Anterior Cervical Spine Decompression and Stabilization

The surgical approach to the anterior cervical spine has not significantly changed for decades, but the various means of stabilization have changed dramatically. Typically, a transverse incision centered on the medial boarder of the sternocleidomastoid muscle, is made on the right side of the neck. Special precautions, however, may be necessary in a spinal cord injury (SCI) patient who has already required tracheostomy. The platysma is divided, and the sternocleidomastoid is sharply dissected from the medial strap musculature down to the prevertebral fascia, which is often swollen and filled with hematoma from the underlying injury. Retractors are used to protect the carotid artery laterally and the esophagus medially. The prevertebral fascia is bluntly dissected off the anterior longitudinal ligament, which may be disrupted from the injury. Even if the injury is obvious, a lateral plain radiograph (or fluoroscopy) is done to confirm the operative level.

If the primary injury is a traumatic herniated disk, the affected disk space is incised and the disk material and end plates of the vertebral bodies above and below are removed in piecemeal fashion using pituitary rongeurs and curettes. Most surgeons use an operating microscope to visualize the posterior aspect of the disk space. Once the disk is removed, the anterior longitudinal ligament—unless already breached by the injury—is removed and complete decompression of the dura is observed. The spine is then stabilized by using a propersized piece of allograft bone. A few surgeons still prefer autogenous bone, but for most patients, the discomfort from iliac crest bone harvesting (unless insensate from SCI) outweighs any advantages. The bone is securely wedged between the affected vertebral bodies.

Although stable fusion rates are high with this approach, supplementation with an anterior cervical titanium plate, secured by screws into the affected vertebral bodies, has become popular in recent years. This follows the general biologic principle of bone healing: the two elements of most importance in achieving a bony fusion are compression and immobilization. A wide variety of plates are available; all provide for immediate compression and immobilization, with subsequent high fusion rates.

For burst fractures at single or multiple levels, an anterior approach is required to adequately decompress the spinal canal. The approach is the same as for a diskectomy, but all portions of the affected bone are removed. Before the late 1990s, the most common form of reconstruction of the spine after corpectomy was with an iliac strut or fibular graft with or without supplementation by an anterior plate. More recently, there has been increasing use of interbody cages, which are intended to provide immediate structural stability. The cage is generally packed with osteoinductive or osteoconductive materials to facilitate fusion.

Tear drop fractures are unstable anteriorly and posteriorly due to disk and ligamentous injury. Thus both an anterior stabilization—cervical diskectomy and fusion with plate—and posterior stabilization are required.

For unstable odontoid fractures, anterior screw fixation may be quite appropriate. As opposed to posterior fixation, this preserves C1-2 mobility and may be better tolerated. A small incision is made near the C5-6 level and, under biplanar fluoroscopy, a guide is passed up to the C2-3 level. Through the guide, a small pilot hole is drilled into the base of C2. An appropriate-length screw is then passed to the tip of C2. If reduction of the fracture is desired, a lag screw will pull the fracture fragments together. Success of fusion exceeds 90%.

Complications from anterior decompression and stabilization are generally acceptable. Development of new neurologic dysfunction occurs generally in less than 2% of cases. Issues related to carotid or esophageal injury are likewise small. The risk of a significant infection leading to diskitis or osteomyelitis is less than 1%. On rare occasions, there can be failure of the fusion/plate/cage construct, leading to injury to surrounding neck structures, instability, and the need for reoperation.

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