Multiple Choice Questions
Basic Sciences
Test your knowledge , learn more and get ready for your orthopaedic exam
100. A researcher compared the mean weight loss in 2 groups of obese patients who were randomised to either standard treatment or standard treatment + new drug.
The data collected was parametric an continuous
Which one of the following is the most appropriate statistical test?
A) Chi square test
B) Life table analysis (log rank test)
C) Paired t test
D) Pearson correlation
E) Unpaired t test
99. Which is true of the shoulder joint?
A) Supraspinatus is active in abduction
B)The nerve to serratus anterior is derived from the lower roots of the brachial plexus
C) The rotator cuff muscles are attached to the capsule which is deficient anteriorly
D) The subacromial bursa communicates with the shoulder joint
E) She subscapular nerve arises from the lateral cord of the brachial plexus
98. What lies in the lateral first layer of the knee?
A) Arcuate ligament, fabellar ligament, capsule, LCL
B) Iliotibial tract, biceps femoris, fascia
C) Patellar retinacular and PFL ligament
D) Sartorius and fascia hyperparathyroidism
E) Superficial MCL, posterior oblique ligament, semimembranosus
97. A 58-year-old woman with a longstanding history of chronic renal failure who has been on haemodialysis for five years complains of bone pain affecting her left hand.
An x ray is performed and is reported as demonstrating osteitis fibrosa cystica.
What is the clinical diagnosis?
A) Osteoarthritis
B) Osteoporosis
C) Paget’s disease
D) Primary hyperparathyroidism
E) Secondary hyperparathyroidism
96. A surgeon is planning the application of a single plane external fixation construct as provisional fixation for an unstable knee dislocation.
There are two pin sizes available, one with twice the diameter of the other.
The bending stiffness of the larger pin is greater than that of the smaller by a factor of which of the following?
A) 2
B) 4
C) 8
D) 16
E) 32
95. The rigidity or bending stiffness of a plate is proportional to:
A) The thickness of the plate
B) The thickness of the plate to the second power
C) The thickness of the plate to the third power
D) The length of the plate
E) The number of screws
94. Which of the following statements regarding diathermy is true?
A) Bipolar diathermy never has any effect on a pacemaker heart lead system
B) Coagulation setting uses continuous current
C) Cutting setting has a sinus wave form
D) Diathermy applied to an implant is likely to result in significant heating of the implant and surrounding tissues
E) Diathermy is always contraindicated when a patient has a cardiac device in situ
93. In a gait lab, temporal-spatial parameters include all of the following except:
A) Step count
B) Stride length
C) Joint angles
D) Step width
E) Swing time and percentage
92. Which of the following statements regarding the peroneal division of the sciatic nerve is true?
A) It crosses anterior to the lateral head of the gastrocnemius muscle through the posterior intermuscular septum
B) An injury at the level of the thigh will denervate the branches to the short head of the biceps and the tibialis anterior
C) It is most commonly injured during an anterior knee dislocation
D) The deep division initially runs medial to the tibial artery and later crosses over to become lateral
E) It originates from the L3-S1 nerve roots
91. 21-year-old infantryman dislocates his shoulder during basic training. He is able to make it through training but continues to experience recurrent dislocations.
A CT demonstrates anterior glenoid bone loss and your sports colleagues indicate him for a Latarjet procedure.
The procedure successfully restores stability to his shoulder, but the patient is referred to your office just over 3 months later because he has persistent difficulty with abduction when the arm is internally rotated. You suspect an iatrogenic nerve injury sustained during anterior shoulder exposure and offer him a nerve transfer procedure involving the branch of the radial nerve that innervates the medial head of triceps.
The nerve that is injured in this patient innervates what muscles?
A) Deltoid, teres minor, and supraspinatus
B) Deltoid, teres minor, and teres major
C) Teres minor and teres major
D) Deltoid and teres major
E) Deltoid and teres minor
Correct Answer : E
Author : Firas Arnaout
90. Based on the stress-strain curve in Figure, which of the following materials has the highest modulus of elasticity?
A) Ceramic
B) PMMA
C) Titanium
D) Cancellous bone
E) Cartilage
Correct Answer : A
89. Which of the following statements is true regarding polymethylmethacrylate (PMMA)?
A) Barium sulfate initiates the polymerization of monomethacrylate
B) It is a ductile material
C) The Young’s modulus is between cortical and cancellous bone
D) It resists shear better than compressive forces
E) The polymerization of PMMA is endothermic
Correct Answer : C
88. Which of the following types of corrosion is defined by the formation of pits, grooves, and oxide debris due to the relative micromotion between two affixed materials placed under a load?
A) Crevice
B) Fretting
C) Galvanic
D) Pitting
E) Stress
Correct Answer : B
87. Which of the following statements defines creep, as it relates to material properties?
A) Progressive deformation response to constant force over an extended period of time
B) A solid material’s ability to deform under tensile stress
C) The ability of a material’s mechanical properties to vary according to the direction of load
D) The rupture of a material under repeated cyclic stresses, at a point below the normal static breaking strength
E) The ability of a material to absorb energy and plastically deform without fracturing
Correct Answer : A
Creep is the tendency of a solid material to move slowly or deform permanently under the influence of stresses. It occurs as a result of long term exposure to high levels of stress that are below the yield strength of the material. Creep is an undesirable property of orthopaedic bio-materials because they release frictional forces necessary to maintain rigid internal fixation. In total hip arthroplasty polyethylene liners, creep is the plastic deformation of the acetabular liner that occurs due to loading without the production of wear debris or particles
anabolic effect .
Author : Firas Arnaout
86. In post menopausal Osteoporosis, the women are losing the Oestrogen effect on bone metabolism.
How does Oestrogen affect bone?
A) Stimulates bone production and prevents resorption
B) Inhibits activation of adenyl cyclase
C) Decrease RANKL
D) All of the above
E) B&C
Correct Answer : D
Estrogen works mainly through decreasing the RANKL, which interfere with activation of adenyl cyclase which is important for osteoclasts activation , and net result it prevents or decreasing the resorption , in addition to its anabolic effect .
Author : Amin Mohamed Abdel Motaleb EL HELW
85. A 70 yr old woman presents to the ED with complaints of inability to bear weight on her Rt lower limb and Rt hip pain following a trivial fall in her nursing home.
X-ray showed Rt femoral neck fracture.
Which of the following is a histological feature of bone death seen in the marrow?
A) Appearance of histiocytes
B) Fibrosis
C) Round cell infiltration
D) Fibrinoid necrosis
E) Granuloma
Correct Answer : A
Bone cells die after 12-48 hours of anoxia, yet the gross appearance of the affected segments remains unaltered.
The most striking histological features are seen in the marrow which includes the loss of fat cell outlines, and the appearance of tissue histiocytes.
Author : Ridhwanullah A. SALAWU
84. The following are common sites for Paget’s diseases except:
A) Pelvis
B) Clavicle
C) Femur
D) Tibia
E) Fibula
Correct Answer : E
The pelvis and tibia are the commonest sites of involvement in Paget’s disease. others are femur, skull and clavicle
Author : Ridhwanullah A. SALAWU
83. Which of the following is responsible for the short neck appearance in paget’s disease?
A) Kyphosis
B) Platybasia
C) Steal syndrome
D) Pathological fracture
E) Osteosclerosis
Correct Answer : B
If the skull base becomes flattened, it gives the appearance of a short neck.
Author : Ridhwanullah A. SALAWU
82. Which of the following cells has receptors for parathyroid hormone (PTH)
(A) Osteoblasts, osteoclasts, and distal kidney nephron
(B) Osteoblasts, osteoclasts, and gastrointestinal cells
(C) Osteoclasts and osteoclast progenitor cells
(D) Osteoblasts and distal kidney nephron
(E) Osteoclast progenitor cells
Correct Answer : D
PTH actions:
– Facilitates absorption of calcium in the gastrointestinal system
– Increases 1,25 dihydroxy vitamin D in the kidney by stimulating 1 alpha hydroxylase
– Facilitates reabsorption of calcium from the distal tubular renal tubular cells ,Calcium is reabsorbed in the proximal and distal tubules, but only distal tubule is PTH dependent
– Inhibits reabsorption of phosphate in the kidney
– Stimulates release of calcium and phosphate from bone (indirectly)
– Causes release of receptor activator of nuclear factor -kB ligand (RANKL) from the surface of the osteoblasts
Parathyroid hormone exerts its effects through receptors on osteoblasts and kidney nephron cells.
Parathyroid hormone effects on the gut are indirect through an increased synthesis of 1,25 dihydroxy vitamin D.
Parathyroid hormone acts on osteoblasts to release RANKL, which then acts on the osteoclast progenitor cells to differentiate into osteoclasts.
Author : Rajesh Bahadur Lakhey
81. A woman has an X-linked recessive condition.
Which of the following is true concerning her offspring?
(A) 100% of the daughters will be affected
(B) 50% of the daughters will be affected
(C) 100% of the sons will be affected
(D) 50% of the sons will be affected
(E) 50% of the sons and daughters will be affected
Correct Answer : D
With X-linked dominant, heterozygotes will have the condition. If a woman has this condition, then she will transmit it to 50% of her sons and daughters.
In contrast, affected men transmit the condition to all of his daughters (because the daughter gets his X chromosome), but to none of the sons because the son gets the Y chromosome.
With X-linked recessive, the patterns are different between women and men. X-linked recessive woman: An X-linked woman with the recessive allele is a carrier, but she is not affected because the allele is recessive. Carrier females (X-linked recessive) transmit the condition to 50% of her daughters (who become carriers) and 50% of her sons (the sons are affected because their only X chromosome has the recessive gene).
Author : Rajesh Bahadur Lakhey
80. Which of the following conditions is transmitted by an X-linked dominant inheritance pattern:
(A) Haemophilia A
(B) Hypophosphatemic rickets
(C) Duchennes muscular dystrophy
(D) Achondroplasia
(E) Hypophosphatasia
Correct Answer : B
There is only one condition that must be remembered for examinations that is transmitted through an X-linked dominant pattern – hypophosphatemic rickets.
Remember: the conditions which are x-linked recessive
Haemophilia A, B – X-linked recessive
Duchennes muscular dystrophy – X-linked recessive
Achondroplasia – Autosomal dominant
Hypophosphatasia – Autosomal recessive
Author : Rajesh Bahadur Lakhey
79. Which of the following describes the inheritance pattern of Marfan’s syndrome:
(A) Autosomal recessive
(B) Autosomal dominant
(C) X-linked recessive
(D) X-linked dominant
(E) Sporadic
Correct Answer : B
Structural defects are usually transmitted by an autosomal-dominant pattern.
In contrast, with metabolic or enzyme deficiencies, the condition is usually transmitted in an autosomal recessive
pattern.
Remember the major autosomal-dominant conditions:
Achondroplasia
Spondyloepiphyseal dysplasia
Multiple epiphyseal dysplasia
Marfan’s syndrome
Ehlers-Danlos syndrome
Osteogenesis imperfecta (I, IV)
Multiple hereditary exostosis
Polydactyly
Author: Rajesh Bahadur Lakhey
78. Which of the following has a catabolic effect on articular cartilage
(A) Bone morphogenetic protein (BMP)-2
(B) BMP-7
(C) Smad3
(D) Insulin-like growth factor 1
(E) Cyclooxygenase (COX-2)
Correct Answer : E
Cartilage Metabolism and Regulation
A. Nutrition through diffusion (low oxygen tension, 1% to 2%)
B. Energy through glycolysis
C. Transforming growth factor beta (TGF-B)
1. Chondroprotective effect
2. Smad3 which is transcription factor activated by TGF-B also is chondroprotective
D. Insulin-like growth factor increases collagen and proteoglycan synthesis
E. Bone morphogenetic protein (BMP)-2 and BMP-7 increase proteoglycan synthesis and maintain chondrocyte phenotype
F. Interleukin-1
1. Inhibits proteoglycan synthesis
2. Stimulates metalloproteinase activity (catabolic enzymes)
G. Tumor necrosis factor alpha
1. Inhibits collagen synthesis
2. Stimulates metalloproteinase activity (catabolic enzymes)
H. Other catabolic enzymes
1. Cyclooxygenase (COX-2)
2. Nitric oxide synthetase
Author : Rajesh Bahadur Lakhey
77. Which of the following statements is true regarding gout:
(A) Gout is more common in females than males
(B) Urate overproduction is the most common cause
(C) Gout is very common in heart transplant patients on cyclosporine
(D) The serum uric acid level is always elevated in an acute attack
(E) Joint space destruction is an early radiographic finding
Correct Answer : C
Gout is caused by the deposition of monosodium urate crystals in tissues typically around joints. Common locations include the great toe, heel, ankle, and knee. In approximately 50% of patients, the first attack is in the great toe.
reasons:
The synovial fluid is a poorer solvent than plasma
Lower temperatures (as in peripheral joints) favour crystallization
One should remember the following:
Gout is much more common in males (ratio of 20:1).
An inability to excrete uric acid is the primary cause.
Gout is very common in transplant patients taking cyclosporine.
Serum uric acid level is often normal in an acute attack.
Joint space is usually preserved on plain radiographs (early disease).
Author : Rajesh Bahadur Lakhey
76. Which of the following zones of the physis is involved in Salter Harris Type I and II fractures?
(A) Proliferative zone
(B) Perichondrial ring
(C) Reserve zone
(D) Node of Ranvier
(E) Zone of provisional calcification
Correct Answer : E
Salter Harris Type I and II fractures occur through the zone of provisional calcification or through the hypertrophic zone.
The reserve and proliferative zone remain intact and growth can proceed normal after healing of the fracture.
Author: Rajesh Bahadur Lakhey
75. Which of the following is the proper sequence when listing biomaterials in order of increasing ultimate tensile strength
(A) Cancellous bone, cortical bone, stainless steel, titanium, cobalt chrome
(B) Cortical bone, cancellous bone, stainless steel, cobalt chrome, titanium
(C) Cortical bone, cancellous bone, cobalt chrome, stainless steel, titanium
(D) Cancellous bone, stainless steel, titanium, cortical bone, cobalt chrome
(E) Cancellous bone, cortical bone, cobalt chrome, titanium, stainless steel
Correct Answer : A
The proper sequence for common orthopedic biomaterials in terms of increasing ultimate tensile strength is: cancellous bone – polyethylene – methylmethacrylate – cortical bone – stainless steel – titanium – cobalt chrome.
Author: Rajesh Bahadur Lakhey
74. Which of the following conditions is characterized by decreased osteoclastic resorption of bone and cartilage with normal bone formation:
(A) Type 1 osteoporosis
(B) Type 2 osteoporosis
(C) Osteopetrosis
(D) Paget’s disease
(E) Secondary hyperparathyroidism
Correct Answer : C
Osteopetrosis is a rare disorder in which there is decreased osteoclastic resorption of bone and cartilage with normal bone formation. There are a number of different forms of the condition.
The most common form of osteopetrosis is an autosomal dominant type with mild features (adult or tarda). Patients may have mild anaemia, have one or more fractures, or be asymptomatic.
The juvenile form of osteopetrosis is a severe autosomal disorder. Children have multiple fractures, severe anaemia, thrombocytopenia, and hepatosplenomegaly. Effected children are also immunocompromised.
Author : Rajesh Bahadur Lakhey
73. Which of the following features is associated with type 2 osteoporosis
(A) High turnover osteoporosis
(B) Female to male ratio is 6:1
(C) Loss of cortical and trabecular bone
(D) Related to Oestrogen deficiency
(E) Greatest bone loss in the first 6 to 10 years following menopause
Correct Answer : C
Type 1 osteoporosis is the most common form of osteoporosis and is found in women during postmenopausal years. Type 1 osteoporosis is related to Oestrogen deficiency rather than a problem in calcium intake or absorption.
Features of type 1 osteoporosis include:
Female to male ratio is 6:1
High turnover osteoporosis
Bone loss rate of 2% to 3% per year for 6 to 10 years following menopause
Trabecular bone is most affected
Related to Oestrogen deficiency rather than calcium intake
Type 2 osteoporosis, also called senile or involutional osteoporosis, is a low turnover osteoporosis and principally occurs in patients older than 75 years of age.
Features of type 2 osteoporosis include:
Female to male ratio is 2:1
Patients older than 75 years of age
Low turnover osteoporosis
Trabecular and cortical bone affected
Associated with hip fractures
Related to a lifelong deficiency of calcium
Author: Rajesh Bahadur Lakhey
72. Parathyroid hormone stimulates which of the following cells to secrete neutral protease that degrades the osteoid bone surface
(A) Osteoblasts
(B) Mast cells
(C) Osteoclasts
(D) Osteocytes
(E) Osteoclast precursor cells
Correct Answer : A
Osteoblasts have receptors for parathyroid hormone. Once stimulated, the cells release interleukin-6 (IL-6). IL-6 signals osteoclasts to resorb bone.
The osteoblasts secrete neutral proteases that degrade the osteoid surface. Osteoclasts then attach to the bone surface and secrete acid proteases that degrade the bone matrix.
Parathyroid hormone related protein increases osteoblast expression of receptor activator of nuclear factor –kB ligand (RANKL). RANKL binds to osteoclast precursor cells for the formation of active osteoclasts.
Author : Rajesh Bahadur Lakhey
71. Which of the following cells has receptors for parathyroid hormone
(A) Osteocytes
(B) Osteoclasts
(C) Plasma cells
(D) Osteoblasts
(E) Osteoclast precursor cells
Correct Answer : D
Osteoblasts have receptors for parathyroid hormone. Once stimulated, the cells release interleukin-6 (IL-6). IL-6 signals osteoclasts to resorb bone.
The osteoblasts secrete neutral proteases that degrade the osteoid surface. Osteoclasts then attach to the bone surface and secrete acid proteases that degrade the bone matrix.
Parathyroid hormone related protein increases osteoblast expression of receptor activator of nuclear factor –kB ligand (RANKL). RANKL binds to osteoclast precursor cells for the formation of active osteoclasts.
Author : Rajesh Bahadur Lakhey
70. Which of the following proteins or vitamins influences growth plate chondrocyte maturation as a potent mitogen in the proliferative zone
A) 1,25 Dihydroxyvitamin D3
(B) 24,24 Dihydroxyvitamin D3
(C) Insulin
(D) 1 Hydroxyvitamin D3
(E) Calcitonin
Correct Answer : B
Traditionally, 24,25 Dihydroxyvitamin D3 was considered an inactive form of vitamin D.
Recent studies suggest that 24,25 Dihydroxyvitamin D3 influences growth plate chondrocyte maturation as a potent mitogen in the proliferative zone and may also contribute to bone formation and fracture repair.
Author : Rajesh Bahadur Lakhey
69. Paget’s disease is common in all of the listed locations except:
(A) England
(B) United States
(C) Northern Europe
(D) Australia
(E) Sub-Saharan Africa
Correct Answer : E
Paget’s is a Remodeling disease caused by excessive osteoclastic activity
Rarely diagnosed in patients younger than 40 years of age; most patients diagnosed after age 50
Most common sites include pelvis, femur, spine, skull, and tibia
Less common sites include clavicles, scapulae, ribs, and facial bones
Rarely found in the hands and feet
Pagetic bone
o is more susceptible to fracture
o is less compact
o is more vascular
o tends to bow in weight bearing areas
Geographic clustering (up to 4% in patients older than 55 years of age)
o England
o Northern Europe
o North America
o Australia, New Zealand
o Rare in Asia, China, Indonesia, Malaysia, and sub-Saharan Africa
Possibly a slow viral disease
o RNA paramyxovirus (e.g., respiratory syncytial virus and measles)
Author : Rajesh Bahadur Lakhey
68. Paget’s disease is common in all of the following bones except
(A) Humerus
(B) Spine
(C) Femur
(D) Hands and feet
(E) Pelvis
Correct Answer : D
Paget’s is a Remodeling disease caused by excessive osteoclastic activity
Rarely diagnosed in patients younger than 40 years of age; most patients diagnosed after age 50
Most common sites include pelvis, femur, spine, skull, and tibia
Less common sites include clavicles, scapulae, ribs, and facial bones
Rarely found in the hands and feet
Pagetic bone:
o is more susceptible to fracture
o is less compact
o is more vascular
o tends to bow in weight bearing areas
Geographic clustering (up to 4% in patients older than 55 years of age)
o England
o Northern Europe
o North America
o Australia, New Zealand
o Rare in Asia, China, Indonesia, Malaysia, and sub-Saharan Africa
Possibly a slow viral disease o RNA paramyxovirus (e.g., respiratory syncytial virus and measles)
Author : Rajesh Bahadur Lakhey
67. The skin of the proximal one-third of the anterior thigh just distal to the inguinal ligament is innervated by which of the following levels
(A) T12
(B) L1
(C) L2
(D) L3
(E) L4
Correct Answer : B
The skin of the proximal one-third of the anterior thigh just distal to the inguinal ligament is innervated by L1, L2, and L3.
Note:
L1 Thigh, proximal third, anterior
L2 Thigh, middle, anterior
L3 Thigh, distal third, anterior
Author : Rajesh Bahadur Lakhey
66. The principle blood supply to the humeral head derives from:
(A) The anterior humeral circumflex artery
(B) Axillary artery
(C) The posterior humeral circumflex artery
(D) Acromial branch of thoracoacromial artery
(E) Subscapular artery
Correct Answer: A
The humeral head has been shown to be perfused primarily by the anterolateral ascending branch of the anterior circumflex artery. This branch runs parallel to the lateral aspect of the tendon of the long head of the biceps and enters the humeral head where the proximal end of the intertubercular groove meets the greater tuberosity.
The posterior circumflex artery provides only the posterior portion of the greater tuberosity and a small posteroinferior part of the head.
Author :Rajesh Bahadur Lakhey
65. Which of the following statements is true concerning molecular events at the site of a healing fracture:
(A) Type II collagen production is lowest during the first 2 weeks
(B) Type I collagen production is highest during the first 2 weeks
(C) Periosteal type III collagen serves as a substrate for migration of osteoprogenitor cells and capillary ingrowth
(D) Type IX collagen initiates mineralization of type II collagen
(E) Types V and XI collagen control the maturation of mineralization crystals
Correct Answer: C
Important points to remember concerning molecular events at the fracture site:
Type II collagen production is highest during the first 2 weeks. Cartilage is the first tissue produced at the fracture site. The chondrocytes hypertrophy and release matrix vesicles that prepare the extracellular matrix for mineralization of the cartilage. Blood vessels grow into the hypertrophied cartilage cells and perivascular cells become osteoblasts and begin mineralization. This is the exact same process that occurs at the growth plate with formation of the primary and secondary spongiosa.
Type I collagen production is low during the first 2 weeks as cartilage is initially formed. Type I collagen production is highest as the cartilage is mineralized later.
Periosteal type III collagen serves as a substrate for the migration of osteoprogenitor cells and capillary ingrowth.
Type IX collagen contributes to the mechanical stability of type II collagen.
Types V and XI collagen regulate the growth and orientation of types I and II collagen fibrils.
Author : Rajesh Bahadur Lakhey
64. Human calcium absorption occurs in the
(A) Stomach
(B) Small intestine
(C) Large intestine
(D) Liver
(E) Parathyroid glands
Correct Answer: B
Dietary calcium is absorbed in the small intestine. This absorption is stimulated by 1,25 Dihydroxyvitamin D3.
Author : Rajesh Bahadur Lakhey
63. With regard to the organic phase of bone, which of the following accounts for 90% of the organic matrix
(A) Type I collagen
(B) Type II collagen
(C) Osteonectin
(D) Osteocalcin (bone Gla protein)
(E) Matrix Gla protein
Correct Answer: A
Bone has the following composition:
Mineral or inorganic phase 70%
Water 5% to 8%
Organic matrix 22% to 25%
Collagen type I 90%
Noncollagenous proteins 5% to 8%
Author: Rajesh Bahadur Lakhey
62. Osteoclasts are activated following disruption of the osteoid layer that covers the bone surface.
Which of the following cells is responsible for this disruption?
(A) Osteoclasts
(B) Resting bone-lining cells
(C) Active osteoblasts
(D) Macrophages
(E) Mast cells
Correct Answer : B
The resting bone-lining cells (flat, elongated osteoblasts) begin the bone resorption process by secreting collagenases that degrade the osteoid layer covering bone. These cells may also contract to expose the bone surface and allow access for the osteoclasts.
Parathyroid hormone (PTH) mediates bone resorption by stimulation of PTH receptors on the osteoblasts. Osteoclasts do not have receptors for PTH.
Author of the question: Rajesh Bahadur Lakhey
61. Osteoclasts bind to the bone surface through which of the following proteins
(A) Osteocalcin (bone Gla protein)
(B) Integrins
(C) Osteopontin (bone sialoprotein 1)
(D) Fibromodulin
(E) Bone sialoprotein 2
Correct Answer: B
Active osteoclasts resorb the mineral and organic matrix of bone. Active osteoclasts also attach the cell to exposed bone matrix.
When osteoclasts are studied with an electron microscope, there are two prominent findings — a ruffled border and a clear zone.
In the clear zone, the osteoclast seals off the area of bone to be resorbed and attaches to the bone surface through a receptor-mediated process with the assistance of proteins called integrins.
The ruffled border is an area found in the infoldings of the cell membrane. At the area of the ruffled border, the osteoclasts lower the pH with hydrogen ions through the carbonic anhydrase system. This lowered pH increases the solubility of the apatite crystals and the mineral can be removed. The organic components of the bone are then hydrolyzed through acidic proteolytic digestion.
Author: Rajesh Bahadur Lakhey
60. Osteoblasts predominantly form which of the following types of collagen?
(A) Type VI
(B) Type IX
(C) Type X
(D) Type I
(E) Type II
Correct Answer: D
Osteoblasts produce type I collagen. This is the major type of collagen found in bone.
Type I collagen is the only collagen capable of mineralization.
Author : Rajesh Bahadur Lakhey
59. Which of the following cells produce osteocalcin and bone sialoprotein?
(A) Osteocytes
(B) Osteoblasts
(C) Mast cells
(D) Osteoclasts
(E) Fibroblasts
Correct Answer: B
Osteoblasts are metabolically active cells that line the bone surface. Osteoblasts produce type I collagen and many non-collagenous proteins such as osteocalcin, bone sialoprotein, and extracellular matrix proteins.
Osteoblasts have large amounts of rough endoplasmic reticulum because they prepare large amounts of protein for export out of the cell. The Golgi apparatus exports the protein.
Author : Rajesh Bahadur Lakhey
58. Which of the following types of bone behaves in an isotropic manner when loaded in different directions
(A) Lamellar bone
(B) Woven bone
(C) Cortical bone
(D) Cancellous bone
(E) Plexiform bone
Correct Answer: B
Woven bone is immature bone that is found in newborns, fractured bone, and the metaphyses of growing bone.
In woven bone, the collagen fibers are oriented in a completely random fashion.
When woven bone is loaded, it performs in an isotropic manner.
The other types of bone (lamellar, cortical, cancellous, and plexiform) contain collagen that is oriented along the long axis of the bone and cause the bone to perform anisotropically.
Author : Rajesh Bahadur Lakhey
57. Which of the following statements is true concerning the changes seen in human articular cartilage as a person ages?
(A) Progressive increase in chondroitin 4-sulfate
(B) Progressive decrease in chondroitin 6-sulfate
(C) Progressive decrease in collagen concentration
(D) Progressive increase in collagen concentration
(E) Progressive increase in keratan sulfate concentration
Correct Answer: E
There are several important points concerning aging and articular cartilage. The collagen content increases quickly after birth, attaining adult levels, and then it does not materially change.
The water level is high in immature individuals but remains constant in the adult.
In contrast to the stable levels of collagen and water, the proteoglycan composition changes.
Chondroitin 4-sulfate levels progressively decrease.
Chondroitin 6-sulfate levels progressively increase.
Keratan Sulfate levels progressively increase in the human. At age 30, the level increases to 25% to 50% of proteoglycan content.
Aggregation decreases with advancing age.
Author : Rajesh Bahadur Lakhey
56. Which of the following is the most prevalent glycosaminoglycan in articular cartilage?
(A) Keratan sulfate
(B) Chondroitin sulfate
(C) Hyaluronate
(D) Dermatan sulfate
(E) Fibromodulin
Correct Answer: B
The three major types of glycosaminoglycans in articular cartilage are Chondroitin Sulfate, Keratan Sulfate, and Dermatan Sulfate.
Chondroitin sulfate is the most common glycosaminoglycan in articular cartilage. Chondroitin 4-sulfate and chondroitin 6-sulfate isomers account for 55% to 90% of the total amount.
The Glycosaminoglycan chains contain repeating carboxyl and sulfate groups that become ionized in
solution. These free-floating ions account for the Donnan osmotic pressure and the large charge-to-charge
repulsive forces of the glycosaminoglycan chains.
Most of the Glycosaminoglycans are in the form of large aggregates called Aggrecan. Link protein
binds to both the G1 domain of Aggrecan and the Hyaluron to form the Aggrecan-Hyaluronate-link
protein complexes, which are called Proteoglycan Aggregates.
Author of the question: Rajesh Bahadur Lakhey
55. Which of the following statements inaccurately describes human bone as a biomaterial?
(A) Bone is isotropic
(B) Bone is viscoelastic
(C) Bone’s strength and elastic modulus are approximately proportional to the square of its density
(D) Bone is a composite
(E) Bone remodels its structure to maintain overall resistance to loading while the material itself weakens
Correct Answer : A
Bone is anisotropic as the properties of the material vary with the direction of loading.
This is true of most biologic materials .
Author : Rajesh Bahadur Lakhey
54. Which of the following occurs when a joint is immobilized
(A) Slow decrease in collagen concentration
(B) Rapid decrease in collagen concentration
(C) Slow decrease in proteoglycan concentration
(D) Rapid decrease in proteoglycan concentration
(E) No change in either collagen or proteoglycan concentration
Correct Answer: D
Motion is essential for normal articular cartilage function. Many changes occur in the articular cartilage, ligaments, capsules, and bone within a joint when it is immobilized.
There is a rapid loss of proteoglycan when a joint becomes immobilized. This loss of proteoglycan results in an increase of deformation and fluid flux when compressive loads are applied to the joint.
The collagen content of the cartilage does not change and the tensile properties are maintained.
The changes are reversible and the recovery depends upon how long the joint is immobilized.
Author of the question: Rajesh Bahadur Lakhey
53. The major biochemical component of a ligament is
(A) Water
(B) Collagen
(C) Proteoglycan
(D) Elastin
(E) Link protein
Correct Answer: A
Approximately 60% to 80% of a ligament is composed of water. Collagen is 70% to 80% of the dry weight of a ligament (90% Type I and smaller amounts of Type III). Other components, in lesser amount, include proteoglycans and elastin.
Author of the question: Rajesh Bahadur Lakhey
52. At higher rates of loading, the failure pattern of a ligament will tend to occur at
A) Proximal insertion site
(B) Distal insertion site
(C) Equally at the proximal and distal insertion sites
(D) Mid-substance
(E) Failure patterns have no relationship to site of failure
Correct Answer: D
The rate of loading has a significant effect on the injury pattern of a ligament. With high strain rates,
the strength and tensile modulus of ligament will be increased. The ligament will tend to fail in the
mid-substance rather than the insertion sites.
At slow rates of loading, the ligament will tend to fail at the insertion site.
Author of the question: Rajesh Bahadur Lakhey
51. A 25-year-old man has a destructive lesion in the medial femoral condyle that extends to the articular
surface. Open biopsy shows a giant cell tumor. There is no evidence of pathologic fracture or major soft
tissue extension. What surgical stage would be assigned according to the system of the Musculoskeletal
Tumor Society
(A) Stage 1
(B) Stage 2
(C) Stage 3
(D) Stage I
(E) Stage II
Correct Answer : B
The lesion is a giant cell tumor. These lesions behave very aggressively and grow to a large size. They can cause pathologic fracture and are prone to local recurrence. This would be a Stage 2 lesion because there is no soft tissue
extension, fracture of the joint, etc.
The Surgical Staging System of the Musculoskeletal Tumor Society is a useful system to both predict prognosis and plan treatment. The system for benign lesions is divided into three groups: Inactive (latent), active, and aggressive:
Stage 1
Inactive (latent) Refers to lesions which are not causing pain and show no evidence of active growth. Stage 1 lesions are generally treated with observation only.
Stage 2
Active Refers to lesions which are causing pain or some form of disability. If a lesion has weakened the structure of
the bone such that fracture may occur, the lesion would also be considered a Stage 2 lesion.
Stage 3
Aggressive Refers to lesions which are large, have broken into the soft tissues, or have caused a pathologic fracture.
These lesions are usually prone to local recurrence and have the potential of causing a major problem for the patient.
Author :Rajesh Bahadur Lakhey
50. With a right-sided anterior cervical spine approach, the structure at increased risk is the:
A) Recurrent laryngeal nerve
B) Superior laryngeal nerve
C) Hypoglossal nerve
D) Thoracic duct
E) Esophagus
49. The triceps tendon insertion has two well-defined components.
The triceps proper inserts:
A) Directly onto the posterior 40% of the olecranon
B) On to the anconeous muscle
C) On to the entirety of the olecranon tip
D) On to the anterior aspect of the olecranon
E) None of the above
48. Dynamic muscular stabilizers of the shoulder play an important role in stability.
Which of the following is the most important dynamic stabilizer?
A) The rotator cuff
B) The labrum
C) The coracobrachialis
D) The latissimus dorsi
E) The biceps brachii
47. Using the three layer description of the medial structures of the knee, the medial patellofemoral ligament is described as being within the:
A) First layer
B) Second layer
C) Third layer
D) All three layers
E) The medial patellofemoral ligament does not exist.
46. A magnetic resonance image of a patient’s right shoulder is shown.
The structure marked by the arrows is innervated by which of the following nerves?
A) Musculocutaneous nerve
B) Branch of the posterior cord of the brachial plexus
C) Branch of the lateral cord of the brachial plexus
D) Branch of the medial cord of the brachial plexus
E) Branch of the superior trunk of the brachial plexus
45. With regard to the meniscofemoral ligaments, the ligament of Humphrey runs ___ to the posterior cruciate ligament (PCL) and the ligament of Wrisberg runs _____ to the PCL.
A) Posterior, anterior
B) Anterior, posterior
C) Anterior, anterior
D) Posterior, posterior
E) Medial, lateral
44. Which of the following describes the correct relationship between the suprascapular nerve and the suprascapular vessels as they pass through the suprascapular notch:
A) The suprascapular nerve, artery, and vein all pass below the transverse scapular ligament.
B) The suprascapular nerve, artery, and vein all pass superficially to the transverse scapular ligament.
C) The suprascapular nerve passes superficially to the transverse scapular ligament while the artery and vein pass deep
D) The suprascapular nerve and artery pass deep to the transverse scapular ligament while the suprascapular vein passes superficially to it.
E) The suprascapular nerve passes deep to the transverse scapular ligament while the suprascapular artery and vein pass above it.
43. The primary restraint to anterior translation of the abducted and externally rotated glenohumeral joint is the:
A) Coracohumeral ligament
B) Superior glenohumeral ligament
C) Middle glenohumeral ligament
D) Inferior glenohumeral ligament
E) Subscapularis muscle
42. Which of the following anatomic landmarks of the knee represents the contact area between the lateral femoral condyle and the anterior horn of the lateral meniscus when the knee is in full extension:
A) Outerbridge’s ridge
B) Blumensatt’s line
C) Notch of Grant
D) David’s point
E) Sulcus terminalis
41. In a congruent patellofemoral joint, the patella centers within the trochlear groove by what degree of flexion:
A) 5° to 10°
B) 10° to 15°
C) 15° to 20°
D) 20° to 25°
E) 25° to 30°
40. Weight training that employs a constant velocity and variable resistance is referred to as:
A) Isometric
B) Isotonic
C) Isokinetic
D) Plyometric
E) Functional
39. Which of the following statements is true regarding the effect of anabolic-androgenic steroid on immobilized skeletal muscle:
A) Steroid administration has no effect on immobilized muscle.
B) Steroid administration leads to muscle hypertrophy only in conjunction with strength training.
C) When compared to controls, steroid administration leads to increased muscle mass but not increased contractile force.
D) When compared to controls, steroid administration leads to increased contractile force but not muscle mass.
E) When compared to controls, steroid administration leads to both increased contractile force and muscle mass.
38. A foot is maximally dorsiflexed during this point of the gait cycle:
A) Midswing
B) Midstance
C) Toe off
D) Heelstrike
E) First one-third of stance
37 .The protein neurofibromin normally acts in which of the following ways:
A) Inhibits fibroblast growth factor
B) Promotes proteoglycan assembly
C) Down regulates Ras protein
D) Causes nerve cells to divide
E) Promotes tumor formation
36. Which of the following mechanisms of bisphosphonate action occurs when used to treat osteoporosis:
A) Increasing calcium absorption in the intestines
B) Decreasing urinary excretion of calcium
C) Stimulating osteoblast precursors
D) Binding to hydroxyapatite crystals
E) Increasing phosphate reabsorption in the kidney
35. Osteoclasts have receptors for which of the following:
A) 1,25 dihydroxyvitamin D3
B) Parathyroid hormone
C) Osteoprotegerin
D) Receptor activator of nuclear factor –kB
E) Calcitonin
34. Parathyroid hormone inhibits the production of:
A) Osteoprotegerin
B) 1,25 dihydroxyvitamin D3 production
C) Interleukin-6
D) Kidney 1 alpha-hydroxylase
E) Receptor activator of nuclear factor –kB ligand (RANKL)
33. Which of the following proteins or hormones assist in the transport of calcium in the kidney against chemical and electrical gradients:
A) Calcitonin
B) Calbindin
C) Osteoprotegerin
D) Parathyroid hormone
E) Vitamin D3
32. Osteoprotegerin (OPG) has which of the following functions or effects:
A) Inhibits osteoclast apoptosis
B) Inhibits osteoclast formation
C) Activates osteoclast precursors
D) Induces hypercalcemia
E) Binds to receptor activator of nuclear factor –kB ligand (RANKL)
31. Which of the following proteins binds to osteoclast precursor cells and positively effects their final differentiation into osteoclasts:
A) Receptor activator of nuclear factor-kappa B (RANK)
B) Osteoprotegerin
C) Bone morphogenetic protein 7
D) Core binding factor alpha 1 (Cbfa1)
D) Parathyroid hormone related protein (PTHrP)
30. Which of the following musculoskeletal complications may occur in patients taking Fluoroquinolones, such as Ciprofloxacin:
A) Osteomalacia
B) Osteoporosis
C) Joint laxity
D) Tendon ruptures
E) Parethesias
29. The skin over the umbilicus is innervated by which of the following levels:
A) T2
B) T4
C) T8
D) T10
E) T12
28. The extensor hallucis longus muscle is innervated by which of the following nerve roots:
A) L1
B) L2
C) L3
D) L4
E) L5
27. The skin of the proximal one-third of the anterior thigh just distal to the inguinal ligament is innervated by which of the following sensory segmental levels:
A) T12
B) L1
C) L2
D) L3
E) L4
26. The skin on the medial aspect of the leg and great toe is innervated by which of the following nerve roots:
A) L2
B) L3
C) L4
D) L5
E) S1
25. Which of the following statements is true concerning the vascularity at a fracture site
A) Periosteal blood vessels are capable of supplying the endosteal region
B) Fracture site blood flow peaks at 2 weeks
C) Reamed intramedullary rods do not significantly interrupt endosteal blood supply
D) In animal studies, blood flow is greater at 120 days in plated vs. rodded tibias
E) In animal studies, blood flow is greater at 42 days in rodded vs. plated tibias
24. A 25-year-old football player sustained a closed tibia fracture when his planted leg was struck by another player. Which of the following would be the most common fracture pattern and mechanism:
A) Short spiral fracture — torsion
B) Oblique fracture — uneven bending
C) Transverse fracture — pure bending
D) Oblique fracture with a butterfly fragment — bending and compression
E) Segmental fracture — four-point bending
23. The net effect of 1,25 dihydroxyvitamin D3 on the calcium and phosphate concentration of the extracellular fluid and serum is:
A) Increased calcium, increased phosphate
B) Increased calcium, decreased phosphate
C) Decreased calcium, decreased phosphate
D) Increased calcium, no effect on phosphate
E) Transient decrease in serum calcium
22. Which of the following serum levels is the best indicator of body stores of Vitamin D3:
A) 7-dehydrocholesterol
B) 1,25 dihydroxyvitamin D3
c) 25 hydroxyvitamin D3
D) 24,25 dihydroxyvitamin D3
E) Parathyroid hormone levels
21. Which of the following cells have receptors for parathyroid hormone:
A) Osteoclasts
B) Osteoblasts
C) Lymphocytes
D) Mast cells
E) Fibroblasts
20. Which of the following areas of the osteoclast is responsible for attachment to the bone surface prior to the bone resorption process:
A) Golgi apparatus
B) Ribosome
C) Clear zone
D) Ruffled border
E) Secretory vesicles
19. Which of the following is characteristic of an active osteoclast:
A) A large amount of rough endoplasmic reticulum
B) Paucity of intracellular smooth vesicles
C) Ruffled border adjacent to the bone surface
D) Few mitochondria
E) Low acid phosphatase activity
18. A genetic mutation accounts for the manifestations of achondroplasia. Which of the following proteins has a genetic mutation that has been linked to achondroplasia:
A) Fibroblast growth factor (FGF) receptor 3
B) Type I collagen
C) Fibrillin
D) Type II collagen
E) Cartilage oligomeric matrix protein (COMP)
17. The tidemark in articular cartilage separates which of the following two zones:
A) The superficial tangential zone and the middle zone
B) The middle zone and the deep zone
C) The superficial zone and the deep zone
D) The deep zone and the calcified zone
E) The calcified cartilage zone and the subchondral bone zone
16. Following a traumatic nerve injury, in which time period would a physician find denervation activity with fibrillation and positive sharp waves in the affected muscles:
A) Immediately following the injury
B) 7 to 10 days following injury
C) 2 to 5 weeks following injury
D) 6 to 8 weeks following injury
E) 12 weeks following injury
15. Which of the following terms is used to describe a localized conduction block in a peripheral nerve in which the nerve is intact and full recovery is expected:
A) First-degree injury (neuropraxia)
B) Second-degree (axonotmesis)
C) Third-degree
D) Fourth-degree
E) Fifth-degree
14. Enchondral ossification is responsible for mineralization in all of the following conditions except:
A) Callus formation during fracture healing
B) Heterotopic bone formation
C) Cartilage degeneration is osteoarthritis
D) Embryonic long bone development
E) Perichondrial bone formation
13. The most common location of a chordoma is:
A) Cervical vertebra
B) Thoracic vertebra
C) Lumbar vertebra
D) Sacrococcygeal region
E) Spheno-occipital region
12. Which of the following processes may produce cystic bone erosions in the cortex on both sides of a joint:
A) Septic Arthritis
B) Synovial chondormatosis
C) Pigmented villonodular synovitis
D) Ochronosis
E) Hemochromatosis
11. What is the most likely complication following treatment of the humeral shaft fracture shown in the figure attached?
A) Nonunion
B) Shoulder pain
C) Infection
D) Elbow injury
E) Radial nerve injury
10. Bleeding is encountered while developing the internervous plane between the tensor fascia lata and the sartorius during the anterior approach to the hip. The most likely cause is injury to what artery?
A) Ascending branch of the lateral femoral circumf ex
B) Superior gluteal
C) Femoral
D) Profunda femoris
E) Medial femoral circumfl ex
9. The anatomy of the sciatic nerve as it exits the pelvis is best described as exiting through the:
A) greater sciatic notch and passing between the inferior gemellus and the obturator externus.
B) greater sciatic notch and passing between the piriformis and the superior gemellus.
C) obturator foramen and passing between the obturator internus and the obturator externus.
D) lesser sciatic notch and passing between the piriformis and the superior gemellus.
E) lesser sciatic notch and passing between the superior gemellus and the inferior gemellus.
8. Through a retroperitoneal approach to the L4-5 disk, what structure must be ligated to safely mobilize the common iliac vessels toward the midline laterally and gain exposure?
A) Obturator vein
B) Iliolumbar vein
C) External iliac vein
D) Middle sacral artery
E) Hypogastric artery
7. What structure is located at the tip of the arrow in the figure attached?
A) Left L3 nerve root
B) Right L3 nerve root
C) Right L4 segmental artery
D) Right L4 nerve root
E) Left lateral disk herniation
6. What structure is most at risk for injury from a retractor against the tracheoesophageal junction during an ant. approach to the cervical spine?
A) Esophagus
B) Trachea
C) Superior laryngeal nerve
D) Recurrent laryngeal nerve
E) Sympathetic chain
5. When harvesting an iliac crest bone graft from the post. approach, what anatomic structure is at greatest risk for injury if a Cobb elevator is directed too caudal?
A) Sciatic nerve
B) Cluneal nerves
C) Inferior gluteal artery
D) Superior gluteal artery
E) Sacroiliac joint
4. The single most important treatment in preventing acute renal failure following crush injury is:
A) maintenance of an alkaline urine (pH > 6) to prevent cast formation
B) maintenance of adequate urine output with mannitol
C) vigourous intravenous fluid replacement
D) administration of xanthine oxidase inhibitors to prevent hyperuricemia
E) emergent dialysis to remove myoglobin from the circulation
3. A 28 years old man was involved in a motorbike road traffic accident sustaining head injury resulting in a coma and hip fracture.
Indomethacin is indicated here to prevent which complication?
A) Non union
B) Infection
C) Vascular compromise
D) Pressure ulcers
E) Heterotopic ossification
2. Number of hits during taper assembly can influence taper seating mechanisms.
Which of the statement is true regarding single hit versus three hits?
A) One-hit assembled tapers exhibit more contact pressure and total seating of the head taper
B) Three-hits assembled tapers provide superior taper seating
C) Three-hits assembled tapers leads to increased plastic strain
D) One-hit imparts low impulse that is insufficient to seat the modular taper
E) It does not make a difference if you hit once or multiple times to sit the modular taper
1. All of the statements regarding the atypical femur fracture due to bisphosphonate therapy are true EXCEPT :
A) Fracture is located along femoral diaphysis from distal to the lesser trochanter to proximal to supracondylar ridge
B) Fracture is sustained with minimal or no trauma
C) Complete fracture extends through both cortices
D) The fracture line originates at the lateral cortex and is usually transeverse
E) The incomplete fracture can involve either the medial or lateral cortex
Correct Answer : D
PTH actions:
– Facilitates absorption of calcium in the gastrointestinal system
– Increases 1,25 dihydroxy vitamin D in the kidney by stimulating 1 alpha hydroxylase
– Facilitates reabsorption of calcium from the distal tubular renal tubular cells ,Calcium is reabsorbed in the proximal and distal tubules, but only distal tubule is PTH dependent
– Inhibits reabsorption of phosphate in the kidney
– Stimulates release of calcium and phosphate from bone (indirectly)
– Causes release of receptor activator of nuclear factor -kB ligand (RANKL) from the surface of the osteoblasts
Parathyroid hormone exerts its effects through receptors on osteoblasts and kidney nephron cells.
Parathyroid hormone effects on the gut are indirect through an increased synthesis of 1,25 dihydroxy vitamin D.
Parathyroid hormone acts on osteoblasts to release RANKL, which then acts on the osteoclast progenitor cells to differentiate into osteoclasts.
Author of the question: Rajesh Bahadur Lakhey
5. A magnetic resonance image of a patient’s right shoulder is shown.
The structure marked by the arrows is innervated by which of the following nerves?
A) Musculocutaneous nerve
B) Branch of the posterior cord of the brachial plexus
C) Branch of the lateral cord of the brachial plexus
D) Branch of the medial cord of the brachial plexus
E) Branch of the superior trunk of the brachial plexus
4. What structure is located at the tip of the arrow in the figure attached?
A) Left L3 nerve root
B) Right L3 nerve root
C) Right L4 segmental artery
D) Right L4 nerve root
E) Left lateral disk herniation
3. A 28 years old man was involved in a motorbike road traffic accident sustaining head injury resulting in a coma and hip fracture.
Indomethacin is indicated here to prevent which complication?
A) Non union
B) Infection
C) Vascular compromise
D) Pressure ulcers
E) Heterotopic ossification
2. Which of the following statements is true regarding the effect of anabolic-androgenic steroid on immobilized skeletal muscle:
A) Steroid administration has no effect on immobilized muscle
B) Steroid administration leads to muscle hypertrophy only in conjunction with strength training
C) When compared to controls, steroid administration leads to increased muscle mass but not increased contractile force
D) When compared to controls, steroid administration leads to increased contractile force but not muscle mass
E) When compared to controls, steroid administration leads to both increased contractile force and muscle mass
1. All of the statements regarding the atypical femur fracture due to bisphosphonate therapy are true EXCEPT :
A) Fracture is located along femoral diaphysis from distal to the lesser trochanter to proximal to supracondylar ridge
B) Fracture is sustained with minimal or no trauma
C) Complete fracture extends through both cortices
D) The fracture line originates at the lateral cortex and is usually transeverse
E) The incomplete fracture can involve either the medial or lateral cortex
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