Simultaneous fracture-dislocations of the distal and proximal interphalangeal joints.

Sixteen cases of simultaneous fracture-dislocations of both the distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints in the same finger that were treated during the past 10 years were classified into three types: the swan-neck injury (dorsal fragment of the base of the distal phalanx at the DIP joint and palmar fragment of the base of the middle phalanx at the PIP joint); the double-hyperextension injury (palmar fragments at the DIP and PIP joints); and the straight-finger injury (with dorsal and palmar bone fragments at the DIP joint). The results of treatment were more satisfactory in PIP joints than in DIP joints.