A 52-year-old man with rheumatoid arthritis has been on long-term corticosteroid therapy for 3 years. He now presents with severe bone pain and pathological fracture of the femoral neck. Which is the most common skeletal complication of chronic corticosteroid use?

Explanation

## Most Common Skeletal Complication of Chronic Corticosteroid Use **Key Point:** Osteoporosis is the most frequent skeletal complication of chronic corticosteroid therapy, occurring in 30–50% of patients on long-term systemic corticosteroids. ### Mechanism of Corticosteroid-Induced Osteoporosis 1. **Decreased bone formation** — corticosteroids inhibit osteoblast proliferation and differentiation 2. **Increased bone resorption** — enhanced osteoclast activity via increased RANKL signaling 3. **Reduced calcium absorption** — decreased intestinal calcium uptake 4. **Increased urinary calcium loss** — enhanced renal excretion 5. **Hypogonadism** — suppression of sex hormone production (both testosterone and estrogen) ### Risk Factors for Severe Bone Loss | Factor | Impact | |--------|--------| | Dose ≥7.5 mg/day prednisolone | High risk | | Duration >3 months | Significant bone loss | | Age >65 years | Accelerated loss | | Female sex, postmenopausal | Additive risk | | Low baseline BMD | Rapid progression | | Immobility | Worsened osteoporosis | **High-Yield:** Bone loss is most rapid in the first 3–6 months of corticosteroid therapy, with 5–10% loss of vertebral bone density in the first year. ### Clinical Manifestations - **Vertebral compression fractures** — most common fracture type (thoracic and lumbar spine) - **Hip fractures** — femoral neck and intertrochanteric - **Wrist and rib fractures** — from minor trauma - **Height loss** and kyphosis from cumulative vertebral collapse **Clinical Pearl:** Pathological fractures in corticosteroid users often occur with minimal or no trauma, distinguishing them from typical osteoporotic fractures. ### Prevention and Management **Key Point:** DEXA scan should be performed at baseline and annually in patients on ≥7.5 mg/day prednisolone for >3 months. **Interventions:** - Calcium supplementation (1000–1200 mg/day) + Vitamin D (800–1000 IU/day) - Bisphosphonates (alendronate, risedronate) — first-line for prevention and treatment - HRT in postmenopausal women (if not contraindicated) - Weight-bearing exercise and fall prevention - Minimize corticosteroid dose and duration **Mnemonic: CRAB** — **C**alcium, **R**educe dose, **A**ctivity, **B**isphosphonates (management of steroid-induced osteoporosis) [cite:KD Tripathi 8e Ch 56] ### Why This is Most Common Osteoporosis develops in nearly all patients on chronic corticosteroids due to the direct inhibition of bone formation combined with increased resorption. While avascular necrosis and stress fractures can occur, they are far less frequent and typically occur only in specific anatomical sites or after prolonged high-dose therapy.