questions 2


Topic updated on 09/29/17 11:46pm


  • A 68-year-old woman presents to her primary care physician with lower back pain of acute onset. She denies any trauma to the spine or any radiation of pain. Her last menstrual period was when she was 51-years-old. On physical exam, she has tenderness to palpation at the level of L4-L5, as well as a loss of lumbar lordosis. A dual-energy x-ray absorptiometry (DEXA) scan reveals a T-score of -2.7.
  • Clinical definition
    • decreased bone mass (osteopenia) that significantly increases the patient's risk of fracture
  • Epidemiology
    • incidence
      • most common types of osteoporosis are
        • post-menopausal
        • senile
    • risk factors
      • post-menopausal women
      • being ≥ 65 years of age
      • people of Caucasian and Asian descent
      • lifestyle factors such as
        • poor physical activity
        • vitamin D deficiency and poor calcium intake
        • smoking
        • alcohol use disorder
      • medications such as
        • warfarin, lithium, proton pump inhibitors, and glucocorticoids
      • hyperparathyroidism
      • hyperthyroidism
      • multiple myeloma
      • malabsorption syndromes
  • Pathogenesis
    • in young adulthood, peak bone mass is achieved and this is determined by a number of factors (e.g., genetics)
      • after this peak bone mass is attained, there is a small decrease in bone formation with every cycle of bone remodeling
        • senile osteoporosis
          • osteoblasts have their biosynthetic and proliferative ability reduced with age
        • poor physical activity
          •  mechanical force on bone stimulates bone remodeling
            • athletes have increased bone density
          • decreased physical activity results in bone loss
        • decreased estrogen levels
          • such as in menopause, decreased estrogen levels increase bone resportion and formation
            • however, the rate of formation is less than resorption resulting in a net bone loss
            • increased osteoclast activity is significant in areas of bone with large surface area
              • such as the vertebral bodies, leading to vertebral compression fractures 
        • there is trabecular and cortical bone loss
  • Prognosis
    • generally good if detected early and appropriately managed
  • Symptoms
    • fractures (e.g., vertberal and hip), otherwise, patients are typically asymptomatic
  • Physical exam
    • may see loss in height


  • DEXA
    • indication
      • all women ≥ 65 and all men ≥ 70 years of age 
    • notes
      • T-score ≤ -2.5
  • Labs
    • serum calcium, phosphorus, parathyroid hormone, and alkaline phosphatase are normal
  • Histology
    • histologically normal; however, there is a decreased quantity of normal bone
Laboratory Abnormalities in Select Bone Disorders
Serum Phosphate
Serum Calcium
Serum Alkaline Phosphatase
Parathyroid Hormone
Osteomalacia / rickets
  • Decreased
  • Decreased
  • Increased
  • Increased
  • Normal
  • Normal
  • Normal
  • Normal
  • Normal
  • Normal or decreased
  • Normal
  • Normal
Paget disease of the bone
  • Normal
  • Normal
  • Increased
  • Normal
Osteitis fibrosa cystica
  • Primary
    • decreased
  • Secondary
    • increased
  • Primary
    • increased
  • Secondary
    • decreased
  • Primary and secondary hyperparathyroidism
    • increased
  • Primary and secondary hyperparathyroidism
    • increased
Hypervitaminosis D
  • Increased
  • Increased
  • Normal
  • Decreased
  • Conservative
    • calcium and vitamin D supplementation
    • strength training
    • smoking cessation
  • Medical
    • bisphosphonates
      • indication
        • first-line for pharmacologic therapy in osteoporosis
    • teriparatide
      • indication
        • considered first-line in patients with a very high risk of fracture
  • Fractures


Qbank (1 Questions)

(M1.MK.4666) A 72-year-old woman comes to you complaining of severe back pain. She reports that she slipped and fell in her shower at home. She also had a wrist fracture two years ago and an ankle fracture last year. The patient reports that she has been taking an over-the-counter vitamin D supplement. She has not had any diffuse bone pain. Figure A shows a radiograph of her spine. Which of the following is the most likely underlying abnormality? Topic Review Topic
FIGURES: A          

1. Superiosteal bone resorption
2. Vitamin D deficiency
3. Excessive unmineralized osteoid
4. Trabecular thinning
5. Hypocalcemia

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