The brachial plexus (brachial means arm and plexus mean communication or meeting point) refers to the nerves that exit the cervical spine and pass down to the shoulder and arm. Five major nerves comprise the brachial plexus: C5, C6, C7, C8, and T1 (C refers to cervical [or neck] and T refers to thorax [or chest]). These nerve pass under the skin in the neck and axilla, where they are vulnerable to injury. When the neck and arm are forced away from each other during trauma (e.g., car accidents, motorcycle accidents, falls) the brachial plexus nerves can be stretched or torn apart. If the force is severe, these nerves can even be pulled away from the spinal cord where they originate. Damage to these nerves causes pain, numbness, and weakness in the shoulder, arm, and hand. The pain can be quite severe, and is often described at burning, pins and needles, or crushing. In general, the C5 nerve controls the rotator cuff muscles and shoulder function, C6 controls flexing the arm at the elbow, C7 partially controls the triceps and wrist flexion, and C8/T1 controls hand movements. Several patterns of injury occur, the most common is referred to as an Erb’s palsy. This is when C5 and C6 are predominantly affected. These patients are unable to lift their arm or flex at the elbow. Severe atrophy can occur in the shoulder muscles. Another pattern of injury is when C8/T1 is mostly damaged. These patients have hand weakness and pain. Some finger movement may remain, however. The most severe type of injury is when the arm is completely paralyzed due to extensive brachial plexus injury.
THREE GENERAL TYPES OF BRACHIAL PLEXUS SURGERY ARE PERFORMED:
Erb’s palsy repair (shoulder/elbow weakness)
Complete brachial plexus reconstruction
Isolated nerve transfers
Each patient may undergo a combination of procedures.
Erb’s palsy surgery requires an incision along the side of the neck and/or the clavicle. The injured C5 and C6 nerves are identified and examined. Depending on the injury, one or more of the following is performed (see technologies and techniques available section): scar tissue is removed, the nerves are re-attached directly or with nerve grafts from the leg, or nerve transfers are performed. This surgery takes about four to six hours.
Severe injuries require a complete exposure of the brachial plexus. Although muscle and bone are preserved, the incision can be long, passing from the neck and over the shoulder. The nerves are examined and reconstructed with multiple nerve grafts and transfers. This surgery can take up to 8-12 hours.
When nerves are found detached from the spinal cord on preoperative imaging, then select nerve transfers away from the site of injury may be recommended. The incisions for these transfers are often placed above the clavicle, behind the shoulder, under the arm, or near the wrist. Your average nerve transfer takes about 90 minutes per nerve transferred. Although certain brachial plexus techniques are associated with postoperative pain (e.g., intercostals nerve transfers), in the majority of patients incisional pain is minimal. Nerve pain before surgery may or may not improve immediately after surgery. More commonly, nerve pain slowly improves as the nerves regenerate.