The proximal interphalangeal joints are the primary joints of finger function, responsible for most of the finger's useful arc of motion and the most commonly injured joints in sport. They have intrinsically stable bony architecture combined with strong collateral ligaments and volar plate that resists dislocation, but when dislocated they are prone to post-traumatic stiffness that is notoriously difficult to treat. Stiffness of the PIP joint has a greater functional impact than stiffness of any other finger joint.
PIP joint dislocations are the most common finger joint dislocation and dorsal dislocations are far more common than volar. Buddy taping and early motion are the treatment for simple dorsal dislocations, while volar dislocations involving central slip injury require 6 weeks of extension splinting to prevent boutonniere deformity. PIP joint stiffness complicates virtually all PIP injuries and aggressive early mobilisation is the single most important treatment principle.
Dorsal or volar finger joint dislocation from axial loading or hyperextension, managed with reduction and buddy taping for dorsal type, extension splinting for volar type to protect the central slip.
Central slip rupture producing PIP flexion and DIP hyperextension deformity from lateral band volar migration, managed with PIP extension splinting for 6 weeks in acute injuries and reconstruction in chronic cases.
