Differences in bone mineral density between the right and left hips in postmenopausal women

Area of Science:

• Endocrinology
• Geriatrics
• Radiology

Background:

• Osteoporosis diagnosis commonly relies on bone mineral density (BMD) measurements.
• Dual-energy X-ray absorptiometry (DEXA) is the standard, typically measuring the spine and one hip.
• The necessity of bilateral hip scanning for osteoporosis diagnosis remains debated.

Purpose of the Study:

• To analyze bone mineral density (BMD) differences at bilateral hips in postmenopausal women.
• To evaluate the concordance and discordance rates of the lowest T-score and BMD between both hips.
• To determine if bilateral hip DEXA scanning is necessary for accurate osteoporosis assessment.

Main Methods:

• Retrospective analysis of DEXA scans from 384 postmenopausal women.
• Comparison of BMD measurements between the left and right hip.
• Evaluation of T-score and BMD concordance and discordance rates.

Main Results:

• Significant differences in BMD were observed between bilateral hips at the femoral neck and trochanter (P < 0.05).
• Discrepancies in the lowest T-scores between hips were also significant (P < 0.05).
• Discordance rates between bilateral hip measurements reached approximately 30%.

Conclusions:

• Significant BMD variations exist between bilateral hips, particularly at the femoral neck and trochanter.
• The high discordance rate (approx. 30%) suggests unilateral hip scanning may underestimate osteoporosis risk.
• Bilateral hip DEXA measurements are recommended to ensure accurate osteoporosis diagnosis and avoid underestimation.