Osteoporotic Vertebral Compression Fracture Cohort Study

Bone Mineral Density (BMD)

DXA will be used to measure lumbar spine (L1-L4) and bilateral hip density, recording the T-score for each site. Instrument precision will be set to 1% (i.e., repeated measurement error \< 1%). Professionals will be responsible for post-use accuracy checks and maintenance.

Muscle Strength

Left and right handgrip strength in kilograms, which is determined by a handheld dynamometer. The normal range varies by age, gender, and dominant hand. When it is lower than the normal range, it may indicate muscle weakness, sarcopenia, or neuromuscular disorders; when it is higher than the normal range, it typically reflects good musculoskeletal health and physical fitness.

The bone marrow fat fraction (FF)

The bone marrow fat fraction (FF) of lumbar vertebrae (expressed as a percentage), which is determined by magnetic resonance imaging (MRI) analysis. The normal range varies with age and vertebral level, typically between 30-50% in healthy adults. When it is higher than the normal range, it may indicate osteoporosis, aging, or metabolic bone disease; when it is lower than the normal range, it may suggest conditions such as bone marrow edema, inflammation, or hematopoietic disorders.

Paravertebral muscle area

The paravertebral muscle area (in cm²), which is determined by magnetic resonance imaging (MRI) analysis. The normal range varies based on vertebral level, age, and gender. When it is smaller than the normal range, it may indicate muscle atrophy, sarcopenia, or degenerative changes.

Fatty infiltration

The degree of paravertebral muscle fatty infiltration (expressed as a percentage or fat fraction), which is determined by magnetic resonance imaging (MRI) analysis. The normal range varies with age and vertebral level. When it is higher than the normal range, it indicates increased intramuscular fat deposition, often associated with aging, disuse, or metabolic disorders.