Sail sign on lateral elbow Xray vs sail sign on CXR:



1. Sail sign on lateral elbow X ray:

- fat pad in joint capsule, outside synovium

- fat pad usually hidden in olecranon and coronoid fossa

- intraarticular injury --> intraarticular haemorrhage --> lifts the fat pad into view resulting in sail sign



2. Sail sign on CXR:

- left lower lobe collapse