II. Indications: Osteoporosis Evaluation
- See Bone Mineral Density
- Gold standard Osteoporosis Screening and monitoring
III. Protocol: Sites for measuring bone mass
- Lumbar Vertebrae
- Assess risk of Vertebral Compression Fractures
- Screening younger patients without Osteoarthritis
- Femoral Neck
- Assess risk of Hip Fractures
- Screening older patients with Osteoarthritis
- Other locations
- References
IV. Advantages
- Negligible radiation
- Accurate, reproducible predictor osteoporotic Fracture
- Excellent measure of treatment response
V. Disadvantages
- Moderate cost
-
Osteoarthritis interferes with Spine DEXA Scan reading
- False elevated BMD on PA Spine views in elderly
- In elderly, use hip or lateral spine views
VI. Scoring
- See Bone Mineral Density (T-Score and Z-Score)
VII. Monitoring: Osteopenia and Osteoporosis
- Recheck DEXA Scan
- Normal or only mild Osteopenia of femoral neck: Recheck DEXA in 15 years
- Moderate Osteopenia: Recheck DEXA in 5 years
- Severe Osteopenia: Recheck DEXA Scan in 1 year
- Osteoporosis: Recheck DEXA every 2 years or less
- Gourlay (2012) N Engl J Med 366(3): 225-33 [PubMed]
- Monitoring for change
- Use absolute value in grams per cm^2 from now and prior DEXA Scan (not the T-Score)
- Use Least Significant Change defined for the particular scanner used
- Calculate the difference in absolute values (g/cm^2) between now and prior DEXA Scan
- Significant difference if change in absolute value exceeds Least Significant Change