Musculoesquelético

Question 1

Tumor lysis syndrome

Answer 1

A constellation of electrolyte disturbances that can occur as a result of cancer treatment. Widespread lysis of tumor cells can release significant quantities of potassium, phosphate, uric acid, and lactate dehydrogenase.
Monosodium urate crystals cause gout and acute kidney injury

Question 2

Patients with refractory rheumatoid arthritis are frequently prescribed glucocorticoids (e.g., prednisone), which induce bone resorption and increase the risk of _____ and _____. Glucocorticoid-induced bone resorption is primarily mediated via the RANKL signaling pathway, a cascade that upregulates osteoclast activity and induces apoptosis of osteoblasts.

Answer 2

osteopenia
osteoporosis

Question 3

Which of the following is the strongest predisposing factor for osteopenia?
Hypoparathyroidism
NSAID use
Obesity
Smoking
Type 2 diabetes mellitus

Answer 3

Smoking

Question 4

Osteonecrosis of the jaw

Answer 4

An area of exposed maxillofacial bone(s) for at least 8 weeks. Can occur secondary to radiation, infection, or steroid or bisphosphonate use.
Bisphonates MOA is binding to hydroxyapatite. Used in multiple myeloma

Question 5

A traction apophysitis that occurs where the patellar tendon inserts onto the tibial tuberosity. Characterized by progressive anterior knee pain that is exacerbated by activity (typically jumping, kneeling, running, squatting), with focal swelling and tenderness at the tibial tuberosity. Most commonly affects adolescents.
Affects the pattelar ligament

Answer 5

Osgood-Schlatter disease

Question 6

A 28-year-old man comes to the physician because of a 3-month history of pain in his left shoulder. He is physically active and plays baseball twice a week. The pain is reproduced when the shoulder is externally rotated against resistance. Injury of which of the following tendons is most likely in this patient?

Answer 6

Infraspinatus

The infraspinatus muscle, along with the teres minor muscle, is responsible for the external rotation of the humerus.

Question 7

A genetic disorder characterized by defective synthesis of type 1 collagen, which is important in bone formation.

Answer 7

Osteogenesis imperfecta

Patients present with signs that are sometimes mistaken for child abuse (e.g., easy bruising, predisposition to bony fractures). Additional clinical features include blue sclerae, joint laxity, hearing loss, and brittle, opalescent teeth.

Question 9

A genetic disorder characterized by defective synthesis of type 1 collagen, which is important in bone formation.

Answer 9

Osteogenesis imperfecta

Patients present with signs that are sometimes mistaken for child abuse (e.g., easy bruising, predisposition to bony fractures). Additional clinical features include blue sclerae, joint laxity, hearing loss, and brittle, opalescent teeth.

Question 10

Myophosphorylase deficiency (McArdle’s disease) is a glycogen storage disease that presents with _____, _____, ______, and early _____ from exercise due to inability to break down glycogen for use as energy in muscle tissues.
What is it’s eponymus?

Answer 10

myalgias, rhabdomyolysis, myoglobinuria, and early fatigue

Question 11

A previously healthy 2-year-old boy is brought to the emergency department by his mother because of persistent crying and refusal to move his right arm. The episode began 30 minutes ago after the mother lifted him up by the arms. He appears distressed and is inconsolable. Vital signs are within normal limits. On examination, the patient’s right forearm is held close to his body in a flexed and pronated position. Which of the following is the most likely diagnosis?
Proximal ulnar fracture
Anterior shoulder dislocation
Supracondylar fracture of the humerus
Olecranon fracture
Radial head subluxation

Answer 11

Radial head sublaxation

Question 12

A t(11;22) chromosomal translocation, resulting in expression of fusion protein EWS-FLI 1, is found in approx. 90% of cases of…..

Answer 12

Ewing sarcoma typically occurs in patients < 20 years of age and involves the diaphysis of long bones. X-ray usually reveals a tumor with multiple lytic lesions that may extend into the surrounding soft tissue and an aggressive lamellated periosteal reaction. A biopsy shows small blue cells with a high nuclear-cytoplasmic ratio. Systemic symptoms, as seen in this patient, are common.

Question 13

The inhibition of Conversion of arachidonic acid to prostaglandin G2 is made by which drugs

Answer 13

NSAID

Question 14

This patient presents with signs and symptoms of rheumatoid arthritis, including fatigue, symmetric polyarthritis of the small joints, prolonged morning stiffness, elevated ESR, and positive rheumatoid factor.
The drug she was prescribed is _____, the disease-modifying antirheumatic drug of choice, which targets the enzyme dihydrofolate reductase.

Answer 14

methotrexate
Trimethroprim and pyrimethamine work too

Question 15

Sunburst appearance, Codman triangle, elevated alkaline phosphatase leves are signs of osteosarcoma. Which cells does it affect?

Answer 15

Periosteum

Question 16

A 31-year-old man comes to the physician because of several months of recurrent abdominal pain and diarrhea. Six months ago, he traveled to Lake Superior for a fishing trip with his friends, during which they often ate their day’s catch for dinner. Physical examination shows pallor. Laboratory studies show macrocytic anemia with eosinophilia. A peripheral blood smear shows hypochromic red blood cells with megaloblasts and hypersegmented neutrophils. A cestode infection is suspected and a drug is prescribed that kills cestodes by inducing uncontrollable muscle spasm in the parasite. The drug prescribed will be?

Answer 16

This patient is most likely treated with the antihelminthic medication praziquantel, which causes contracted muscle paralysis in parasites by increasing calcium influx into the sarcoplasm of the parasite.

Question 17

Fever, lower back pain, focal spinal tenderness, and a positive psoas sign are characteristic of vertebral osteomyelitis. Constitutional symptoms such as weight loss and fever as well as the history of treatment with a TNF-alpha inhibitor (adalimumab) suggest __________ infection.

Answer 17

Mycobacterium tuberculosis

The cord factor is a glycolipid in the cell wall of M. tuberculosis that inhibits phagosome-lysosome fusion and prevents lysis of phagocytosed mycobacteria

Question 18

A group of rare disorders characterized by impaired energy production that mainly affects organs with a high energy requirement (e.g., brain, skeletal muscle). Muscle biopsy shows an accumulation of abnormal mitochondria that have a ragged red fiber appearance.

Answer 18

Mitochondrial myopathies

Question 19

Loss of cortical bone mass and thinning of trabecular bone are the microscopic hallmarks of….

Answer 19

osteoporosis

Question 20

A previously healthy 5-year-old boy is brought to the emergency department because of fever, irritability, malaise, and left knee pain for 4 days. Four days ago, he fell off his bike and scraped his elbow. His temperature is 39.1°C (102.4°F). The patient walks with a limp. Examination shows swelling and point tenderness over the medial aspect of the left knee. An MRI of the left knee shows edema of the bone marrow and destruction of the medial metaphysis of the tibia. Which of the following is the most likely causal organism?

Answer 20

Staphylococcus aureus caused hematogenous osteomyelitis

Question 21

Ankylosing spondylitis is a chronic inflammatory disease of the axial skeleton that leads to partial or even complete fusion and rigidity of the spine (Males are disproportionately affected and > 90% of patients are positive for the HLA-B27 genotype, which predisposes to the disease). What symptoms it may cause?

Answer 21

progressively worsening back pain that is worse in the morning, impaired spinal flexion, and bilateral hip pain

Question 22

Histological examination of skeletal muscles affected by _____ typically shows endomysial infiltration of CD8+ T cells and macrophages, with areas of muscle necrosis and regeneration of muscle fibers. In addition, overexpression of MHC-I on the sarcolemma is an immunohistochemical finding that is classic for ______

Answer 22

polymyositis: proximal skeletal muscle weakness, increased serum creatine kinase concentration, and evidence of myositis on EMG and biopsy

Question 23

A postmenopausal woman presenting with a fracture on a background of decreased bone mineral density suggests osteoporosis. Bisphosphonates are indicated. Which substance do ypu give her?

Answer 23

Inorganic pyrophosphates are compounds formed by the linkage of two phosphate ions and are found endogenously in all cells.
They attach to binding sites on hydroxyapatite to interfere with osteoclasts