How do they fix hammer toes?

Age, severity. This would depend on the severity of the condition, the age of the patient and which toes are involved. Generally younger patients are better candidates for fusion as this could give better long term results for toes 2 and 3. Older patients usually have arthroplasties done.
Surgery. Surgical treatment of hammertoes can vary depending on the surgeon, which toes are involved and severity of deformity. Many times wires are used that will stick out the end of the toe to maintain alignment after the toes are straightened. In our office these are removed around the 3 1/2 week mark. Usually y the patient will need to be in some type of surgical shoe or boot for 4-6 weeks. Dr. L.
Surgery vs. padding. If you catch hammertoes in the early stages, a small, in-office procedure to release one of the tendons will often allow the toe to lie straight again. If the toe deformity has become rigid, the surgery is more involved. It's an outpatient procedure in an operating room, and can involve bone cuts, pins, screws, or other implants. Without surgery, your best bet is padding to reduce your discomfort.
Many options. The joint may be left separated or fusion of the ends may be attempted. For fusion, the cartilaginous ends of the bone are removed and the ends are approximated and stabilized via a wire, screw, pin, or implant. The contracted tendons may need to be cut or lengthened.