What is the recommended treatment for a patient with a femoral neck T score of -2.1 and Z score of -1.0, indicating low bone mass?

Management of Femoral Neck T-score -2.1 (Osteopenia)

This patient has osteopenia (low bone mass), not osteoporosis, and does not require pharmacologic treatment based on bone density alone unless additional high-risk factors are present. 1, 2

Diagnostic Classification

• A femoral neck T-score of -2.1 falls in the osteopenia range (T-score between -1.0 and -2.5), not osteoporosis (T-score ≤ -2.5). 2, 3, 4
• The Z-score of -1.0 indicates bone density is within 1 standard deviation of age-matched peers, which is normal and does not suggest secondary causes of bone loss. 4
• The femoral neck is one of the primary diagnostic sites recommended by the International Society for Clinical Densitometry and WHO for osteoporosis assessment. 2

Risk Stratification Required

Treatment decisions should be based on absolute fracture risk, not the T-score alone. 3, 5

Calculate 10-Year Fracture Risk:

• Use FRAX or similar clinical risk calculators to determine 10-year probability of hip fracture and major osteoporotic fracture. 4
• Treatment may be warranted if 10-year hip fracture risk >5% or major osteoporotic fracture risk >20%. 4

High-Risk Features That Would Warrant Treatment Despite Osteopenia:

• Prior fragility fracture (most important risk factor - indicates severe osteoporosis regardless of T-score). 1, 2
• Age ≥65 years with additional risk factors. 6
• Long-term glucocorticoid therapy (≥7.5 mg prednisone daily for ≥3 months). 1, 7
• Maternal hip fracture before age 60. 1
• Height loss >4 cm or radiographic evidence of vertebral fracture. 1, 2
• Very low body mass index (<19 kg/m²). 1
• Current smoking or excessive alcohol use. 1

Recommended Management Approach

For ALL Patients with Osteopenia (Non-Pharmacologic):

Lifestyle modifications are essential regardless of treatment decisions: 1

• Weight-bearing exercise regularly to maintain bone strength. 1, 3
• Smoking cessation if applicable. 1
• Alcohol reduction if excessive intake. 1
• Fall prevention strategies to reduce fracture risk. 3

Nutritional supplementation: 1, 3

• Calcium 1000-1200 mg daily (dietary plus supplementation). 1
• Vitamin D 800-1000 IU daily to maintain adequate levels. 1

Pharmacologic Treatment Decision Algorithm:

DO NOT treat with bisphosphonates if: 3, 5

• T-score is between -1.0 and -2.5 (osteopenia range)
• No prior fragility fractures
• 10-year fracture risk is low (<5% hip, <20% major osteoporotic)
• No other high-risk features listed above

CONSIDER treatment with bisphosphonates if: 5

• T-score between -1.6 and -2.5 AND existing vertebral fracture present
• High calculated 10-year fracture risk despite osteopenia range T-score
• Multiple additional risk factors present

First-line pharmacologic therapy when indicated: 1, 2

• Oral bisphosphonates (alendronate 70 mg weekly or risedronate) are first-line. 1, 2, 7
• Alendronate has demonstrated efficacy in reducing vertebral fractures even in women with T-scores between -1.6 and -2.5, particularly those with existing vertebral fractures. 5

Monitoring Recommendations

For patients NOT on pharmacologic treatment: 1

• Repeat DXA in 2 years to assess for progression. 1
• Use the same DXA machine for accurate comparison. 1, 2
• Compare absolute BMD values (g/cm²), not T-scores, to assess change. 1, 2

For patients on treatment: 2, 8

• Repeat DXA after 1 year of therapy to assess response. 2, 8
• Significant change requires exceeding the least significant change (LSC), typically 2.8-5.6% depending on precision error. 1

Important Clinical Caveats

• Osteopenia is not a disease and the label can cause unnecessary anxiety in approximately 50% of postmenopausal women who fall in this range. 3
• Absolute fracture risk varies widely within the osteopenia range - a T-score of -2.4 carries much higher risk than -1.1. 3
• In younger individuals (premenopausal women, men <50 years), a Z-score ≤-2.0 should prompt evaluation for secondary causes of bone loss. 2, 8, 4
• Vertebral fracture assessment (VFA) should be considered if height loss, kyphosis, or back pain is present, as vertebral fractures may exist even with osteopenia-range BMD. 1, 2
• The decision to treat should incorporate patient preferences regarding medication burden versus fracture risk reduction. 3