MD - Doctor of Medicine Musculoskeletal and Connective Tissue Questions and Answers — Questions and Answers
Question 1: A 28-year-old African American female presents with fatigue, a facial rash that worsens with sun exposure, and joint pain in her hands and wrists. Laboratory workup is initiated for a suspected autoimmune condition. Which of the following clinical findings is most characteristic of Systemic Lupus Erythematosus (SLE)?
- Painless oral ulcers (Correct answer)
- Proximal muscle weakness
- Sclerodactyly
- Asymmetric oligoarthritis
Correct answer: Painless oral ulcers
Painless oral or nasopharyngeal ulcers are a specific clinical criterion for the diagnosis of SLE according to both the ACR and SLICC classification systems. While symmetric small joint arthritis is common in SLE, asymmetric oligoarthritis is more characteristic of spondyloarthropathies. Proximal muscle weakness is characteristic of myositis, and sclerodactyly (thickening and tightening of the skin on the fingers) is a hallmark feature of systemic sclerosis.
Question 2: A 72-year-old woman is diagnosed with osteoporosis after a DEXA scan reveals a T-score of -2.8 at the femoral neck. She has no contraindications to standard therapy. Which of the following best describes the mechanism of action of bisphosphonates, the first-line treatment for this condition?
- Stimulates osteoblasts to increase bone formation
- Inhibits osteoclast-mediated bone resorption (Correct answer)
- Acts as a selective estrogen receptor modulator in bone
- Increases intestinal calcium absorption and renal calcium reabsorption
Correct answer: Inhibits osteoclast-mediated bone resorption
Bisphosphonates are potent inhibitors of bone resorption. They bind to hydroxyapatite in bone and are taken up by osteoclasts, where they interfere with cellular processes, leading to osteoclast apoptosis. This action reduces the breakdown of bone, allowing for a net increase in bone density. Teriparatide stimulates osteoblasts, raloxifene is a SERM, and parathyroid hormone (in a complex way) and Vitamin D metabolites increase calcium absorption.
Question 3: A 35-year-old man with a history of intravenous drug use presents to the emergency department with a 2-day history of severe right knee pain, swelling, and an inability to bear weight. On examination, the knee is erythematous, warm, and exquisitely tender. He has a fever of 39.0°C (102.2°F). What is the most crucial next step in the diagnosis and management of this patient?
- Obtain an MRI of the knee
- Initiate empiric intravenous antibiotics
- Perform an immediate arthrocentesis (Correct answer)
- Order blood cultures and C-reactive protein
Correct answer: Perform an immediate arthrocentesis
The clinical presentation is highly suggestive of septic arthritis, which is a medical emergency requiring prompt diagnosis to prevent joint destruction. The most critical step is to perform an immediate joint aspiration (arthrocentesis). Analysis of the synovial fluid for cell count, Gram stain, and culture is essential to confirm the diagnosis and guide antibiotic therapy. While antibiotics, blood cultures, and imaging are all important, confirming the diagnosis via arthrocentesis is the highest priority and should ideally be done before starting antibiotics.
Question 4: A 65-year-old male with a history of chronic kidney disease (stage 3) presents with excruciating pain, redness, and swelling in his right great toe that began overnight. Arthrocentesis reveals negatively birefringent, needle-shaped crystals. What is the most appropriate initial pharmacologic treatment for this patient's acute gout flare?
- Allopurinol
- High-dose NSAIDs (e.g., indomethacin)
- Probenecid
- Prednisone (Correct answer)
Correct answer: Prednisone
The patient is having an acute gout flare. While high-dose NSAIDs are a first-line treatment, they should be avoided or used with extreme caution in patients with chronic kidney disease (CKD) due to the risk of worsening renal function. Allopurinol and probenecid are urate-lowering therapies used for long-term prevention and are not indicated for treating an acute flare. Oral corticosteroids, like prednisone, are a first-line option for acute gout and are a safer choice in this patient with underlying CKD.
Question 5: A 45-year-old female presents with a 6-month history of symmetric pain and swelling in her metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints, associated with morning stiffness lasting over an hour. Which of the following laboratory findings is most specific for the diagnosis of rheumatoid arthritis?
- Positive antinuclear antibody (ANA)
- Positive anti-cyclic citrullinated peptide (anti-CCP) antibody (Correct answer)
- Elevated C-reactive protein (CRP)
- Elevated rheumatoid factor (RF)
Correct answer: Positive anti-cyclic citrullinated peptide (anti-CCP) antibody
While RF, CRP, and ANA can be positive in rheumatoid arthritis, anti-CCP antibodies have the highest specificity (around 95-98%) for the disease. RF can be positive in other autoimmune diseases, infections, and even healthy individuals. CRP is a nonspecific marker of inflammation. ANA is more characteristic of SLE but can be seen in RA.
Question 6: A 75-year-old woman was recently diagnosed with polymyalgia rheumatica (PMR). During a follow-up visit, she reports developing a new, unilateral headache over her right temple and jaw claudication when chewing. Which of the following conditions is most likely associated with her PMR and new symptoms?
- Fibromyalgia
- Giant Cell Arteritis (GCA) (Correct answer)
- Trigeminal neuralgia
- Cervical spondylosis
Correct answer: Giant Cell Arteritis (GCA)
Polymyalgia rheumatica and Giant Cell Arteritis are closely related inflammatory conditions. Approximately 50% of patients with GCA also have PMR, and about 15-20% of patients with PMR will develop GCA. The new onset of headache, jaw claudication, and temporal tenderness in an elderly patient with PMR is highly suspicious for GCA, a vasculitis that can lead to irreversible blindness if not promptly treated with high-dose corticosteroids.
MD - Doctor of Medicine Musculoskeletal and Connective Tissue Questions and Answers
A 28-year-old African American female presents with fatigue, a facial rash that worsens with sun exposure, and joint pain in her hands and wrists.
Laboratory workup is initiated for a suspected autoimmune condition.
Which of the following clinical findings is most characteristic of Systemic Lupus Erythematosus (SLE)?