A 68-year-old Caucasian woman comes to the emergency department due to several hours of severe upper back pain. The patient developed the pain after experiencing a sudden jolt while driving over a pothole. She has no previous history of back pain or major trauma and has not seen a doctor in many years. The patient is retired and lives a sedentary lifestyle. She drinks a glass of wine daily and eats a healthy, balanced diet. BMI is 18.4 kg/m². On examination, there is point tenderness over the T10 vertebra. Neurologic examination is unremarkable. X-ray of the spine reveals a T10 compression fracture. On the graph, area C represent the normal serum concentrations of calcium and parathyroid hormone. Which of the following areas most likely corresponds to this patient's current metabolic state?

Question

Quizplus · Accepted Answer

11ec160b_3b65_c7aa_9249_f5d03248f964_MD0001_00 This patient with a thoracic compression fracture has multiple risk factors for osteoporosis (Caucasian ethnicity, female sex, postmenopausal status). Osteoporosis is characterized by decreased bone strength resulting from low bone mass and microarchitectural deterioration of bone tissue. The presence of a fragility fracture due to minimal trauma (eg, fall from a standing height) is strongly suggestive of osteoporosis. Early postmenopausal osteoporosis primarily involves cancellous bone, which is especially important for maintaining the integrity of the vertebral column. Therefore, vertebral fractures are the most common manifestation of osteoporosis. With advancing age, the cortical bone (compact bone) that makes up the shafts of long bones and outer envelopes of all bones becomes more involved, leading to an increased risk of hip fracture. In primary osteoporosis (ie, osteoporosis that is not due to an underlying medical disorder), serum calcium, phosphorus, and parathyroid hormone (PTH) levels are typically in the normal range. (Choice A) High serum PTH with low serum calcium (area A in the diagram) is usually seen in patients with renal failure or vitamin D deficiency. (Choices B and E) High calcium, high PTH (area B) is consistent with primary hyperparathyroidism. High calcium levels with low PTH (area E) would be seen in patients with PTH-independent hypercalcemia (PTH is appropriately suppressed by high calcium levels), which can occur with humoral hypercalcemia of malignancy and vitamin D toxicity. (Choice D) In patients with hypoparathyroidism, low PTH levels cause hypocalcemia. Educational objective: Patients with osteoporosis have low bone mass, resulting in increased susceptibility to fragility fractures (ie, those occurring with minimal or no trauma). In primary osteoporosis (not caused by a medical disorder), serum calcium, phosphorus, and parathyroid hormone levels are typically normal.

A 68-Year-Old Caucasian Woman Comes to the Emergency Department Due