Basic Science 2013

Question 1

9. Which treatment technique for segmental nerve defects leads to the best motor recovery?
10. Silicon tube
11. Collagen tube
12. Nerve allograft
13. Nerve autograft
14. Direct repair with tension

Answer 1

4. Nerve autograft

RECOMMENDED READINGS

Giusti G, Willems WF, Kremer T, Friedrich PF, Bishop AT, Shin AY. Return of motor function after

segmental nerve loss in a rat model: comparison of autogenous nerve graft, collagen conduit, and

processed allograft (AxoGen). J Bone Joint Surg Am. 2012 Mar 7;94(5):410-7. PubMed PMID: 22398734.

􀀧􀁈􀁄􀁏􀀃􀀧􀀱􀀏􀀃􀀪􀁕􀁌􀁉􀂿􀁑􀀃􀀭􀀺􀀏􀀃􀀫􀁒􀁊􀁄􀁑􀀃􀀰􀀹􀀑􀀃􀀱􀁈􀁕􀁙􀁈􀀃􀁆􀁒􀁑􀁇􀁘􀁌􀁗􀁖􀀃􀁉􀁒􀁕􀀃􀁑􀁈􀁕􀁙􀁈􀀃􀁕􀁈􀁓􀁄􀁌􀁕􀀃􀁒􀁕􀀃􀁕􀁈􀁆􀁒􀁑􀁖􀁗􀁕􀁘􀁆􀁗􀁌􀁒􀁑􀀑􀀃􀀭􀀃􀀤􀁐􀀃􀀤􀁆􀁄􀁇􀀃􀀲􀁕􀁗􀁋􀁒􀁓􀀃

Surg. 2012 Feb;20(2):63-8. Review. PubMed PMID: 22302443.

Question 2

22. Figure 22 is the sagittal MRI scan of the spine of a 68-year-old woman with a history of chronic back painradiating into her right lower extremity. She reports paresthesias involving the right great toe and parts ofher shin. Nonsurgical treatment consisting of pain medications and epidural steroid injections has failed toprovide relief. Assessment of ambulation is most likely to reveal which pathologic gait pattern?
23. Quadriceps avoidance gait attributable to L5 compression and radiculopathy
24. Scissor gait attributable to spondylolisthesis at L4-5 and bilateral radiculopathy
25. Trendelenburg gait attributable to L4 compression and weakness of the gluteus medius
26. Trendelenburg gait attributable to L5 compression and weakness of the gluteus medius
27. Varus thrust gait during stance attributable to L5 compression and posterolateral cornerweakness

Answer 2

4. Trendelenburg gait attributable to L5 compression and weakness of the gluteus medius

RECOMMENDED READINGS

􀀥􀁒􀁑􀁒􀀃􀀦􀀰􀀏􀀃􀀶􀁆􀁋􀁒􀁈􀁑􀁉􀁈􀁏􀁇􀀃􀀤􀀏􀀃􀀪􀁄􀁕􀂿􀁑􀀃􀀶􀀵􀀑􀀃􀀯􀁘􀁐􀁅􀁄􀁕􀀃􀁇􀁌􀁖􀁆􀀃􀁋􀁈􀁕􀁑􀁌􀁄􀁗􀁌􀁒􀁑􀁖􀀑􀀃􀀬􀁑􀀝􀀃􀀫􀁈􀁕􀁎􀁒􀁚􀁌􀁗􀁝􀀃􀀫􀀱􀀏􀀃􀀪􀁄􀁕􀂿􀁑􀀃􀀶􀀵􀀏􀀃􀀨􀁌􀁖􀁐􀁒􀁑􀁗􀀃

FJ, Bell GR, Balderston R, eds. Rothman-Simeone The Spine. 6th ed. Philadelphia, PA: WB Saunders;

2011:887-914.

Keenan MA. Normal and pathologic gait. In: Lieberman JR, ed. AAOS Comprehensive Orthopaedic

Review. Vol 1. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2009:163-170.

Question 3

24. Following laceration, peripheral nerves heal in which manner?
25. Direct repair across the gap by Schwann cells
26. Direct repair of the axon
27. Antegrade growth of the axon
28. Retrograde growth of the axon
29. Formation of collagen bridges by fibroblasts

􀀃 􀀘􀀑􀀃􀀃􀀃􀀃􀀩􀁒􀁕􀁐􀁄􀁗􀁌􀁒􀁑􀀃􀁒􀁉􀀃􀁆􀁒􀁏􀁏􀁄􀁊􀁈􀁑􀀃􀁅􀁕􀁌􀁇􀁊􀁈􀁖􀀃􀁅􀁜􀀃􀂿􀁅􀁕􀁒􀁅􀁏􀁄

􀀃 􀀘􀀑􀀃􀀃􀀃􀀃􀀩􀁒􀁕􀁐􀁄􀁗􀁌􀁒􀁑􀀃􀁒􀁉􀀃􀁆􀁒􀁏􀁏􀁄􀁊􀁈􀁑􀀃􀁅􀁕􀁌􀁇􀁊􀁈􀁖􀀃􀁅􀁜􀀃􀂿􀁅􀁕􀁒􀁅􀁏􀁄􀁖􀁗􀁖

Answer 3

3. Antegrade growth of the axon

RECOMMENDED READINGS

Dodds SD. Peripheral nervous system. In: Lieberman JR, ed. AAOS Comprehensive Orthopaedic Review.

Rosemont, IL: American Academy of Orthopaedic Surgeons; 2009:71-81.

Lee SK, Wolfe SW. Peripheral nerve injury and repair. J Am Acad Orthop Surg. 2000;8(4):243-52. PMID:

10951113.

Gupta R, Mozaffar T. Neuromuscular diseases. In: Einhorn TA, O’Keefe RJ, Buckwalter JA, eds.

Orthopaedic Basic Science: Foundations of Clinical Practice. 3rd ed. Rosemont, IL: American Academy

of Orthopaedic Surgeons; 2007:427-443.

Question 4

38.

A 7-year-old boy with short stature, bowed legs, and back pain has 2 sisters whose appearances

are unremarkable. Laboratory studies show low serum phosphate; his serum calcium, and 25

􀁋􀁜􀁇􀁕􀁒􀁛􀁜􀁆􀁋􀁒􀁏􀁈􀁆􀁄􀁏􀁆􀁌􀁉􀁈􀁕􀁒􀁏􀀃􀁏􀁈􀁙􀁈􀁏􀁖􀀃􀂿􀁑􀁇􀁌􀁑􀁊􀁖􀀃􀁄􀁕􀁈􀀃􀁚􀁌􀁗􀁋􀁌􀁑􀀃􀁇􀁈􀂿􀁑􀁈􀁇􀀃􀁏􀁌􀁐􀁌􀁗􀁖􀀏􀀃􀁅􀁘􀁗􀀃􀁋􀁌􀁖􀀃􀀔􀀏􀀕􀀘􀀐􀁇􀁌􀁋􀁜􀁇􀁕􀁒􀁛􀁜􀁆􀁋􀁒􀁏􀁈􀁆􀁄􀁏􀁆􀁌􀁉􀁈􀁕􀁒􀁏􀀃

levels are below normal. The boy has a male cousin with the same disorder. What type of rickets is the

most likely diagnosis?

1. Renal
2. Vitamin D-deficient

􀀃 􀀕􀀑􀀃􀀃􀀃􀀃􀀹􀁌􀁗􀁄􀁐􀁌􀁑􀀃􀀧􀀐􀁇3. X-linked hypophosphatemic

4. Type I vitamin D-dependent
5. Type II vitamin D-dependen

Answer 4

􀀃 􀀕􀀑􀀃􀀃􀀃􀀃􀀹􀁌􀁗􀁄􀁐􀁌􀁑􀀃􀀧􀀐􀁇􀁈􀂿􀁆􀁌􀁈􀁑􀁗3. X-linked hypophosphatemic

RECOMMENDED READINGS

Carpenter TO, Imel EA, Holm IA, Jan de Beur SM, Insogna KL. A clinician’s guide to X-linked

hypophosphatemia. J Bone Miner Res. 2011 Jul;26(7):1381-8. doi:10.1002/jbmr.340. Epub 2011 May 2.

Review. PubMed PMID: 21538511.

Dietz FR, Murray JC. Genetic basis of disorders with orthopaedic manifestations. In: Einhorn TA, O’Keefe

RJ, Buckwalter JA, eds. Orthopaedic Basic Science: Foundations of Clinical Practice. 3rd ed. Rosemont,

IL: American Academy of Orthopaedic Surgeons; 2007:25-47.

Question 5

52. A 5-year-old boy has superficial heterotopic bone around his chest and difficutly breating. He has one sibling who died of respiratory distress at age 13. The most likely genetic cause of this disorder is a varient in
53. SOX9
54. matrilin 3
55. the FGF3 receptor
56. the BMP type 1 receptor
57. the PTH-PTHrP receptor

Answer 5

4. the BMP type 1 receptor

RECOMMENDED READINGS

Carvalho DR, Navarro MM, Martins BJ, Coelho KE, Mello WD, Takata RI, Speck-Martins CE.

􀀰􀁘􀁗􀁄􀁗􀁌􀁒􀁑􀁄􀁏􀀃􀁖􀁆􀁕􀁈􀁈􀁑􀁌􀁑􀁊􀀃􀁒􀁉􀀃􀀤􀀦􀀹􀀵􀀔􀀃􀁊􀁈􀁑􀁈􀀃􀁌􀁑􀀃􀀥􀁕􀁄􀁝􀁌􀁏􀁌􀁄􀁑􀀃􀂿􀁅􀁕􀁒􀁇􀁜􀁖􀁓􀁏􀁄􀁖􀁌􀁄􀀃􀁒􀁖􀁖􀁌􀂿􀁆􀁄􀁑􀁖􀀃􀁓􀁕􀁒􀁊􀁕􀁈􀁖􀁖􀁌􀁙􀁄􀀃􀁓􀁄􀁗􀁌􀁈􀁑􀁗􀁖􀀑􀀃􀀦􀁏􀁌􀁑􀀃

Genet. 2010 Feb;77(2):171-6. Epub 2009 Oct 1. PubMed PMID: 19796185.

Seo SW, Lee FY. Cellular and molecular biology, immunology, and genetics. In: Lieberman JR, ed. AAOS

Comprehensive Orthopaedic Review. Vol 1. Rosemont, IL: American Academy of Orthopaedic Surgeons;

2009:3-13.

Medvecky MJ. Skeletal muscle. In: Lieberman JR, ed. AAOS Comprehensive Orthopaedic Review. Vol 1.

Rosemont, IL: American Academy of Orthopaedic Surgeons; 2009:83-91.

Question 6

61. Postnatal skeletal linear growth occurs most rapidly during
62. puberty.
63. prepuberty.
64. preschool years.
65. first year of life􀀃 􀀗􀀑􀀃􀀃􀀃􀀃􀂿􀁕􀁖􀁗􀀃􀁜􀁈􀁄􀁕􀀃􀁒􀁉􀀃􀁏􀁌􀁉􀁈􀀑
66. early elementary school years.

Answer 6

3. preschool years

RECOMMENDED READINGS

Dimeglio A. Growth in pediatric orthopaedics. In: Morrissey RT, Weinstein SL, eds. Lovell and Winter’s Pediatric Orthopaedics. 6th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2006:35-65.Herring JA. Limb length discrepancy. In: Herring JA, ed. Tachdjian’s Pediatric Orthopaedics. 4th ed. Philadelphia, PA; WB Saunders; 2008:1191-1263.

Question 7

72. In the setting of skeletal muscle lacerations, which effect does transforming growth factor-beta have on scar tissue formation?
73. Stimulates the proliferation of myocytes and enhances healing
74. Stimulates the proliferation of myofibrobalsts and increases fibrosis􀀃 􀀕􀀑􀀃􀀃􀀃􀀃􀀶􀁗􀁌􀁐􀁘􀁏􀁄􀁗􀁈􀁖􀀃􀁗􀁋􀁈􀀃􀁓􀁕􀁒􀁏􀁌􀁉􀁈􀁕􀁄􀁗􀁌􀁒􀁑􀀃􀁒􀁉􀀃􀁐􀁜􀁒􀂿􀁅􀁕􀁒􀁅􀁏􀁄􀁖􀁗􀁖􀀃􀁄􀁑􀁇􀀃􀁌􀁑􀁆􀁕􀁈􀁄􀁖􀁈􀁖􀀃􀂿􀁅􀁕􀁒􀁖􀁌􀁖
75. Enhances the differentiation of myoblasts and enhances healing
76. Decreases the proliferation of myofibroblasts and reduces fibrosis􀀃 􀀗􀀑􀀃􀀃􀀃􀀃􀀧􀁈􀁆􀁕􀁈􀁄􀁖􀁈􀁖􀀃􀁗􀁋􀁈􀀃􀁓􀁕􀁒􀁏􀁌􀁉􀁈􀁕􀁄􀁗􀁌􀁒􀁑􀀃􀁒􀁉􀀃􀁐􀁜􀁒􀂿􀁅􀁕􀁒􀁅􀁏􀁄􀁖􀁗􀁖􀀃􀁄􀁑􀁇􀀃􀁕􀁈􀁇􀁘􀁆􀁈􀁖􀀃􀂿􀁅􀁕􀁒􀁖􀁌􀁖
77. Decreases the proliferation of myocytes and reduces healing

Answer 7

2. Stimulates the proliferation of myofibrobalsts and increases fibrosis

RECOMMENDED READINGS

Gulotta LV, Rodeo SA. Muscle, tendon, and ligament. In: Flynn JM, ed. Orthopaedic Knowledge Update10. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2011:37-48.Pereira BP, Tan BL, Han HC, Zou Y, Aung KZ, Leong DT. Intramuscular nerve damage in lacerated􀁖 􀁎􀁈􀁏􀁈􀁗􀁄􀁏􀀃􀁐􀁘􀁖􀁆􀁏􀁈􀁖􀀃􀁐􀁄􀁜􀀃􀁇􀁌􀁕􀁈􀁆􀁗􀀃􀁗􀁋􀁈􀀃􀁌􀁑􀃀􀁄􀁐􀁐􀁄􀁗􀁒􀁕􀁜􀀃􀁆􀁜􀁗􀁒􀁎􀁌􀁑􀁈􀀃􀁕􀁈􀁖􀁓􀁒􀁑􀁖􀁈􀀃􀁇􀁘􀁕􀁌􀁑􀁊􀀃􀁕􀁈􀁆􀁒􀁙􀁈􀁕􀁜􀀑􀀃􀀭􀀃􀀦􀁈􀁏􀁏􀀃􀀥􀁌􀁒􀁆􀁋Jul;113(7):2330-45. doi: 10.1002/jcb.24105. PubMed PMID: 22573552.

Question 8

84. What cell is responsible for the production of receptor activator of nuclear factor kappa beta ligand and

osteoprotegerin?

1. Osteocyte
2. Osteoclast
3. Osteoblast
4. Macrophage
5. Preosteoclast

Answer 8

3. Osteoblast

RECOMMENDED READINGS

Boyle WJ, Simonet WS, Lacey DL. Osteoclast differentiation and activation. Nature. 2003 May 15;423(6937):337-42. Review. PubMed PMID: 12748652. Miller JD, McCreadie BR, Alford AI, Hankenson KD, Goldstein SA. Form and function of bone. In: Einhorn TA, O’Keefe RJ, Buckwalter JA, eds. Orthopaedic Basic Science: Foundations of Clinical Practice. 3rd ed. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2007:129-159.

Question 9

100. Which change, if any, will most likely occur within the articular cartilage of the knee as a result of

nonweight bearing for 2 months?

1. No change
2. Cartilage thinning
3. Decreased water content
4. Increased collagen synthesis
5. Increased proteoglycan concentration

Answer 9

2. Cartilage thinning

RECOMMENDED READINGS

Hinterwimmer S, Krammer M, Krötz M, Glaser C, Baumgart R, Reiser M, Eckstein F. Cartilage atrophyin the knees of patients after seven weeks of partial load bearing. Arthritis Rheum. 2004 Aug;50(8):2516-20. PubMed PMID: 15334465.

Sun HB. Mechanical loading, cartilage degradation, and arthritis. Ann N Y Acad Sci. 2010 Nov;1211:37-50. doi: 10.1111/j.1749-6632.2010.05808.x. Review. PubMed PMID: 21062294.

Millward-Sadler SJ, Wright MO, Davies LW, Nuki G, Salter DM. Mechanotransduction via integrins andinterleukin-4 results in altered aggrecan and matrix metalloproteinase 3 gene expression in normal, but notosteoarthritic, human articular chondrocytes. Arthritis Rheum. 2000 Sep;43(9):2091-9. PubMed PMID:11014361.

Question 10

110. At the time of heel strike in normal gait, what is the pattern of activation of the anterior tibialis?
111. Relaxation
112. Isotonic contraction until midstance
113. Concentric contraction followed by relaxation
114. Eccentric contraction throughout the stance phase
115. Eccentric contraction followed by concentric muscle activity

Answer 10

5. Eccentric contraction followed by concentric muscle activity

RECOMMENDED READINGS

Perry J. Normal gait. In: Smith DG, Michael JW, Bowker JH, eds. Atlas of Amputations and Limb􀀧􀁈􀂿􀁆􀁌􀁈􀁑􀁆􀁌􀁈􀁖􀀝􀀃􀀶􀁘􀁕􀁊􀁌􀁆􀁄􀁏􀀏􀀃􀀳􀁕􀁒􀁖􀁗􀁋􀁈􀁗􀁌􀁆􀀏􀀃􀁄􀁑􀁇􀀃􀀵􀁈􀁋􀁄􀁅􀁌􀁏􀁌􀁗􀁄􀁗􀁌􀁒􀁑􀀃􀀳􀁕􀁌􀁑􀁆􀁌􀁓􀁏􀁈􀁖. 3rd ed. Rosemont, IL: AmericanAcademy of Orthopaedic Surgeons; 2004:353-365.

Winter DA. Energy generation and absorption at the ankle and knee during fast, natural, and slowcadences. Clin Orthop Relat Res. 1983 May;(175):147-54. PubMed PMID: 6839580.

Question 11

116. In performing a study comparing infection rates for patients undergoing elective orthopaedic surgery whoreceived irrigation with or without the addition of antibiotics in the solution, what is the most appropriate statistical test to determine whether the proportion of patients developing infection is significant?

􀁖􀁗􀁄􀁗􀁌􀁖􀁗􀁌􀁆􀁄􀁏􀀃􀁗􀁈􀁖􀁗􀀃􀁗􀁒􀀃􀁇􀁈􀁗􀁈􀁕􀁐􀁌􀁑􀁈􀀃􀁚􀁋􀁈􀁗􀁋􀁈􀁕􀀃􀁗􀁋􀁈􀀃􀁓􀁕􀁒􀁓􀁒􀁕􀁗􀁌􀁒􀁑􀀃􀁒􀁉􀀃􀁓􀁄􀁗􀁌􀁈􀁑􀁗􀁖􀀃􀁇􀁈􀁙􀁈􀁏􀁒􀁓􀁌􀁑􀁊􀀃􀁌􀁑􀁉􀁈􀁆􀁗􀁌􀁒􀁑􀀃􀁌􀁖􀀃􀁖􀁌􀁊􀁑􀁌􀂿􀁆􀁄􀁑􀁗􀀢

1. ANOVA
2. Paired t test
3. Unpaired t test
4. Chi-square test
5. Bonferroni correction

Answer 11

4. Chi-square test

RECOMMENDED READINGS

Bhandari M. Evidence-based orthopaedics: issues in research design, analysis, and critical appraisal.In: Einhorn TA, O’Keefe RJ,

Buckwalter JA, eds. Orthopaedic Basic Science: Foundations of ClinicalPractice. 3rd ed. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2007:87-101.

Kocher MS, Zurakowski D. Clinical epidemiology and biostatistics: a primer for orthopaedic surgeons. J Bone Joint Surg Am. 2004 Mar;86-A(3):607-20. Review. PubMed PMID: 14996892.

Question 12

119. What component of bone is most responsible for tensile strength?
120. Hydroxyapatite
121. Type I collagen
122. Type II collagen
123. Type X collagen
124. Tricalcium phosphate

Answer 12

2. Type I collagen

RECOMMENDED READINGS

Miller JD, McCreadie BR, Alford AI, Hankenson KD, Goldstein SA. Form and function of bone. In:

Einhorn TA, O’Keefe RJ, Buckwalter JA, eds. Orthopaedic Basic Science: Foundations of ClinicalPractice. 3rd ed. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2007:129-159.

Clohisy JC, Lindskog D, Abu-AmerY. Bone and joint biology. In: Lieberman JR, ed. AAOSComprehensive Orthopaedic Review. Rosemont, IL: American Academy of Orthopaedic Surgeons;2009:41-51.

Question 13

126. A randomized placebo-controlled study of 100 patients was performed to test the hypothesis that Drug A would improve the rate of fracture healing. The study found that patients who received Drug A had a shorter time to fracture healing (P < .05). A subsequent multicenter follow-up study with 1000 patients showed that there was no real difference in fracture healing rates when comparing the drug to the placebo (P=.25). Which kind of error occured in the first study?

􀀋􀀳􀀃􀀠􀀃􀀑􀀕􀀘􀀌􀀑􀀃􀀃􀀺􀁋􀁌􀁆􀁋􀀃􀁎􀁌􀁑􀁇􀀃􀁒􀁉􀀃􀁈􀁕􀁕􀁒􀁕􀀃􀁒􀁆􀁆􀁘􀁕􀁕􀁈􀁇􀀃􀁌􀁑􀀃􀁗􀁋􀁈􀀃􀂿􀁕􀁖􀁗􀀃􀁖􀁗􀁘􀁇1. Type 1

2. Type 2
3. Design
4. Surgeon bias
5. Underpowered study

Answer 13

􀀋􀀳􀀃􀀠􀀃􀀑􀀕􀀘􀀌􀀑􀀃􀀃􀀺􀁋􀁌􀁆􀁋􀀃􀁎􀁌􀁑􀁇􀀃􀁒􀁉􀀃􀁈􀁕􀁕􀁒􀁕􀀃􀁒􀁆􀁆􀁘􀁕􀁕􀁈􀁇􀀃􀁌􀁑􀀃􀁗􀁋􀁈􀀃􀂿􀁕􀁖􀁗􀀃􀁖􀁗􀁘􀁇1. Type 1

RECOMMENDED READINGS

Fosgate GT. Practical sample size calculations for surveillance and diagnostic investigations. J Vet DiagnInvest. 2009 Jan;21(1):3-14. Review. PubMed PMID: 19139495.

Petrisor BA, Bhandari M. Orthopaedic research: health research methodology. In: Flynn JM, ed. Orthopaedic Knowledge Update 10. Rosemont, IL: American Academy of Orthopaedic Surgeons;2011:167-177.

Question 14

134. What is the etiology of fretting corrosion?
135. Oxidation
136. Differences in oxygen tension
137. Micromotion at contact sites under load
138. Impurities entering metal during manufacturing
139. Electrochemical potential between 2 metals in a conductive medium

Answer 14

3. Micromotion at contact sites under load

RECOMMENDED READINGS

Singh K. Biomaterials. In: Lieberman JR, ed. AAOS Comprehensive Orthopaedic Review. Rosemont, IL:American Academy of Orthopaedic Surgeons; 2009:21-28.

Srinivasan A, Jung E, Levine BR. Modularity of the femoral component in total hip arthroplasty. J AmAcad Orthop Surg. 2012 Apr;20(4):214-22. Review. PubMed PMID: 22474091.

Question 15

142. An 85-year-old woman with osteoarthritis of the knee wants to discuss treatment options for her pain.Which drug is most likely to result in serious renal impairment?
143. Tramadol
144. Ibuprofen
145. Oxycodone
146. Hydrocodone
147. Acetaminophen

Answer 15

2. Ibuprofen

Question 16

152. Figure 152 is an arthroscopic view of a reconstructive procedure performed on a 28-year-old man who had a medial femoral osteochondral lesion that measured 1.5 cm x 1.5 cm. The grafts were harvested fromthe superolateral aspect of the trochlea. What is the most accurate description for the process of graftincorporation?
153. The bone graft will be incorporated into the subchondral bone, and the overlying cartilageremains viable.
154. The bone graft will be incorporated into the subchondral bone, but the overlying cartilage isnonviable.
155. The bone graft will be incorporated while the overlying cartilage is used as a scaffold to generate a new cartilage layer.
156. The bone graft will not be incorporated; healing will occur only within the cartilage layer.
157. The bone graft and cartilage will both be resobred and replaced by fibrocartilaginous matrix

􀀃 􀀘􀀑􀀃􀀃􀀃􀀃􀀷􀁋􀁈􀀃􀁅􀁒􀁑􀁈􀀃􀁊􀁕􀁄􀁉􀁗􀀃􀁄􀁑􀁇􀀃􀁆􀁄􀁕􀁗􀁌􀁏􀁄􀁊􀁈􀀃􀁚􀁌􀁏􀁏􀀃􀁅􀁒􀁗􀁋􀀃􀁅􀁈􀀃􀁕􀁈􀁖􀁒􀁕􀁅􀁈􀁇􀀃􀁄􀁑􀁇􀀃􀁕􀁈􀁓􀁏􀁄􀁆􀁈􀁇􀀃􀁅􀁜􀀃􀁄􀀃􀂿􀁅􀁕􀁒􀁆􀁄􀁕􀁗􀁌􀁏􀁄􀁊􀁌􀁑􀁒􀁘􀁖􀀃􀁐􀁄􀁗􀁕􀁌􀁛􀀑

Answer 16

1. The bone graft will be incorporated into the subchondral bone, and the overlying cartilageremains viable.

RECOMMENDED READINGS

O’Driscoll SW, Saris DBF. Articular cartilage repair. In: Einhorn TA, O’Keefe RJ, Buckwalter JA, eds. Orthopaedic Basic Science: Foundations of Clinical Practice. 3rd ed. Rosemont, IL: American Academyof Orthopaedic Surgeons; 2007:349-364.

Hangody L, Dobos J, Baló E, Pánics G, Hangody LR, Berkes I. Clinical experiences with autologous osteochondral mosaicplasty in an athletic population: a 17-year prospective multicenter study. Am J Sports Med. 2010 Jun;38(6):1125-33. Epub 2010 Apr 1. PubMed PMID: 20360608.

Question 17

154. Rivaroxaban is a novel anticoagulant approved for use in thromboprophylaxis after total hip and knee arthroplasty. What is its mechanism of action?
155. Blocks factor V
156. Activates antithrombin III
157. Directly inhibits thrombin
158. Directly inhibits factor Xa
159. Inhibits vitamin K-dependent factors

Answer 17

4. Directly inhibits factor Xa

Question 18

165. Shoulder examination under anesthesia reveals symmetric forward elevation and external rotation in the abducted position. However, external rotation with the arm by the side is decreased by 25 degrees when compared to the contralateral shoulder. Which structure is contracted?
166. Biceps tendon
167. Anterior-inferior capsule
168. Anterior-superior capsule
169. Posterior-superior capsule
170. Acromioclavicular joint capsule

Answer 18

3. Anterior-superior capsule

RECOMMENDED READINGS

Harryman DT 2nd, Sidles JA, Harris SL, Matsen FA 3rd. The role of the rotator interval capsule in passivemotion and stability of the shoulder. J Bone Joint Surg Am. 1992 Jan;74(1):53-66. PubMed PMID:1734014.

Kim KC, Rhee KJ, Shin HD, Kim YM. Estimating the dimensions of the rotator interval with use ofmagnetic resonance arthrography. J Bone Joint Surg Am. 2007 Nov;89(11):2450-5. PubMed PMID:17974888.

Question 19

169. Rheumatoid factor as clinically measured detects antibodies to which antigen?
170. IgG
171. Scl-70
172. Histone
173. Nuclear antigens
174. Ribonucleoprotein

Answer 19

1. IgG

RECOMMENDED READINGS

Gardner GC, Kadel NJ. Ordering and interpreting rheumatologic laboratory tests. J Am Acad Orthop Surg.2003 Jan-Feb;11(1):60-7. Review. PubMed PMID: 12699372.

Mortazavi JSM, Parvizi J. Arthritis. In: Flynn JM, ed. AAOS Orthopaedic Knowledge Update 10.Rosemont, IL: American Academy of Orthopaedic Surgeons; 2011:213-224.

Question 20

179. Figure 179 is a recent pelvic radiograph of a 73-year-old woman who cannot ambulate. She developed blindness as an infant and has a history of difficulty with healing of limb fractures. What defect is associated with her disorder?
180. PEX gene
181. Fibrillin 1
182. Collagen I
183. Collagen oligomeric protein
184. Carbonic anhydrase

Answer 20

5. Carbonic anhydrase

RECOMMENDED READINGS

Dietz FR, Mathews KD. Update on the genetic bases of disorders with orthopaedic manifestations. J Bone Joint Surg Am. 1996 Oct;78(10):1583-98. Review. PubMed PMID: 8876589.

Einhorn TA. Metabolic bone disease. In: Einhorn TA, O’Keefe RJ, Buckwalter JA, eds. Orthopaedic Basic Science: Foundations of Clinical Practice. 3rd ed. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2007:415-426.

Question 21

185. Figures 185a through 185c are the biopsy specimen and radiographs of a 43-year-old man with a slowly enlarging mass in his right proximal tibia. He has normal kidney function. Examination reveals a firm mass with slight tenderness. Which laboratory value is most likely elevated?
186. Serum calcium
187. Serum phosphorous
188. Serum gamma globulin
189. Serum creatine phosphokinase
190. Prostate-specific angiten

􀀃 􀀘􀀑􀀃􀀃􀀃􀀃􀀳􀁕􀁒􀁖􀁗􀁄􀁗􀁈􀀐􀁖􀁓􀁈􀁆􀁌􀂿􀁆􀀃􀁄􀁑􀁗􀁌􀁊􀁈􀁑

Answer 21

1. Serum calcium

RECOMMENDED READINGS

Singhal S, Johnson CA, Udelsman R. Primary hyperparathyroidism: what every orthopedic surgeon should know. Orthopedics. 2001 Oct;24(10):1003-9; quiz 1010-1. Review. PubMed PMID: 11688768.

Mankin HJ, Mankin CJ. Metabolic bone disease: a review and update. Instr Course Lect. 2008;57:575-93.Review. PubMed PMID: 18399611.

Question 22

192. Dessication of the nucleus pulposus results from loss or degradation of which molecule?
193. Matrilin
194. Proteoglycan
195. Type I collagen
196. Type II collagen
197. Type X collagen

Answer 22

2. Proteoglycan

RECOMMENDED READINGS

An HS, Masuda K, Cs-Szabo G, Zhang Y, Chee A, Andersson GB, Im HJ, Thonar EJ, Kwon YM. Biologicrepair and regeneration of the intervertebral disk. J Am Acad Orthop Surg. 2011 Jul;19(7):450-2. Review.PubMed PMID: 21724924.

Kepler CK, Anderson DG, Tannoury C, Ponnappan RK. Intervertebral disk degeneration and emerging biologic treatments. J Am Acad Orthop Surg. 2011 Sep;19(9):543-53. Review. PubMed PMID: 21885700.

Question 23

195. A study was undertaken to compare outcomes of 3 different treatment alternatives. The study wasinitiated after treatments had been completed. What is the best term for this type of study?
196. Case-control
197. Prospective cohort
198. Retrospective cohort
199. Single blinded
200. Prospective randomized blinded and controlled

Answer 23

3. Retrospective cohort

RECOMMENDED READINGS

Petrisor BA, Bhandari M. Orthopaedic research: health research methodology. In: Flynn JM, ed. Orthopaedic Knowledge Update 10. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2011:167-177.

Cox CL, Spindler KP. The design of clinical investigations: randomized, cohort and case studies. In: O’Keefe RJ, Jacobs JJ, Chu CR, Einhorn TA, eds. Orthopaedic Basic Science: Foundations of Clinical Practice. 4th ed. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2013:437-443.

Question 24

199. What is the inheritance pattern of Duchenne muscular dystrophy?
200. Mitochondrial
201. X-linked recessive
202. X-linked dominant
203. Autosomal recessive
204. Autosomal dominant

Answer 24

2. X-linked recessive

RECOMMENDED READINGS

Zane MSM: Pediatric neuromuscular disorders. In: Lieberman JR, ed. AAOS Comprehensive Orthopaedic Review. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2009:293-309.

Dietz FR, Murray JC. Genetic basis of disorders with orthopaedic manifestations. In: Einhorn TA, O’Keefe RJ, Buckwalter JA, eds. Orthopaedic Basic Science: Foundations of Clinical Practice. 3rd ed. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2007:25-47.

Question 25

203. What cell type is responisible for repir of cartilage defects with fibrocartilage following microfracture? 􀀺􀁋􀁄􀁗􀀃􀁆􀁈􀁏􀁏􀀃􀁗􀁜􀁓􀁈􀀃􀁌􀁖􀀃􀁕􀁈􀁖􀁓􀁒􀁑􀁖􀁌􀁅􀁏􀁈􀀃􀁉􀁒􀁕􀀃􀁕􀁈􀁓􀁄􀁌􀁕􀀃􀁒􀁉􀀃􀁆􀁄􀁕􀁗􀁌􀁏􀁄􀁊􀁈􀀃􀁇􀁈􀁉􀁈􀁆􀁗􀁖􀀃􀁚􀁌􀁗􀁋􀀃􀂿􀁅􀁕􀁒􀁆􀁄􀁕􀁗􀁌􀁏􀁄􀁊􀁈􀀃􀁉􀁒􀁏􀁏􀁒􀁚􀁌􀁑􀁊􀀃􀁐􀁌􀁆􀁕􀁒􀁉􀁕􀁄􀁆􀁗􀁘􀁕􀁈􀀢1. Synovial fibroblasts􀀃 􀀔􀀑􀀃􀀃􀀃􀀃􀀶􀁜􀁑􀁒􀁙􀁌􀁄􀁏􀀃􀂿􀁅􀁕􀁒􀁅􀁏􀁄􀁖􀁗􀁖 2. Marrow mesenchymal cells 3. Deep-zone chondrocytes 4. Middle-zone chondrocytes 5. Superficial-zone chondrocytes􀀃 􀀘􀀑􀀃􀀃􀀃􀀃􀀶􀁘􀁓􀁈􀁕􀂿􀁆􀁌􀁄􀁏􀀐􀁝􀁒􀁑􀁈􀀃􀁆􀁋􀁒􀁑􀁇􀁕􀁒􀁆

Answer 25

2. Marrow mesenchymal cells RECOMMENDED READINGS Biswas D, Bible JE, Grauer JN. Articular cartilage. In: Lieberman JR, ed. AAOS Comprehensive Orthopaedic Review. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2009:53-63. Shapiro F, Koide S, Glimcher M. Cell origin and differentiation in the repair of full-thickness defects of articular cartilage. J Bone Joint Surg Am 1993 75A:532–553. PMID: 8478382. Mithoefer K, Williams RJ III, Warren RF, Potter HG, Spock CR, Jones EC, Wickiewicz TL, Marx RG. The microfracture technique for the treatment of articular cartilage lesions in the knee. A prospective cohort study. J Bone Joint Surg Am. 2005 Sep;87(9):1911-20. PubMed PMID: 16140804.

Question 26

2206. A weightlifter is engaged in a curling exercise using a free barbell. He is focused on resisting the weight while his elbow extends. During this maneuver, he feels a snap in his right arm and drops the weight suddenly. He is seen in the emergency department with a palpable prominence in his right biceps. During which type of muscle contraction did this injury occur? 1. Isotonic eccentric 2. Isotonic concentric 3. Isometric eccentric 4. Isokinetic eccentric 5. Isokinetic concentric

Answer 26

1. Isotonic eccentric RECOMMENDED READINGS Lieber RL. Form and function of skeletal muscle. In: Einhorn TA, O’Keefe RJ, Buckwalter JA, eds. Orthopaedic Basic Science: Foundations of Clinical Practice. 3rd ed. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2007:223-243. Gulotta LV, Rodeo SA. Muscle, tendon, and ligament. In: Flynn JM, ed. Orthopaedic Knowledge Update 10. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2011:37-48.

Question 27

229. Parents bring in their 8-year-old son for an evaluation. They are concerned because the boy’s paternalgrandfather and uncle both died from osteosarcoma in their 40s. In addition, rhabdomyosarcoma was recently diagnosed in the boy's first cousin. The family is requesting genetic testing to ascertain their son's risk for developing malignancy. Which gene is most likely responsible for the increased risk for the malignancy? 1. EXT1 2. tX,18 3. t12,22 4. NF1 5. p53

Answer 27

5. p53 RECOMMENDED READINGS Jones KB. Musculoskeletal oncology. In: Flynn JM, ed. Orthopaedic Knowledge Update 10. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2011:193-212. Seo SW, Lee FY. Cellular and molecular biology, immunology, and genetics. In: Lieberman JR, ed. AAOS Comprehensive Orthopaedic Review. Vol 1. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2009:3-13.

Question 28

244. Patients with factor V Leiden are at increased risk for deep vein thrombosis following surgery. What is the effect of the mutation in factor V? 1. Blocks antithrombin III 2. Increases the activity of factor Xa 3. Prevents inhibition by activated protein C 4. Prevents the factor Xa conversion of prothrombin to thrombin 5. Makes it highly susceptible to inhibition by activated protein C

Answer 28

3. Prevents inhibition by activated protein C

Question 29

254. Infliximab (antitumour necrosis factor-alpha antibody) is associated iwth which adverse condition? 􀀬􀁑􀃀􀁌􀁛􀁌􀁐􀁄􀁅􀀃􀀋􀁄􀁑􀁗􀁌􀁗􀁘􀁐􀁒􀁕􀀃􀁑􀁈􀁆􀁕􀁒􀁖􀁌􀁖􀀃􀁉􀁄􀁆􀁗􀁒􀁕􀀐􀁄􀁏􀁓􀁋􀁄􀀃􀁄􀁑􀁗􀁌􀁅􀁒􀁇􀁜􀀌􀀃􀁌􀁖􀀃􀁄􀁖􀁖􀁒􀁆􀁌􀁄􀁗􀁈􀁇􀀃􀁚􀁌􀁗􀁋􀀃􀁚􀁋􀁌􀁆􀁋􀀃􀁄􀁇􀁙􀁈􀁕􀁖􀁈􀀃􀁆􀁒􀁑􀁇􀁌􀁗􀁌􀁒􀁑􀀢1. Osteolysis 2. Osteoporosis 3. Hyperglycemia 4. Atypical fracture 5. Opportunistic infection

Answer 29

5. Opportunistic infection RECOMMENDED READINGS Mortazavi JSM, Parvizi J. Arthritis. In: Flynn JM, ed. Orthopaedic Knowledge Update 10. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2011:213-224. Bongartz T, Sutton AJ, Sweeting MJ, Buchan I, Matteson EL, Montori V. Anti-TNF antibody therapy in rheumatoid arthritis and the risk of serious infections and malignancies: systematic review and metaanalysis of rare harmful effects in randomized controlled trials. JAMA. 2006 May 17;295(19):2275-85. Review. Erratum in: JAMA. 2006 Jun 7;295(21):2482. PubMed PMID: 16705109.

Question 30

270. Figures 270a through 270c are the MRI scans of a 65-year-old man who has pain in his right groin and buttocks. He had a metal-on-metal hip replacement 3 years ago. What is the most likely cause of hispain? 1. Infection 2. Lymphoma 3. Sarcomatous change 4. Large-particle wear debris disease 5. Pseudotumor hypersensitivity response

Answer 30

5. Pseudotumor hypersensitivity response RECOMMENDED READINGS Campbell P, Ebramzadeh E, Nelson S, Takamura K, De Smet K, Amstutz HC. Histological features of pseudotumor-like tissues from metal-on-metal hips. Clin Orthop Relat Res. 2010 Sep;468(9):2321-7.PubMed PMID: 20458645. Kwon YM, Thomas P, Summer B, Pandit H, Taylor A, Beard D, Murray DW, Gill HS. Lymphocyte proliferation responses in patients with pseudotumors following metal-on-metal hip resurfacing arthroplasty. J Orthop Res. 2010 Apr;28(4):444-50. PubMed PMID: 19834954.