---
# System prepended metadata

title: Untitled

---

- Credits
	- Section Writer: Dr. Om J Lakhani
	- Section Editor: Dr. Om J Lakhani
	- Contributions from:
	    - Dr. Om J Lakhani

> Download the new "Notes in Endocrinology" App
> Apple iOS- https://shrtm.nu/H45n
> Android - https://shrtm.nu/SyBG
 
- Q. What is the definition of Osteoporosis?
	- It is a disease characterized by
		- Low bone mass
		- Microarchitectural disruption
		- Increase skeletal fragility
		- Leading to an increase in fracture risk
	- WHO defines it as T score <-2.5

This is edited by Dr. Om J Lakhani

- Q. Give the WHO diagnostic criteria for osteoporosis?
	- Normal T score >-1.0
	- Osteopenia – T score -1.0 to -2.5
	- Osteoporosis – T score <-2.5
	- Severe osteoporosis- T score < -2.5 + Fragility fracture


- **Q. What are the diagnostic criteria based on AACE 2020 guidelines ?**
	- 1. T-score − 2.5 or below in the lumbar spine, femoral neck, total proximal femur, or 1/3 radius
	- 2. Low-trauma spine or hip fracture (__regardless of bone mineral density__)
	- 3. T-score between − 1.0 and − 2.5 and a fragility fracture of the proximal humerus, pelvis, or distal forearm
	- 4. T-score between − 1.0 and − 2.5 and high FRAX® (or if available, TBS-adjusted FRAX®) fracture probability based on country-specific thresholds


- Q. What are T-score and Z-score?
	- The T-score is the number of standard deviations of the BMD from the normal value of a young adult
	- The Z-score represents the number of standard deviations of the BMD from the normal value of the age, sex, race/ethnicity matched control subjects


- Q. When to use T-score and when to use Z-score?
	- T-score is used for the standard diagnosis of osteoporosis in postmenopausal and elderly men
	- Z-score is used to diagnose low bone mass or vulnerable bones in premenopausal women or young men.


- Q. What Z score cutoff is used for diagnosis of osteoporosis in Young premenopausal women?
	- If the Z score is < -2.0 the lady is said to have "low bone mass". Osteoporosis may not be a suitable term to use for premenopausal women, but a low bone mass term may be used as a substitute to "osteoporosis" and means the same diagnostically
	- In premenopausal women - the search for the secondary cause is a must 


- **Q. Is FRAX for India available ?**
	- Yes
	- Please use the link https://www.sheffield.ac.uk/FRAX/tool.aspx?country=51


- **Q. What is the cut-off for treatment based on the FRAX score ?**
	- FRAX shows 10 years probability of fracture
	- The indications for intervention are :
		-  3% for hip fracture or
		- ≥ 20% for major osteoporotic fracture


- **Q. If a patient has a fragility fracture, does she need a DEXA scan for the diagnosis of Osteoporosis ?**
	- No
	- A fragility fracture is diagnostic of osteoporosis
	- It does not need a DEXA scan to prove the diagnosis


- **Q. What is a fragility fracture ?**
	- "A fragility fracture is usually a fracture sustained from force similar to a fall from a standing position or less that would not have occurred in healthy bone, excepting fractures of the skull, face, fingers, and toes."


- Q. What are the current screening guidelines for osteoporosis by NOF?
	- All women >/= 65 years
	- All men >/= 70 years
	- All between ages 50-69 years with risk factors for osteoporosis
	- Adults having fractures after 50 years
	- Those with low bone mass and RA
	- Those with low bone mass on Gc of dose predinisolone equivalents >/= 5 mg for >/= 3 months


- Q. What is the mortality rate following a hip fracture in postmenopausal women?
	- 2-year mortality rate in postmenopausal women following a hip fracture is 12-20%


- Q. Enlist the risk factors for Osteoporosis?
	- Advancing age
	- Rheumatoid arthritis
	- Current cigarette smoking
	- Excessive alcohol consumption
	- Glucocorticoid use
	- Family history of hip fracture
	- Rheumatoid arthritis
	- Previous fragility fracture
	- Other secondary causes
	- Hypogonadism
	- Early menopause
	- Malabsorption
	- IBD
	- CLD
	- Primary hyperparathyroidism


- Q. What is the indication for lateral X-ray in the elderly?
	- All men >80 years and women >70 years with BMD T score <-1.0
	- All men 70-79 years and women 65-69 years with T score <-1.5
	- Postmenopausal women and men >50 years with
		- Historical height loss > 4cm (>1.5 inch)
		- Prospective height loss >2 cm (0.8 inch)
	- Low trauma fracture
	- Recent or ongoing Glucocorticoid use


- Q. What are the preferred screening tests?
	- DEXA


- Q. What are the sites for DEXA for screening?
	- Hip and spine
	- In the elderly Hip alone is enough


- Q. Which hip should be measured, right or left?
	- Ideally at baseline both hips should be measured


- Q. Which specific sites are to be measured?
	- 1.  Total Hip
	- 2. Femoral neck
	- 3. Lumbar spine L1-L4


- Q. When is BMD repeated if the initial BMD does not show osteoporosis?
	- Women > 65 years
	- Initial BMD <-2.0 – 2.5 at any site or having a risk factor for ongoing bone loss- every 2 years
	- Initial BMD <1.5 to -2.0 at any site – every 3-5 years
	- Initial BMD <1.0-  1.5 with no other risk factor – every 10-15 years


- Q. What are the arguments in favor of screening for osteoporosis?
	- BMD has a definite link with fracture risk
	- Treatment is available which can prevent fracture
	- Knowledge of risk will help improve compliance with lifestyle and treatment
	- It is a common disease with a high impact on morbidity and mortality
	- Screening tests are easily available


- Q. What are the arguments against screening?
	- BMD is not the only criteria that define the risk of fracture
	- If BMD Is normal- does it rule out the risk of fracture?
	- Cost of screening 
	- Single measurement of BMD less important than serial measurements


- Q. For what duration of glucocorticoid use, should DEXA be done?
	- For post-menopausal women, if glucocorticoids are given for >3 months or anticipated to be given for >3 months, a  DEXA must be done at baseline without fail


- **Osteoporotic fracture risk assessment**
- Q. What are the methods for assessment of osteoporosis fracture risk?
	- FRAX
	- BMD measurement
	- Assessment of bone microarchitecture (beyond BMD)


- Q.  How is bone microarchitecture assessed?
	- HR pQCT
	- Tetracycline labeled transiliac bone biopsy
	- Micro MRI
	- High-resolution MRI
	- Trabecular bone score – indirect marker


- \[\[FRAX]]
- Q. In FRAX, the Risk of fracture is expressed as absolute risk or relative risk?
	- It is expressed as an absolute risk of fracture in the next 10 years


- Q. FRAX is applicable for age group patients?
	- Patients between the age of 40-90 years


- Q. Which are the factors considered in FRAX?
	- Age
	- Sex
	- BMI
	- Parental fracture of the hip
	- Previous fracture (A previous fracture denotes more accurately a previous fracture in adult life occurring spontaneously, or a fracture arising from trauma which, in a healthy individual, would not have resulted in a fracture. Enter yes or no (see also notes on risk factors)
	- Current smoking
	- Alcohol - >/= 3 units/day
	- Rheumatoid arthritis
	- Glucocorticoid use – Prednisolone >5 mg for >3 months
	- Secondary osteoporosis
	- Femoral neck BMD


- Q. Which are factors included in secondary osteoporosis?
	- Type 1 diabetes
	- Hypogonadism
	- Premature menopause
	- PHPT
	- CLD
	- Malabsorption
	- Malnutrition
	- Uncontrolled hyperthyroidism
	- Osteogenesis imperfecta


- Q. What will the results give you?
	- 10-year risk of
		- Major osteoporotic fracture
		- Hip fracture
	- Each in percentage


- Q. Is FRAX for India available?
	- Yes
	- Please use the link https://www.sheffield.ac.uk/FRAX/tool.aspx?country=51


- Q. What is the bias of basing treatment based on FRAX?
	- Treatment based on FRAX will treat more older patients with higher T scores compared to younger patients with the lower T scores


- Q. What are the limitations of FRAX?
	- Limited to 4 ethnicities
	- Only takes into account Hip BMD and not lumbar or other BMD
	- Other cases it may underestimate the risk (see below)
	- All regions data not available


- Q. FRAX is used for which ethnicities?
	- Black
	- Hispanic
	- Asian
	- Caucasian


- Q. In which patients do FRAX underestimate the fracture risk?
	- Type 2 diabetics
	- Multiple fractures
	- Family history of non-hip fracture
	- High dose Gc >7.5 mg
	- Severe vertebral fractures
	- Low Lumbar BMD with normal hip BMD


- Q. Overall does FRAX underestimate or overestimate fracture risk?
	- Overall, FRAX underestimates future fracture risk
	- Also fall events and the risk of falls are not directly captured by FRAX


- Q. Which other fracture risk calculator also takes risk of fall into account?
	- Garvan Fracture risk calculator


- **Measurement of BMD**
- Q. What are the methods for measurement of  BMD?
	- DEXA
	- Peripheral DEXA
	- pQCT
	- Quantitative ultrasound


- Q. How much does fracture risk increase for every 1 SD fall in BMD T score?
	- 2 times increase risk


- Q. Where is peripheral QCT measured?
	- Forearm
	- Calcaneus
	- Finger


- Q. What are the advantages and disadvantages of pDEXA (Peripheral DEXA)?
	- Advantage- Portable
	- Disadvantage
		- Cannot be used for classifying based on the WHO model
		- Cannot be used for follow-up treatment


- Q. What parameters are measured using quantitative ultrasound (QUS)?
	- It does not measure BMD
	- But measures
		- SOS – speed of sound
		- Stiffness Index- SI
		- Quantitative ultrasound index
		- Broadband ultrasound attenuation


- Q. Is QUS a good fracture predictor?
	- Yes


- Q. What are the disadvantages of QUS?
	- WHO criteria are not based on QUS
	- It cannot be used to monitor therapy as it changes very slowly
	- It cannot be used for treatment decisions as no trials are based on it


- **pQCT **


- Q. What is measured in pQCT?
	- Volumetric BMD – in mg/cm3
	- DEXA measure in g/cm2


- Q. What is the biggest advantage of pQCT?
	- Measurement of Cortical and trabecular fractions of the bone
	- It is mainly a research tool at present since it is more expensive and more radiation is used


- Q. Can it be used for FRAX calculation?
	- Yes hip QCT adjusted for BMD can be entered into the FRAX data


- **Newer techniques **
- Q. What is \[\[TBS (Trabecular bone score)]]?
	- It is the trabecular bone score
	- It is a software addition to the DEXA machine
	- It gives the texture of the bone  which correlates with the bone microarchitecture
	- It can be used with FRAX


- Q. How do you interpret TBS?
	- High TBS values suggest a more homogenous texture of bone suggesting good bone microarchitecture and lower fracture risk
	- Low TBS suggests a higher fracture risk
	- This has been validated in several studies


- Q. What are the interpretation based on exact values?
	- TBS 
		- ≥1.350 → Normal
		- 1.200-1.350 → Partially degraded microarchitecture
		- ≤1.200 → degraded microarchitecture 


- Q. In which cases is TBS particularly useful?
	- It is a useful addition to FRAX, especially in cases where FRAX is likely to underestimate the fracture risk
	- Examples are \[\[Type 2 Diabetes mellitus]] and \[\[Primary hyperparathyroidism (PHPT)]]


- Q. What is the advantage of HR- pQCT?
	- Cell tells about the bone microarchitecture
	- micro MRI can give similar information


- Q. What is Hip structural analysis?
	- It takes data obtained from the DEXA to look at hip parameters
	- It measures Hip axis length which correlates with fracture risk  and other parameters like Neck shaft angle etc


- **Skeletal site to measure**


- Q.  Which are common sites for DEXA?
	- ISCD recommends
		- Hip
		- Lumbar
	- For assessment commonly
	- However, if they cannot be assessed – a distal radius can be used
	- Lumbar is less useful in the elderly who have degenerative disc disease and aortic calcification


- Q. Which are the 2 most important non-BMD risk factors for fracture?
	- Advancing age
	- Previous fracture


References:

1. Camacho PM, Petak SM, Binkley N, Diab DL, Eldeiry LS, Farooki A, Harris ST, Hurley DL, Kelly J, Lewiecki EM, Pessah-Pollack R. American Association of Clinical Endocrinologists/American College of Endocrinology clinical practice guidelines for the diagnosis and treatment of postmenopausal osteoporosis—2020 update. Endocrine Practice. 2020 May 1;26:1-46