This practice set contains high-yield board review questions covering key concepts in 1. General Principles & Basic Science. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 1101
Topic: 1. General Principles & Basic Science
Which subtype of Ehlers-Danlos syndrome (EDS) is caused by lysyl hydroxylase deficiency?
Correct Answer & Explanation
. EDS type VI
Explanation
Many of the mutations responsible for the differing subtypes of Ehlers-Danlos syndrome (EDS) have not been identified (EDS types I, II, and III). Lysyl hydroxylase deficiency has been identified as the cause of type VI. A mutation in type I collagen has been identified as the cause of EDS VII.
Question 1102
Topic: 1. General Principles & Basic Science
The most common type of chronic inflammatory arthritis in childhood is:
Correct Answer & Explanation
. Pauciarticular juvenile rheumatoid arthritis
Explanation
Forty percent to 60% of children afflicted with juvenile rheumatoid arthritis (JRA) have the pauciarticular subtype. Polyarticular JRA is the second most common type occurring in 30%-40%. Systemic onset JRA is the least common form and occurs in approximately 20% of children. Seronegative spondyloarthropathy is more rare in patients <20 years old. Polyarticular JRA comprises about 30%-40% of JRA. Systemic onset JRA is the least common form of JRA. Seronegative spondyolarthropathy is uncommon in childhood. Reactive arthropathy is not a chronic inflammation.
Question 1103
Topic: Infection, Pharmacology & VTE
A 14-year-old ice hockey player had a jersey pulled over his head in a brawl during a game. He finished the game without incident and denies any other traumatic event. The boy presents the following day with a stiff neck tilted to the right side and an inability to bring his head to a neutral position. On more careful physical examination, the boy's head is tilted to the right 20°, rotated to the left 20°, and slightly flexed. Attempts at passive rotation to a neutral position produce pain. The exam is otherwise unremarkable. Computerized tomography scans show atlantoaxial rotatory displacement with no anterior displacement of C1 on C2. Treatment should include:
Correct Answer & Explanation
. Use of a soft collar, exercises, and nonsteroidal anti-inflammatory drugs (NSAIDs)
Explanation
A soft collar, exercises, and nonsteroidal anti-inflammatory drugs (NSAIDs) should be tried for 1 week if the diagnosis of atlantoaxial rotatory displacement is made within a week of its onset. The patient's progress must be followed closely. If NSAIDs and a collar do not work after 1 week, the patient should be hospitalized and head halter traction should be administered along with muscle relaxants. If head halter traction successfully reduces the deformity, the patient should be placed in a Philadelphia collar with Minerva casting for 6 weeks. If the patient has no neurologic findings and no anterior displacement, the condition is likely to resolve with conservative measures alone. If surgery becomes necessary, the occiput should not be included in surgical treatment of atlantoaxial rotatory displacement.
Question 1104
Topic: Biology, Genetics & Bone Healing
Marfan syndrome is now recognized as a defect in the following molecule:
Correct Answer & Explanation
. Fibrillin-1
Explanation
Marfan syndrome is due to an abnormality in fibrillin-1, a component of elastic connective tissue. Type I collagen is most commonly abnormal in osteogenesis imperfecta. Type I collagen is normal in Marfan syndrome. Type II collagen is a homotrimer (encoded by a single gene) and is mainly located in cartilaginous tissues. Type II collagen is abnormal in spondyloepiphyseal dysplasia congenita and Stickler syndrome. The sulfate transport protein is important for cartilage formation. The sulfate transport protein is impaired in diastrophic dysplasia. Type IX collagen is also found in cartilage. Type IX collagen is abnormal in some forms of multiple epiphyseal dysplasia.
Question 1105
Topic: 1. General Principles & Basic Science
In the early stages of osteoarthritis, which of the following best describes the characteristic biochemical changes that occur in the articular cartilage?
Correct Answer & Explanation
. Increased water content and decreased proteoglycan concentration
Explanation
The hallmark biochemical change in early osteoarthritis is the breakdown of the collagen matrix, which leads to increased permeability and an influx of water, alongside a decrease in proteoglycan concentration.
Question 1106
Topic: Biology, Genetics & Bone Healing
During the process of endochondral ossification in secondary fracture healing, which type of collagen is most predominantly synthesized by chondrocytes in the soft callus phase?
Correct Answer & Explanation
. Type II collagen
Explanation
The soft callus is primarily composed of cartilage, where chondrocytes predominantly synthesize Type II collagen. As healing progresses to hard callus, osteoblasts replace this with Type I collagen.
Question 1107
Topic: Biology, Genetics & Bone Healing
Which type of collagen is predominantly synthesized during the soft callus phase of secondary fracture healing?
Correct Answer & Explanation
. Type II
Explanation
During the soft callus (chondrogenesis) phase of secondary fracture healing, chondrocytes predominantly produce Type II collagen. As the hard callus forms, osteoblasts replace this with Type I collagen.
Question 1108
Topic: Biology, Genetics & Bone Healing
A 30-year-old woman presents with knee pain. Radiographs reveal an eccentric, lytic epiphyseal lesion in the proximal tibia without a sclerotic margin. Histology shows multinucleated giant cells. Which of the following is the standard medical treatment targeting the underlying pathophysiology?
Correct Answer & Explanation
. Denosumab
Explanation
Giant cell tumors of bone express high levels of RANKL, which drives the formation of osteoclast-like giant cells. Denosumab, a monoclonal antibody against RANKL, is specifically used for unresectable or recurrent cases.
Question 1109
Topic: 1. General Principles & Basic Science
A 4-year-old girl is diagnosed with pauciarticular (oligoarticular) juvenile idiopathic arthritis (JIA). Which of the following routine screening examinations is highly recommended due to the high risk of asymptomatic, sight-threatening complications?
Correct Answer & Explanation
. Slit-lamp eye examination
Explanation
Patients with oligoarticular JIA, especially those who are Antinuclear Antibody (ANA) positive, are at a very high risk for developing chronic, asymptomatic anterior uveitis. Routine slit-lamp screening by an ophthalmologist is mandatory to prevent blindness.
Question 1110
Topic: Biology, Genetics & Bone Healing
Multiple Epiphyseal Dysplasia (MED) is characterized by delayed and irregular ossification of the epiphyses. Which of the following genes is NOT typically associated with MED?
Correct Answer & Explanation
. RUNX2
Explanation
RUNX2 mutations are associated with Cleidocranial Dysplasia, not MED. MED is typically caused by mutations in the genes encoding COMP, matrilin-3 (MATN3), or type IX collagen (COL9A1, COL9A2, COL9A3).
Question 1111
Topic: 1. General Principles & Basic Science
Which of the following variants of Ehlers-Danlos syndrome is caused by a mutation in the COL3A1 gene (resulting in a type III collagen defect) and carries a high risk of fatal arterial rupture?
Correct Answer & Explanation
. Vascular type
Explanation
Vascular Ehlers-Danlos syndrome is caused by mutations in the COL3A1 gene. It is considered the most severe and life-threatening form due to the propensity for spontaneous rupture of medium and large arteries, the bowel, and the uterus.
Question 1112
Topic: Biology, Genetics & Bone Healing
A 10-year-old child presents with delayed closure of the cranial sutures, dental anomalies, and absent clavicles allowing extreme shoulder protraction. This condition is caused by a mutation in which of the following transcription factors?
Correct Answer & Explanation
. RUNX2 (CBFA1)
Explanation
Cleidocranial dysplasia is an autosomal dominant condition caused by a mutation in the RUNX2 (CBFA1) gene, which is an essential transcription factor for osteoblast differentiation. Patients characteristically present with absent or hypoplastic clavicles and delayed fontanelle closure.
Question 1113
Topic: 1. General Principles & Basic Science
Immobilization as a postoperative therapy for flexor tendon repair is recommended for:
Correct Answer & Explanation
. C hildren
Explanation
As children have difficulties in following the detailed flexor tendon rehabilitation program that is recommended for adults after flexor tendon repair, it is advisable to completely immobilize them to protect the repair and avoid inadvertent rupture.
Question 1114
Topic: 1. General Principles & Basic Science
Optimization of early active motion protocols for flexor tendon rehabilitation includes:
Correct Answer & Explanation
. Multi-strand repair
Explanation
The use of 6- and 8-strand repair techniques allow the flexor tendon repair to withstand the force applied by early active motion protocols. The addition of epitendinous tendon repair also strengthens the repair.
Question 1115
Topic: 1. General Principles & Basic Science
Flumazenil can be administered to reverse the effects of which of the following drugs:
Correct Answer & Explanation
. Midazolam
Explanation
Midazolam is a benzodiazepine. Flumazenil is the only commercially available benzodiazepine antagonist. The recommended dose is 0.01 mg/kg every minute until reversed to a maximum dose of 1 mg. Fentanyl is an opioid and is reversible with naloxone. Flumazenil is a benzodiazepine antagonist and has no effects on the effects of opioids. Propofol, ketamine, and methohexital have no known antagonists.
Question 1116
Topic: Biology, Genetics & Bone Healing
Osteogenesis imperfecta (OI) is caused by defects in:
Correct Answer & Explanation
. Type I collagen
Explanation
Both quantitative and qualitative defects in type I collagen lead to the various types of osteogenesis imperfecta (OI). Several hundred different collagen I mutations have been found in patients with OI. The less severe forms of OI are caused by mutations in which the defective gene product is not incorporated into collagen, so that formation of cells using the unimpaired strands can continue.
Question 1117
Topic: 1. General Principles & Basic Science
Which of the following etiologies is not thought to be associated with pseudarthrosis of the clavicle:
Correct Answer & Explanation
. Stress lesion from dominant arm
Explanation
Several theories have been proposed to explain the rare phenomenon of isolated pseudarthrosis of the clavicle. The most accepted theory is pressure from the higher riding right subclavian artery. Pseudarthrosis has also been described in patients with prominent cervical ribs. Finally, some believe that this condition is caused by failure of fusion of the medial and lateral ossification centers of the clavicle. C leidocranial dysplasia may be associated with pseudarthrosis of the clavicle. There is no evidence that they are related to stress.
Question 1118
Topic: 1. General Principles & Basic Science
Which form of chronic inflammatory arthritis is more common in boys than in girls?
Correct Answer & Explanation
. Polyarticular
Explanation
Overall, juvenile rheumatoid arthritis (JRA) is much more common in girls. In pauciarticular JRA, the ratio is 4:1 female. In polyarticular JTA, it is 3:1 female, and in systemic JRA the ratio is 1:1. Seronegative spondylarthropathy is more common in males. The incidence of polyarticular JRA is 3 times higher in girls than in boys. The incidence of pauciarticular JRA occurs 4 times more often in girls than in boys. Girls and boys are equally affected by systemic onset JRA.
Question 1119
Topic: 1. General Principles & Basic Science
Which of the following subtypes of juvenile rheumatoid arthritis (JRA) results in the highest risk of developing iritis:
Correct Answer & Explanation
. Pauciarticular JRA
Explanation
Patients with pauciarticular juvenile rheumatoid arthritis (JRA) have the highest risk of developing iritis, cataracts, and blindness. Polyarticular JRA has the second highest risk. Patients with systemic JRA rarely develop iritis. All newly diagnosed JRA patients should be acutely evaluated and closely followed by an ophthalmologist. Systemic-onset JRA has the lowest risk of uveitis There is a distinct difference among the types of JRA in terms of risk of eye involvement. Eye involvement is one of the problems physicians should be alert for in order to make an early diagnosis and prevent cataracts and blindness.
Question 1120
Topic: Infection, Pharmacology & VTE
In the evaluation of a child with possible inflammatory arthritis, which tests should be ordered for possible juvenile rheumatoid arthritis?
Correct Answer & Explanation
. CBC, ANA, RF, ESR, CRP, ophthalmology consult
Explanation
Juvenile rheumatoid arthritis (JRA) is primarily a clinical diagnosis; however, routine screening tests should be ordered as part of a routine work-up. All patients should have a CBC, RF, ANA, ESR, CRP, and ophthalmology consult to look for eye involvement. An echocardiogram is not necessary unless a pericardial rub or other cardiac symptoms are present. HLA associations have been made with the different sub-types of the disease; however, this test is not necessary or diagnostic. The CBC helps to rule out hematologic malignancy and assess the patient's general health. The ANA looks at the possibility of systemic lupus erythematosus and, if positive at low titer, heralds an increased risk of uveitis. A positive RF helps rule in JRA and makes the risk of later erosive disease more likely. ESR and CRP are helpful for monitoring disease activity. Ophthalmology consultation will help to rule out or detect uveitis at an early stage. HLA typing is not indicated in the typical patient with JRA; it may be useful in the older male with axial symptoms. Synovial fluid analysis yields inflammatory fluid in this condition, but no information specific for the diagnosis.
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