Lesson
Bone Strength Is More Than Density
Osteoporosis is a failure of skeletal strength, not simply a low number on a scan. Remodeling, mineralization, cortical porosity, trabecular connectivity, accumulated damage, muscle function, and falls determine whether a load becomes a fracture.
- Osteoclasts
- Osteoblasts
- Trabecular structure
- Cortical porosity
- Fragility fracture
Acid and enzymes remove a packet of mineralized matrix
New osteoid fills the site and mineralizes over time
Mechanical sensing and signaling tune both sides of the cycle
Trace the remodeling unit
Osteoclast lineage cells resorb mineralized bone. Osteoblast lineage cells replace and mineralize matrix, while osteocytes sense mechanical strain and coordinate signaling. Menopause, aging, glucocorticoids, immobility, endocrine disease, and some medicines can shift the balance toward net loss.
Recognize the sentinel event
A low-trauma hip or vertebral fracture demonstrates skeletal fragility regardless of whether the measured T-score is below -2.5. A new fracture after age 50 also signals a period of especially high near-term risk and should trigger prompt secondary prevention.
Search for a driver
Review glucocorticoids, aromatase inhibitors, androgen deprivation, anticonvulsants, excess thyroid replacement, malabsorption, hyperparathyroidism, hypogonadism, CKD-MBD, alcohol, smoking, nutrition, and other secondary causes. The workup follows the history rather than a universal laboratory panel.
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Lesson
Find Risk Before the Fracture
Screening is a pathway from population recommendation to individual risk, not a single age cutoff applied to everyone. Prior fracture and secondary osteoporosis already move a patient beyond routine screening into diagnostic care.
- Age
- Menopause
- Clinical risk
- Secondary osteoporosis
- USPSTF
Use current recommendations for people without known disease
Fractures, medicines, diseases, falls, and family history change urgency
A sentinel fracture or secondary cause moves beyond routine screening
Apply the 2025 recommendation
USPSTF recommends DXA screening for women age 65 or older. For younger postmenopausal women with one or more risk factors, use a clinical risk assessment tool and screen those at increased risk. These recommendations address adults without known osteoporosis or prior fragility fracture.
Interpret the evidence gap
For men, USPSTF finds evidence insufficient to determine the balance of benefits and harms of population screening. This is not a recommendation against DXA. Age, fracture, hypogonadism, medicines, secondary causes, and how the result would change care guide clinical judgment.
Move beyond screening when needed
A fragility fracture, height loss, vertebral symptoms, long-term glucocorticoid exposure, or a high-risk disease warrants focused evaluation rather than waiting for routine screening eligibility.
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Lesson
DXA, FRAX, and the Diagnostic Frame
DXA and FRAX answer different questions. DXA measures areal mineral density at specific sites, while FRAX estimates 10-year probability from clinical factors with optional femoral-neck BMD. Neither replaces fracture history or clinical judgment.
- T-score
- Z-score
- Least significant change
- FRAX
- Treatment threshold
Confirm site, score, artifact, and least significant change
Calculate ten-year hip and major osteoporotic fracture probability
Add fracture recency, falls, multiplicity, and secondary causes
Read the scan correctly
In postmenopausal women and men age 50 or older, a T-score of -2.5 or lower at an accepted site supports osteoporosis diagnosis. A T-score from -1.0 through -2.5 represents low bone mass. Z-scores compare with age-matched peers and can support evaluation for an unexpected secondary cause.
Respect measurement limits
Confirm site, positioning, artifact, machine comparability, and the facility's least significant change before calling a serial difference real. Degenerative spine change can falsely elevate lumbar density, while one site can obscure risk at another.
Use probability in context
For US adults with low bone mass, BHOF supports treatment when FRAX estimates at least 3 percent 10-year hip risk or at least 20 percent major osteoporotic risk. FRAX can underrepresent recency, multiple fractures, falls, and some dose effects, so it cannot veto compelling clinical risk.
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Lesson
Build the Fracture Prevention System
Food, supplements, exercise, balance, vision, medicines, and the home environment form one prevention system. No supplement compensates for untreated falls, and more calcium or vitamin D is not automatically better.
- Elemental calcium
- Vitamin D
- Resistance exercise
- Balance
- Fall hazards
Fill nutritional gaps and correct measured deficiency
Progress resistance, weight-bearing activity, and safe movement
Correct hazards, vision, orthostasis, footwear, and sedative burden
Calculate total calcium
BHOF recommends 1,000 mg daily for men age 50 to 70 and 1,200 mg daily for women age 51 or older and men age 71 or older. Estimate food first and supplement only the gap. Calcium carbonate is 40 percent elemental and acid dependent; calcium citrate is 21 percent elemental and less dependent on gastric acidity.
Individualize vitamin D
For known or suspected metabolic bone disease, BHOF maintains serum 25-hydroxyvitamin D at least 30 ng/mL but not above 50 ng/mL, often with 800 to 1,000 units daily after repletion. Malabsorption and deficiency can require higher individualized doses and follow-up.
Prevent the next fall
Use weight-bearing activity, progressive resistance, balance training, safe movement, vision and footwear review, home hazard correction, orthostatic assessment, and medication optimization. Sedatives, polypharmacy, poor lighting, and weak transfer mechanics can be more immediate than the DXA value.
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Lesson
Choose a Sequence, Not Just a Drug
Treatment begins with fracture type and timing, DXA, probability, age, secondary causes, comorbidities, adherence, route, and patient priorities. The initial choice also determines what must come next.
- High risk
- Very-high risk
- Antiresorptive
- Bone-forming therapy
- Sequential care
Use a supported oral, intravenous, or biologic option that can be sustained
Consider anabolic or sclerostin therapy when the expected benefit justifies it
Maintain gains and prevent rebound with a planned antiresorptive
Recognize an indication
Treat a qualifying osteoporotic T-score, a hip or vertebral fracture regardless of BMD, and selected proximal humerus, pelvis, or distal forearm fractures with low bone mass. In osteopenia, current US FRAX thresholds can support primary prevention.
Match intensity to risk
Bisphosphonates or denosumab fit many high-risk patients. Multiple or recent vertebral fractures, very low BMD, or severe combined risk can justify teriparatide, abaloparatide, or romosozumab first when eligible.
Protect the sequence
After teriparatide, abaloparatide, or romosozumab, use an antiresorptive to retain gains. Denosumab cannot be stopped or substantially delayed without a subsequent antiresorptive. A bisphosphonate holiday is reserved for selected lower-risk patients after reassessment.
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Lesson
Bisphosphonates: Exposure, Bone, and Time
Bisphosphonates bind hydroxyapatite and inhibit osteoclast-mediated resorption. Their skeletal retention creates durable effect, but administration, renal function, fracture-site evidence, rare harms, and duration determine the right product.
- Hydroxyapatite
- Farnesyl pyrophosphate synthase
- Oral absorption
- Renal function
- Drug holiday
Plain water, fasting separation, and upright posture protect exposure and safety
Check calcium, hydration, creatinine clearance, and infusion duration
Continue, change, or consider a monitored holiday after a full risk review
Teach oral therapy precisely
Alendronate is taken after an overnight fast with 6 to 8 ounces of plain water at least 30 minutes before food, beverages, or other medicines. Remain upright for at least 30 minutes and until after the first food. Avoid in patients unable to follow posture instructions or with esophageal emptying abnormalities.
Use intravenous therapy safely
Reclast is 5 mg intravenously for osteoporosis at labeled intervals and must infuse over at least 15 minutes. Calculate creatinine clearance before each dose, avoid use below 35 mL/min or in acute renal impairment, correct hypocalcemia, and ensure appropriate hydration.
Reassess rather than stop by calendar
Review fracture history, BMD, adherence, thigh or groin pain, dental risk, and ongoing risk after about five years oral or three years intravenous therapy. Selected modest-risk patients can enter a monitored holiday; high-risk patients may continue or change treatment.
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Lesson
Denosumab Requires Continuity
Denosumab blocks RANKL and rapidly suppresses osteoclast formation and activity. It avoids renal clearance, but that does not make it uncomplicated in kidney disease, and its reversible effect makes missed doses and discontinuation clinically dangerous.
- RANKL
- Six-month schedule
- Hypocalcemia
- CKD-MBD
- Rebound fractures
Prevent osteoclast formation, function, and survival
Advanced kidney disease can turn hypocalcemia into a life-threatening event
Use subsequent antiresorptive therapy before rebound accelerates remodeling
Administer deliberately
Give Prolia 60 mg subcutaneously every six months. Correct hypocalcemia, ensure calcium and vitamin D, review dental and infection risks, and do not combine it with another denosumab product. Monitor for ONJ, atypical femoral fracture, skin reactions, and clinically important infection.
Respect the kidney warning
No renal dose adjustment is required, yet advanced CKD, including dialysis, and CKD-MBD markedly increase severe hypocalcemia risk. Current labeling carries a boxed warning and requires CKD-MBD evaluation, specialist supervision, and a structured mineral-monitoring plan.
Prevent rebound
Do not delay or stop denosumab without subsequent antiresorptive therapy. Rapid rise in remodeling, BMD loss, and multiple vertebral fractures can occur after effect wanes. The next medicine and timing are individualized, but an unprotected holiday is not acceptable.
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Lesson
Build First in Very-High Risk
Teriparatide, abaloparatide, and romosozumab can shift therapy toward bone formation in suitable very-high-risk patients. Their finite treatment windows, distinct mechanisms, contraindications, and mandatory follow-on therapy prevent them from being interchangeable.
- PTH1 receptor
- PTHrP
- Sclerostin
- Cardiovascular warning
- Antiresorptive follow-on
Intermittent receptor signaling produces a net formative response
Increase formation and decrease resorption during a fixed twelve-dose course
Protect new bone after the formation window closes
Use PTH pathway therapy
Teriparatide 20 mcg and abaloparatide 80 mcg are given subcutaneously daily. Teach initial orthostatic precautions, calcium-related risks, injection technique, and storage. Avoid patients with increased osteosarcoma risk. Current teriparatide labeling no longer imposes an absolute lifetime two-year prohibition when high risk remains or returns.
Use sclerostin inhibition safely
Romosozumab is 210 mg monthly as two injections for 12 doses in high-risk postmenopausal women. Do not initiate within one year after myocardial infarction or stroke. Correct hypocalcemia, provide calcium and vitamin D, and discontinue if MI or stroke occurs during therapy.
Complete the sequence
The bone-forming advantage fades without maintenance. Follow teriparatide, abaloparatide, or romosozumab with an antiresorptive selected for the patient's risk, kidney function, route, and ability to sustain therapy.
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Lesson
Selective Options Have Selective Evidence
Raloxifene, estrogen-containing products, and calcitonin occupy narrower roles than common first-line antiresorptives. Their nonbone effects, fracture-site evidence, and contraindications determine when a theoretical benefit becomes a clinically good fit.
- Raloxifene
- Estrogen
- Bazedoxifene
- Calcitonin
- Site-specific efficacy
Vertebral protection and breast-risk reduction with thrombotic limits
Integrate symptom goals, uterus, route, age, and vascular and cancer history
Use only when better-supported alternatives are unsuitable
Target vertebral risk with a SERM
Raloxifene reduces vertebral fractures and can reduce invasive breast-cancer risk in selected postmenopausal women. It does not have proven hip-fracture efficacy. Active or prior VTE is contraindicated, and boxed warnings address VTE and death from stroke in at-risk women.
Place estrogen in context
Systemic hormone therapy can prevent bone loss, but the decision integrates menopausal symptoms, age, time since menopause, route, uterus status, VTE, cardiovascular and cancer history, and alternatives. Provide endometrial protection when required and use current product-specific labeling.
Reserve calcitonin
Calcitonin salmon nasal spray is reserved for women more than five years postmenopause when alternatives are unsuitable. Fracture reduction has not been demonstrated. Alternate nostrils, monitor nasal tissue, and periodically reassess because of possible malignancy association.
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Lesson
Keep Protection Intact Over Time
Osteoporosis remains active after the prescription. New fractures, height loss, falls, adherence, administration, dental and thigh symptoms, kidney function, calcium balance, BMD, and treatment transitions determine whether risk is actually controlled.
- Adherence
- Reassessment
- Vertebral imaging
- Glucocorticoids
- Transition
Track falls, height, pain, mobility, adherence, and treatment burden
Use comparable DXA plus product-specific laboratory and clinical monitoring
Continue, pause, switch, or sequence without leaving risk unprotected
Measure what can change care
Review fractures, falls, back pain, height, adherence, technique, adverse effects, secondary causes, and new medicines at follow-up. Repeat DXA at an interval suited to risk and treatment, using the same qualified facility when possible and interpreting change against least significant change.
Act early with glucocorticoids
ACR recommends prompt fracture-risk assessment for adults beginning or continuing at least 2.5 mg prednisone equivalent daily for more than three months. Age, dose, duration, pregnancy potential, BMD, fracture history, and comorbidity guide therapy. Do not wait for the T-score to reach -2.5.
Define the next state
A bisphosphonate may continue, pause, or change after reassessment. Denosumab requires timely continuation or antiresorptive transition. Bone-forming therapy requires antiresorptive follow-on. New fracture on therapy triggers an adherence, secondary-cause, and risk reassessment rather than an automatic conclusion about drug failure.
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Module test
Check the connections.
Each attempt draws 10 questions from the complete 104 question bank.
Each attempt draws a fresh set and rearranges the answer choices.
References
Current clinical foundation.
Lecture material was synthesized with the following contemporary guidance. Verify local policy and current guidance before applying clinical information.
- Bone Health and Osteoporosis Foundation, Clinician's Guide to Prevention and Treatment of Osteoporosis
- USPSTF, Osteoporosis Screening Recommendation, January 2025
- Endocrine Society, Pharmacological Management of Osteoporosis in Postmenopausal Women
- American College of Rheumatology, 2022 Glucocorticoid-Induced Osteoporosis Guideline
- DailyMed, Prolia denosumab prescribing information
- DailyMed, Evenity romosozumab prescribing information
- DailyMed, Teriparatide prescribing information
- DailyMed, Tymlos abaloparatide prescribing information
- DailyMed, Reclast zoledronic acid prescribing information
- DailyMed, Alendronate sodium prescribing information