Partial articular fracture of the proximal end segment

Partial articular fractures of a metacarpal base are classified by the AO/OTA as 77.2–5.1B, where 2–5 indicates which metacarpal is injured.

These fractures include avulsion fractures of the extensor carpi ulnaris with the basal ulnar tubercle of the 5th metacarpal.

Fractures of the 5th metacarpal base may be associated with a dislocation of the carpometacarpal (CMC) joint.

AP, lateral, and oblique views should be obtained.

CT images help to evaluate the fracture pattern and compromise of the joint.