The distal phalanx is divided into three anatomical parts: most proximally,
the metaphysis, followed by the diaphysis (“shaft”), and finally the ungual
The base of the distal phalanx has a prominent dorsal crest at the insertion of
the extensor tendon. The tendon is also adherent to the distal interphalangeal
(DIP) joint capsule.
On the palmar surface is the insertion of the flexor digitorum profundus
tendon. This is also adherent to the volar plate.
The flexor tendon inserts into the whole width of the base of the distal
The volar plate is very flexible, allowing hyperextension of the DIP joint and
The vascularity of the extensor tendons is more precarious than that of the
flexor tendons. This prolongs extensor tendon healing time.