One small maneuver may help the patient avoid an extension lag at the DIP joint. As we know, stress applied to healing tissue elongates it. Since most mallet finger injuries are treated closed with splinting, our desire is to eliminate stress to the healing tendon ends over the DIP joint.

Patients naturally hold their finger in extension to assist with splint application and removal. During this active finger extension, tension is transmitted through the dorsal apparatus to the terminal tendon insertion (via the lateral bands).

If there is disruption of the tendon due to a mallet injury, tension potentially causes a “gap” to form between the healing tendon ends.

My preference is to teach the patient to place the tip of the finger on the palm of the hand/thenar eminence (flexing only the PIP joint) with the superficialis muscle (see photo). In this position tension cannot be transferred across the healing tendon. While maintaining this position the patient removes the splint, cleans the finger, and re-applies the splint. The little finger may appear too short for this maneuver. Allowing the ring finger to flex along with the little finger will make it easier for the little finger DIP joint to be supported by the palm.

Source : Handlab