A 68-year-old man with a history of chronic obstructive pulmonary disease on long-term oral corticosteroids presents with a pathological fracture. Which is the most common site of osteoporotic fracture in this patient?

Explanation

## Epidemiology of Osteoporotic Fractures **Key Point:** Vertebral compression fractures are the most common osteoporotic fractures overall, occurring in approximately 25% of postmenopausal women and 5–10% of men with osteoporosis. In corticosteroid-induced osteoporosis, vertebral fractures are even more prevalent due to preferential trabecular bone loss. ## Fracture Sites and Frequency | Site | Frequency | Bone Type Affected | Clinical Presentation | Risk in Corticosteroid Use | |------|-----------|-------------------|----------------------|---------------------------| | Vertebral body | ~45% of all osteoporotic fractures | Trabecular | Often asymptomatic; height loss, kyphosis | **Very high** | | Femoral neck | ~20% of osteoporotic fractures | Mixed | Hip fracture; severe morbidity | High | | Distal radius (Colles) | ~15% of osteoporotic fractures | Cortical | Wrist fracture; fall on outstretched hand | Moderate | | Proximal humerus | ~5% of osteoporotic fractures | Cortical | Shoulder fracture; less common | Lower | **High-Yield:** Vertebral fractures are the **most common** osteoporotic fractures, but femoral neck fractures cause the **most morbidity and mortality**. In corticosteroid-induced osteoporosis specifically, vertebral fractures are even more common because glucocorticoids preferentially affect trabecular bone. ## Why Vertebral Fractures Dominate in Corticosteroid-Induced Osteoporosis 1. **Trabecular bone loss:** Corticosteroids cause rapid trabecular bone resorption (spine is 75% trabecular) 2. **Early onset:** Vertebral fractures can occur within months of starting high-dose corticosteroids 3. **Often silent:** Many vertebral fractures are asymptomatic and detected only on imaging 4. **Cumulative effect:** Multiple vertebral fractures lead to progressive kyphosis and height loss **Clinical Pearl:** A patient on chronic corticosteroids who develops a pathological fracture has a very high likelihood of it being a vertebral compression fracture, even if the patient is asymptomatic. Screening with lateral spine radiographs or DEXA is recommended. **Mnemonic:** **VFF** — Vertebral fractures are most **Frequent** in osteoporosis; Femoral neck fractures are most **Fatal** (in terms of morbidity).