Ddx: Osteoporosis

Question 1

DDx: Osteoporosis

Answer 1

Osteoporosis

Low Bone Mass

Osteomalacia

Paget Disease of Bone

Question 2

Osteoporosis

Answer 2

The recommended age for osteoporosis screening (age 65 years in average-risk women), her risk factors (family history, low body mass index, and smoking history) are indications for bone mineral density testing.

Dx: Osteoporosis is diagnosed by a DEXA T-score of less than –2.5 or the presence of fragility fractures; a fragility fracture (fracture sustained in a fall from a standing height) defines osteoporosis regardless of bone mineral density results.

Fracture Risk Assessment Tool (FRAX)

Tx: The National Osteoporosis Foundation (NOF) recommends antiosteoporotic therapy for persons whose risk of major osteoporotic fracture over the next 10 years is 20% or greater or whose risk of hip fracture over the next 10 years is 3% or greater.

Bisphosphonates: Alendronate is approved for both osteoporosis prevention and treatment by the Food and Drug Administration (FDA).

Zoledronic acid (IV bisphosphonate) is preferred for women with postmenopausal osteoporosis who are unable to take oral bisphosphonates (gastroesophageal reflux disease) or who desire the convenience of less frequent dosing.

Raloxifene, a selective estrogen receptor modulator, is also approved for osteoporosis prevention by the FDA. However, vasomotor symptoms are highly associated with its use.

Teriparatide, or recombinant human parathyroid hormone (1-34), is an anabolic agent that increases bone density and decreases fracture risk. However, it is considered second-line therapy to bisphosphonates, is expensive, and has been associated with an increased risk of osteosarcoma.

Question 3

Low Bone Mass

Answer 3

Dx: Low bone mass is defined as a bone mineral density score that is between 1.0 and 2.5 SD below the young adult mean.

Question 4

Osteomalacia

Answer 4

Osteomalacia is a generalized disorder of bone resulting in decreased mineralization of newly formed osteoid at sites of bone turnover. Although it may be asymptomatic, osteomalacia may present with diffuse bone and joint pain, muscle weakness, and difficulty walking. It most commonly occurs in patients with low levels of vitamin D, hypophosphatemia, hypocalcemia, and increased serum parathyroid hormone and alkaline phosphatase levels.

Question 5

Paget disease of bone

Answer 5

Paget disease of bone is a focal disorder of bone metabolism characterized by an accelerated rate of bone remodeling that results in overgrowth of bone at a single or multiple sites and impaired integrity of affected bone. Although Paget disease is usually asymptomatic, if symptoms are present they are usually due to overgrowth of the affected bone, either in the bone itself or from bony overgrowth due to fracture or nerve impingement. The serum alkaline phosphatase level is typically elevated, and radiographs show increased bone density in involved areas

Question 6

Secondary causes

Answer 6

hypogonadism, vitamin D deficiency, primary hyperparathyroidism, calcium malabsorption (celiac disease), and multiple myeloma.