Q: How is the identification of elbow joint effusion on x-rays? show answer

A: On x-ray, the elbow's effusion is identified by dorsal displacement of the posterior fat pad and the sail sign, representing an anterior fat pad's elevation.

Q: Can cross-sectional imaging contribute to evaluating radial head fractures? show answer

A: Cross-sectional imaging, CT and MR, are useful for identifying radial head fractures. CT may provide enhance images in complex injury or comminuted fractures. MR provides superior views of soft tissue.

Q: How can CT scan contribute to the diagnosis and workup of radial head fractures? show answer

A: CT provides a more accurate evaluation than radiographs. CT helps identify the location and the size of the fracture and is excellent in assessing the degree of comminution, morphology, articulate margin, fracture gap, and displacement. CT also contributes to investigate associated bone injuries, and also it distinguishes the type of fracture in Mason classification. Besides, CT can provide useful 3-dimensional images.

Q: How can magnetic resonance (MR) contribute to the diagnosis and workup of radial head fractures? show answer

A: MR can contribute by detecting associated injuries as ligamentous injuries or injuries to the capitellum.

Q: What are the four types of radial head fractures in the Mason classification system? show answer

A: The four types of radial head fractures in the Mason classification system are type 1, defined by marginal fractures with no or only minimal (< 2 mm) displacement and no mechanical block to movement; type 2, characterized by marginal fractures with articular surface involvement of less than 30%, and displacement of 2 mm or more; type 3, comminuted fractures with displacement; and type 4, fractures of the radial head associated with dislocation of the elbow joint.