Capsulo-ligamentous Injuries of the Proximal Interphalangeal Joint

Abstract

Joint stability is related to various anatomical elements, mainly:

• The collateral ligaments, spreading from the head of the 1st phalanx to the base of the 2nd phalanx, the volar plate and the flexor sheath. The principal fascicle is tensed between the head of the 1st phalanx and the base of the 2nd phalanx, with an insertion on the volar plate. The accessory fascicle is tensed from the head of the 1st phalanx to the volar plate and the flexor sheath. The collateral ligaments are tensed in extension (maximal tension in the accessory fascicle) and in complete flexion (phalangeal pulley wider frontwards than backwards). They are relatively relaxed in an intermediary position.

• The volar plate is a very resistant fibrocartilage, anchored between the 1st and 2nd phalanges on the palmar side by the “check reins”, which also are the insertions of the A3 pulley and flank the flexor sheath. It’s tensed in extension and slides on the anterior side of the 1st phalanx in flexion (hinge system) to avoid its early abutment on the anterior side of the head of the 1st phalanx.

An injury in one of these elements can cause stiffness or instability.

Rehabilitation must be realized early and with very soft and progressive techniques in order not to “attack” the damaged tissues. As Madden reminds us, “tissues don’t know enthusiasm but stress”.