As has been explained in the section on neuropathic pain, there are various pain conditions arising from injuries and surgical interventions in which nerves can be entrapped within the scar tissue. The pain that develops usually has neuropathic characteristics and can lead to real despair. Especially common examples are entrapped nerves after trauma and surgery to the ankle, knees and groin. Sometimes a nerve can become entrapped within a mesh which has been implanted in the operative site, as with hernia repair. Abdominal cutaneous nerves can become entrapped in the fascial linings of the muscles, constricting the nerves as they make their exit towards the skin to which they supply sensation (ACNES syndrome). Because the suffering is immense, patients are often prepared to try almost anything to be relieved of the pain. Nerve entrapment in the upper limb is less common.

Hydrodissection technique is based on injecting volumes of fluid around the entrapped nerve to release it from the surrounding scar tissue. One should perform these injections under ultrasound so that the procedure will be safe, effective and precise. A method that has become more popular in recent years is the injection of sterile water mixed with a very low concentration of dextrose. The water can penetrate the scar tissue and soften it. Cortisone is not necessary. Several treatments are necessary but each treatment lasts longer until one gets long-lasting relief. Patients are satisfied with the results and their quality of life has much improved.