Injury to the spinal cord, facet joint, dura, or nerve root can complicate posterior cervical spine surgery resulting in pain or deficit for the patient and occasionally requiring re-operation. Cerebrospinal fluid leaks due to dural tears during cervical laminectomy can be difficult to manage and occasionally require re-operation as well.
Many of the complications of cervical laminectomy are common to all posterior spinal procedures:
Table: Neurosurgical Risks & Complications
Complications particular to cervical laminectomy include:
Cervical skeleton posterior oblique (at an angle) view
The spinal cord can be injured during cervical laminectomy by a number of mechanisms. Usually an instrument has directly impacted against the substance of the cord. The severity of the spinal cord injury does not necessarily correlate to the degree of dural damage in cases where forces are applied to the spinal cord with this membrane intact.
Intraoperative:
Posterior cervical fusion injury to the spinal cord can occur during cervical laminectomy most frequently during the process of removing the lamina. Sometimes the surgeon is aware of having pushed an instrument farther than intended or having slipped with movement of the instrument into the spinal cord. The spinal cord is so soft that the surgeon can ram an heavy metal instrument into its substance without the tactile feedback to alert him to having done so.
Immediate post operative:
Unless the surgeon or assistant saw the injury occur, an injury to spinal cord during cervical laminectomy may be apparent only as a neurologic deficit discovered typically when the patient is asked to move arms and legs as he or she emerges from general anesthesia. A neurologic deficit resulting from injury to spinal cord during cervical laminectomy should be apparent to the surgical team, at the latest, shortly after arrival in Recovery.
Surgeon -- judgment:
posterior cervical fusion contributing to injury to the spinal cord during cervical laminectomy is sometimes an error in the surgeon's judgment about the severity of the spinal cord compression when selecting his laminectomy instruments and techniques. For severe stenosis with very little room around the cord, drills that remove bone from above (as opposed to ronguers whose foot plates must be placed into the spinal canal) are preferred.
Surgeon -- technique:
posterior cervical fusion injury to spinal cord during cervical laminectomy may, with even the most careful technique, in the most severe cases be almost inevitable, but unless something that shouldn't be is pushed on only a small number of patients are neurologically worse after than before cervical laminectomy.
Patient -- anatomy:
although patients with short necks and arthritis are difficult to position -- sometimes despite maximal forward flexion of the neck the surgeon's access to the cervical lamina remains poor. This can make visualization and manipulation of instruments more difficult which is of course the major cause of errors in judgment and technique leading to injury to spinal cord during cervical laminectomy.
Patient -- disease:
severe spinal stenosis can contribute to injury to spinal cord during cervical laminectomy -- it gives him or her less instrumentation movement lee-way when the ligamentum flavum directly pushes against the dura. Signal changes see on pre-operative MR scans indicate a situation where there is already pressure sufficient to cause ishemia, infarction, and scar formation. The slightest disruption during removal of lamina and ligamentum flavum during decompression (as by placing the footplate of a ronguer) can precipitate more ischemia, infarction, and neural tissue injury.
Neurologic deficit:
injury to spinal cord during cervical laminectomy is usually either clinical silent (no signs or symptoms) or presents with a neurologic deficit. Cervical spinal cord deficits depend on the level where the injury occurred.
Irreversible:
Spinal cord injury is frequently irreversible. The extent of recovery may be improved by the administration as early as possible, of high dose steroids.
Intraoperative: Whatever is being done that is possibly applying any force to the spinal cord must be stopped and the instruments applying that force removed from the surgical field.
Acute post operative: Steroids at high doses should be continued for up to 48 hours after an iatrogenic (caused by the procedure; as opposed to pathogenic -- caused by disease) spinal cord injury.
Long term: Like spinal cord injuries caused by disease iatrogenic injuries
The frequency of spinal cord injury during cervical laminectomy is very low.
The facet joint is the point of contact between the vertebral body above with the one below it .
Facet joint injury can usually be recognized intraoperatively because these injuries occur when the facets are exposed for manipulations on and around them and thus in full view of the surgeons.
Surgeon -- judgment:
The cervical lamina ends at the facet joint. The facet joint is frequently involved with arthritis which has caused overgrowth of the bone and contributes to the narrowing of the spinal canal (stenosis).
injury to facet joint during cervical laminectomy
Surgeon -- technique:
injury to facet joint during cervical laminectomy
Facet injuries are iatrogenic. The facet must
Physiologic compromise: may lead to development of arthritis at joints that become hypermobile due to excessive removal of facet joint.
Prolongation of surgery: severe compromise of a facet joint might prompt a neurosurgeon to consider adding fusion across the hypermobile segment to the laminectomy procedure . This would prolong the operation for several hours.
Reoperation: Hypermobility at the facet joint is also associated with the development of a cervical spinal deformity. Cosmetic and pain considerations frequently lead to reoperation for patients who develop an abnormality of the alignment of their cervical spines.
No consequence:
Pain:
Irreversible: facet joint injury is not reversible but the delayed consequences of spinal instability and deformity can often be anticipated and prevented by timely intraoperative, acute post operative, and long term management.
Intraoperative
Acute post operative
Long term
The frequency of facet injury during cervical laminectomy is low
Facet injury is avoided or minimized by
The dura can be torn during cervical laminectomy by the drill or other instruments used in the surgical exposure.
Intraoperatively the tear may be recognized as a sudden welling up in the wound of clear cerebrospinal fluid (CSF).
The cause of a dural tear during cervical laminectomy is
Neurologic deficit:
Neurophysiologic compromise
Prolongation of surgery:
Repair of a dural tear during cervical laminectomy may prolong surgery.
Reoperation:
Reoperation may be required to repair a CSF leak
No consequence:
Dural tears are managed intraoperatively by an attempt to re-approximate and secure the dural edges tightly approximated.
The frequency of dural tears during posterior cervical spinal surgery is lower than that for surgery of the posterior lumbar spine.
Technique: Dural tears can be avoided by placing a cottonoid over the dura whenever possible when doing manipulations over the dura.
The dura can be torn during cervical laminectomy by the drill or other instruments used in the surgical exposure.
Intraoperative:
manipulations of the drill bit or other dissecting instrument in the vicinity of a neural foramen can result in injury to a cervical root recognized immediately intraoperatively at the time of injury. Intraoperatively nerve root injury should be suspected whenever an instrument has been applied too forcefully to an exposed (or covered only by dura) nerve root.
Acute post operative:
Patients immediately after surgery with a focal weakness in an upper extremity consistent with the site of surgical manipulation should be assumed to have an iatrogenic (resulting from the surgical procedure) nerve root injury.
The cause of nerve root injury during posterior cervical spinal procedures is usually too aggressive and forceful application of instruments in proximity to nerve roots. Stretching or pressing can cause deficits that may be transient but are sometimes permanent.
Neurologic deficit, pain:
If an injury to a nerve root results in a neurologic deficit it is limited to sensory loss and/or pain in the dermatomal distribution of the nerve root , motor weakness in the muscles supplied by the nerve root.
Prolongation of surgery: Nerve root injury laminectomy may prolong surgery.
Reoperation:
No consequence:
Overlap in the sensory distribution of nerve roots may
The management of a nerve root injury during posterior cervical spinal surgery
The frequency of nerve root injury during posterior cervical spinal surgery is low and related to the severity of cervical pathology (usually ligamentous and facet hypertrophy). Worse pathology is associated with a higher risk of nerve root injury at the time of laminectomy for either decompression or as part of posterior cervical fusion.
The risk of nerve root injury during cervical laminectomy is lessened by
A collection of blood in the epidural space can become large enough to press against and distort the spinal cord to the extent that dysfunction with neurologic deficit results.
An epidural hematoma is usually discovered in the recovery room or within a few hours after arrival to the ICU or ward with the new onset of myelopathy (weakness of both lower extremities, numbness from the site of the epidural (neck, chest, lower back, ....) down.
Intraoperative:
Immediate post operative: A blood clot can form in the epidural space and compress the cervical spinal cord resulting in weakness of all four extremities (quadriparesis) or even complete paralysis (quadriplegia).
Delayed post operative:
Delayed:
Surgeon -- judgment:
before beginning to close epidural hematoma from cervical laminectomy
Surgeon -- technique:
failure to obtain good hemostasis may be technical.
Patient -- physiology:
patients with a coagulopathy (inclined to bleeding due to absence of factors and/or cells required for clotting) are more liable to develop epidural hematoma following cervical laminectomy with or without stabilization.
The consequence of epidural
Irreversible: epidural hematoma from cervical laminectomy
Intraoperative: epidural hematoma from cervical laminectomy
Acute post operative: A cervical epidural hematoma presents clinically as myelopathy in the acute post operative period.
Long term
The frequency of epidural hematoma following cervical laminectomy is low
The risk of epidural hematoma following cervical laminectomy is lowered by careful attention to hemostasis during the procedure.
Epidural abscess is an uncommon complication of a posterior cervical procedure below a cervical lamina.
The abscess can act as a mass compressing the spinal cord resulting in myelopathy .
Intraoperative:
Immediate post operative:
Delayed post operative:
Delayed:
Long term: A cervical epidural abscess is frequently clinical manifest only several days or even weeks after a cervical laminectomy.
Surgeon -- technique:
deficiencies in sterile operative technique may be the cause of the contamination that eventually blossoms into a full blown epidural abscess.
Patient -- physiology:
patients with immune deficiency and chronic debilitating disease are more vulnerable to infectious complications of any surgery, and to the formation of epidural abscess following posterior cervical surgery in particular.
Neurologic deficit:
Cervical epidural abscess from cervical decompressive laminectomy can cause myelopathy.
Neurophysiologic compromise:
Inflammation of the spinal cord adjacent to an epidural abscess can result in phlebitis and obstruction of arteries supplying the cord with ischemia, infarct, and irreversible neurologic deficit (stroke).
Reoperation:
A cervical epidural abscess threatens the spinal cord with compression and infarction -- surgical removal is usually indicated if the abscess is associated with neurologic symptoms.
No consequence:
Management of epidural hematoma complicating posterior cervical spine surgery must include elimination of the infection causing the abscess as well as removal of any clinically significant (causing weakness, numbness, ...) epidural mass lesion.
The frequency with which epidural abscess complicates posterior cervical spine surgery is
The risk of cervical epidural abscess complicating cervical laminectomy is reduced by strict sterile technique and administration of intravenous (IV) antibiotics perioperatively (just before, during, and after surgery).
The dura can be torn during cervical laminectomy by the drill or other instruments used in the surgical exposure.
Intraoperatively the tear may be recognized as a sudden welling up in the wound of clear cerebrospinal fluid (CSF).
Intraoperative:
Immediate post operative:
Delayed post operative:
Delayed:
Surgeon -- judgment:
cerebrospinal fluid leak from cervical decompressive laminectomy
Surgeon -- technique:
cerebrospinal fluid leak from cervical decompressive laminectomy
Patient -- disease:
cerebrospinal fluid leak from cervical decompressive laminectomy
Neurophysiologic compromise cerebrospinal fluid leak from cervical decompressive laminectomy
Prolongation of surgery: cerebrospinal fluid leak from cervical decompressive laminectomy
Reoperation: cerebrospinal fluid leak from cervical decompressive laminectomy
No consequence: cerebrospinal fluid leak from cervical decompressive laminectomy
Intraoperative:
cerebrospinal fluid leak from cervical decompressive laminectomy
Acute post operative:
cerebrospinal fluid leak from cervical decompressive laminectomy
Long term:
cerebrospinal fluid leak from cervical decompressive laminectomy
The frequency of cerebrospinal fluid leak (CSF) leak complicating cervical laminectomy is
Technique:
Instruments that are less likely to tear the dura should be used when doing cervical laminectomy
The direction of the curvature of the cervical spine is called lordosis.
Progressive kyphosis of the cervical spine usually takes years to develop following multiple level decompressive cervical laminectomy.
The usual cause of a progressive spinal deformity following decompressive cervical laminectomy
progressive spinal deformity following decompressive cervical laminectomy can cause pain and disability and may require surgical correction (usually with fusion with graft, plates, and screws.