion of peroneus brevis

Answer 17

ANSWER: C (FHL insertion)

Question 18

18. Which of the following most closely correlates with peak growth velocity?
19. Menarche in a female patient
20. Risser 1
21. Olecranon apophysis closure
22. Tri-radiate closure

Answer 18

ANSWER: C (Olecranon closure)

• 2011, 2014, 2015
• Charley YP (JBJS 2007) Skeletal age assessment from the olecranon for idiopathic scoliosis at Risser Grade 0
• Tri-radiate cartilage closure is closely related to peak height velocity and precedes the appearance of Risser grade 1. Tri-radiate cartilage closure occurs approximately halfway through the phase of accelerated growth velocity
• Complete fusion of the olecranon ….indicates pubertal growth velocity decreases rapidly from this point. Complete olecranon physeal fusion divides the two main phases of accelerating and decelerating height velocity from each other
• Lovell and Winter:

Question 19

 19. GSW with anteromedial axillary entry wound. ORIF through anterolateral brachialis muscle splitting approach. Post-op, inability to flex elbow, with sensation numbness lateral forearm and dorsolateral hand. Wrist flexion and extension normal. Hand function normal. Cause of injury?

1. musculocutaneous injury
2. radial nerve injury
3. compartment syndrome
4. Muscle stripping from plate dissection

Answer 19

ANSWER: A (Musculocutaneous injury)

• 2011

Question 20

20. Patient with knee pain. Which could not cause it?
21. L3
22. L1
23. Knee OA
24. Hip OA

Answer 20

ANSWER: B (L1)

• 2013

Question 21

21. Injury to what causes of retrograde ejaculation
22. Inferior hypergastic plexus
23. Superior hypogastric plexus
24. Inferior hypogastric plexus
25. Superior hypergastric plexus

Answer 21

ANSWER: B (Superior Hypogastric plexus)

• 2014
• Retrograde Ejaculation After Anterior Lumbar Interbody Fusion: Transperitoneal Versus Retroperitoneal Exposure. Sasso, Burkus and LeHuec. Spine. 2003
• Damage to the superior hypogastric plexus during exposure of the anterior lumbosacral spine can denervate this bladder neck sphincter, resulting in retrograde ejaculation.

Question 22

22. During a retroperitoneal approach to L4/5 you see a vessel running over the vertebrae. What is it?
23. Iliolumbar
24. Genitofemoral
25. External iliac
26. Superior hypogastric

Answer 22

ANSWER: A (Iliolumbar artery)

• 2009, 2010

Question 23

23. Lateral femoral cutaneous nerve. Where do you find it anatomically over the pelvis?
24. 2cm distal to ASIS
25. AIIS
26. Iliac crest
27. ASIS

Answer 23

ANSWER: A (2cm distal to ASIS)

• 2009
• Emerges at pelvic brim under the inguinal ligament, overtop of iliopsoas medial to ASIS then travels laterally over sartorius to pass under ASIS 2cm distal

Question 24

24. Picture of Short External rotators. What is the line coming from the bottom of the picture pointing to?

Answer 24

ANSWER: A (Obturator internus)

• 2008, 2013

Question 25

25. The main branch of the medial femoral circumflex artery is anterior to all of the following structures EXCEPT?
26. Superior gemellus
27. Inferior gemellus
28. Obturator externus
29. Obturator internus

Answer 25

ANSWER: C (Obturator externus)

• 2014
• Gautier (JBJS Br 2000) Anatomy of the medial femoral circumflex artery and its surgical implications.
  
  • The course of the deep branch of the MFCA was constant in its extracapsular segment. In all cases there was a trochanteric branch at the proximal border of quadratus femoris spreading on to the lateral aspect of the greater trochanter. This branch marks the level of the tendon of obturator externus, which is crossed posteriorly by the deep branch of the MFCA.
• Course of the deep branch of MCFA
  
  • Profunda femoris
  • Runs towards intertrochanteric crest between the pectineus (medially) and Iliopsoas (laterally) on the inferior border of the obturator externus
  • Identify posteriorly between QF and IG
  • Gives off branches:
  • Constant branch –> branches at inferior QF, crosses GT (trochanteric branch)
  • Main division crosses posterior to tendon of OE, and anterior to SG, OI, IG
  • Perforates the capsule just cranial to the insertion of the tendon to the SG and distal to the tendon of the piriformis
  • Divides into 2-4 terminal retinacular branches

Question 26

26. All of the following are solely innervated by only the obturator nerve, except:
27. Adductor Longus
28. Adductor Brevis
29. Adductor Magnus
30. Gracilis

Answer 26

ANSWER: C (Adductor Magnus)

• 2016
• Adductor magnus has contributions from both sciatic and obturator nerves

TRICK: think Magnus has Many innervations

Question 27

27. Nerve injured in obtaining bone graft from PSIS and patient has decreased sensation to ass?
28. Superior gluteal
29. Cluneal
30. Lateral Femoral Cutaneous Nerve
31. Posterior Femoral Cutaneous Nerve

Answer 27

ANSWER: B (Cluneal)

• 2009, 2013
• Netter’s Anatomy (p.243)
  
  • Superior gluteal has no sensory innervation
  • LFCN = lateral thigh
  • PFCN = posterior thigh, does have some contribution to inferior buttocks through inferior cluneal branch
  • Superior Cluneal (L1-3 dorsal rami) = superior 2/3 buttocks
  • Medial Cluneal (S1-3 dorsal rami) =sacral and medial buttocks

Question 28

28. The superior gluteal nerve is disrupted during your surgery. What muscle will be affected?
29. Gluteus maximus
30. Tensor fascia lata
31. Piriformis
32. Obturator internus

Answer 28

ANSWER: B (TFL innervated by SGN)

• 2016
• Netter’s Anatomy:
• Gluteus maximus = inferior gluteal
• Piriformis = nerve to piriformis
• OI = nerve to obturator internus

Question 29

29. What quadrant of the obturator foramen are the obturator artery and nerve located?
30. Superior Medial
31. Superior Lateral
32. Inferior Medial
33. Inferior Lateral

Answer 29

ANSWER: B (Superior Lateral)

• 2016
• Netter’s Orthopedic Anatomy:
  
  • Foramen appears to be at the superomedial or superolateral depending on orientation of obturator foramen
• JAAOS - Nerve Injuries in Total Hip Arthroplasty:
  
  • “obturator nerve arises from the L2, L3, and L4 nerve roots within the posterior psoas and then emerges medially at the sacral ala to travel along the iliopectineal line”
  • “the obturator nerve exits the pelvis at the superior aspect of the obturator foramen, where it supplies the adductor muscles”

Question 30

30. While operating on a proximal femur a retractor is placed posterior. Significant bleeding occurs. Which vessel has been injured?
31. Medial femoral circumflex
32. Profunda femoris
33. Superior gluteal
34. Superficial femoral

Answer 30

ANSWER: A (Medial Femoral Circumflex)

• 2016
• Both femoral artery and profunda could be damaged with ANTERIOR retractor
• Superior gluteal is possible but is generally more proximal than proximal femur (acetabular exposures)
• Generally injured with dissection, not retractors if posterior approach to the hip
• Charles: perforators of the profunda femoris, depends on how proximal, medial Fem. Circumflex makes most sense if most proximal part.

Question 31

31. Anterior approach to the hip, what is the interval?
32. Tensor fascia latae and gluteus medius
33. Tensor fascia latae and Sartorius
34. Gluteus medius and gluteus minimus
35. Sartorius and adductors

Answer 31

ANSWER: B

(TFL and Sartorius)

• 2013
• Smith-Pete Exposure

Question 32

32. What guides the dissection to the popliteal fossa?
33. medial sural cutaneous nerve
34. small saphenous vein
35. peroneal nerve
36. Achilles tendon

Answer 32

ANSWER: A

(Medial sural cutaneous nerve)

• 2011
• Hoppenfeld

Question 33

33. All of the following make up the quadrangular space except? REPEAT
34. Humerus
35. Teres major
36. Infraspinatus
37. Long head of triceps

Answer 33

ANSWER: C

(infraspinatus not part of the quadrangular space)

• 2012
• Netter’s Orthopedics (p96)
• Quadrangular space:
• Teres minor, teres major, long head of triceps, humerus
• Axillary nerve, posterior circumflex artery, humeral artery

Question 34

34. Pic showing lateral epicondyle and marking on lateral upper arm just proximal to epicondyle in ellipse. Asked what is the blood supply to the area?
35. Superior recurrent radial artery
36. Posterior radial collateral artery
37. Inferior humeral artery

Answer 34

ANSWER: B

(Should be posterior radial collateral artery – poorly recalled answer)

• 2009
• The flap is supplied by the radial collateral artery. It originates from the brachial artery and wraps posteriorly around the humerus, descending on the lateral aspect of the humerus and then branching into an anterior and posterior segments. The posterior branch supplies the lateral arm and lateral forearm flaps.
• Brachial artery –> profunda brachii –> posterior radial collateral artery

Question 35

35. A benign tumor is resected from within the supinator muscle. What may occur post-operatively?
36. Loss of wrist extension
37. Loss of thumb IP extension
38. Loss of sensation to the dorsum of the thumb and 1st webspace

Answer 35

ANSWER: B

(loss of thumb IP extension)

• 2016
• PIN palsy
• PIN does not have cutaneous sensory function (just capsule)

Question 36

36. With respect to the relationship of radius and ulna, all are true EXCEPT:
37. TFCC allows 6mm of longitudinal translation with axial load
38. The fibers of the interosseous membrane are oriented from proximal on the radius to distal on the ulna
39. The most important part of the interosseous membrane is a narrow central band

Answer 36

ANSWER: A

• 2011
• Noda K - Interosseous Membrane of the Forearm: An Anatomical Study of Ligament Attachment Locations
• The most representative component of the IOM is the central band
• Runs obliquely from the proximal radial shaft to the distal ulnar shaft
• TFCC - allows 3-4 mm axial translation (Sagars/millers)

Question 37

37. When doing an FCR approach, the nerve at greatest risk is: *REPEAT
38. Recurrent motor branch of median nerve
39. Palmar cutaneous branch of median nerve
40. Median nerve
41. Superficial radial nerve

Answer 37

ANSWER: B

• 2012, 2015, 2016 (variants)
• McCann PA (Ann R Coll Surg 2012) The cadaveric anatomy of the distal radius
  
  • The structure most at risk was the palmar cutaneous branch of the median nerve. It was located on average 3.4mm from the FCR tendon
  • Radial artery 7.8mm
  • Median nerve 8.9mm
  • SRN 24.4

Question 38

38. AIN after it branches off median nerve is likely to match up with which of the following
39. FCR
40. FCU
41. FDS
42. FDP

Answer 38

ANSWER: D

• 2008

Course

• arises 5-8 cm distal to lateral epicondyle
• passes between two heads of pronator teres
• runs along the volar surface of the FDP
• courses distally along the interosseous membrane
• terminates in PQ near wrist joint

Question 39

39. What doesn’t AIN innervate?
40. PQ
41. All of FDP
42. Volar joint capsule (DRUJ)
43. Volar joint capsule (carpals)

Answer 39

ANSWER: B

• 2009
• Only D2/3
• D3/4 by ulnar nerve

Question 40

40. Recurrent laryngeal nerve is branch of what
41. Vagus
42. Superior branch of laryngeal
43. Accessory spinal nerve

Answer 40

ANSWER: A

• 2013

Question 41

41. With regards to pulleys in the hand, what is false?
42. A1 has no useful function
43. C1 is distal to A2
44. C2 is distal to A4
45. A2 and A4 are the most important

Answer 41

ANSWER: C

• 2009

Question 42

42. List 4 poor prognostic factors for septic arthritis. (2011, 2014)

Answer 42

• Weston WC (Ann Rheum Dis 1999) Clinical features and outcome of septic arthritis in a single Uk Health District 1982-1991
  
  • Risk Factors of Mortality:
    
    • Confusion at presentation
    • Age > 65
    • Multiple joint sepsis
    • Elbow involvement
  • Risk Factors of Morbidity
    
    • Age > 65
    • DM
    • Open surgical drainage
    • Gram positive infection other than S aureus
• Gupta MN (Rheum 2001) Prospective 2 year study of 75 patients with adult-onset septic arthritis
  
  • Poor prognosis/mortality
  • Elevated WBC at presentation
  • Development of abnormal renal function
• Shirtliff ME (Clin Microbiol Rev 2002) Acute Septic Arthritis
  
  • Underlying joint disease (delay in diagnosis)
  • Poly-articular involvement

Question 43

43. 16 yr old with Gr II open tibia with zero tetanus vaccinations and an anaphylactic reaction to penicillin:

• What abx to use?
• What immunization?
• What surgical treatment needed?

Answer 43

What antibiotic to use ?

• Clindamycin
• Piptazo also an option
  
  • Redfern J (JOT 2016) Surgical site infections in patients with type 3 open fractures : comparing cefazolin plus genta vs piptaz

What Immunization?

Tetanus Prone Wound:

• More than 6 hours old
• Stellate
• Avulsion or abrasion configuration
• Depth more than 1 cm
• Mechanism: missile, crush, burn, frostbite
• Signs of infected/devitalized tissue
• Grossly contaminated

What surgical treatment to implement?

• Irrigation and debridement
• Early flap coverage if needed (shouldn’t be needed for grade II)
• Reamed IM nail

Question 44

43. A previously healthy kids presents with pain to mid tibia with a fever and elevated ESR. Consistent with osteomyelitis. Kid comes from an area with a high prevalence of MRSA. What antibiotic do you start?
44. Rifampin
45. Cefazolin
46. Clindamycin
47. SMP-TMX

Answer 44

ANSWER: C

• 2016
• See 2009, 2013 question below

Similar to 2013 Questions, but Vanco an option for answer on this

• Their Reference:
• Bratzler, D. W., Dellinger, E. P., Olsen, K. M., Perl, T. M., Auwaerter, P. G., Bolon, M. K., et al. (2013). Clinical Practice Guidelines for Antimicrobial Prophylaxis in Surgery. Surgical Infections, 14(1), 73–156. doi:10.1089/sur.2013.9999
  
  • Talks about clean procedures, those with hardware
  • MRSA = use vanco, some decolonization stuff
• JAAOS 2015 – MRSA Infections in Kids
  
  • Vancomycin at 15mg/kg q6h
  • If stable: then consider Clindamycin at daily dose of 40mg/kg
  • If regional clindamycin resistance is low (<10%)

Question 45

44. You are performing joint replacement surgery in a hospital with a high frequency of MRSA. What antibiotic should you give pre op?
45. Cefazolin
46. Clindamycin
47. Vancomycin
48. Pipericillin

Answer 45

ANSWER: A

• 2009, 2013
• Antimicrobial prophylaxis for surgery: An Advisory Statement from the National Surgical prevention project
• ..”there is no evidence that routine use of vancomycin for prophylaxis in institutions with perceived high rates of MRSA infection will result in fewer SSIs than do agents such as cefazolin”
• Bhandari - Evidence Based Medicine
• “cephalosporins remain the standard prophylactic antibiotic. MRSA screen and treatment of carriers is not universal. Vancomycin is not routinely used for surgical prophylaxis, but may be used in patients with known or suspected MRSA infection or carriage”
• If confirmed colonization or prev MRSA in one pt would give ancef and vanco together.

Question 46

45. All are ways to decrease HIV transmission in HIV patients except:
46. Use single gloves only when doing arthroscopy
47. Doing instrument ties
48. Wearing waterproof gowns
49. Passing sharps in a bin

Answer 46

ANSWER:A

• 2012
• JAAOS 1996 - HIV transmission in surgical setting
  
  • Step by step minimization of sharps
  • Use of instrument ties
  • Use of magnetic trays or basins to pass sharps
  • Lower blood contact if double gloved

Question 47

46. C-diff, all true except?
47. Toxic megacolon can be a deadly complication
48. Associated with toxins A & B
49. Treatment of choice is oral Vanco or Flagyl
50. Cannot caused by 1 dose of prophylactic abx

Answer 47

ANSWER: D

• 2012
• CDC Guidelines
  
  • Enzyme immunoassay (EIA) testing for C. difficile toxin A and B is rapid but is less sensitive than the cell cytotoxin assay, and it is thus a suboptimal alternative approach for diagnosis (B-II).
  • Metronidazole (flagyl) is the drug of choice for the initial episode of mild-to-moderate CDI. The dosage is 500 mg orally 3 times per day for 10–14 days. (A-I)
  • Vancomycin is the drug of choice for an initial episode of severe CDI. The dosage is 125 mg orally 4 times per day for 10–14 days. (B-I)
  • Vancomycin administered orally (and per rectum, if ileus is present) with or without intravenously administered metronidazole is the regimen of choice for the treatment of severe, complicated CDI. The vancomycin dosage is 500 mg orally 4 times per day and 500 mg in approximately 100 mL normal saline per rectum every 6 hours as a retention enema, and the metronidazole dosage is 500 mg intravenously every 8 hours.
  • Receipt of antimicrobials increases the risk of CDI because it suppresses the normal bowel flora, thereby providing a “niche” for C. difficile to flourish. Both longer exposure to antimicrobials, as opposed to shorter exposure,47 and exposure to multiple antimicrobials, as opposed to exposure to a single agent, increase the risk for CDI.47 Nonetheless, even very limited exposure, such as single-dose surgical antibiotic prophylaxis, increases a patient’s risk of both C. difficile colonization82 and symptomatic disease.

Question 48

47. Which is most sensitive for detecting infection?
    a. Technecium Bone scan
    b. MRI
    c. WBC Scan
    d. XRAY

Answer 48

ANSWER: B

(MRI most sensitive)

• 2012, 2015
• AAOS Review:
  
  • MRI can detect subtle marrow changes associated with early osteomyelitis with almost 100% sensitivity
• JPO 2015 - Pediatric Osteoarticular Infection Update
  
  • MRI remains the best available study for anatomic detail
  • Addition of gad improves abscess detection
• JAAOS - Acute Hematogenous OM in Children
  
  • MRI has a reported sensitivity of 88-100%. Technetium 99m bone scintigraphy …reported sensitivity from 84-100%

Question 49

48. A kid presents with hip pain with inability to weightbear, elevated ESR (50), elevated WBC (14) and a temperature of 37.8. What is the risk this is septic arthritis?
49. 10%
50. 30%
51. 50%
52. 90%

Answer 49

ANSWER: D

• 2016
• Kocher MS (JBJS 1999)
  
  • Criteria: NWB, WBC > 12, Temp > 38.3oC, ESR >40
  • 0 – 0.2%; 1 – 3.0%; 2 – 40.0%; 3 – 93.1%; 4- 99.6%
• Kocher MS (JBJS 2004)
  
  • Validation of the tool
  • 0 – 0.2%; 1 – 9.5%; 2 – 35.0%; 3 – 72.8%; 4 – 93.0%

Question 50

49. How does bacteria adherence to a plate promote infection and allow resistance to systemic antibiotics ?
50. Builds a scaffold that allows bacterial growth
51. Coated in host proteins
52. Shields itself with a biolfilm

Answer 50

ANSWER: C

• Presumably a biofilm question
• Lancet 2004 – Osteomyelitis:
  
  • A biofilm is a microbial community characterized by cells that attach to substratum or interface or to each other, embedded in a matrix of extracellular polymeric substance, and showing an altered phenotype in terms of growth, gene expression, and protein production
  • Bacterial resistance through low metabolic rates, adaptive stress responses and downregulated cell division 
• JAAOS 2015 – Novel developments in the prevention, diagnosis and treatment of Periprosthetic joint infections
  
  • Allows bacterial population to evade antimicrobial therapies and immune response of the host
  • Bacteria may go into quiescent state once in film, making them even harder to kill (so not growing)
  • 1000x more resistant to antibiotics
  • Low metabolic levels and drastically down regulated cell division
  • Dispersion via detachment à micro-colonies
  • S. aureus can hide in osteoblast to evade immune system
• JAAOS – Chronic Infection
  
  • Chronic osteomyelitis is a biofilm infection caused by complex colonies of phenotypically diverse microorganisms propagating freeing within a microbial-based, polysaccharide matrix that provides an immunity to host defenses and systemic concentrations of antimicrobial agents
• Biofilms: Survival mechanisms of clinically relevant microorganism (Clin Microb Reviews 2002)
  
  • The new definition of a biofilm is a microbially derived sessile community characterized by cells that are irreversibly attached to a substratum or interface or to each other, are embedded in a matrix of extracellular polymeric substances that they have produced, and exhibit an altered phenotype with respect to growth rate and gene transcription

Question 51

50. Aquatic environments. All true except:
51. Vibrio is the most common bacteria in fresh and salt water
52. Clostridium present
53. Need antibiotic coverage for Aeromonas Hydrophilia
54. Pseudomonas and Aeromonas Hemophilia are uncommon bacteria in salt water

Answer 51

ANSWER: A

• 2008
• Management of extremity trauma and related infections occurring in the aquatic environment
  
  • Animals inoculated with ocean water have infection with Vibrio, aeromonas hydrophilia, pseudomonas putrefaciens
  • Still the most common infection is staph and strep
  • Clostridium species are present in seawater, patients treated with wounds in brackish or ocean water should be treated with tetanus
    
    • Vibrio are common in oceans and costal waterways
    • Present with rapidly progressive cellulitis
    • Doxycycline, ceftazidime, cipro
  • Aeromonas hydrophilia
    
    • Freshwater lakes, ponds, streams
    • Can develop bullous cellulitis
    • Ciprofloxacin, ceftazidime

Question 52

52. All of the following regarding transient osteoporosis is true except:
53. Happens mostly in middle aged men
54. Half of cases are in the upper extremity
55. It is associated with no significant loss of range of motion
56. It is self-limiting

Answer 52

ANSWER: B

2012

JAAOS 2008 - Transient Osteoporosis

• TO affects mostly young and middle-aged men and, rarely, women during the last 3 months of pregnancy or immediate postpartum period
• Typically involves only the lower extremities, especially the hip joint and, less frequently, the knee, ankle and foot
• Pain worse with weight bearing and associated with limping, then gradual subsidence in 4-9 months
• Minimal restriction of ROM and pain at extremes
• Cause unknown
• Labs usually non-contributory, but differentiate from other pathologies
• Demineralization on radiographs (delayed 3-6 weeks from onset)
• TO is a self-limited disease

Question 53

53. All of the following are true, EXCEPT?
54. Both rickets and osteomalacia are due to deficient mineralization of osteoid
55. Osteoporosis in Caucasian females is defined as a bone mineral density T-score 1.5 below the mean
56. Estrogen preserves bone mineral density by decreasing the frequency of bone remodeling cycles
57. Vertebral compression fractures are twice as common as hip fractures

Answer 53

ANSWER: B

2014

Rickets = osteomalacia

Osteoporosis t < -2.5

Question 54

54. What are two mechanisms of action of BMP? (2011)

Answer 54

OKU 10

• Induces differentiation of mesenchymal stem cells to osteoprogenitor cells
• Recruitment of mesenchymal stem cells
• Stimulation of angiogenesis

Question 55

55. What are 4 adverse effects of BMP-2 in spinal fusion? (2016)

Answer 55

JAAOS - BMP in Spine Surgery:

• Retrograde ejaculation
• Post-operative radiculitis
• Osteolysis
• Seroma formation
• Ectopic bone formation
• Massive soft-tissue swelling

Red ROSES

Question 56

56. 65yo female with history of bisphosphonate use presents with proximal femur fracture. List 5 X-RAY findings associated with bisphosphonate therapy (atypical femur fracture). (2015)

Answer 56

JAAOS - Atypical Femur Fractures

• Lateral cortical beaking
• Generalized increase in cortical thickness of femoral diaphysis
• Transverse tension side fracture line
• Minimal fracture comminution
• Bilateral incomplete diaphyseal fractures

Question 57

57. Which drug do you have to stop before TKA for a rheumatoid patient
58. Hydroxychloroquine
59. Glucosamine and Chondroitan
60. Prednisone
61. Methotrexate

Answer 57

ANSWER: B

2013

• Lower extremity arthroplasty in patients with inflammatory arthritis: pre and perioperative management. J Am Acad Orthop Surg. June 2013. vol. 21 no. 6 355-363
• the 5 g’s of herbal medicines to stop before surgery: Gingko balboa, garlic, glucosamine, guava, ginseng. They increase bleeding time (PTT)
• Hydroxycholorquine: This is Not an immunosuppressant and may confer benefits for anti-embolism post-op. Therefore, it should be continued peri-operatively. 
• Prednisone: There is an increased risk of infection if the patient is using over 5mg per day, and this risk increases with increasing duration of therapy. You cannot stop it peri-operatively though because the patient will have their endogenous steroid production chronically suppressed from their prednisone treatment. They therefore cannot mount a stress response to produce their own corticosteroid. The European league against rheumatism has recommended stress dose of 100mg hydrocortisone intraop
• Methotrexate: This is continued perioperatively as recommended by an international task force. There is slight increase in post op infection risk, but the infection risk is higher with corticosteroids 
• Anti-tnf agents such as infliximab should be stopped – they increase infection risk. Can be restarted 2 weeks after surgery.

Question 58

58. What is the mechanism of action of Botox?
59. Inhibits ACTH release from presynaptic vesicles
60. Inhibits calcium release from sarcoplasmic reticulum
61. Blocks ACTH post-synaptic receptor
62. GABA agonist

Answer 58

ANSWER: A

2012

JAAOS 2003 - Botulinum Neurotoxin Type A

The final effect of the toxin is a reduction in the release of acetylcholine at the nerve terminal

Question 59

59. What is a side effect of bisphosphonates
60. femoral head necrosis
61. mandible osteonecrosis
62. osteopenia
63. Hypocalcemia

Answer 59

ANSWER: B

2008

Question 60

60. Regarding bisphosphonate use in the pediatric population, all are true EXCEPT?
61. Osteonecrosis of jaw
62. Flu-like symptoms
63. Limb pain
64. May have delayed healing of osteotomies performed in osteogenesis imperfecta patients

Answer 60

ANSWER: A

2014

• JAAOS - Osteogenesis Imperfecta:
• 29 - “pamidronate therapy was associated with a delay in bone healing after osteotomy but not after fracture”
• Osteonecrosis of the jaw is a condition associated with bisphosphonate therapy
• JAAOS - Orthopedic Implications of Diphosphonate Therapy
• IV bisphosphonates associated with low grade fever, myalgai, arthralgia and malaise for 24-72 hours
• Up to 32% with first infusion
• Lovell and Winter, 7th ed:
• “despite the concern about osteonecrosis of the jaw in adult patients taking bisphosphonates, there is no clinical evidence of this complication among pediatric patients with dental procedures nor is the author aware of case reports of this complication in children
• Hernandez M (J Oral Pathol Med 2016) Use of new targeted cancer therapies in children: effect on dental development and risk of jaw osteonecrosis
• To date, there has been no reported case of ONJ in children treated with bisphosphonates

 

Question 61

61. Mechanism of function of biologics in RA:
62. TNF agonist
63. TNF antagonist
64. IL-2 antagonist
65. IL-2 agonist

Answer 61

ANSWER: B

• 2015
• JAAOS 2015 - Perioperative treatment of patients with Rheumatoid Arthritis
• Majority of biologics are TNFa - Etanercept, infliximab, adalimumab
• Are some IL-1 (Anakirnra, Rituximab-4 weeks)

Question 62

62.  Fight bite. What antibiotic?
63. Keflex
64. Amox-Clav
65. TMP/SMX

Answer 62

ANSWER: B

2009, 2011, 2016 (variation on options)

JAAOS 2015 - Human and Other Mammalian Bite Injuries of the Hand

• Common Bacteria Isolated from Infected Bite Wounds:
• Aerobic - Step, Staph, Eikenella, Haemophilus, Enterobacteriacae, Gernella, Neisseria
• Anaerobic - Prevotella, Fusobacterum, Eubacterium, Veillonella, Peptostreoptococcus

Question 63

63. Vancomycin. All are true EXCEPT
64. Cleared by glomerular filtration
65. Red man syndrome can be prevented by slow administration
66. Measuring peaks is more useful than measuring troughs in determining effective dosing
67. Inhibits cell wall formation

Answer 63

ANSWER: C

2008

Question 64

64. In your hospital, among patients with a post-op wound infection, 35% of them have MRSA. What do you use for pre-op prophylaxis?
65. Cefazolin
66. Vanco
67. Clinda
68. Gentamicin

Answer 64

ANSWER: A

2009

2013 ASHP Clinical practice guidelines for anti-microbial prophylaxis in surgery

• “Routine use of vancomycin prophylaxis is not recommended for any procedure. Vancomycin may be included in the regimen of choice when a cluster of MRSA cases have been detected at an institution. Vancomycin prophylaxis should be considered in patients with known MRSA colonization or at high risk for MRSA colonization in the absence of surveillance data”
• “Although vancomycin is commonly used when the risk of MRSA is high, data suggest that vancomycin is less effective than cefazolin for preventing SSIs caused by MSSA.”

Question 65

65. All of the following medications for osteoporosis are anti-resorptive, except:
66. Risedronate
67. Alendronate
68. Denosumab
69. Teraperitide

Answer 65

ANSWER: D

 2016

JAAOS 2004 – Parathyroid Hormone

• “approved antiresorptive treatments include the bisphosphonates alendronate and risendronate, raloxifene ( a selective estrogen receptor modulator) and calcitonin”
• “Unlike antiresorptive medications that reduce bone resorption, parathyroid hormone is an anabolic agent that enhances osteoblastic bone formation”

Question 66

66. What is the mechanism of action of teraparitide?
67. Causes osteoclast apoptosis
68. Causes increased osteoblast activity
69. Increased RANK-L and decreased OPG, therefore increased osteoclasts and resorption
70. Increased serum calcium by blocking renal excretion

Answer 66

ANSWER: B

2016

JAAOS 2004 – Parathyroid Hormone

Preferential stimulation of osteoblastic activity over osteoclastic activity

Jilka RL (J Clin Invest 1999) Increased bone formation by prevention of osteoblast apoptosis with PTH

Question 67

67. 16 yo female with epilepsy, on Dilantin. Hx of osteomalacia. Why?
68. Failure of hydroxylation of 24-25 vitamin D
69. Failure of hydroxylation of 25- vitamin D
70. Failure of resorption calcium in kidney
71. Decrease calcium gut absorption

Answer 67

ANSWER: D

2011

• Pack AM (CNS Drugs 2001) Adverse effects of antiepileptic drugs on bone structure
• Rat studies indicated phenytoin caused marked decrease in intestinal calcium transport
• Patients taking Dilantin have low levels of 25-vitamin D
• • As it relates to patients taking phenytoin, it is known that these patients have lower levels of 25-hydroxyvitamin D levels and can begin to manifest as early as 60 days after starting phenytoin.
• The mechanism for this reduction in 25-hydroxyvitamin D is due to phenytoin’s ability to cause a dose-dependent inhibition of active calcium transport by intestinal epithelial cells (see figure provided).
• Charles- multiple theories, most accepted is decrease gut calcium absorption but another is activation of 24-hydoxylase that removesssss 25-hydroxyl from 25-vitamin D
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5493830/pdf/ijcn-11-048.pdf
• Vitamin D inactivation by AEDs occurs mainly by induction of hepatic enzymes and by their activation of pregnane X receptor (PXR) and steroid and xenobiotic receptors (SXR) (22, 30). Activation of vitamin D (D2 and D3) occurs initially in the liver where they are hydroxylated to 25(OH) D by vitamin D hydroxylase CYP27A. The antiepileptic drug binds and activates SXR. This complex binds to RXR, which then activates the 24-hydroxylase enzyme by interacting with its vitamin D responsive element (31, 32). This enzyme mediates the removal of 25-hydroxyl group from both 25-hydroxyvitamin D and 1,25 dihydroxy vitamin D. This accelerated inactivation of vitamin D causes a cascade of events to adapt to the progressive insufficiency leading to secondary hyperparathyroidism. Further hypovitaminosis D results in decreased absorption of calcium from the gut. It has a detrimental effect on bone mineralization and metabolism. The above mechanism have been attributed to AEDs which are inducers of cytochrome P450 enzyme system (phenobarbitol, phenytoin and carbamazepine) (33).The other mechanism postulated include reduced intestinal calcium absorption (phenytoin) (34), impaired response to parathyroid hormone (phenobarbitone and phenytoin), (35) hypovitaminosis K (phenytoin) (36), and calcitonin deficiency (37).

Question 68

8. What is true of the Osteoporosis Screening Index (OST) for men?
9. Age and weight
10. BMI
11. History of fragility fractures
12. History of low energy fractures

Answer 68

ANSWER: A

2010

• The simplest tool is the Osteoporosis Self-assessment Tool (OST), which is based on age and body weight alone
• https://reader.elsevier.com/reader/sd/pii/S8756328213001841?token=0F84E4F451665C70FE744C77AA927DA471C84BE4F9106CF085D4D94083FB20CD803C987D88CCB668E607E24B3520D017
• OST = (weight in kg - age in years) x 0.2
• Correlates with risk of osteoporosis
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3960559/pdf/JOS2014-781897.pdf

Question 69

69. Which of the following is most likely to be associated with Type I osteoporosis :
70. Intertrochanteric fracture
71. Femoral neck fracture
72. Femoral shaft fracture
73. Pubic ramus fracture

Answer 69

ANSWER: A

2008

• JAAOS 1993 - OP Role Orthopod
• Type 1 - Hormone Related
  
  • 50-75, female 6:1
  • Trabecular bone
  • Vertebrae, distal radius, intertrochanteric fractures
• Type 2 - old age
  
  • Age > 75, female 2;1
  • Cortical and trabecular bone loss
  • Vertebral body, femoral neck fractures, pelvic fractures

Question 70

70. All are true with regards to HIT, except:
71. Cannot be caused by LMWH
72. Mild to Moderate thrombocytopenia in general
73. Get arterial thrombosis

Answer 70

ANSWER: A

2013

• DiGiovanni (FAI 2008) Current concepts review: Heparin-Induced Thrombocytopenia
• Clinically significant form of HIT occurs in 1-3% of patients receiving UFH and in only 0.3-0.8% of patients receiving LMWH
• Type 1:
• Not immune mediated
• Not thromboembolic or hemorrhagic
• Mild, transient decrease in platelets 1-2 days after exposure…usually not below 100,000
• Type 2:
• Systemic autoimmune response triggered by completes between heparin and platelet factor 4
• At least 4 days after exposure
• Life threatening
• Increased rate of thrombotic events for up to 30 days
• Precipitous drop in platelets greater than 50% from baseline

Question 71

71. What is true about anabolic steroids?
72. Does not impact musculotendinous junction
73. Decreased threshold to tendon rupture (Dal Stem)
74. Effects are irreversible
75. Increased strength of tendons

Answer 71

ANSWER: B

2010

• Evans (AJSM 2004) Current Concepts Anabolic Steroids
• Tendon rupture is based on small number of case reports
• Induces reversible changes in tendon structure
• Stiffer, less elastic tendon
• Ultimate strength is unaffected
• Rapid increases in skeletal muscle are not matched in tendon structures (weak link in chain)

Question 72

72. Effect of T3 and T4 on bone
73. Increases bone resorption and deposition
74. Decreases bone resorption and deposition
75. Increases resorption, decreases deposition
76. Increases deposition, decreases resorption

Answer 72

ANSWER: A

2009

Uptodate.com

• “High levels of T3 and T4 are associated with increased bone turnover. Bone cells are stimulated to both increase bone resorption and bone synthesis. The more profound effect of resorption results in demineralization of bone and therefore increases the risk of fractures and mineral abnormalities i.e hypercalcemia. Both osteoblastic and osteoclastic activities are upregulated, but the osteoclastic activity dominates, resulting in decreased BMD and an increased risk of fragility fractures.”

Question 73

73. 4 ways a plate can function other than buttress (2012)

Answer 73

• Bridge plate
• Compression Plate
• Neutralization Plate
• Spring Plate
• Tension-band
• Rim Plate
• Locking/Fixed Angle Device

Question 74

74. Definition of the area under the curve in a stress-strain curve:
75. Energy to yield point
76. Energy to fatigue
77. Energy to failure
78. Stiffness

Answer 74

ANSWER: C

2012, 2015

Orthobullets:

Toughness = amount of energy per volume a material can absorb before failure/fracture

Question 75

75. Young’s modulus greatest to least:
76. stainless steel, titanium, cortical bone, PMMA
77. stainless steel, cobalt-chrome, PMMA, cortical bone
78. stainless steel, titanium, PMMA, cortical bone

Answer 75

ANSWER - A

2011, 2014

From Orthobullets

Young’s modulus of elasticity measure of the stiffness (ability to resist deformation) of a material in the elastic zone

Calculated by measuring the slope of the stress/strain curve in the elastic zone

A higher modulus of elasticity indicates a stiffer martial 

Relative values of Young’s modulus of elasticity (numbers correspond to numbers on illustration to right)

1. Ceramic (Al2O3)
2. Alloy (Co-Cr-Mo)
3. Stainless steel
4. Titanium
5. Cortical bone
6. Matrix polymers
7. PMMA
8. Polyethylene
9. Cancellous bone
10. Tendon / ligament
11. Cartilage

Question 76

76. What is an anisotropic substance?
77. Stainless steel
78. Bone
79. CoCr

Answer 76

ANSWER: B

2016

AAOS Comprehensive Review (p63)

• “Isotropic materials (for example, stainless steel, titanium alloys) have the same mechanical properties along all axes or in all directions within these materials”
• “In contrast to isotropic materials, anisotropic materials (bone, cartilage, muscle, ligaments, carbon-fiber composites) exhibit varying mechanical properties along different axes or in different directions within these materials under loading. This anisotropic behavior is a result of specifically oriented constituent parts of these materials, such as collage fibrils or crystals. “
• “Bone is anisotropic as a result of the orientation of its components”

Question 77

77. What type of healing do you have with a statically locked femoral IM nail?
78. Absolute stability, primary healing
79. Relative stability, secondary (callus) healing
80. Absolute stability, secondary (callus) healing
81. Relative stability, primary healing

Answer 77

ANSWER: B

2014

Question 78

78. The ability of a surface to resist plastic deformation is defined as:
79. Scratch resistance
80. Surface tension
81. Hardness
82. Elasticity

Answer 78

ANSWER: C

2015

Wisdom from Richard:

• Hardness is the resistance to plastic deformation (e.g., a local dent or scratch). Thus, it is a measure of plastic deformation, as is the tensile strength, so they are well correlated. Historically, it was measured on an empirically scale, determined by the ability of a material to scratch another, diamond being the hardest and talc the softer. Now we use standard tests, where a ball, or point is pressed into a material and the size of the dent is measured

Question 79

79. Shown a stress-strain curve of 2 materials. Material N had a steeper initial slope, a lower yield point and a larger plastic deformation stage. Material M had a more gradual slope with a higher yield point and a larger zone of elasticity, but more or less no plastic deformation zone. Picture below is basically what the curve looked like.
80. N has more plastic deformation
81. N has a higher elastic limit
82. N has a lower modulus of elasticity

Answer 79

ANSWER: A

2016

Note: above curve is drawn wrong: axis should be switched

• Miller’s Orthopedics/Orthobullets
• Young’s Modulus of Elasticity = Stress/strain  So C is wrong
• Elastic Limit (yield point)
• Transition between elastic to plastic
• Beyond this point it is irreversibly changed
• First change in the slope of the curve

Question 80

80. Which of the following describes hydrodynamic lubrication?
81. Water phase pushed out of cartilage
82. Fluid between two surfaces with plastic deformation
83. Decrease in friction between two opposing surfaces with a fluid boundary
84. Fluid prevents two moving surfaces from contacting each other

Answer 80

ANSWER: D

2008, 2010, 2011, 2014 (variations)

Miller’s Review - page 43-44

• Elastohydrodynamic lubrication - elastic deformation of articular surfaces and thin films of joint lubricants separate surfaces
• Coefficient of friction a function of lubricant, not surfaces
• Boundary Lubrication - bearing surface is non-deformable, lubrication only partially separates surfaces
• Boosted (fluid entrapment) - lubricating fluid in pools, trapped by regions of surfaces that are in contact
• Hydrodynamic - fluid separates surfaces when one surface is sliding on the other
• Weeping - fluid shifts out of cartilage in response to load

Question 81

81. What decreases strain on the plate in plating a lateral tibial plateau fracture:
82. Medial purchase with the screws (Other schools - Medial cortical contact)
83. Larger screws
84. Subchondral locking screws
85. Decreased working length’

Answer 81

ANSWER: A

2015

• Lots of effort/stress by 2016 group….mainly around use of strain in the stem (likely word remember issues, as strain of the plate is inherent to its shape and materials and wouldn’t change)
• Logic:
• Larger screws increase level force placed through plate
• Subchondral locking screws –> locking screws move as a single unit and therefore transfer more force to the plate
• Decreased working length increases point stresses between closes screws
• Medial purchase reduces cantilever effect, therefore reducing force transfer

Question 82

82. Regarding tension band wiring, all are true EXCEPT?
83. The medial malleolus is an example of a dynamic tension band
84. Tension band wire can neutralize tensile forces, and in fact can convert them in compression forces with joint flexion
85. A plate on the tension side of bone can act as a tension band
86. Using it on the tension side of a bone will lead to compression on the opposite cortex

Answer 82

ANSWER: A

2009, 2014

Example of a static tension band

AO Surgery Reference:

• “If a tension band produces fairly constant force at the fracture site during motion, such as the medial malleolus, it is called a static tension band. Conversely, if the compression increases with motion, such as in the patella with knee flexion, the tension band is called dynamic”

Question 83

83. Regarding functional loads in stable joints, all are true except?
84. Small change in direction of functional loads will not result in sudden shift in the joint
85. There is edge loading with normal ROM
86. Joints have a smooth ROM
87. Functional loads will not result in pain during normal ROM

Answer 83

ANSWER: B

2012

Question 84

84. What are 3 advantaging of coning the xrays. (2011, 2013)

Answer 84

• Collimation reduces the size of the beam –> reduces scatter exposure to the surgeon
• Reduce radiation dose to the patient
• Better quality image

Question 85

85. Three phases of muscle repair (2012)

Answer 85

• Inflammatory
• Muscle Regeneration/Repair
• Fibrosis/Remodeling

Question 86

86. Four changes in muscles with endurance training (2012)

Answer 86

AAOS Comprehensive Review 2

Endurance Training:

• Changes in central and peripheral circulation (increased capillary density)
• Muscle metabolism
• Increased mitochondrial size, number and density
• Increase in Krebs enzymes
• Increased use of fatty acids over glycogen
• Oxidative capacity of all fibre types increased
• Increased percentage of type I fibres

Question 87

87. 45 yr old male going for a TKA (hemophilia). (2010)
88. What level should their factor level (hemophilia) be pre-op ?
89. How long should these levels be maintained post-op ?
90. Bogus question - Exact wording “How would this patient’s outcome compare with an unaffected person with Hemophilia” ?

Answer 87

JAAOS 2008 - Hemophilic Arthropathy

• 80-100% fact infusion 30 min before surgery
• Factor levels maintained at 80-100% over 2 days, then taper to day 6
• Similar results to a matched cohort of patients
• MARKED higher risk of infection in hemophiliacs

Length of stay for hemophilic patients after TKA is sub- stantially longer than for those with other types of arthritis. In a report of 23 TKAs in 15 hemophilic patients, Thomason et al32 indicated a mean length of stay of 38 days (range, 21 to 73 days). The usual length of stay at our center is 12 to 16 days, which is necessary to closely monitor factor levels and provide a physical thera- py regimen that could not be accom- plished on an outpatient basis. The greatest likelihood of postoperative hemarthrosis is between postopera- tive days 7 and 10, regardless of clot- ting factor leve

Question 88

88. With depletion of ATP in hypoxia secondary to hypovolemia, which of the following represents the correct description for changes in the intracellular milieu? REPEAT
89. Decreased sodium, increased potassium, decreased water
90. Decreased sodium, decreased potassium, decreased water
91. Increased sodium, decreased potassium, no change in water
92. Increased sodium, decreased potassium, increased water

Answer 88

ANSWER: D

2011, 2012 (variants)

If pump doesn’t work, NO ATP, NA+ Cl- stains intra, water stays with Na+, and K+ can’t get in

Question 89

89. What electrolyte abnormality is associated with hypovolemic shock resuscitated with normal saline?
90. Hyperchloremic metabolic alkalosis
91. Hypochloremic metabolic acidosis
92. Hyperchloremic metabolic acidosis
93. Increased sodium bicarb

Answer 89

ANSWER: C

2012, 2015

Lira (Annals of Intensive Care 2014) Choices in fluid type and volume during resuscitation

Normal saline use is associated with hyperchloremic metabolic acidosis and increased risk of AKI. The risk is decreased when balanced salt solutions are used.

Question 90

90. Which of the following is false regarding proteoglycans? REPEAT 
91. They consist of 30% of the articular cartilage by weight
92. They are composed of a protein core
93. They are hydrophobic
94. They are sulfated

Answer 90

ANSWER: C

2012

Hydrophilic –> draw in water

make up 10% of wet weight of cartilage (but 30% of DRY weight)

Question 91

91. What cells produce hyaluronic acid for the synovial fluid?
92. Synoviocytes
93. Chondrocytes near the tide mark
94. Specialized synovial neutrophils
95. Chondrocytes at the surface of the articular cartilage

Answer 91

ANSWER - A

2011, 2014

AAOS Comprehensive Review 2 - pg 95-100

• Synovial Cells:
• Type A - important in phagocytosis
• Type B - fibroblast-like cells that produce synovial fluid
• Zones of cartilage (from joint space to bone):
• Superficial: collagen oriented parallel to joint; only zone where progenitor cells are found
• Middle/intermediate: collagen oriented randomly
• Deep: collagen oriented perpendicular to joint; highest concentration of proteoglycans
• Tidemark: transition from cartilage to subchondral zone (remnant of cartilage anlage)

Question 92

92. Which cell is not present in inflammatory phase of healing?
93. osteocytes
94. osteoclasts
95. PMNs
96. Macrophages Paste

Answer 92

ANSWER: A

2011

Osteocyte Apoptosis and Osteoclast Presence in Chicken Radii 0–4 Days Following Osteotomy – Calcified tissue international 2005 Clark

Question 93

93. After fracture healing, when is blood flow greatest? (prob after fracture, during healing)
94. 5-7 days
95. 2 weeks
96. 6 weeks
97. 4 weeks

Answer 93

ANSWER: B

2011

Miller’s Orthopedics:

Blood flow initially decreases then rises within hours and peaks at week 2, returning to normal at 3-5 months

Question 94

94. Type 2 collagen is the primary component of which structure
95. Annulus fibrosis
96. Nucleus pulposis
97. Vertebral body

Answer 94

ANSWER - B

2014

Roberts S (JBJS 2006) - Histology and Pathology of the Human Intervertebral Disc

Nucleus pulposus cells generally synthesize only type-II collagen in alginate beads, whereas anulus fibrosus cells produce both type-I and type-II collagen

Question 95

95. What causes muscular tears?
96. Eccentric contractures
97. Concentric contractures
98. Repetitive exertion to sub-injury levels
99. Cannot remember the last option

Answer 95

ANSWER: A

2009, 2014

JAAOS 1999 - Muscle Strain Injury

Forcible stretching of a muscle…most often during an eccentric contraction when the muscle is being lengthened as it contracts

Generates higher forces than concentric

Question 96

96. All of the following are true regarding somatosensory evoked potentials (SSEP), EXCEPT?
97. IV anesthetics interfere with SSEP more than inhalational
98. Muscle relaxation will not interfere with SSEP & actually may be beneficial as it improves quality of readings
99. SSEP may have to be volume averaged to decrease background noise
100. SSEP may involve stimulation of posterior tibial nerve and recording transcranial cortical response

Answer 96

ANSWER: A

2009, 2014

AAOS Comprehensive Review 2

• Not a real-time test because information is averaged to extract background noise
• Cortical or subcortical responses to the repetitive stimulation of a mixed peripheral nerve
• Gives information on the posterior spinal column
• 50% change in amplitude is cause for concern than changes in latency
• Can be changed by anesthetics, nitrous oxide, hypothermia, hypotension
• JAAOS - Spinal Monitoring
• Mention SSEP compromised by halogenated anesthetic agents and NO (inhalational)
• JAAOS - Neurologic Injury in the Surgical Treatment of Idiopathic Scoliosis
• To facilitate intubation, aesthesia is typically induced with IV propofol and a single dose of a non-depolarizing neuromuscular relaxant. This combination allows excellent sedation without interfering with neuromonitoring
• Inhalation agents may cause false reduction in recorded amplitude and increased latencies
• Motor Evoked Potential (MEP)
• Function
• monitor integrity of lateral and ventral corticospinal tract of the spinal cord
• Technique signal initiation
• transcranial stimulation of motor cortex
• signal recording
• muscle contraction in extremity (gastroc, soleus, EHL of lower extremity)
• Advantages
• effective at detecting a ischemic injury (loss of anterior spinal artery) in anterior 2/3 of spinal cord
• Disadvantages
• often unreliable due to effects of anesthesia
• Intraoperative considerations
• loss of signals during distraction mandates immediate removal of device and repeated assessment of monitoring signals
• Mechnical Electromyography (spontaneous)
• Introduction
• monitor integrity of specific spinal nerve roots
• Technique concept
• microtrauma to nerve root during surgery causes deplorization and a resulting action potential in the muscle that can be recorded
• contact of a surgical instrument with nerve root will lead to “burst activity” and has no clinical significance
• significant injury or traction to a nerve root will lead to “sustained train” activity, which may be clinically significance
• signal initiation
• mechanical stimulation (surgical manipulation) of nerve root
• signal recording
• muscle contraction in extremity
• Advantages
• allows monitoring of specific nerve roots
• Disadvantages
• may be overly sensitive (e.g., sustained train activity does not neccessary reflect nerve root injury)

Question 97

97. What is associated with sickle cell anemia? *REPEAT
98. RBC’s can sickle at normal oxygen tension
99. Presentation of bone infarct is similar to osteomyelitis
100. Heterozygous individuals are symptomatic
101. No increased risk of infection

Answer 97

ANSWER: B

2015

• Almeida A (British Journal of Hematology 2005) Bone Involvement in Sickle Cell Disease
• Osteomyelitis usually presents with pain, swelling and tenderness over the affected area. The most common sites are the femur, tibia or humerus. Most patients also have fever and elevated inflammatory markers (but the fever may be modest). These signs and symptoms are similar to those found in vaso occlusive crises, making the distinction between a painful crisis and osteomyelitis extremely difficult on clinical grounds.
• Skaggs DL (JBJS 2001)
• Differentiation between osteomyelitis and bone infarct is challenging
• JAAOS 2005 “Total hip arthroplasties in sickle cell hemoglobinopathies”
• Pyogenic infections occur secondary to splenic autoinfection. Makes you more susceptible to polysaccharide-encapsulated organisms. These can cause osteomyelitis

Question 98

98. What is the first change, which occurs in muscle fibers with the initiation of a resistance-training program (also remembered as: what allows you to become stronger during initial phase of training?)
99. Increased number of myofibrils
100. Increased capillaries
101. Recruitment of more motor unit
102. Increase of oxidative capacity

Answer 98

ANSWER: C

2013

AAOS Comprehensive Review 2

Strength training:

Increased muscle cross-sectional area

Muscle hypertrophic rather than hyperplasia

Increased motor unit recruitment or synchronization

Adaptation of all fibre types

Question 99

99. What is an example of a closed chain exercise:
100. Hamstring curls
101. Straight leg raise in a cast
102. Eccentric contraction of biceps while holding a dumbbell
103. Squatting 10lbs with feet on the ground

Answer 99

ANSWER: D

2015

Closed Chain = feet fixed

Question 100

100. Regarding MRI with gadolinium, which is true?
101. Can be fatal in patients with renal insufficiency
102. Cannot distinguish between an abscess and a phlegmon
103. Cannot differentiate between cyst and tumor
104. Cannot differentiate between tumor and necrotic tissue

Answer 100

ANSWER: A

2015

Patients with kidney failure can get nephrogenic systemic fibrosis (NSF)

Question 101

101. Which of the following is true regarding a typical gait cycle?
102. Maximal vertical displacement at mid stance
103. Maximal vertical displacement occurs at the same time as maximal horizontal displacement
104. 50% kinetic energy becomes ….
105. Stance phase takes up 70% of gait cycle

Answer 101

ANSWER: A

2016

Orthobullets/AAOS Comprehensive Review

• Maximal vertical displacement at midstance
• Maximal horizontal displacement as weight transferred to support leg so….terminal swing/initial contact, not mid swing
• Stance phase 60-62%

Question 102

102. What muscles are firing during mid-swing phase of gait?
103. only tib-ant
104. psoas and tib-ant
105. psoas, hamstrings, tib-ant
106. psoas, quads, tib-ant

Answer 102

ANSWER - A

2014, 2015

JAAOS 2002 - A Practical Guide to Gait Analysis

Miller’s , orthobullets and https://ouhsc.edu/bserdac/dthompso/web/gait/kinetics/mmactsum.htm

Initial swing = hip flexors and knee extensors continue preswing activity, dorsiflexors act concentrically to clear ground

Mid swing = muscle activity CEASES EXCEPT dorsiflexors to continue clearing ground (pendulum)

Terminal swing = hamstring decelerate forward motion of thigh

AAOS Core Review

Mid swing - hip flexion, knee extension, ankle DF

Knee extension provided by momentum of hip flexors

Question 103

103. Vertebral body forms from?
104. mesoderm
105. ectoderm
106. endoderm
107. neural crest

Answer 103

ANSWER: A

2011, 2014

Lovell and Winter:

• Mass of ectodermal cells forms archenteron
• Floor of this becomes notochondral plate
• Forms neural structures
• Mesoderm breaks up into blocks of cells to form the somites which become vertebral bodies and discs

Question 104

104. Rheumatoid Factor
105. It has prognostic value
106. It has diagnostic value
107. Positive in 15% of general population
108. It is an IgG

Answer 104

ANSWER: A

2008

• JAAOS 2003 - Ordering and Interpreting Rheumatologic Laboratory Tests
• RF is an IgM antibody against an IgG
• Only found in 1-2% of normal people
• RF is only present in 20% of JRA, 80% of adults
• Level of RF is prognostic, the higher the level the worse the prognosis

Question 105

105. Ankylosing Spondylitis, what is false
106. Seronegative spondyloarthropathy
107. HLA B27 95% of time
108. 10-15% positive family history
109. Starts in the disc before SI joints

Answer 105

ANSWER: D

2008

Sacroiliitis is hallmark of early disease

Question 106

106. Woven bone has the following characteristics (need help for stems here)
107. Collagen is randomly oriented (or in disorder)
108. Haversians
109. Cement line interdigitation
110. Canaliculi or something like that

Answer 106

ANSWER: A

2009

Question 107

107. With the large c-arm. All of the following decrease radiation except:
108. Giving surgeon control
109. Inverting c-arm
110. Placing limb closer to x-ray generator
111. Something about collimation that was true 

Answer 107

ANSWER: C

2009

JAAOS 2005:

• Potential decrease in radiation exposure can be accomplished by:
• Reduced exposure time
• Increased distance from beam
• Increased shielding
• Beam collimation (narrower beam)
• Using lower dose
• Inverting the C-arm
• Surgeon control of C-arm

Question 108

108. What is true about hemophilia A
109. Associated with Factor IX
110. Women never get hemophilia A
111. Hemophilia is X-linked recessive
112. Usually sporadic mutation

Answer 108

ANSWER: C

• 2019
• Hemophilia is X-linked recessive
• Types
• Classic (Hemophilia A) – Deficiency of factor VIII
• Christmas disease (Hemophilia B) – Deficiency of factor IX
• Also x-linked recessive
• 1/3 spontaneous
• Sex-linked recessive inheritance
• Therefore usually MALES however in rare cases, females (therefore not NEVER)

Question 109

109. Distal humeral alignment in relation to the humeral shaft (these are the ACTUAL answers, for sure):
110. Anteversion 5, valgus 5, IR 6
111. Anteversion 5, varus 5, ER 6
112. Anteversion 30, valgus 5, IR 6
113. Anteversion 30, varus 5, ER 6

Answer 109

ANSWER: C

2019

• anteversion 30, valgus 5, IR 6
• Valgus 5
• The medial plate incorporates 6–8° valgus alignment for the carrying angle. As the articular surface of the two condyles are not in the same coronal plane, the distal end of the medial plate was rotated about 5° internally and bent 30° anteriorly in relation with the humeral shaft. 

Question 110

110. You injure the superior gluteal nerve. What is affected?
111. Glut max
112. TFL
113. Pectineus
114. Obturator internus

Answer 110

ANSWER: B

2019

Netter’s anatomy

GLut max = inf gluteal

Repeat 2016

Question 111

111. Tranexamic acid. All true except
112. Can cause colour blindness
113. Cleared by liver. So no need to renally dose
114. Can be administered IV, orally or topically
115. Is a synthetic compound that inhibits fibrinolysis and clot degradation.

Answer 111

ANSWER: B

2019

• https://rdcr.org/wp-content/uploads/symp2012pdf/Effects%20of%20tranexamic%20acid%20-%20Joseph%20Rappold.pdf
• Can cause color vision changes….contraindication to TXA is color blindness since cannot determine if TXA toxicity or previously acquired

Question 112

112. What is true about brachial plexus palsy?
113. C5-C6 is associated with Horner’s
114. If there is no return of biceps function at 3 months, this is suggestive of a neurotmetic injury (nerve and nerve sheath disrupted, most severe)
115. Primary repair of neurotmetic root avulsion is possible
116. Phrenic nerve injury suggests a preganglionic injury

Answer 112

ANSWER: D

2019

• JAAOS 1997 - Obstetric Brachial Plexus Injuries: Evaluation and Management
• Specifically, the presence of Horner’s syndrome (sympathetic chain), an elevated hemidiaphragm (phrenic nerve), or a winged scapu- la (long thoracic nerve) raises serious concern about a preganglionic lesion, as does the absence of rhomboid (subscapular nerve), rotator cuff (suprascapular nerve), and latissimus dorsi (thoracodorsal nerve) function.

Question 113

113. What is true about far cortical locking plates?
114. More stiff than standard femoral locking plate
115. Asymmetric callus
116. Increased volume of callus
117. Decreased density of the callus

Answer 113

ANSWER: C

2019

JOT - Biomechanics of Far Cortical Locking, less stiff and more callus

JBJS - Far Cortical Locking Can Improve Healing of Fractures Stabilized with Locking Plates

Conventional Locking plates = asymmetric callus

Far cortical locking plates = less stiff = more callus

Question 114

114. What is true about adaptive changes in endurance athletes?
115. Muscle hypertrophy
116. More efficient oxygen extraction
117. Increased contractile myoproteins

Answer 114

ANSWER: B

2019

• https://www.orthobullets.com/knee-and-sports/3118/exercise-science
• Endurance (aerobic) Training
• results in changes in circulation and muscle metabolism
• contractile muscle adapts by increasing energy efficiency
• increases in mitochondrial size, number, and density
• increases in enzymes involved in Krebs cycle, fatty acid processing, and respiratory chain
• over time, increased use of fatty acids > glycogen
• over time, oxidative capacity of Type I, IIA, and IIB fibers increase
• percentage of more highly oxygenated IIA fibers increases
• Aerobic Threshold: level of effort at which anaerobic energy pathways become significant energy producer
• Anaerobic (lactate) Threshold: level of effort at which lactate production > lactate removal

Question 115

115. Which is not soley innervated by the obturator nerve?
116. Gracilis
117. Adductor Longus
118. Adductor Magnus
119. Adductor Brevis

Answer 115

ANSWER: C

2019

b. Adductor magnus – obt + sciatic
c. Obturator internus – n to OI
d. Pectineus – fem vs obt
e. Semimembranosis – sciatic

MAGNUS has MANY innervations

Question 116

16.What are the 3 main static stabilizers of the posterolateral corner?

1. Fibular collateral ligament, arcuate ligament, popliteus tendon
2. Fibular collateral ligament, popliteus tendon, popliteofibular
3. Fibular collateral ligament, fabellofibular, popliteofibular
4. Fibular collateral ligament, popliteofibular ligament, arcuate ligament

Answer 116

ANSWER: B

2019

• Posterolateral corner structures
• three major static stabilizers of the lateral knee
• lateral collateral ligament (LCL)
• most anterior structure inserting on the fibular head
• primary varus stabilizer of the knee
• popliteus tendon (PLT)
• popliteofibular ligament
• originates at the musculotendinous junction of the popliteus
• anterior and posterior divisions
• other static stabilizers
• lateral capsule thickening
• meniscofemoral and meniscotibial ligaments
• arcuate ligament (variable)
• fabellofibular ligament (variable)
• dynamic structures
• biceps femoris
• inserts on the posterior aspect of the fibula posterior to LCL
• popliteus muscle
• iliotibial band (ITB)
• lateral head of the gastrocnemius
• Function
• popliteus works synergistically with the PCL to control external tibial rotation, varus, and posterior tibial translation
• popliteus and popliteofibular ligament function maximally in knee flexion to resist external rotation
• LCL is primary restraint to varus stress at 5° (55%) and 25° (69%) of knee flexion
• Definitions
• arcuate complex includes the static stabilizers: LCL, arcuate ligament, and popliteus tendon

Question 117

117. With respect to the vascularity of the femoral head, all is true EXCEPT:
118. The ascending lateral branch is the main blood supplies the antero-lateral epiphysis occurring at age 3-4
119. The ascending lateral cervical branch is a branch of the LFCA
120. Attenuation of the MFCA and LFCA occurs resulting in no communication of vascularity between epiphysis and metaphysis until age 14-16
121. Lig teres is primary blood supply until age 4 months, then decreases by 8 years, then becomes 20% of blood supply to femoral head by early adulthood

Answer 117

ANSWER: B

2019

• The posterior superior branch of the lateral ascending circumflex artery travels posterosuperior to the physis and enters the anterolateral capital femoral epiphysis as the dominant capital blood supply at age 3 to 4 years.
• The posterior superior branch of the lateral ascending circumflex artery travels posterosuperior to the physis and enters the anterolateral capital femoral epiphysis as the dominant capital blood supply at age 3 to 4 years. This vessel arises proximally from the medial femoral circumflex artery.
• Branches of the medial and lateral femoral circumflex arteries traverse the physis at birth but attenuate by age 3 to 4 years, leaving no vascular communication between the metaphysis and epiphysis until physeal fusion occurs at age 14 to 17 years.
• The contribution of vessels from the ligamentum teres decreases from birth to age 4 months and increases from age 8 years to provide a peak of 20% of total supply to the femoral head in early adulthood before declining with age.

Question 118

118. All of the following are true about hypercalcemia, except?
119. Psychosis
120. Polyuria
121. Polydipsia
122. Carpopedal spasm

Answer 118

ANSWER: D

2019

Question 119

119. Some huge stem about multiple ankle sprains, but then asks, which of the following is not a major criteria for the Beighton score:
120. Passive Thumb dorsiflexion to the forearm (yes they said dorsiflexion)
121. Hyperextension of the knee by 10deg
122. Index finger MCP (yes they said index finger) past 90 deg
123. Able to touch palms to floor with knees fully extended

Answer 119

ANSWER: A and C

2019

Question 120

120. In an L4-L5 far lateral disc, what is the functional deficit
121. EHL extension
122. Ankle dorsiflexion
123. Ankle plantar flexion
124. Hip flexion

Answer 120

ANSWER: B

2019

Question 121

121. What is true with respect to radiation safety?
122. Mini c arm may not decrease radiation exposure to the surgeon
123. The radiation exposure to the hand is equivalent thyroid and eyes
124. With a mini-C, not necessary to wear eye protection
125. Wearing lead gloves does not help reduce radiation to the hands

Answer 121

ANSWER: A

2019

The relative safety and decreased scatter radiation exposure associated with a mini-C-arm is the

result of imaging smaller body parts, which are held directly against the image intensifier at lower kilovoltage settings. Singer et al34 reported that a mini C-arm, if used for imaging

identical body parts and in identical configurations as a standard C-arm, is associated with 53% to 70% greater scatter radiation exposure than a standard C-arm. The use of a mini C-arm rather than a standard C-arm for a given case should not alter a surgeon’s vigilance with regard to

radiation safety.

Question 122

122. With respect to HIV associated arthritis?
123. A synovial aspirate will be non –inflammatory
124. Knee and elbow are the most commonly affected sites
125. Symptoms typically develop over 3 to 6 months
126. Xray findings look the same as primary osteoarthritis

Answer 122

ANSWER: A

• 2019
• There is an NON inflammatory, but sterile pattern on synovial fluid analysis with white cell count in the region of 50–2600 cells/μL, and normal glucose. ANA, Rheumatoid Factor and HLA B27 are negative
• The asymmetric, oligo arthritis variant is the most common form, has a male preponderance, and predominately affects the knees and ankles
• HIV-associated arthritis tends to be short lived with its peak intensity occurring in 1 to 6 week
• Radiological changes can occasionally mimic RA, with joint space narrowing, erosions and periarticular osteopenia
• Think its between B&D

JAAOS 2002

HIV-Associated Arthritis

HIV-associated arthritis, a subacute oligoarthritis, was first described by Rynes et al24 in 1988 and is unique to HIV-infected patients. Symptoms typically develop over 1 to 6 weeks and may last up to 6 months. Characteristic features include exquisite, incapacitating joint pain, predominantly in the knee and ankle. Synovial fluid analysis reveals a noninflammatory reaction with a white blood cell count in the range of 50 to 2,600/mm3. Radiographic findings are typically unremarkable, although osteopenia may be evident from disuse or chronic synovitis. Synovial biopsy shows a chronic process with a predominantly mononuclear cell infiltrate.

Proposed etiologies include a reactive mechanism to deposited immune complexes or direct HIV infection of the synovium. The latter theory has been supported by a positive culture assay for HIV in the synovial fluid of a patient with this condition.27 Neither rheumatoid factor nor HLA-B27 antigen are associated with this particular arthritis, which may help distinguish it from other arthropathies. Intraarticular steroid injections have proved to be an extremely effective, safe, and rapid treatment, and no cases of secondary infections have been reported. HIV infection should be considered with any suspicion of bacterial or mycobacterial arthritis.

Question 123

123. With respect to proximal hamstring anatomy, what is true? 
124. SemiT and Semi M make up the conjoint tendon 
125. Long head of biceps to the antero-medial ischial tuberosity 
126. Semi-membranosus attaches antero-lateral to the semi-membranosus (semi-t?)
127. Conjoint tendon attaches to the postero-lateral aspect of the ischial tuberosity 

Answer 123

ANSWER: C

2019

Question 124

124. What is a valgus stabilizer of the elbow in extension? 
125. FDP  
126. Pronator teres 
127. Posterior bunder of MCL 
128. Olecranon 

Answer 124

ANSWER: D

2019

Biomechanics. The medial soft-tissue structures of the elbow are subjected to tensile forces with valgus stress. In 1983 Morrey and An24 showed that the structures that resist valgus force contribute different amounts depending on the angle of elbow flexion. In full extension, roughly one third of valgus force was resisted by the UCL (31%), one third by the anterior capsule (38%), and one third by the bony architecture (31%). At 90° of flexion, the UCL increased its relative contribution to 54%, whereas the anterior capsule provided only 10% to valgus stability, and the bony anatomy contribution remained unchanged (36%).

Question 125

125. You are doing a lateral approach the hip, what nerve is most risk with proximal dissection with an abductor split? 
126. SGN 
127. IGN 
128. Obturator 
129. LFCN 

Answer 125

ANSWER: A

2019

Question 126

126. What is the primary blood supply to the ligamentum teres of the hip? 
127. Obturator artery 
128. Femoral artery 
129. Superior gluteal artery 
130. Inferior gluteal artery 

Answer 126

ANSWER: A

2019

Question 127

127. What is the correct order of volar wrist ligaments from radial to ulnar? 
128. Radioscaphocapitate, long radio-lunate, short radio lunate,  ulno-lunate, unlo-triquetral 
129. Radioscapholunate, long radio-lunate, short radio-lunate, ulno-lunate, unlo-triquetral 
130. Radioscaphocapitate, short radio lunate, long radiolunate, ulno-lunate, unlo-triquetral 
131. Radioscapholunate, short radio lunate, long radiolunate, ulno-lunate, unlo-triquetral 

Answer 127

ANSWER: A

2019

Question 128

128. Which of the following has an attachment to the volar plate in the hand? 
129. FDS 
130. Part of the collateral ligaments 
131. Lumbricals 
132. Natatory ligament

Answer 128

ANSWER: B

2019

of the finger 

Netter’s

Accessory collateral ligament (so tight in extension)

Question 129

129. What is the arrow pointing to…
130. Common iliac artery
131. Internal iliac artery
132. Superior gluteal artery
133. Pudendal artery

Answer 129

Answer: B (2017) – internal iliac

Question 130

130. What is true regarding vitamin D
131. Supplementation is shown to decrease non-union rates
132. Supplementation definitely improves fracture healing
133. >60% of elderly people with fractures have low vitamin D
134. The recommended dose is 200 IU daily

Answer 130

Answer: C (2017)

A- False – only true if vitD Deficient

B – False. Nothing is definite.

C- True – can’t find source

D – False. Too low.

• Those over 50 or those younger adults at high risk (with osteoporosis, multiple fractures, or conditions affecting vitamin D absorption) should receive 800 – 2,000 IU daily.
• • Metabolic and endocrine abnormalities have long been linked with decreased fracture healing. In a re- cent series of 683 orthopaedic trauma patients diagnosed with frac- ture nonunion, 37 were referred to an endocrinologist for evaluation of an endocrine or metabolic abnormal- ity.21 Of these, 84% (31 of 37 pa- tients) had a newly diagnosed endo- crine abnormality, and 68% (25 of 37) were found to be vitamin D defi- cient. In eight of these patients, the nonunion healed following medical treatment alone . JAAOS

Question 131

131. In regards to TXA use, all the following statements are true except
132. Can be administered IV, orally or topically
133. Is a synthetic compound that inhibits fibrinolysis and clot degradation.
134. Can cause visual disturbances and impairment of color vision.
135. TXA is cleared by the liver, so no adjustments need to be made for patients with impaired renal function.

Answer 131

Answer: D (2017)

True

True

True

false

Question 132

132. All of the following are true about the MFCA and femoral head blood supply except?
133. Anastomoses with SGA
134. Must dissect superior to piriformis to protect blood supply
135. MFCA is the major blood supply
136. MCFA and LCFA branch off of profunda

Answer 132

Answer: A (2017)

A – False – the inferior gluteal artery anastamoses with MFCA

B – IGA & MFCA along distal/inferior border of piriformis muscle

C – true

D- true

The transverse branch of lateral circumflex femoral artery is a small artery in the thigh. It is the smallest branch of the lateral circumflex femoral artery and passes lateralward over the vastus intermedius, pierces the vastus lateralis, and winds around the femur, just below the greater trochanter, anastomosing on the back of the thigh with the medial femoral circumflex artery, the inferior gluteal artery, and the perforating arteries of the profunda femoris artery.

The lateral femoral circumflex artery arises from the lateral side of the profunda femoris artery

Question 133

133. Which of the following nerve(s) can cause scapular winging?
134. Long thoracic
135. Dorsal scapular
136. Spinal accessory
137. All of the above

Answer 133

ANSWER: D

2018

• Medial winging is the long thoracic nerve (serratus anterior) and dorsal scapular nerve (rhomboids and levator scap)
• lateral wining is spinal accessory nerve (traps)

Dorsal scapular nerve syndrome typically presents with a weakness of the levator scapulae and the rhomboid muscles, and results in a winged scapula

Question 134

134. What is NOT true about the axillary nerve?
135. If comes out of the quadrangular space and is LATERAL to the long head of the triceps
136. It comes off of the posterior cord and is located ANTERIOR to the subscap
137. The posterior branch innervates the teres minor but has no sensory contribution

Answer 134

ANSWER: C

2018

Charles changed question to NOT true– both a and b are true

-both anterior and posterior branches have sensory contribution

It is protected at the inferior aspect of the glenoid by abducting the arm à decreases distance when abduct arm

Question 135

135. What is the dominant blood supply to the humeral head
136. Posterior circumflex
137. Anterior circumflex
138. Medial circumflex
139. ? some other weird option

Answer 135

ANSWER: A

2018

• -constroversial, older studies say anterior circ but newer studies postulate posterior circ
• -we thought exam would opt to favour newer literature
• Between the two circumflex arteries, ACHA was previously reported to gives off one arcuate artery which entered the proximal humerus to provide dominant blood supply for the humeral head [9,10]. However, PCHA was believed to play a greater role in the blood supply to humeral head in most of the recent studies [4,11,14]. In our study, the diameter of PCHA was observed to be much larger than that of ACHA, which provided indirect evidence for the dominance of PCHA in the blood supply of humeral head.
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4099027/pdf/1471-2482-14-39.pdf/?tool=EBI

Question 136

136. In regard to Rheumatoid IL-1/TNF inhibitors, what is recommended perioperatively?
137. Hold for 2 weeks pre op and 2 weeks post op
138. Hold for 3 weeks post op
139. Hold them and but give a longer duration of antibiotics
140. ?don’t hold them

Answer 136

ANSWER: A

2018

Question 137

137. What is the mechanism of BMP
138. Induces cells that stay alive in the donor bone
139. Induces the RANK-L pathway
140. Stimulates cells to become mature osteoblasts
141. Something about mesynchymal stem cells

Answer 137

ANSWER: C

2018