The smallest four toes of each foot have three bony segments connected by two joints. Hammertoe is a deformity in which one or more of the small toes develops a bend at the joint between the first and second segments. The tip of the toe turns downward, making it look like a hammer or claw. The second toe is the one most often affected.
Hammertoe may be more likely to occur when the second toe is longer than the first toe or when the arch of the foot is flat.
Most hammertoes are caused by wearing ill-fitting, tight or high-heeled shoes over a long period of time. Shoes that don't fit well can crowd the toes, putting pressure on the middle toes and causing them to curl downward. Other causes include:
If the toes remain in the hammertoe position for long periods, the tendons on the top of the foot will tighten over time because they are not stretched to their full length. Eventually, the tendons shorten enough that the toe stays bent, even when shoes are not being worn.
The symptoms of hammertoe include:
In its early stages, hammertoe is not obvious. Frequently, hammertoe does not cause any symptoms except for the claw-like toe shape.
Most health care professionals can diagnose hammertoe simply by examining your toes and feet. X-rays of the feet are not needed to diagnose hammertoe, but they may be useful to look for signs of some types of arthritis (such as rheumatoid arthritis) or other disorders that can cause hammertoe.
If the deformed toe is very painful, your doctor may recommend that you have a fluid sample withdrawn from the joint with a needle so the fluid can be checked for signs of infection or gout (arthritis from crystal deposits).
Hammertoe can usually be prevented by wearing shoes that fit properly and give the toes plenty of room.
Treating hammertoe involves straightening the toe, making tendons in the toes flexible again, and preventing the problem from returning. Some simple treatments include:
In advanced cases in which the toe has become stiff and permanently bent, the toe can be straightened with surgery. One type of surgery involves removing a small section of the toe bone to allow the toe to lie flat.
Surgery for hammertoe usually is classified as a cosmetic procedure. Cosmetic foot surgeries sometimes cause complications such as pain or numbness, so it's better to treat the problem with a shoe that fits properly.
Source: https://www.health.harvard.edu/feet-and-foot-care/hammertoe