Which imaging finding is commonly seen in CRPS on plain X-ray?

• A. Soft tissue swelling with regional osteopenia
• B. Subchondral sclerosis
• C. Joint space narrowing
• D. Calcifications in soft tissue

Answer: (A)

The main idea is that CRPS often produces radiographic changes in the affected limb due to sympathetic and microvascular dysfunction. On plain X-ray, the classic finding is soft tissue swelling with regional osteopenia—edema in the soft tissues accompanied by decreased bone mineral density in the nearby bones. This regional osteopenia reflects reduced bone perfusion and increased bone turnover associated with CRPS.

This pattern helps distinguish CRPS from other conditions. Subchondral sclerosis and joint space narrowing point more toward degenerative joint disease, while calcifications in soft tissue aren’t typical hallmark features of CRPS on plain radiographs. Keep in mind that early CRPS can have a normal X-ray, but when abnormalities appear, soft tissue swelling with regional osteopenia is the most characteristic finding.