Ultrasound-guided hydrodissection is a new method of treating an entrapped nerve. Nerves, naturally, are supposed to glide smoothly around surrounding tissue, but an entrapped nerve can be stuck or adhered to the surrounding tissue which causes pain. 

Symptoms range from mild discomfort to numbness or paralysis or pain. Nerve hydrodissection a technique used when treating nerve entrapment involves injection of an anesthetic, saline, or dextrose in water to separate the nerve from surrounding tissue, fascia, or adjacent structures.