Overview
Recognise fragility fracture as a sentinel event, quantify fracture risk, exclude reversible skeletal disease, begin effective treatment promptly, and plan duration, sequential therapy and safe discontinuation from the outset.
Osteoporosis is reduced bone strength that makes low-energy fracture more likely. A T-score of −2.5 or lower at the femoral neck, total hip or lumbar spine is a densitometric definition, not the only treatment route. Many fractures occur above that threshold because age, previous fracture, falls, glucocorticoids and bone quality alter risk. Ask about every adult fracture, height loss, new thoracic or lumbar pain, falls, menopause or hypogonadism, steroid dose and duration, parental hip fracture, smoking, alcohol, diet, mobility, gastrointestinal disease, kidney disease, endocrine symptoms and medicines affecting bone.
The immediate objective after a fragility fracture is preventing the next event. A fracture liaison service can identify patients, arrange vertebral and secondary-cause assessment, initiate treatment and verify persistence. FRAX estimates ten-year hip and major osteoporotic fracture probability; current NOGG thresholds distinguish reassurance, DXA refinement, treatment and very-high-risk specialist referral. DXA refines probability where needed, while a recent vertebral or hip fracture often justifies treatment before scanning.
Aetiology
Age and hormone loss
Menopause accelerates trabecular loss through oestrogen withdrawal, while ageing reduces osteoblast function, sex hormones, muscle strength, balance and vitamin-D production in all sexes.
Clinical risk exposure
Previous fragility fracture, parental hip fracture, low body weight, smoking, excess alcohol, falls and prolonged immobility increase risk independently or through bone and muscle loss.
Secondary osteoporosis
Glucocorticoids, aromatase inhibitors, androgen deprivation, hypogonadism, hyperthyroidism, hyperparathyroidism, malabsorption, inflammatory disease, kidney or liver disease and haematological disorders require active consideration.
Pathophysiology
- 1Remodelling imbalance
When osteoclast resorption persistently exceeds osteoblast formation, trabeculae perforate and cortical bone becomes porous, reducing strength beyond the change captured by mineral density alone.
- 2Microarchitectural failure
Loss of trabecular connectivity, cortical thinning and accumulated microdamage impair load distribution, allowing a fall from standing height to cause fracture.
- 3Imminent refracture risk
A recent fracture identifies vulnerable bone and ongoing falls exposure; another fracture is especially likely over the next two years, making treatment delay clinically important.
- 4Medicine-specific biology
Bisphosphonates persist in mineralised bone, denosumab suppression reverses rapidly when dosing stops, and anabolic treatment needs subsequent antiresorption to retain gained bone.
Clinical features and red flags
A low-energy hip, vertebral, wrist or proximal-humerus fracture is clinical evidence of skeletal fragility and predicts another fracture.
Height loss, increasing kyphosis, rib-to-pelvis discomfort or incidental compression may reveal vertebral fractures without a remembered acute event.
Risk rises early and is not fully represented by BMD; record daily dose, cumulative duration, intermittent high-dose courses and expected continuation.
Poor balance, sarcopenia, visual impairment, postural hypotension, sedating medicines and environmental hazards can dominate immediate risk despite modest density loss.
Premature menopause, sexual dysfunction, diarrhoea, weight loss, renal stones, bruising, thyroid signs or inflammatory disease directs additional testing.
Investigations
- 01
First-line FRAX probabilityFirst stepFirst line - Why
- Integrate age and validated clinical factors to decide reassurance, DXA refinement, treatment or specialist referral.
- Interpretation and limitations
- Enter femoral-neck BMD when available, not lumbar T-score; compare with current NOGG thresholds and apply judgement for falls, dose exposure and recent fracture.
- 02
DXA hip and lumbar spine - Why
- Measure mineral density, refine risk, establish a baseline and help classify discordant or treatment-resistant cases.
- Interpretation and limitations
- Use the lowest valid site while recognising degenerative spine change can falsely elevate lumbar BMD; T-score above −2.5 does not negate high clinical probability.
- 03
Vertebral fracture assessment - Why
- Find unrecognised compression fractures that materially increase risk and may move care into a very-high-risk pathway.
- Interpretation and limitations
- Use DXA lateral imaging or spine radiographs for height loss, kyphosis, compatible pain or strong risk; distinguish fracture from degenerative wedging.
- 04
Secondary-cause screen - Why
- Identify correctable disease and establish safety before antiresorptive or anabolic treatment.
- Interpretation and limitations
- Usually include FBC, ESR or CRP, calcium, phosphate, ALP, renal and liver profile, vitamin D and thyroid tests; add coeliac, PTH, testosterone or monoclonal studies when indicated.
Differential diagnosis
Osteomalacia
Defective mineralisation produces diffuse pain, proximal weakness and raised alkaline phosphatase, often with low phosphate or vitamin D; osteoporosis usually has normal bone biochemistry.
Malignant bone disease
Myeloma or metastasis can cause vertebral collapse and low density but is suggested by disproportionate pain, anaemia, renal dysfunction, hypercalcaemia or destructive lesions.
Endocrine high-turnover disease
Hyperparathyroidism, thyrotoxicosis and Cushing syndrome alter bone turnover; distribution, biochemistry and directed endocrine assessment separate them from primary age-related loss.
Non-fragility fracture
Clarify injury energy and morphology; lesion-centred, high-energy or atypical subtrochanteric fractures need cause-specific investigation rather than automatic fragility classification.
Management
01First-line risk pathwayTreat without avoidable delayFirst stepFirst lineA fragility fracture, strong clinical risk profile or opportunistic imaging raises osteoporosis concern.+
- 1Confirm fracture mechanism and site, calculate FRAX where appropriate, assess falls and request DXA only when it will refine rather than postpone the decision.
- 2Search for vertebral fractures and secondary causes, check renal function, calcium and vitamin D, and address nutrition, smoking, alcohol, strength, balance and home hazards.
- 3Begin an appropriate anti-fracture medicine promptly after recent fracture, documenting administration, duration review and the response to missed doses or discontinuation.
- 4Use a fracture liaison service where available to connect acute fracture care, primary-care prescribing, adherence and repeat risk review.
02Preferred antiresorptivesMatch delivery to feasibility
Complications
Hip-fracture consequences
Hip fracture causes pain, immobility, delirium, thrombosis, infection, lost independence and substantial mortality; many survivors never regain previous function.
Vertebral fracture burden
Multiple compression fractures cause height loss, kyphosis, chronic pain, restrictive respiratory mechanics, abdominal crowding and greatly increased further-fracture risk.
Discontinuation harm
Unplanned denosumab delay or cessation can cause rebound remodelling and multiple vertebral fractures; ending anabolic treatment without consolidation rapidly loses benefit.
Rare antiresorptive toxicity
Jaw osteonecrosis and atypical femoral fracture are uncommon at osteoporosis doses but require prevention advice, symptom recognition and reassessment of continued treatment.
Monitoring and follow-up
- Record the next administration and review date at initiation; use recall systems to prevent unintended gaps, especially with denosumab.
- Ask about new fractures, falls, height loss, back pain, thigh or groin pain, jaw symptoms, dental procedures, adherence and oral administration technique.
- Check calcium, vitamin-D status and renal function before intravenous bisphosphonate or denosumab as appropriate, with earlier post-dose calcium monitoring in severe kidney disease.
- Repeat DXA after an interval likely to affect management, often two to three years in treated high-risk disease, using the same valid sites when possible.
- Reassess oral bisphosphonate at five years and zoledronate at three; extend treatment for older age, hip or vertebral fracture, glucocorticoids or fracture during treatment.
- After denosumab cessation or anabolic completion, verify that planned antiresorptive therapy was actually administered.
Special situations
Fracture can diagnose risk
A recent hip or vertebral fragility fracture can justify immediate treatment before DXA because waiting exposes the patient during the highest-risk period.
Normal chemistry is expected
Primary osteoporosis usually has normal calcium, phosphate and ALP; abnormal bone chemistry raises osteomalacia, hyperparathyroidism, malignancy or another secondary explanation.
Denosumab needs an ending
Its effect wears off rapidly, unlike retained bisphosphonate in bone; the safest time to design subsequent therapy is before the first injection.
Rare harms need proportion
At osteoporosis doses, jaw osteonecrosis and atypical femur fracture are uncommon, while untreated high fracture risk is frequent and consequential.
Sequence alters benefit
Very-high-risk patients may gain more from early anabolic treatment, but every anabolic course needs antiresorptive consolidation to retain improvement.
Common pitfalls
- 01
Do not wait for DXA after a recent high-risk fragility fracture when the scan would not alter the need for treatment.
- 02
Do not call calcium and vitamin D complete osteoporosis treatment; they correct substrate but lack adequate anti-fracture efficacy for high-risk disease.
- 03
Do not prescribe oral alendronate without checking whether fasting, water and upright instructions are feasible.
- 04
Do not start denosumab without a reliable recall system and named cessation plan, and never substitute an informal drug holiday.
- 05
Do not call a new fracture pharmacological failure before checking adherence, duration, falls, secondary causes and expected onset of protection.
- 06
Do not stop antiresorptive treatment solely because dental extraction is planned; coordinate individual fracture and dental risk.