Posterior Cervical Laminectomy and Fusion
Sheeraz A. Qureshi, MD
Andrew C. Hecht, MD
Dr. Qureshi or an immediate family member has received royalties from Zimmer; is a member of a speakers’ bureau or has made paid presentations on behalf of Medtronic, Stryker, and Zimmer; serves as a paid consultant to or is an employee of Stryker, Zimmer, and Medtronic; and serves as a board member, owner, officer, or committee member of the American Academy of Orthopaedic Surgeons, the Cervical Spine Research Society, the Musculoskeletal Transplant Foundation, and the North American Spine Society. Dr. Hecht or an immediate family member has received royalties from Zimmer; is a member of a speakers’ bureau or has made paid presentations on behalf of Stryker and DePuy; serves as a paid consultant to or is an employee of Stryker, Zimmer, and Medtronic Sofamor Danek; has stock or stock options held in Johnson & Johnson; and serves as a board member, owner, officer, or committee member of the American Academy of Orthopaedic Surgeons and the Musculoskeletal Transplant Foundation.
PATIENT SELECTION
Cervical degenerative disease is the most common form of acquired disability in patients older than 50 years.1 The most common clinical manifestations of degenerative changes in the cervical spine are neck pain, radiculopathy, and myelopathy. A combination of symptoms is not unusual. Patients who continue to be symptomatic despite an appropriate trial of nonsurgical management are indicated for surgical intervention.
Once the decision has been made to proceed with surgical management, a number of variables are taken into consideration to determine the optimal surgical approach. These variables include alignment of the cervical spine, number of levels involved, nature of the pathologic process, and surgeon preference.
In general, posterior approaches to decompress the cervical spine are chosen in patients with neutral to lordotic cervical alignment and more than two levels of compressive pathology. Certain pathologic processes, such as ossification of the posterior longitudinal ligament and intradural tumors, are preferentially treated through a posterior approach. In the presence of cervical kyphosis or if there is significant ventral compression of the spinal cord, anterior procedures should be considered before posterior decompressive procedures.
Options for central and foraminal decompression of the cervical spinal cord and nerves from a posterior approach include laminoplasty and laminectomy/fusion. Either procedure can be combined with foraminotomies to directly decompress the cervical nerve roots from a posterior approach. When cervical laminectomy is decided upon as the treatment of choice, we strongly recommend concomitant posterior cervical fusion to prevent the extremely complicated and disabling complication of postlaminectomy kyphosis.2
PREOPERATIVE IMAGING
We strongly recommend that all patients have weight-bearing AP, lateral, flexion, and extension radiographs prior to surgery. Plain radiographs can provide valuable information with regard to spinal alignment and the fixed or flexible nature of any preexisting spinal deformity. All patients should also have an MRI and CT scan or CT myelogram before surgery (Figure 1). CT scans are very helpful for surgical planning for the sizes of lateral mass screws and upper thoracic pedicle screws and for identifying any variations of the vertebral anatomy that may complicate placement of hardware. The surgeon should always take note of aberrant vertebral artery anatomy even though vertebral artery injury from posterior cervical subaxial instrumentation is extremely rare.
VIDEO 101.1 Posterior Cervical Laminectomy and Fusion. Sheeraz A. Qureshi, MD, MBA; Andrew C. Hecht, MD (19 min)Video 101.1
PROCEDURE
Room Setup/Patient Positioning
Posterior cervical laminectomy and fusion is performed with the patient under general endotracheal anesthesia. Although most patients tolerate standard intubation techniques, if an exacerbation of symptoms occurs with flexion or extension of the neck, or if there is severe spinal cord compression, the surgical team should strongly consider an awake fiberoptic intubation. The patient’s symptoms should be discussed with the anesthesiologist so that a mutual decision can be made as to the best method of intubation. It is our practice to obtain spinal cord monitoring baselines—SSEP (somatosensory-evoked potentials)
and MEP (motor-evoked potentials)—before placing the patient in the prone position. General endotracheal anesthesia is induced with the patient on a Jackson table with flat board. It is important to remind the anesthesiologist that the tube cannot be secured with a tie around the head, as this would be in the surgical field. The tube should be heavily taped in position, as any prepositioning ties will need to be removed once the patient is prone.
and MEP (motor-evoked potentials)—before placing the patient in the prone position. General endotracheal anesthesia is induced with the patient on a Jackson table with flat board. It is important to remind the anesthesiologist that the tube cannot be secured with a tie around the head, as this would be in the surgical field. The tube should be heavily taped in position, as any prepositioning ties will need to be removed once the patient is prone.
 FIGURE 1 A, Axial T2-weighted MRI shows cervical spinal cord compression. B, Sagittal T2-weighted MRI shows multilevel cervical spinal cord compression. |
We use SSEP and MEP monitoring as well as intraoperative electromyography in all patients undergoing posterior cervical laminectomy and fusion. Although evidence is lacking that such monitoring improves outcomes, we believe that changes in motor or sensory potentials can be predictive of neurologic dysfunction. Malpositioned instrumentation can result in abnormal electromyographic activity if there is resultant nerve root irritation. In addition, most monitoring changes are due to blood pressure changes, and this monitoring can ensure that the appropriate mean arterial pressure is maintained during surgery. A bite block should be placed by the anesthesiologist when evoked potential monitoring is being used.
After general endotracheal anesthesia is induced and with the patient in the supine position, a Foley catheter is placed using standard sterile technique. Sequential compression devices are applied for prophylaxis against deep vein thrombosis, and evoked potential monitoring leads are placed. We obtain baseline potentials at this point.
After baseline potentials are obtained, Gardner-Wells tongs are applied in standard fashion below the equator of the skull and immediately above and just anterior to the pinnae. We prefer to use Gardner-Wells tongs because of their simplicity and ability to be applied by a single operator. The pins of the Gardner-Wells tongs are tightened simultaneously until the indicator pin protrudes 1 mm. At this point, a pressure of 6 to 8 in-lb (13.6 kg) is achieved, which correlates with a pull-out strength of 60 to 120 lb. For continuous in-line skull traction and maintenance of head position throughout the procedure, 20 pounds of weight are then hung from the Gardner-Wells tongs. Bivector traction is occasionally used to place a slight extension moment on the skull after decompression.
Preparations are then made to perform a rotisserie turn using the Jackson table so that the patient can be positioned prone. A soft facial pillow is placed on the patient, and pillows are positioned along the patient’s lower extremities. The Jackson table with four posts (hip and thigh pads) and a chest board is then placed on top of the patient and locked into position with care taken to provide as much compression on the patient as possible so that the patient is firmly held between the two frames (Figure 2, A). We then use four belts that are tightened around the two frames for additional support.
At this point, the entire team is positioned around the patient and the endotracheal tube is disconnected from the circuit. The rotational control on the Jackson table is released, and the rotisserie turn is performed quickly with the surgeon at the head of the table (Figure 2, B). This is demonstrated in the video supplement. The rotational lock is once again applied, and the endotracheal tube is reconnected. The belts are then removed, and the flat board is disconnected from the frame of the Jackson table, leaving the patient in a prone position on the four-post frame with chest board and face pillow and the head in traction provided by 20 lb of weight on the Gardner-Wells tongs. Evoked potentials are again checked to make
sure that there has been no change during positioning. One member of the team should be assigned to hold each arm once the patient is prone and before the straps are released to make sure the arms do not fall before the arm boards are reattached to the table.
sure that there has been no change during positioning. One member of the team should be assigned to hold each arm once the patient is prone and before the straps are released to make sure the arms do not fall before the arm boards are reattached to the table.
 FIGURE 2 Photographs show patient positioning for posterior cervical laminectomy and fusion. A, The patient is placed supine on a Jackson table with a flat board. A four-post frame with chest board is placed over the patient, and all pads and pillows are positioned appropriately in preparation for the rotisserie turn. B, After the rotisserie turn is completed, the flat board is removed and the patient is now in the prone position on the four-post frame.
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