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July 2011 CME

1. Which of the following is not correct concerning mesenchymal stem cells at the fracture site in the early stages of healing

a. They can be derived from the bone marrow, circulating blood, periosteum or local tissues
b. They do not express class II major histocompatibility molecules
c. They induce the proliferation of lymphocytes
d They inhibit natural killer cells
e. They suppress cytokine production in response to alloantigens

2. If 10 million mononuclear cells are obtained from a sample of bone marrow, approximately how many of these will be mesenchymal stem cells

a. 50
b. 500
c. 5000
d. 50000
e. 500000

3. Which of the following combinations of reagents can be used to stimulate the transformation of mesenchymal stem cells in culture into osteoblasts

a. Ascorbic acid and alendronate
b. Calcium and Vitamin D
c. Dexamethasone and Vitamin C
d. Insulin and Vitamin E
e. Zinc and Foetal Calf Serum

4. What concentration, in cells/cm3 of graft, appears to be the minimum necessary to be effective in stimulating fracture healing in a non-union.

a. 102
b. 103
c. 104
d. 105
e. 106

5. If the survivorship of total knee replacements with revision at 10 years as the endpoint is compared with success as measured by revision or moderate to severe pain as alternative endpoints, by approximately what proportion is the failure rate increased

a. The failure rate is doubled
b. The failure rate is quadrupled
c. The failure rate increases by 1%
d. The failure rate increases by 10%
e. The failure rate increases by 20%

6. What is the most common form of the metal found in the hip capsule of patients with metallosis

a. Chromium Oxide
b. Chromium Phosphate
c. Cobalt Oxide
d. Molybdenum Oxide
e. Molybdenum Phosphate

7. Which of the following statements concerning aseptic lymphocytic vasculitis associated lesions (ALVAL) is correct

a. Such lesions are always symptomatic
b. There is an acute inflammatory infiltrate around the capillaries in the tissues
c. They are caused by the oxidation products of fine metal wear particles
d. They occur in a variety of modes of failure with metal stems, not only metal on metal
e. They only occur in the presence of significant wear of the femoral head component

8. If it is assumed that a single step taken by a patient with a metal-on-polyethylene total hip replacement releases 100 wear particles, under identical conditions otherwise, how many wear particles would have been released if it had been a metal-on-metal bearing

a. 10
b. 100
c. 1000
d. 10000
e. 100000

9. After being exposed to the environment of the lysosome, which component of metallic wear debris from a metal-on-metal bearing becomes most toxic to the phagocyte

a. Cobalt
b. Chromium
c. Iron
d. Molybdenum
e. Nickel

10. Which of the following statements concerning long term reviews of patients with joint replacements, compared to the general population for cancer risk, is not correct

a. The overall incidence of cancer is the same in both groups
b. The orthopaedic implant group have a late increase in melanoma
c. The orthopaedic implant group have less lung cancers
d. The orthopaedic implant group have more bowel cancers
e. The orthopaedic implant group have more prostate cancers

11. After a metal-on-metal hip replacement a patient has their serum cobalt measured at various time points. From the list below, at which time point would the patients serum cobalt level be highest

a. Preoperatively
b. 6 weeks
c. 9 months
d. 18 months
e. five years

12. In the statistical analysis of a range of data points, what is the definition of an outlier

a. Within the standard error of the mean of value of the most extreme measurement
b. More than one standard deviation
c. More than 2 standard deviations
d. The extreme 5% of data points
e. Third quartile plus 2x the interquartile range

13. What has been the most common reason for revision of resurfacing hip replacements

a. Dislocation 
b. Metallosis
c. Periprosthetic fracture
d. Pseudotumour
e. Sepsis

14. What does the Medicines and Healthcare Products Regulatory Agency advise about the follow up of patients with metal-on-metal bearing hip replacements beyond five years after surgery

a. Annual serum metal ion concentration measurements
b. Continue annual review of all with radiographs
c. Continue to follow-up only symptomatic patients
d. Increased frequency of review
e. No review needed

15. Which of the following clinical signs of scaphoid fracture has the highest positive predictive value

a. Anatomical snuff box pain in ulnar deviation/pronation
b. Anatomical snuff box swelling
c. Anatomical snuff box tenderness
d. Longitudinal thumb compression causing pain
e. Scaphoid tubercle tenderness

16. Which of the following radiological views of the scaphoid is best for detecting a humpback deformity

a. 45° oblique posteroanterior (semi pronated) view
b. 45° oblique posteroanterior (semi supinated) view
c. Neutral posteroanterior view
d. Ulnar deviated postero-anterior view
e. Ziter's (banana) view

17. Approximately what proportion of true scaphoid fractures are missed on initial clinical examination and four view radiographs

a. One in a hundred
b. One in twenty
c. One in ten
d. One in three
e. One in two

18. When a study used CT scans to investigate suspected scaphoid fractures, what proportion of the patients were found to have an undisplaced fracture of the distal radius or other carpal bone

a. One in a hundred
b. One in twenty
c. One in ten
d. One in three
e. One in two

19. Which of the following statements concerning the screening of patients with suspected scaphoid fracture is true

a. A series of 4 clinical tests is as good as bone scintigraphy at excluding scaphoid fracture
b. Bone scanning, CT and MRI are comparable in detecting fracture
c Bone scintigraphy is more specific than MRI in detecting fracture
d. In the population screened, false positives are extremely rare if MRI is used
e. Radiological tests have a less than 95% negative predictive value

20. Which of the following imaging modalities has the poorest positive predictive value when screening patients with suspected scaphoid fracture

a. Bone scintigraphy
b. Contrast enhanced MRI
c. CT
d. MRI
e. Ultrasound

1, Which of the following is not correct concerning mesenchymal stem cells at the fracture site in the early stages of healing
C, They induce the proliferation of lymphocytes

2, If 10 million mononuclear cells are obtained from a sample of bone marrow, approximately how many of these will be mesenchymal stem cells
B, 500

3, Which of the following combinations of reagents can be used to stimulate the transformation of mesenchymal stem cells in culture into osteoblasts
C, Dexamethasone and Vitamin C

4, What concentration, in cells/cm3 of graft, appears to be the minimum necessary to be effective in stimulating fracture healing in a non-union.
B, 103

5, If the survivorship of total knee replacements with revision at 10 years as the endpoint is compared with success as measured by revision or moderate to severe pain as alternative endpoints, by approximately what proportion is the failure rate increased
E, The failure rate increases by 20%

6, What is the most common form of the metal found in the hip capsule of patients with metallosis
B, Chromium Phosphate

7, Which of the following statements concerning aseptic lymphocytic vasculitis associated lesions (ALVAL) is correct
D, They occur in a variety of modes of failure with metal stems, not only metal on metal

8, If it is assumed that a single step taken by a patient with a metal-on-polyethylene total hip replacement releases 100 wear particles, under identical conditions otherwise, how many wear particles would have been released if it had been a metal-on-metal bearing
D, 10000

9, After being exposed to the environment of the lysosome, which component of metallic wear debris from a metal-on-metal bearing becomes most toxic to the phagocyte
A, Cobalt

10, Which of the following statements concerning long term reviews of patients with joint replacements, compared to the general population for cancer risk, is not correct
D, The orthopaedic implant group have more bowel cancers

11, After a metal-on-metal hip replacement a patient has their serum cobalt measured at various time points. From the list below, at which time point would the patients serum cobalt level be highest
C, 9 months

12, In the statistical analysis of a range of data points, what is the definition of an outlier
E, Third quartile plus 2x the interquartile range

13, What has been the most common reason for revision of resurfacing hip replacements
C, Periprosthetic fracture

14, What does the Medicines and Healthcare Products Regulatory Agency advise about the follow up of patients with metal-on-metal bearing hip replacements beyond five years after surgery
C, Continue to follow-up only symptomatic patients

15, Which of the following clinical signs of scaphoid fracture has the highest positive predictive value
B, Anatomical snuff box swelling

16, Which of the following radiological views of the scaphoid is best for detecting a humpback deformity
B, 45° oblique posteroanterior (semi supinated) view

17, Approximately what proportion of true scaphoid fractures are missed on initial clinical examination and four view radiographs
D, One in three

18, When a study used CT scans to investigate suspected scaphoid fractures, what proportion of the patients were found to have an undisplaced fracture of the distal radius or other carpal bone
D, One in three

19, Which of the following statements concerning the screening of patients with suspected scaphoid fracture is true
B, Bone scanning, CT and MRI are comparable in detecting fracture

20, Which of the following imaging modalities has the poorest positive predictive value when screening patients with suspected scaphoid fracture
E, Ultrasound