Presentation
Motorcycle accident. Deformity of the left 4th finger upon physical examination.
Patient Data
Hand radiographs confirmed the suspected dislocation of the proximal interphalangeal (PIP) joint of the 4th finger.
There is an associated fracture on the volar side of the base of the middle phalanx, indicating a volar plate avulsion fracture.
(See annotated image below)
Annotated image demonstrates the avulsion fracture.
Case Discussion
Dorsal proximal interphalangeal joint dislocations are usually the result of a hyperextension mechanism.
Plain radiographs are often sufficient to diagnose a PIP joint dislocation, but it is important to study the digit with proper frontal and lateral radiographs, which unfortunately were not performed in this case. Hand radiographs alone may miss more subtle fractures and/or dislocations of a digit, such as the volar plate avulsion fracture present in this case.