Trauma to the neck and/or arm can be severe enough to pull the brachial plexus right off. This injury is called a brachial plexus avulsion. These are serious injuries that are complex and difficult to treat. A little understanding of the anatomy may help for starters.
A nerve plexus is an area where nerves branch and rejoin. The brachial plexus is a group of nerves in the cervical spine (neck) from C5 to C8-T1. This includes the lower half of the cervical nerve roots and the nerve root from the first thoracic vertebra.
The brachial plexus begins with five roots that merge or join together to form three trunks. The three trunks are upper (C5-C6), middle (C7), and lower (C8-T1). Each trunk then splits in two, to form six divisions. These divisions then regroup to become three cords (posterior, lateral, and medial).
The nerves leave the spinal cord, go through the neck, under the clavicle (collar bone) and armpit, and then down the arm. The final branches result in three nerves to the skin and muscles of the arm and hand: the median, ulnar, and radial nerves.
Brachial plexus avulsion injuries don’t just cause pain and numbness in the shoulder, arm, and hand. This injury disrupts nerve messages to the shoulder, arm, and hand so the patient’s arm becomes paralyzed. Efforts to find ways to restore nerve function after such injuries are ongoing.
Often, major reconstruction surgery involving nerve transplants, nerve transfers, and muscle transplantation is required. Many times, the procedures are “staged” or done in a series one-at-a-time.
Recovery time can be very long and the rehab required is extensive.
It can take many years to fully recover from an avulsion injury of a nerve plexus. Studies show that results are often better for patients who are compliant (following the surgeon and therapist’s directions). It can take up to four years for some patients to regain as much sensory and/or motor recovery they are going to get. You didn’t mention how long ago the injury occurred so it may be your husband is still in that prolonged recovery time.
The most difficult recovery is usually finger flexion. Regaining some sensation is common but movement can be more difficult to restore. If the patient had even protective sensory recovery (ability to feel hot, cold, pressure), then the results are still considered a “functional” success.
Patients must expect an intense, focused period of rehab lasting years. Complete independent function of the arm and hand isn’t promised but improved function is possible. During this time, they must remain dedicated to their exercise program. As the results of some studies show, those who stick with it are often rewarded with the best results.
Even with complete compliance there are some people who have poor recovery — especially of the hand. There are several reasons why this may happen. First, the distance the nerve has to regenerate may be just too great to reach all the way down to the muscles of the hand.
Second, the muscles themselves might have been damaged during the injury. Extreme, prolonged swelling or bone fracture piercing the muscles could have this effect. And finally, irreparable damage to the blood vessels can account for poor results.