What T-score is considered to indicate severe osteoporosis according to the WHO?

• A. -1.0 SD or lower
• B. -2.0 SD or lower
• C. -2.5 SD or lower with a fragility fracture
• D. -3.0 SD or lower

Answer: (C)

A T-score of -2.5 standard deviations or lower, combined with the presence of a fragility fracture, is defined by the World Health Organization (WHO) as indicating severe osteoporosis. This classification is significant because it highlights not just the bone density measurement but also considers the clinical implication of fractures, which are a critical aspect of osteoporosis.

The T-score measures how much the patient's bone density deviates from that of a healthy young adult, and a score of -2.5 SD or lower signifies a notable reduction in bone density, suggestive of osteoporosis. However, the additional criterion of a fragility fracture indicates that the patient has already sustained a fracture from minimal trauma, further substantiating the severity of the condition. In clinical practice, this distinction is vital for determining appropriate treatment and management strategies to prevent further fractures and complications associated with severe osteoporosis. Thus, this classification aids healthcare providers in identifying patients at high risk for fractures and guiding therapeutic interventions.