Nerves are communication systems that carry signals from the brain to various parts of the body and transmit signals from various parts of the body to the brain. A nerve contains millions of fibers, which travel in groups within the nerve like cables surrounded by a protective sheath. This system, which carries signals in the form of cables, is also surrounded by a protective insulating material.

Nerves are of two types: motor nerves, which carry signals from the brain to the muscles and control movement, and sensory nerves, which carry sensations such as pain, pressure, and temperature from various parts of the body.

Nerves can be damaged by stretching, pressure, and cutting. In stretching and pressure injuries, the structure of the protective layer around the nerve remains intact, but the damage to the fibers disrupts the communication system, rendering the nerve non-functional. In the case of a cut, both the nerve fibers and the surrounding protective layer are damaged. After damage, signals from the brain cannot be transmitted to the muscles, and functions cannot be performed, or sensory signals from various parts of the body cannot be transmitted to the brain.

When nerve fibers are damaged, the structure of the surrounding protective layer remains intact. Injured nerve endings die and disintegrate up to their upper conduction station. The protective sheath remains as hollow tubes. After a while, the healing process begins. If the protective sheath is undamaged or repaired, the growth of the fibers continues through the hollow tubes, ensuring healing to the conduction endpoints (receptors) of motor or sensory nerves. Nerves are the slowest-healing tissue in the body. If the protective sheath structure is not repaired, the nerve endings that are undergoing the healing process and continuing to grow cannot find their way and form masses called neuromas at the nerve end. When pressure is applied to these masses, painful electrical impulses are generated.

In treatment, if a complete nerve transection has occurred, the two ends of the nerve are fixed, and the surrounding protective sheath is repaired with the finest possible sutures (Figure 1). The aim of treatment is to ensure the continuity of the surrounding sheath tissue and to enable the nerve fibers undergoing the healing process to find their way to their final conduction points. To avoid creating excessive scar tissue and putting pressure on the nerve healing area, the nerve sheaths must be carefully repaired using microsurgical techniques with the finest possible sutures. Nerves, especially at the hand and finger level, are very thin and generally run alongside vascular structures. Damage to these vascular structures is very common when nerve injury is detected. Because very fine sutures are used, a 3-week plaster cast is applied to protect the repaired area.

Nerve sheaths are surgically reattached to their original position with the help of the vascular structures on the nerve, but even with the most thorough reattachment, the hollow tubes do not always find their original location. It is impossible for millions of fibers to find their original position.

If the wound is very dirty and will be left open, nerve reattachment may not be performed during the first operation. If there is a nerve defect (absence), a nerve graft (part) taken from the leg is usually placed to ensure nerve continuity.

After nerve repair, nerve fiber growth begins 3-4 weeks later. Depending on factors such as the patient’s age, type of injury, and smoking, fibers generally advance an average of 1 mm per day through the nerve tubes. Therefore, achieving sensory recovery can take anywhere from 1-2 months to 6-8 months, depending on the distance of the injury from the target area. During this period, the patient should be careful not to injure their fingertips when touching heat or performing tasks. While waiting for nerve recovery, it is important that the activity of the muscles innervated by the nerve is not lost.