The transverse fracture on the left is easy to see
The fracture on the right is more subtle - close observation shows an oblique fracture
Both examples show soft tissue swelling - often a useful sign of a finger fracture
Intra-articular fractures have a worse prognosis and are often the most difficult to see. Check all views available. If a fracture is not visible and there is sufficient clinical suspicion of bone injury then a request for further views may be helpful.
The thumb metacarpal base intra-articular fracture is much more easily seen on the oblique image
This injury is termed a 'Bennett's' type injury - as in this case there is invariably a degree of subluxation/dislocation of the metacarpal base
Mallet finger injury
Hyperflexion of the DIP joints may result in avulsion of the distal phalanx base on the dorsal side. More commonly there is tearing of the extensor tendon which is an injury not directly visible with X-ray.
If there is a clinically evident mallet deformity, but no bone injury, do not make the mistake of thinking there is no significant injury.