Heredity and biomechanics play an important role in the development of hammertoes.
During the gait cycle if an abnormal amount of force is misdirected, (the arch being too low or the foot being too unstable) the toes must over grip and increase their actions. Often times this leads to a muscular imbalance causing deformity to the toes.
If a hammer toe deformity progresses it can lead to irritation in shoe gear and to the development of a corn or bursa. A large development of keratinized skin of the outer layer (stratum corneum) builds up to prevent further irritation of the epidermis. Often, a small fluid filled sac between the bone and the skin which tries to cushion the bone, usually to no avail and with the development of further pain.
Hammer toe deformity can be congenital (such as in polydactyly and syndactyly) or developmental such as in adducto Varus deformity, flexor stabilization or flexor substution.
In the congenital development, an abnormal development of the bones, skin or insertion of the tendon has occurred which produces an abnormal position of the toe.
In the developmental development of hammer toe deformity, muscular imbalance with progressive shortening of the flexor tendons (the deforming force) and the extensor tendons (the holding force). The result is an angular mal position of the toe causing rubbing in shoes with pain.
Conservative treatment for hammer toes includes deeper shoes and padding.
Surgical treatment of a hammer toe deformity is addressed by lengthening the contracted tendon and joint capsule and by removing a piece of the joint (knuckle) to allow the toe to straighten. Pins are often used stabilize the toe during the healing period.