Osteoporosis: bone density, fracture risk, and what actually works

What osteoporosis actually is

Osteoporosis is a condition of reduced bone mineral density and disrupted bone microarchitecture, leading to bones that fracture from forces that would not normally cause injury. The disease is silent until it isn’t — most people only learn they have it after a wrist fracture from a household fall, an unexpected vertebral compression behind new back pain, or a hip fracture after a slip. According to Healthy Bones Australia, about 1 in 3 Australian women and 1 in 5 men over 50 will sustain a minimal-trauma fracture during their lifetime, and roughly 165,000 such fractures occur in Australia every year.

Two parallel framings are used in Australian general practice. The first is bone density: a DEXA T-score of ≤ −2.5 at the hip or lumbar spine meets the World Health Organization densitometric definition of osteoporosis, with T-scores between −1.0 and −2.5 classified as osteopenia (2024 RACGP / Healthy Bones Australia guideline). The second is fracture-based: any minimal-trauma fracture at age 50 or over is diagnostic of osteoporosis regardless of the DEXA result, because the fracture itself confirms the disease. Both pathways are valid entry points to treatment, and both shape risk reassessment.

A. Core clinical — the AU primary-care framework

The 2024 RACGP and Healthy Bones Australia guideline and the corresponding MJA 2025 publication anchor Australian general practice. The RACGP Red Book prompts targeted screening rather than universal DEXA.

Who needs screening

History should target the modifiable and unmodifiable risks that change pre-test probability:

• Menopause and reproductive history — natural menopause age, early menopause or primary ovarian insufficiency under 45, prior hysterectomy with oophorectomy, hypothalamic amenorrhoea
• Prior fractures — site, mechanism (was the trauma minimal?), age at fracture
• Family history — particularly maternal hip fracture
• Glucocorticoid exposure — ≥7.5 mg prednisolone (or equivalent) for ≥3 months elevates fracture risk before bone density changes
• Lifestyle — current smoking, alcohol intake (>3 standard drinks per day raises risk), physical inactivity
• Malabsorption — coeliac disease, inflammatory bowel disease, bariatric surgery
• Endocrine — hyperthyroidism (including over-replacement of levothyroxine), primary or tertiary hyperparathyroidism, male hypogonadism, aromatase inhibitor therapy for breast cancer, androgen deprivation therapy for prostate cancer
• Other drugs — long-term proton pump inhibitors, anti-epileptics (phenytoin, carbamazepine), heparin, ciclosporin, SSRIs (modest)
• Falls — falls history is a strong independent predictor; see also balance, vision, and polypharmacy

Examination

A focused examination notes BMI (low BMI under about 19 is a risk factor), measured height compared to recalled younger height (loss of more than 3 cm suggests vertebral fracture), thoracic kyphosis, midline spinal tenderness, gait and balance, postural blood pressure, footwear, and dental condition (relevant before bisphosphonate or denosumab therapy).

Investigations

DEXA at the femoral neck, total hip, and lumbar spine is the imaging gold standard. The MBS rebates bone densitometry under item 12306 when clinical criteria are met — post-fracture, age ≥70 with risk factors, glucocorticoid ≥7.5 mg for ≥3 months, premature menopause, male hypogonadism, primary hyperparathyroidism, malabsorption, hyperthyroidism, or chronic liver or kidney disease. Lateral spine vertebral fracture assessment (item 12320) is added where height loss or thoracic kyphosis suggests an undiagnosed vertebral compression.

Bloods aim to exclude secondary causes: FBC, urea/creatinine/electrolytes, calcium, phosphate, magnesium, alkaline phosphatase, liver function, TSH, 25-hydroxyvitamin D, PTH, coeliac serology if suspected, testosterone in men, and serum/urine protein electrophoresis if vertebral fracture is present in an older adult (to exclude myeloma).

Fracture-risk calculators

Two complementary tools support borderline decisions:

• FRAX-AU — Australian-calibrated 10-year probability of major osteoporotic fracture and hip fracture, run with or without femoral neck DEXA
• Garvan fracture risk calculator — Australian-developed, incorporates falls history

Treatment thresholds in Australian general practice typically activate at FRAX 10-year major-fracture risk ≥20% or hip-fracture risk ≥3%, or at T-score ≤ −2.5, or after any minimal-trauma fracture at age ≥50.

B. Pharmacotherapy — bisphosphonates, denosumab, anabolics, and MHT

The Australian Medicines Handbook and eTG set the pharmacotherapy framework, with PBS Authority criteria shaping access.

Bisphosphonates — usually first-line

Alendronate 70 mg oral weekly and risedronate 35 mg oral weekly are the standard first-line oral options. Both are taken on an empty stomach with a full glass of water, sitting upright for 30 minutes, and require eGFR ≥30 mL/min. They are PBS-listed as Authority Required (Streamlined) for osteoporosis with T-score ≤ −2.5, for documented minimal-trauma vertebral or hip fracture (T-score not required), or for glucocorticoid-induced osteoporosis (separate criteria).

Zoledronate 5 mg intravenously once yearly is an alternative for those with gastro-oesophageal intolerance, poor oral adherence, or polypharmacy. eGFR should be ≥35 mL/min, calcium and vitamin D repleted before infusion, and patients counselled about flu-like symptoms in the days after the first infusion (about 30% incidence, much less with subsequent doses).

Standard durations are 5 years (oral) or 3 years (intravenous zoledronate), with a “drug holiday” considered for those at low or moderate ongoing risk because bisphosphonate effect persists in bone after cessation. People at continued high risk — T-score still ≤ −2.5, further fragility fractures — generally continue therapy.

Denosumab — equivalent efficacy but a critical caveat

Denosumab (Prolia) 60 mg subcutaneously every 6 months reduces fracture risk by about 30–50%, similar to bisphosphonates, with the advantage of useability in chronic kidney disease and a simple twice-yearly schedule. The 2024 RACGP and Healthy Bones Australia guideline carries an important safety message: denosumab must not be stopped without transition to a bisphosphonate. The medication produces no lasting effect in bone, and abrupt cessation causes a rebound rise in bone turnover that can lead to multiple vertebral fractures within 6–12 months. If denosumab is stopped, the standard transition is oral alendronate or risedronate for at least 12 months, or a single zoledronate infusion at the time the next denosumab dose would have been due.

Calcium and vitamin D must be repleted before each denosumab dose to avoid severe hypocalcaemia.

Osteoanabolic therapy — specialist-initiated

Two PBS-listed agents build new bone rather than slowing resorption:

• Teriparatide (Forteo) — recombinant PTH 1-34, 20 mcg subcutaneously daily for 18–24 months. PBS Authority Required (specialist application) for severe osteoporosis with multiple fragility fractures meeting strict criteria.
• Romosozumab (Evenity) — anti-sclerostin antibody, 210 mg subcutaneously monthly for 12 months. PBS Authority Required (specialist initiation) for very severe osteoporosis; cardiovascular caution per the AMH black box note.

Both must be followed by anti-resorptive consolidation (bisphosphonate or denosumab) to maintain the gains.

Menopausal hormone therapy and other hormonal options

Menopausal hormone therapy is an effective bone-protective option for younger postmenopausal women with vasomotor symptoms, and is reasonable as part of an overall menopause plan rather than as a standalone bone treatment in older women. Tibolone is an alternative in select patients. Raloxifene provides modest bone protection and reduces breast cancer risk, but carries venous thromboembolism risk and is not first-line. Testosterone replacement is indicated only for confirmed male hypogonadism with osteoporosis. Strontium ranelate was removed as first-line therapy in the 2024 RACGP and Healthy Bones Australia guideline because of cardiovascular concerns.

Rare but important risks

Atypical femoral fracture — characteristically transverse, often bilateral, with weeks of prodromal lateral thigh or groin pain — is uncommon (roughly 3–10 per 100,000 person-years on long-term bisphosphonate or denosumab) but warrants imaging and specialist input.

Osteonecrosis of the jaw — exposed necrotic bone in mandible or maxilla persisting beyond 8 weeks — is rare in standard osteoporosis dosing (about 0.001–0.01% per patient-year on oral bisphosphonate) but more common with high-dose cancer regimens. A pre-treatment dental review is recommended for all patients before starting bisphosphonate or denosumab.

C. Lifestyle and load — what actually works

Weight-bearing and resistance exercise

The Cochrane 2019 review of exercise for preventing falls confirms that structured exercise programmes targeting balance and strength reduce falls in community-dwelling older adults. For bone outcomes specifically, the Nelson JAMA 1994 trial was an early demonstration that high-intensity strength training preserves bone density in postmenopausal women. More recently, Australian work by Watson and colleagues — the LIFTMOR trial in postmenopausal women and LIFTMOR-M in older men with low bone mass — showed that supervised heavy resistance and impact training improved bone density and functional measures with strong safety outcomes when done under guidance.

A pragmatic prescription:

• 3–5 sessions per week combining weight-bearing impact (brisk walking, jogging, jumping) with progressive resistance training
• Once established osteoporosis is present, high-impact loading is generally avoided because of vertebral fracture risk — physiotherapist or exercise physiologist supervision is recommended
• Tai chi, yoga, and Pilates contribute to balance and falls reduction with modest bone effects
• Older adults with falls risk benefit from multifactorial assessment (Cochrane 2019)

Calcium and vitamin D

The NHMRC Nutrient Reference Values recommend about 1300 mg of calcium per day for postmenopausal women and men over 70. A food-first approach is preferred — dairy products, calcium-fortified plant milks, sardines with bones, tofu set with calcium, leafy greens, and almonds — because excess supplementation may slightly raise cardiovascular and gastrointestinal risks. Supplements are used to top up an inadequate diet rather than as default therapy.

The RACGP and Healthy Bones Australia guideline targets a serum 25-hydroxyvitamin D level ≥50 nmol/L year-round. People who are deficient typically need 1000–2000 IU per day of cholecalciferol, with higher loading regimens if severely deficient. Sensible sun exposure — a few minutes most days for fair skin, longer for darker skin and in winter — contributes, balanced against skin-cancer prevention messaging from Cancer Council Australia.

Falls prevention

Multifactorial assessment and intervention reduce falls and fractures in community-dwelling older adults (Cochrane 2019). Practical elements: a home hazard review, vision check, footwear assessment, polypharmacy review (especially benzodiazepines, opioids, antipsychotics, antihypertensives), strength and balance exercise, and continence management.

Smoking and alcohol

Smoking substantially raises fracture risk; cessation is a core part of the plan. Alcohol intake above 3 standard drinks per day raises fracture risk; ≤2 standard drinks per day is the AU primary-tier moderation threshold.

Protein

In older adults, dietary protein intake of about 1.0–1.2 g/kg/day supports bone matrix and muscle. People with severe chronic kidney disease need individualised guidance.

D. Australian operations

PBS Authority criteria converge on two pathways: a T-score ≤ −2.5 with documented secondary causes treated or excluded, or a documented minimal-trauma vertebral or hip fracture (T-score not required). Alendronate, risedronate, zoledronate, and denosumab are listed under Authority Required (Streamlined). Teriparatide and romosozumab require specialist application.

MBS bone densitometry item 12306 is rebatable when clinical criteria are met, with repeat scans typically at 2–5 year intervals during therapy and earlier if a new fracture occurs. Item 12320 covers vertebral fracture assessment.

Healthy Bones Australia — formerly Osteoporosis Australia — provides patient-friendly resources, the Know Your Bones risk calculator, and clinician materials. The Endocrine Society of Australia supports referrer guidance for complex cases.

For anyone on glucocorticoid therapy at ≥7.5 mg prednisolone for ≥3 months expected, bisphosphonate prophylaxis is started early per the AU corticosteroid-induced osteoporosis pathway, with separate PBS Authority criteria.

Chronic disease care coordination is supported via GP Chronic Conditions Management Plan items 965 and 967, which enable referrals to exercise physiologists, physiotherapists, and dietitians for allied-health support of osteoporosis management.

E. Special populations

Aboriginal and Torres Strait Islander Australians. Bone health is consistently under-screened in ATSI populations despite higher fracture rates and earlier onset (Healthy Bones Australia). The MBS ATSI Health Assessment item 715 is one practical entry point to embedding bone-health screening into culturally safe care.

Men. Osteoporosis in men is frequently missed because clinical attention focuses on postmenopausal women. The T-score threshold of ≤ −2.5 applies equally, but secondary-cause workup is more important — testosterone, LH, FSH, screening for haemochromatosis, alcohol intake, and androgen deprivation therapy history all warrant attention.

Early menopause and primary ovarian insufficiency. Early oestrogen loss accelerates bone loss; menopausal hormone therapy is generally the anchor of prevention when not contraindicated. The Australasian Menopause Society provides AU-specific guidance.

Glucocorticoid-induced osteoporosis. Prophylaxis starts early — usually at the time of starting ≥7.5 mg prednisolone for ≥3 months expected — rather than waiting for DEXA changes. Calcium and vitamin D repletion plus a bisphosphonate is the standard combination.

Chronic kidney disease. CKD-mineral and bone disorder overlays standard osteoporosis assessment, with disturbed calcium, phosphate, PTH, and vitamin D metabolism. Denosumab is sometimes preferred because bisphosphonates are limited by eGFR; renal physician input is usually warranted.

Pregnancy and lactation osteoporosis. A rare but real entity; vertebral fractures may occur in the third trimester or early postpartum. Specialist referral is needed, and pharmacotherapy choices are constrained.

When to escalate — endocrinology and rheumatology referral

Referral to endocrinology or rheumatology is appropriate when:

• Premenopausal osteoporosis or male osteoporosis with unclear secondary cause
• T-score severely low (≤ −3.5) or multiple fragility fractures
• Candidacy for osteoanabolic therapy (teriparatide, romosozumab)
• Complex glucocorticoid-induced osteoporosis management
• Denosumab cessation requiring tailored transition
• Suspected atypical femur fracture, osteonecrosis of the jaw, or severe hypocalcaemia

Urgent escalation is warranted for acute hip or vertebral fracture, severe hypocalcaemia symptoms (perioral or digital paraesthesia, cramps, tetany), suspected osteonecrosis of the jaw, and new prodromal lateral thigh or groin pain on long-term bisphosphonate or denosumab.

What this article is and is not

This is general health information drawn from current Australian primary-care guidelines — the 2024 RACGP and Healthy Bones Australia osteoporosis guideline, Therapeutic Guidelines, the Australian Medicines Handbook, NPS MedicineWise, the NHMRC Nutrient Reference Values, Healthy Bones Australia, and the Endocrine Society of Australia, together with major peer-reviewed trials and reviews. It is not personal medical advice and does not create a doctor–patient relationship. Decisions about screening, medications, exercise prescription, and follow-up are made with your own general practitioner and treating clinicians.

For Australian consumer-friendly sources: Healthy Bones Australia, HealthDirect — Osteoporosis, Better Health Channel — Osteoporosis, and the Know Your Bones risk calculator.

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Sources cited

1. RACGP / Healthy Bones Australia — 2024 Guideline
2. MJA 2025 — Osteoporosis management and fracture prevention
3. Therapeutic Guidelines (eTG)
4. Australian Medicines Handbook
5. NPS MedicineWise
6. NHMRC Nutrient Reference Values
7. Healthy Bones Australia
8. Know Your Bones risk calculator
9. PBS — Osteoporosis medicines
10. MBS Online — Bone densitometry item 12306
11. MBS Online — Vertebral fracture assessment item 12320
12. MBS Online — GPCCMP items 965/967
13. MBS Online — ATSI Health Assessment item 715
14. RACGP Red Book
15. HealthDirect — Osteoporosis
16. Better Health Channel — Osteoporosis
17. FRAX-AU fracture risk calculator
18. Garvan fracture risk calculator
19. Watson SL et al. — LIFTMOR randomised controlled trial (J Bone Miner Res 2018)
20. Sherrington C et al. — Exercise for preventing falls (Cochrane 2019)
21. Nelson ME et al. — High-intensity strength training (JAMA 1994)
22. Endocrine Society of Australia
23. Australasian Menopause Society
24. Cancer Council Australia