1. General Principles & Basic Science MCQs

A 50-year-old female with the CREST variant of scleroderma presents with a gangrenous tip of her index finger due to severe Raynaud phenomenon. She has failed conservative management. Before proceeding with surgical amputation, what intervention is recommended to optimize healing of the adjacent tissue?

A 60-year-old female with a history of celiac disease presents with generalized bone pain and proximal muscle weakness. Her radiographs demonstrate pseudofractures.

Which of the following laboratory profiles is most consistent with her diagnosis?

A 7-year-old boy with sickle cell disease presents with fever, focal tibial pain, and swelling. While Staphylococcus aureus remains the most common overall cause of osteomyelitis in this population, which of the following organisms is disproportionately more prevalent in patients with this underlying disease compared to the general pediatric population?

A 48-year-old woman presents with generalized bone pain and muscle weakness. Radiographs reveal bilateral radiolucent bands perpendicular to the cortex in her femoral necks.

Histological analysis of these bands would most likely demonstrate an accumulation of which of the following?

A 35-year-old patient on long-term phenytoin therapy develops osteomalacia. Which of the following best explains the mechanism of antiepileptic-induced bone disease?

A 5-year-old boy presents with short-trunk dwarfism, a waddling gait, myopia, and a history of cleft palate. Radiographs show delayed ossification of the femoral heads and severe coxa vara. He is diagnosed with spondyloepiphyseal dysplasia (SED) congenita. This disorder is caused by a mutation affecting which of the following proteins?

A 60-year-old diabetic patient presents with acute, severe leg pain out of proportion to exam findings, swelling, and bullae. In the operating room, an incision reveals "dishwater pus" and non-bleeding fascia. Which of the following is the most critical intervention for patient survival?

Which of the following organisms is most heavily reliant on the production of a polysaccharide glycocalyx (slime layer) to adhere to orthopedic implants and evade host immune responses in chronic periprosthetic joint infections?

A 5-year-old girl is diagnosed with X-linked hypophosphatemic rickets (PHEX mutation). Which of the following is the gold standard medical therapy to prevent progression of skeletal deformity?

During surgical debridement of chronic osteomyelitis, the surgeon removes a piece of dense, isolated bone. By definition, a sequestrum represents which of the following?

A 2-week-old neonate presents with pseudoparalysis of the right leg and irritability with diaper changes. Ultrasound shows a hip effusion and radiographs reveal subtle changes as shown.

Besides Staphylococcus aureus, which organism is a leading cause of septic arthritis in this age group?

A 2-year-old boy with a history of anterolateral tibial bowing develops a pseudoarthrosis after a minor fall. He has multiple cafe-au-lait spots. The underlying genetic mutation affects a protein primarily involved in which of the following cellular pathways?

A 7-year-old girl from Massachusetts presents with a massive, painless effusion of her right knee. She is afebrile and inflammatory markers are minimally elevated. Joint aspiration yields 45,000 WBCs/microL. After sending synovial fluid for testing, what is the recommended initial management for this likely diagnosis?

A 17-year-old male presents with chronic neck pain. Radiographs demonstrate an expansile lesion in the posterior elements of C4.

Histologically, the lesion consists of woven bone trabeculae lined by prominent osteoblasts. Which of the following strongly differentiates this lesion from an osteoid osteoma?

A 9-year-old boy presents with severe thigh pain, high fever, and a swollen, erythematous leg. MRI confirms osteomyelitis of the femur and an adjacent deep venous thrombosis (DVT). Blood cultures grow gram-positive cocci. Which of the following virulence factors is most strongly associated with this severe clinical presentation?

An 11-year-old girl presents with recurrent episodes of clavicular and tibial pain with mild swelling. Radiographs show lytic and sclerotic changes in the medial clavicle and proximal tibia. Multiple biopsies show chronic inflammation but all bacterial, fungal, and mycobacterial cultures remain sterile. What is the most appropriate initial treatment?

A 7-year-old girl with homozygous sickle cell disease (HbSS) presents with severe bone pain, high fever, and swelling over the midshaft of her radius. MRI confirms diaphyseal osteomyelitis. While Staphylococcus aureus is highly prevalent, this patient is uniquely at high risk for infection from which of the following organisms?