1. Regarding the structure of articular cartilage, which of the following is true?
A. Calcified layer secures cartilage to bone
B. Deep radial zone collagen fibres are arranged obliquely at right angles to each other
C. Middle transitional zone is the thinnest layer
D. Superficial (tangential) zone provides good resistance to shear forces but poor tensile strength
E. Tidemark provides main resistance to compression
2. The main function of articular cartilage is to do which?
A. Act as a shock absorber
B. Allow smooth gliding movements between bones with low frictional coefficient.
C. Facilitate the transmission of loads to the underlying subchondral bone
D. Minimise peak pressures on the subchondral bone
E. Resist the compressive forces encountered across the joint under loading conditions
3. Which of the following correctly describes compositional changes that occur in articular cartilage?
A. Chondrocytes are most numerous in the superficial zone
B. Chondrocytes start to produce type IV collagen with aging
C. Collagen fibres decrease in size with depth
D. Proteoglycan concentration decreases with depth
E. Water concentration increases with depth
4. What is the best option options for treating a 2 × 2cm articular cartilage defect in the medial femoral condyle of a 22-year-old athletic male?
B. Autologous matrix-induced chondrogenesis (AMIC)
C. Osteochondral allograft
D. Osteochondral autograft transfer system (OATS/mosaicplasty)
5. Which of
A. Decreased permeability
B. Decreased chondrocytes
C. Increased compressive strength
D. Increased keratin sulfate
E. Increased water content
6. Regarding the collagen composition of articular cartilage, which is true?
A. Type III collagen is involved in cartilage mineralisation
B. Type IX regulates the diameter of articular cartilage
C. Type VI forms a nest-like enclosure around each chondrocyte
D. Type X is found following injury
E. Type XI is involved in the stabilisation of the collagen II network
7. When comparing osteoarthritis with aging, which of the following is found?
A. Collagen concentration increased in OA/decreased in aging
B. Keratin sulphate increased in OA/decreased in aging
C. Metabolic activity increased in OA/decreased in aging
Proteoglycan synthesis decreased in OA/increased in aging
E. Water content increased in OA/decreased in aging
8. In early osteoarthritis when chondrocytes detect a disruption or alteration of their matrix, which of the following occurs?
A. Chondrocytic catabolic response
B. Decreased degradation of the matrix
C. Decreased synthesis of the matrix
D. Increase in chondrocyte numbers
E. Increase in metabolic activity
9. The biomechanical changes of articular cartilage in osteoarthritis include which?
A. Decreased permeability
B. Decreased water content
C. Increased compressive strength
D. Increased tensile stiffness and strength
E. Loss of interstitial fluid pressure
10. Concerning the blood supply of bone, which is correct?
A. Nutrient artery system is low pressure
B. During early fracture healing, blood flow is centrifugal because the periosteal system is often disrupted
C. Periosteal system supplies outer two-thirds of bone
D. IM reaming devascularises the inner one-
E. Recovery of endosteal bone circulation after reaming takes around 3 months
11. The main function of the annulus fibrosis (AF) of the intervertebral disc is which of the following?
A. To prevent intervertebral distraction
B. To act as a shock absorber
C. To contain the axial-load-related deformation of the nucleus
D. To provide high-tensile, torsional and radial strength
E. To remain flexible enough allow motion
12. Intervertebral disc degeneration involves which?
A. Decreased cell density
B. Drop in nucleus pressure
C. Increased cross-linking of the disc’s collagen
E. Increased activity of matrix degrading enzymes
13. Which is true concerning the structure of the annulus fibrosis?
A. It contains chondrocyte like cells
B. It contains large quantities of proteoglycans
C. Lamellae are more abundant and stronger in the posterior and posterolateral aspects of the disc
D. Type I collagen and water increase in proportion from the outer annulus towards the inner annulus and transitional zone
E. Type I collagen fibres are attached to the ring apophysis
14. Figure 19.1 ). The ED registrar is concerned about the general appearance of the tibia. They suspect the patient has a bone dysplasia
Figure 19.1 Anteroposterior (AP) and lateral radiographs left tibia demonstrating fracture
The likely diagnosis would be which of the following?
D. Progressive diaphyseal dysplasia
15.
Regarding mechanism of action of bisphosphonates, which is true?
A. Alendronate (Fosamax) stimulates protein prenylation within the mevalonate pathway, blocking farnesyl pyrophosphate synthase enzyme.
B. They are categorised into two classes based on the presence or absence of a pyrophosphate side chain
C. Didronel (etidronate) is metabolised into a non-functional adenosine triphosphate (ATP) analogue inducing apoptosis
D. Nitrogen-containing bisphosphonates have a simple mechanism of action
E. There is a loss of adenosine triphosphate (ATPase) formation, which is needed for ruffled border formation and cell survival
16.
A. According to the Hueter–Volkmann Law, compression forces stimulate bone growth and tension forces inhibit bone formation
B. Compression side of bone is electropositive, stimulating osteoblast formation
C. During bone formation, decreased levels of osteocalcin are observed
D. Macrophages, B-cells and T-cells are involved in bone remodelling
E. Tension side of bone is electronegative, stimulating osteoclast resorption
17.
Concerning the properties of allograft bone, which is correct?
A. Freeze-dried is the least immunogenic
B. Fresh has the least structural integrity
C. Osteoconduction is good
D. Osteogenic cells are fair
E. Osteoinduction is excellent
18.
Blood tests would show which of the following?
A. Elevated calcidiol (25[OH]D)
B. Increased alkaline phosphate levels
C. Increased phosphate levels
19.
What would laboratory findings include?
D. Low serum alkaline phosphatase
E. Normal calcidiol 25[OH]D3
20.
A. Collagen fibrils exhibit a 57nm D-period banded appearance on electron microscopy
B. Each polypeptide chain is a right-handed helix
C. It is a fibril-forming collagen
D. The structural unit is called tropocollagen, which is a trimer composed of three α1 polypeptide chains
E. The triple helix is a left-handed superhelix (i.e. the opposite way around to the polypeptide chain)
21. Which of the following acts on the osteocyte to decrease sclerostin expression?
A. Ankylosing spondylitis
22. What is correct concerning the structure of the annulus fibrosis?
A. Compression damages the AF
B. Lamellae are more abundant and stronger in the posterior and lateral aspects of the disc
On progressing from the outer to the inner annulus, type II collagen level decreases whilst type I increases
D. Outer AF contains chondrocytes
E. With degeneration, the inner AF undergoes an increase in collagen content with type II collagen fibrils becoming type I
23.
What do you mention?
A. Blood flow is reversed with reaming from centripetal to centrifugal stimulating fracture healing
B. Reamed nailing reduces the risk of compartment syndrome
C. The risk of mal-union is increased when using unreamed nails
D. Using an unreamed nail increases the infection risk
E. With an unreamed nail, there is an increased risk of nail breakage
24. Concerning the structure of bone, the major defining difference between cortical and cancellous bone is which of the following?
A. Cortical bone has a basic structural unit of an osteon, whereas cancellous bone is composed of a 3D lattice of rods and plates
B. Cortical bone is dense and low porosity while cancellous bone is spongy and high porosity
C. Cortical bone is harder, stronger and stiffer than cancellous bone, which is highly vascular
D. Cortical bone is located in the diaphysis, while cancellous is located in the metaphysis or epiphysis
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