What joint does a Hammertoe affect?

A Hammertoe primarily affects the proximal interphalangeal (PIP) joint. In this condition, the toe bends downward at the PIP joint, causing the tip of the toe to point up. This deformity often develops as a result of muscle imbalances or imbalances in the toe tendons, leading to the characteristic position of the toe. The PIP joint is involved in this deformity because it is where the bending occurs, making it the crucial joint in the definition of Hammertoe.

While the distal interphalangeal (DIP) joint may also be involved in the overall appearance of the Hammertoe or show secondary effects, the primary affliction is the PIP joint. The metatarsophalangeal (MTP) joint is at the base of the toe and largely unaffected in cases of Hammertoe, as the bending occurs higher in the toe structure. The subtalar joint is not involved in Hammertoe at all, as it does not pertain to the phalangeal structure of the toes but rather to the relationships between the talus and calcaneus bones in the foot.