The brachial plexus is the assembly of nerves that originate from the cervical and upper thoracic spinal cord and can be considered the electrical panel of the upper limb, because it controls all the muscles and the sensitivity from the shoulder to the hand. Its anatomy is extremely complex and frequently presents morphological variations.
The spinal cord (considered a transformer) is the extension of the brain (power plant) to distribute all motor and sensory nerves to the body. In a peripheral nerve (the electrical cable) there are several fibers that transmit motor or sensory information: axons (electrical wires). These axons are grouped into bundles corresponding to a specific function (bend the elbow, bend the fingers …).
A nerve can be motor (controls a muscle and thus a function) or sensitive (it is responsible for the sensitivity of the skin). The contact between a motor nerve (which reaches the muscle to control it) and the muscle itself is made through a motor plate. The motor plate degenerates after 12 months if the nerve is broken or avulsed, meaning that no nerve transfer or neurotization would work after so long time after the traumatic injury.
Traumatic palsy of the brachial plexus in adults mainly affects the young subject aged between 18 and 30 years. This is in 90% of cases a motorcycle accident. The traumatic mechanism corresponding to a forced stretch of the brachial plexus nerves can lead to three types of injury:
- stretching of the nerves without rupture – temporary loss of function that will recover from itself or after an open or an endoscopic neurolysis
- avulsion or rupture of the roots of the spinal cord
- rupture of the plexus nerves: the nerve is interrupted between the root and the terminal branches, most often producing a neuroma in continuity.
The same can happen to the newborn, only that the injury arises from obstetric causes, at birth and is called: obstetric paralysis of brachial plexus of the newborn.
In orthopedics, another common cause is plexus paralysis after shoulder dislocation.
Surgical exploration and treatment is a relative emergency. Recent publications highlight the crucial role of surgery (neurolysis, nerve transfers and anastomoses, neurotization, transposition of peripheral nerves, etc.) performed up to 6 months after trauma, regardless of the level of peripheral nerve injury. If it is performed beyond 6-12 months, the surgical treatment is, per definition, a palliative one, since the motor plate will no longer function no matter what nerve transfer is performed. In this case, selective arthrodesis and functional muscle-tendon transfers may be helpful, but only with… palliative results.
In the last decade, nerve transfers and neurotizations have revolutionized the treatment of traumatic lesions of the brachial plexus. Dr. Popescu has a complementary training in peripheral nerve and brachial plexus surgery, being able to manage rare and especially complex lesions in the upper limb, including pathologies associated with muscles, bones, tendons, blood vessels but also with peripheral nerves.