Cervical Microdiscectomy

Overview

Cervical microdiscectomy is a surgical procedure used to decompress the spinal nerve roots in the neck. Cervical radiculopathy is a condition caused by compression of the cervical nerve roots by herniation of the intervertebral disc in the neck.

Cervical microdiscectomy may be performed from the back, known as posterior cervical discectomy, or from the front, known as an anterior cervical discectomy. Anterior cervical discectomy may be performed with the help of an endoscope or using the traditional approach.

MRI image in the sagittal section showing herniated cervical disc.

The cervical vertebral column connects the skull to the thoracic spine. The cervical vertebrae are stacked upon each other with intervening intervertebral discs. The central canal hosts the spinal cord covered by dural sheath and nerve roots exit at each level through the neural foramen. The nerve roots exiting the neck region supply mainly the upper extremities. The cervical nerves are responsible for the sensation and movement of the shoulders, arms, forearm, and hands.

Cervical degenerative disc disease occurs due to the wear and tear of the intervertebral discs in the cervical spine. The degeneration may lead to prolapse of the inner nucleus pulposus through the outer annulus ring. The intervertebral disc may also prolapse/herniate as a result of traumatic injury.

The compression of nerve roots may lead to inflammation and irritation at the involved segment. Patients with cervical radiculopathy frequently complain of neck pain that radiates down the shoulder into the arm and hand. There may be weakness or clumsiness of the hands and patients may report dropping objects or not being able to make a firm grip. Patients may also complain of numbness and tingling sensation in parts of the upper extremities.

The diagnosis of cervical radiculopathy is established by a detailed physical examination by a spine surgeon and followed by imaging studies. Imaging or radiological studies may be done in the form of x-rays, CT scans, and MRIs. Electromyography and nerve conduction tests may sometimes be done to differentiate cervical radiculopathy from peripheral neuropathy.

Non-surgical treatments

The conservative or non-surgical treatments consist of activity modification, pain medications, physical therapy, or heat/cold therapy. Patients may also benefit from epidural injections or nerve root block injections. Surgical management is indicated only in patients who have failed to benefit from conservative treatment.

Surgical management

The most commonly performed surgical management for cervical radiculopathy is anterior cervical discectomy and fusion (ACDF). ACDF involves the removal of the entire disc along with the fusion of the adjoining vertebrae. The fusion ensures the stability of the spine segment and increases the neural foramen diameter due to distraction. The ACDF surgery however leads to a decrease in neck motion. The surgery also requires the placement of metallic hardware in the cervical spine.

The anterior cervical discectomy without fusion involves the removal of the herniated part of the intervertebral disc along with the bone spurs. The surgery is performed with the patient under general anesthesia. The surgeon gives an incision on either side of the neck depending upon the side of herniation. The surgeon carefully retracts the muscles, food pipe, air pipe, and the various major blood vessels and nerves to reach the involved level.

On reaching the front of the cervical spine, the surgeon confirms the level with the help of an image intensifier. The surgeon then proceeds to remove the herniated part of the disc along with any bone spurs. The surgeon then closes the incision back in layers and a bandage is applied at the incision site.

Similarly, the surgery may be performed with a minimally invasive technique using an endoscope. The surgeon gives a smaller incision in front of the neck on either side of the midline. The surgeon then used tubular dilators to serially separate the tissues and reach the involved spine segment.

The surgeon then introduces an endoscope which has a small camera attached at its end. The endoscope projects the camera image on a screen the surgeon uses to guide the instruments. The surgeon then uses instruments to remove the herniated intervertebral disc.

The posterior cervical microdiscectomy is performed using an incision from the back of the neck. The surgeon gives a midline incision over the involved segment of the spine. The surgeon then uses an operating microscope to magnify and separate the muscles and tissues through the small incision.

The surgeon removes a small portion of the lamina and the facet joint to see the intervertebral disc. The herniated portion of the disc is removed and the incision is closed in layers.

As compared to the anterior approach, in the posterior approach the surgeon has less visibility of the intervertebral disc as compared to the anterior approach. In the posterior approach, the surgeon is mainly able to access the herniation to the side of the spinal cord.

While cervical microdiscectomy is a highly successful surgical procedure, there may be potential complications. Intraoperative complications may occur in the form of inadequate removal of herniation, excessive bleeding, damage to the nerve roots, tear of the dural sheath, and leakage of the CSF. In the anterior approach, there may be additional complications in the form of inadvertent injury to the food pipe, air pipe, major blood vessels, or the nerves supplying the voice box.

Microdiscectomy of the cervical spine is a highly successful surgery that helps to relieve symptoms of cervical radiculopathy. The type and approach of cervical microdiscectomy should be discussed with the spine surgeon.

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