Irreducible volar dislocation of the proximal interphalangeal finger joint.

Volar dislocation of the proximal interphalangeal finger joint is rare. The trauma that causes this injury consists in a rotation mechanism in almost all cases. It may be initially missed and diagnosed at a late sequel stage. Closed reduction should always be attempted first but this procedure may result in failure, necessitating a surgical intervention. In irreducible cases, the surgical investigation shows a longitudinal split which separates one of the lateral bands (ulnar or radial) from the central slip of the terminal extensor tendon. In addition, the lateral band is displaced to the volar aspect of the head of the first phalanx, and partially entrapped into the proximal interphalangeal joint, the head of the first phalanx being trapped between the central slip and the displaced lateral band. Surgical relocation of the displaced lateral band gives an immediate reduction of the dislocated joint. We present a case of irreducible dislocation of the proximal interphalangeal joint of the right index finger in a 42-year-old female patient who required a surgical treatment. We present the diagnostic, anatomic and therapeutic aspects of this rare injury, together with a review of the literature.