Nerve entrapment is a compressive neuropathy cause by constriction, scar tissue, or mechanical cause. It can even be vascular in nature. When nerves don't have adequate room they don't function properly with the result being pain, numbness, tingling and sometimes temp and color change in the limb. Nerve Entrapment and also injury is an imitator of CRPS. Injuries to nerves are not unusual during surgical procedures, hardware can cause problems too. Somtimes the damage/compression can be helped by injections to reduce scar tissue or surgery to make a repair or remove a painful neuroma. I posted links to resources under NErve Injury Resources just a couple days down in the threads. PM&R doctors with the right training can sometimes find a problem with a nerve on ultrasound by looking for swelling or scar tissue on it. A doctor who does hydrodissections will have the skills to look for this kind of problem. Might be worth a try....