The interphalangeal joints Surface Anatomy

Location

The interphalangeal joints exist at the articulations of the phalanges of the toes. The great toe has one interphalangeal joint while the lesser toes have two – a distal and a proximal. Often a skin crease develops on the dorsum of the distal interphalangeal joints of the toes.

Significance

Hyperextension at the metatarsophalangeal joint and distal interphalangeal joint and hyperflexion of the proximal interphalangeal joint is called a hammer toe. Such a deformity leaves the dorsal aspect of the proximal interphalangeal joint susceptible to callus formation.

Hyperflexion of the proximal and distal interphalangeal joints is called a claw toe. Such a deformity leaves the proximal interphalangeal joint and tip of the toe susceptible to callus formation.

Hyperflexion of the distal interphalangeal joint is called a mallet toe. Such a deformity leaves the tip of the toe susceptible to callus formation.