Osteoporosis — Diagnosis & Long-Term Management

Decision support only — use with the current RACGP/Healthy Bones Australia guidance, specialist advice, eTG and live PBS restrictions. In adults over 50, a minimal-trauma fracture often establishes bone fragility even when the DXA says osteopenia. Correct calcium/vitamin D before potent therapy, plan every denosumab exit before the first dose, and verify all doses and funding criteria locally.

1 The treatment decision — fracture risk drives the drug

Find the fracturedo not wait for T-score ≤−2.5

Age >50 with minimal-trauma fracture; hip or vertebral fracture without major trauma is diagnostic in practice.

Investigate and treat promptly. DXA is useful for baseline risk and monitoring, but a normal-ish T-score does not undo the fracture.

High riskantiresorptive territory

T-score ≤−2.5; or T-score −1.5 to −2.5 with FRAX major osteoporotic fracture ≥20% or hip ≥3%.

Oral bisphosphonate, IV zoledronate or denosumab, selected by renal function, upper-GI disease, adherence and a credible long-term plan.

Denosumab commitmentthe common preventable disaster

Considering or already receiving 6-monthly denosumab.

Never pause it casually. Give a late dose promptly. If stopping, arrange bisphosphonate cover around the next due date; specialist input is sensible.

Very high / imminent riskbuild bone first where feasible

Recent hip/vertebral fracture, multiple fractures, fracture on treatment, very low BMD, or FRAX major ≥30% / hip ≥4.5%.

Refer early for anabolic-first treatment (romosozumab, teriparatide or abaloparatide where eligible), then antiresorptive therapy without a gap. This sequence is consistent across Australian guidance, Endocrine Society, AACE/ACE and NOGG.

The DXA trap: most fractures occur outside the densitometric osteoporosis range because far more people sit in the osteopenic range. A recent fracture carries its own short-term risk; treating only the number misses the patient.

2 Diagnose, image & quantify risk

What establishes osteoporosis?

ClinicalAge >50 + minimal-trauma fracture (fall from standing height or less) = presumptive osteoporosis; hip or vertebral fracture without major trauma is enough to treat.
DXAT-score ≤−2.5 at lumbar spine or proximal femur. Measure spine and hip; use the lowest valid site.
OsteopeniaT-score −1.0 to −2.5. Add fracture history, age, falls, glucocorticoids and FRAX; the label alone does not make risk low.
YoungerPremenopausal women and men <50 need Z-scores and a secondary-cause approach; specialist review is usually appropriate.

Case-finding & thresholds

DXA nowAll Australians ≥70; anyone >50 with minimal-trauma fracture; earlier with major clinical risks or accelerated bone loss.
FRAX → DXANo fracture but risk factors: if FRAX major osteoporotic fracture risk ≥10%, obtain DXA; below 10%, routine DXA is generally not recommended by RACGP/HBA.
TreatT-score ≤−2.5, or T-score −1.5 to −2.5 plus FRAX major ≥20% and/or hip ≥3%.
Very highRecent fracture (12–24 months), multiple fractures, fracture on therapy, FRAX major ≥30% / hip ≥4.5%, or very low BMD → bone specialist.

Look for the silent vertebral fracture

TriggerAcute back pain with risk factors, kyphosis, ≥4 cm historical height loss, long-term glucocorticoids, or T-score ≤−2.5.
MethodVertebral fracture assessment on DXA or lateral thoracolumbar imaging. Review old CT/chest/abdominal films; the spine is often already visible.
CautionA single mild vertebral deformity, especially under 60, is not automatically osteoporotic. Check morphology and alternatives.

FRAX is useful, not clairvoyant

UnderreadsFalls, dose/duration of glucocorticoids, recent or multiple fractures and some secondary causes are incompletely captured.
RefineUse femoral-neck BMD; adjust with trabecular bone score where available. Garvan includes falls and provides 5- and 10-year estimates.
RuleDo not use a low calculated risk to veto treatment after a convincing hip or vertebral fragility fracture.

3 Secondary causes — baseline work-up

A fracture plus a low T-score is a starting point, not an explanation. The yield is highest in men, younger patients, unexpectedly severe disease, low Z-score, recurrent fracture or apparent treatment failure.

Initial investigations

BloodsFBE; U&E/creatinine; LFT/ALP; corrected Ca; PO₄; 25-OH vitamin D; PTH; TSH; ESR/CRP.
Before drugConfirm renal function, calcium and vitamin D. Correct hypocalcaemia and aim 25-OH vitamin D >50 nmol/L.
Odd ALP/PO₄Do not wave away persistent abnormalities: Paget disease, osteomalacia and hypophosphataemic disorders change the diagnosis.

Targeted tests

MyelomaSPEP, immunoglobulins, serum free light chains ± urine studies.
Gut/endocrineCoeliac serology; testosterone in men; oestradiol/FSH if premature menopause suspected; cortisol screen if phenotype fits.
Calcium24-hour urine calcium/creatinine when malabsorption, hypercalciuria or calcium disorder is suspected.
TurnoverCTX/P1NP for selected diagnostic or monitoring questions; usually specialist territory.

Medication & disease audit

DrugsGlucocorticoids, aromatase inhibitors, androgen deprivation, excess thyroxine; also consider anticonvulsants and other exposure-specific risks.
DiseaseCoeliac/IBD, RA, hyperparathyroidism, thyrotoxicosis, hypogonadism, CKD/liver disease, diabetes, HIV, transplant and myeloma.
Failure?New fracture on therapy → first check adherence, administration, absorption, secondary causes and whether enough time has elapsed.

4 Drug selection — regimen, gate & exit

Agent	Usual osteoporosis regimen	Best fit / evidence	Before, avoid, or follow
Alendronate / risedronate oral bisphosphonates	alendronate 70 mg weekly risedronate 35 mg weekly	Low cost; first-line when adherence and absorption are credible. FIT/FLEX	Standard tablets: fasting, full glass of water, upright ≥30 min; avoid active major upper-GI disease. Check renal suitability and separate calcium.
Zoledronic acid IV bisphosphonate	5 mg IV over ≥30 min, usually every 12 months; 12–18-month intervals may suit selected patients	Adherence/GI problems; after hip fracture; spine, hip and non-vertebral efficacy. HORIZON	Correct vitamin D/hypocalcaemia; hydrate; check creatinine. Contraindicated if CrCl <35 mL/min. Acute-phase reaction after first dose is common.
Denosumab RANKL inhibitor	60 mg SC every 6 months	Potent antiresorptive; useful with upper-GI intolerance and in renal impairment, but hypocalcaemia risk rises as eGFR falls. FREEDOM	No holiday and no unplanned stop. Check calcium/vitamin D; recheck calcium ~2 weeks after dose in low eGFR. If ceasing, use bisphosphonate cover.
Romosozumab sclerostin inhibitor	210 mg SC monthly (two 105-mg injections) for 12 months	Very high/imminent risk; anabolic-first pathway. FRAME ARCH	Contraindicated with previous MI or stroke in Australia. Correct hypocalcaemia; follow immediately with long-term antiresorptive.
Teriparatide PTH 1–34	20 micrograms SC daily; PBS course commonly 18 months	Very high risk / fracture despite treatment; superior to risedronate for vertebral endpoints in severe disease. VERO	Avoid Paget disease, skeletal irradiation, bone malignancy/metastases and hypercalcaemia. Do not switch denosumab directly to teriparatide alone; follow course with antiresorptive.
Abaloparatide new PTHrP analogue	80 micrograms SC daily for 18 months	TGA-approved for postmenopausal women at increased fracture risk; anabolic-first or rescue pathway where accessible. ACTIVE	Follow immediately with antiresorptive. PBS-listed from 1 Aug 2026 under first- and second-line authority pathways; 18-month lifetime maximum.

5 PBS map — funding is narrower than clinical indication

Common antiresorptive pathways

FractureRadiologically documented fracture due to minimal trauma can qualify regardless of age or BMD; wording and eligible fracture sites vary by item.
Age/BMDCommon pathway: age ≥70 with T-score ≤−2.5 at femoral neck or lumbar spine; record date, site and score.
Sole agentMany restrictions require the medicine to be the sole PBS-subsidised antiresorptive. Do not assume combination funding.
Live checkUse the current PBS item/restriction at prescribing; drug-specific and glucocorticoid pathways differ.

Anabolic access — specialist initiation

First-lineRomosozumab or abaloparatide: untreated, T-score ≤−2.5, symptomatic minimal-trauma fracture, plus hip/symptomatic vertebral fracture within 24 months or ≥2 fractures including one symptomatic new fracture within 24 months. Check the exact item.
Second-lineT-score ≤−3.0 + ≥2 minimal-trauma fractures + ≥1 symptomatic new fracture after ≥12 months continuous adequate antiresorptive therapy.
CourseRomosozumab 12 months; teriparatide or abaloparatide 18 months; then long-term antiresorptive. Consultant physician initiates; GP may continue under the relevant restriction.
AbaloparatideActive PBS items: 15468D first-line and 15436K second-line, listed 1 Aug 2026. Sole PBS osteoporosis therapy; lifetime maximum 18 months including private use.

6 Sequencing, duration & the stop rules

Denosumab: exit before entry

LateGive as soon as practical, preferably within 4–6 weeks of the missed dose.
StopStart oral or IV bisphosphonate promptly, around the next scheduled denosumab dose; HBA advises within 4 weeks of that due date.
WhyRapid rebound bone resorption and multiple vertebral fractures, especially after longer use or prior vertebral fracture.

Bisphosphonate reassessment

ReviewReassess after about 5 years oral or 3 years IV; do not make the stop automatic.
ContinueOlder age, hip/vertebral fracture, T-score still ≤−2.5, high-dose glucocorticoids or fracture on treatment.
PauseConsider only if lower risk, no recent fracture and BMD has responded; reassess clinically and with DXA ± turnover markers.

Anabolic → antiresorptive

SequenceStart alendronate, zoledronate or denosumab immediately after romosozumab, teriparatide or abaloparatide.
OrderAnabolic first generally builds more BMD than using it after a potent antiresorptive.
AvoidDenosumab → teriparatide monotherapy can cause transient hip and cortical bone loss.

7 Rare harms, dental work & monitoring

MRONJ — do not let a rare harm create a common fracture

BeforeDental review before antiresorptive therapy for high-risk patients; treat active infection and maintain oral hygiene.
BisphosphonateRoutine cessation before extraction offers little biologic benefit after long exposure. Coordinate extensive procedures; do not delay urgent osteoporosis care without a reason.
DenosumabCoordinate invasive work with dentist/maxillofacial and prescriber. Do not create a prolonged dosing gap; the fracture consequence is real.
ContextAt osteoporosis doses, MRONJ is uncommon; fracture benefit usually dominates in high-risk patients.

AFF, hypocalcaemia & cardiovascular risk

Thigh painNew thigh/groin pain after long antiresorptive exposure → bilateral femur imaging; involve orthopaedics if stress reaction/incomplete AFF.
CalciumCorrect vitamin D deficiency and hypocalcaemia first. Denosumab risk is greatest in CKD 4–5/dialysis; check calcium after dosing in low eGFR.
RomosozumabPrevious MI or stroke is an Australian contraindication. In others, weigh near-term fracture risk against baseline cardiovascular risk.
BalanceMRONJ and AFF are rare. Fear of them is a poor reason to leave a recent hip or vertebral fracture untreated.

8 Follow-up, calcium, protein & falls

Review the treatment

ClinicalReview 3–6 months after starting, then every 6–12 months: adherence, administration, adverse effects, falls and interval fracture.
DXAUsually no more often than 2-yearly, preferably same machine. A ≥5% fall in BMD warrants review; shorter intervals often measure noise.
New fractureRepeat risk and secondary-cause assessment; check adherence before declaring failure. Refer if fracture occurs despite credible treatment.

Substrate — food first

CalciumAim 1000 mg/day; 1300 mg/day for women >50 and men >70 on treatment. Add 500–600 mg/day only if diet is short.
Vitamin DTarget 25-OH vitamin D >50 nmol/L. If deficient with poor bone health, 1000 IU/day is a common maintenance approach after correction.
ProteinOlder adults, especially frail/sarcopenic: roughly 1.0–1.5 g/kg/day, individualised for renal and nutritional context.

Prevent the next fall

ExerciseProgressive resistance ≥2 days/week, weight-bearing impact most days where safe, and genuinely challenging balance training.
TailorPhysio/exercise-physiology supervision for frailty, high vertebral risk or recent fracture; build from current capacity.
SystemsMedication review, vision/feet, home hazards and mobility aids. Every fragility fracture should trigger a Fracture Liaison Service pathway where available.

9 Fracture → treatment algorithm

For an adult over 50 with a convincing minimal-trauma fracture. Do the secondary-cause work-up, falls plan and calcium/vitamin D correction in parallel; DXA refines risk but should not hold up treatment after a hip or vertebral fracture.

START ↓ Confirm fracture site, timing and prior osteoporosis treatment

RecordHip, vertebral or other site; symptomatic versus incidental; date; trauma mechanism; prior fractures; current/previous antiresorptive exposure and adherence.
BaselineDXA spine/hip, corrected calcium, PO₄, 25-OH vitamin D and renal function. Screen secondary causes. Hip or vertebral fragility fracture warrants treatment regardless of BMD.

↓

DECISION 1 — Very high / imminent risk?

Recent hip or symptomatic vertebral fracture; ≥2 fractures including a recent symptomatic fracture; fracture on credible therapy; very low BMD; or FRAX major ≥30% / hip ≥4.5%. If yes, assess anabolic eligibility before giving a potent antiresorptive.

YES ↓ Untreated + PBS first-line pattern

GateT-score ≤−2.5 plus hip or symptomatic vertebral fracture within 24 months, or ≥2 fractures including one symptomatic new fracture within 24 months.
ReferConsultant physician for romosozumab 210 mg monthly for 12 months or abaloparatide 80 micrograms daily for 18 months where the exact authority criteria are met.
CV gatePrevious MI or stroke excludes romosozumab. Abaloparatide is TGA-approved for postmenopausal women; specialist selection still matters.
No accessDo not leave the patient untreated while referral drifts. Discuss early parenteral antiresorptive therapy with the bone service if anabolic treatment is not feasible.

YES ↓ Fracture despite antiresorptive

RecheckAdministration, adherence, duration, absorption, calcium/vitamin D and secondary causes before calling treatment failure.
PBS gateCommon second-line pattern: T-score ≤−3.0, ≥2 minimal-trauma fractures and ≥1 symptomatic new fracture after ≥12 months continuous adequate antiresorptive therapy.
ReferConsider romosozumab, teriparatide or abaloparatide under the live restriction. Avoid a direct denosumab → teriparatide-only switch.
AfterBegin antiresorptive therapy immediately when the anabolic course ends.

NO ↓ Standard fracture pathway

Hip or vertebral fracture

TreatDo not require T-score ≤−2.5. Start once calcium/vitamin D and agent-specific safety checks are addressed.
HipZoledronic acid 5 mg IV is a strong default after hip fracture if CrCl ≥35 mL/min and infusion is suitable.
AlternateOral alendronate/risedronate if reliable; denosumab if bisphosphonate is unsuitable and a long-term/exit plan is secure.

Other-site fracture

T ≤−1.5Treat: oral/IV bisphosphonate or denosumab, chosen using the gates below.
T >−1.5Check fracture morphology and alternative causes; refine with FRAX ± TBS. Seek specialist advice if bone fragility remains convincing.
RecentA recent fracture still raises imminent risk. Recheck whether the patient belongs in the very-high-risk branch.

Complex bone / renal disease

CKD 4–5Consider CKD-MBD and adynamic bone disease; involve renal/bone specialists. Denosumab can cause severe hypocalcaemia.
YoungerPremenopausal women or men <50: use Z-scores and investigate the cause; do not drop them into this routine pathway.
Odd labsHypercalcaemia, low PO₄, raised ALP, paraprotein or features of osteomalacia → diagnose first.

↓ Choose the antiresorptive

Oral bisphosphonate

Use when: renal function permits, upper-GI anatomy is suitable and weekly fasting/upright administration will actually happen. Low cost; easy to stop or pause after reassessment.

IV zoledronic acid

Use when: hip fracture, oral intolerance, malabsorption or adherence concern. Correct hypocalcaemia/vitamin D, hydrate and confirm CrCl ≥35 mL/min.

Denosumab

Use when: bisphosphonate is unsuitable and 6-monthly dosing can be guaranteed. Correct calcium/vitamin D; monitor calcium in low eGFR. No holiday. No unplanned stop.

↓

FINISH — write the exit plan at initiation

AnabolicRomosozumab / teriparatide / abaloparatide → antiresorptive immediately when the course ends.
DenosumabDose every 6 months. If ceasing, transition promptly to oral or IV bisphosphonate around the next due date with specialist input.
BisphosphonateReassess around 5 years oral or 3 years IV; continue if risk remains high rather than granting an automatic holiday.

Primary sources. RACGP & Healthy Bones Australia, Osteoporosis management and fracture prevention in postmenopausal women and men over 50 years, 3rd ed (Mar 2024); Healthy Bones Australia, Position Statement on the Management of Osteoporosis, 2nd ed (Aug 2026); ANZBMS position statements, including TBS (2025), densitometry standards and HBA/RACGP guidance; Healthy Bones Australia/ANZBMS/ADA/ESA/ARA MRONJ consensus statement (Mar 2026); Endocrine Society guideline (2019) and romosozumab update (2020); AACE/ACE postmenopausal osteoporosis guideline (2020); NOGG 2021 guideline / 2022 publication and NOGG 2024 update; current TGA product information and safety advice; PBS Schedule item restrictions checked 18 Aug 2026. Key trials. FIT/FLEX (alendronate; JAMA 1998/2006); HORIZON-PFT and HORIZON Recurrent Fracture Trial (zoledronate; NEJM 2007); FREEDOM and extension (denosumab; NEJM 2009); FRAME and ARCH (romosozumab; NEJM 2016/2017); VERO (teriparatide vs risedronate; Lancet 2018); ACTIVE/ACTIVExtend (abaloparatide then alendronate; JAMA 2016 / JCEM 2018); Reid 2018 and Bolland 2025 infrequent zoledronate trials; Iuliano 2021 residential-care calcium/protein trial. Caveats. RACGP/HBA treatment thresholds and PBS subsidy rules are different questions. Abaloparatide items 15468D and 15436K were active in the August 2026 Schedule despite conflicting wording within the HBA statement. Live restrictions can change; verify the item at prescribing. US/UK thresholds are not substituted for Australian FRAX/PBS thresholds. eTG was not publicly accessible during compilation. Verify all doses, renal cut-offs, sequencing and dental timing locally.