Elbow
Page index: Tips | Anatomy| Anterior fat pad | Posterior fat pad sign |
Tips:
1. Assess anterior fat pad
2. Assess posterior fat pad
Normal: Frontal
1. Humerus. 2. Lateral epicondyle. 3. Capitulum. 4. Humero-radial joint. 5. Radial head. 6. Radial neck. 7. Radius (Shaft). 8. Ulna (Shaft). 9. Radial tuberosity. 10. Proximal radio-ulnar joint. 11. Trochlea of humerus. 12. Olecranon. 13. Medial epicondyle. 14. Olecranon fossa. 15. Trochlear notch. 16. Intercondylar fossa. 17. Coronoid process. 18. Ulnar tuberosity.
Normal: Lateral
1. Humerus. 2. Lateral epicondyle. 3. Capitulum. 4. Humero-radial joint. 5. Radial head. 6. Radial neck. 7. Radius (Shaft). 8. Ulna (Shaft). 9. Radial tuberosity. 10. Proximal radio-ulnar joint. 11. Trochlea of humerus. 12. Olecranon. 13. Medial epicondyle. 14. Olecranon fossa. 15. Trochlear notch. 16. Intercondylar fossa. 17. Coronoid process. 18. Ulnar tuberosity.
Anterior fat pad / Sail sign
The sail sign on an elbow radiograph, also known as the anterior fat pad sign, describes the elevation of the anterior fat pad to create a silhouette similar to a billowing spinnaker sail from a boat. It indicates the presence of an elbow joint effusion.
In the context of acute trauma, where a fat pad is raised and no fracture is demonstrated, an occult fracture should be suspected.
Posterior fat pad sign
The posterior fat pad sign is the visualization of a lucent crescent of fat located in the olecranon fossa on a true lateral view. Normally, the posterior fat pad will not be seen in this view
In the setting of trauma, it suggests an occult non-displaced fracture. In children, it most often indicates a supracondylar fracture, other common fractures are those of the proximal ulna, lateral condyle, and radial neck 2. In adults, look for a radial head fracture.
Elbow radiograph (an approach)
