Cervical myelopathy is caused by static components like stenosis, and probably worsened by movement. From this point of view, decompression with fusion will have better clinical results when compared to decompression solely. In literature,…
ID
Source
Brief title
Condition
- Spinal cord and nerve root disorders
- Therapeutic procedures and supportive care NEC
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Primary endpoints
Several score systems exist for grading the severity of cervical myelopathy.
The modified Japanese Orthopedic functional score (Appendix A) evaluates four
groups: the function of the arms, of the legs, the micturation, and the
sensibility. It has the major advantage that it assesses motor function of the
arms and of the legs separately, sensation, and evaluates urinary symptoms[6].
Although it has been established that outcome after decompressive surgery
reaches a plateau at six months postoperatively[7], the primary endpoint will
be evaluated at one year postoperatively just to be sure.
Secondary outcome
Secondary endpoints
Since instrumentation is added in the fusion group, the costs will be higher.
Otherwise it is assumed that a mean better recovery will take place in the
fusion group. Therefore, the additional costs (nursing costs, auxillary
supports, etc.) may be lower. A careful evaluation of the costs of the
treatment related to the outcome is performed. To obtain a reliable insight in
the costs the following will be noted in a kind of diary: hospitalisation, out
- patient contacts, additional medication, house keeping support, instruments
to support daily activities, e.g. walking, eating etcetera. Of each item the
sort and amount will be recorded.
Apart from the cost - effectiveness, the difference in the general quality of
life will be evaluated. It is assumed that the quality of life of a laminectomy
will improve after adding a fusion. This will be reflected in a difference of
the SF - 36 score (Appendix B). SF - 36 Health Status Questionnaire is a
widely-used generic health status. This instrument consists of eight subscales
and two summary scales. On each scale higher scores indicate better outcomes.
Scores can be compared with published age - and sex - matched general
population or disease-specific norms[8].
Complications are separately registered. Complications related to the cervical
myelopathy are postoperative hemorrhage, postoperative infection, temporary or
permanent impairment of neurologic function, and kyphotic deformation of the
cervical spine[4]. Complications related to adding lateral mass screws or/and
pedicle screws are vertebral artery injury and temporary or permanent nerve
root damage[4]. In order to prevent damage to the spinal cord , the
instrumentation should be completed before the laminectomy.
Background summary
Cervical spondylosis is a progressive degenerative disease of the spine. As
people grow older, the prevalence of cervical spondylosis increases. It is a
natural process of aging. Cervical spondylosis is seen in 10% of individuals in
the age of 25 years, whereas in 95% of the persons of 65 years[1].
Due to the degenerative process reduction of height of the intervertebral
discs, formation of spondylophytes and sometimes instability occurs. This may
lead to a stenosis of the cervical spinal canal. In most instances it will
remain asymptomatic. However, in some persons the stenosis of the spinal canal
leads to a compression of the spinal cord. It is important to realize that not
only static compression leads to neurological symptoms, but also dynamic
factors do. In a normal situation the spinal cord will move during flexion and
extension. Ventral osteophytes in the spinal canal prevent up - and downward
movement[1]. Furthermore, the spinal cord is more stretched over the anterior
bars increasing axial tension within the spinal cord. These forces are
multidirectional creating secondary shearing forces resulting in strech and
shear injury to myelin and neural elements[2-4].
Patients may present with a diversity of well known signs and symptoms with
variable intensities. Disturbance of the sensibility in the arms, clumsiness of
the hands and problems with micturation may occur. However, the hallmark
symptoms are gait abnormalities, weakness of the legs or stiffness of the
legs[1,5].
The natural course of the cervical myelopathy is variable. But patients
developing mild or moderate symptoms are less likely to improve spontaneously.
Non operative treatment will mainly affect neck pain or accompanying
radiculopathy. Improvement has been noted but is variable[6,7]. Patients with
myelopathic signs and symptoms will, however, likely benefit from
surgery[5,7,8].
Surgical approaches for cervical myelopathy due to cervical spondylosis can be
anterior, posterior or combined. The last option is reserved for deformity
correction. In most instances a lordotic or slight kyphotic cervical spine is
present. The choice for an anterior or posterior approach is dependent on the
main site of compression, the shape of the cervical sagittal curvature and to a
lesser account on the preference of the surgeon.
Dorsal approaches are laminectomy or laminoplasty. A difference in clinical
outcome has never been established. Prevention of post - laminectomy kyphosis
is a reason for laminoplasty. If an additional, instrumented dorsal fusion is
performed, the change of developing a post-surgical kyphosis is nearly zero[9].
It should be memorized that spondylotic processes also generate reduced motion
of the spinal segments, a natural course[1]. Frequently used dorsal fusion
techniques today use lateral mass screws and cervical pedicle screws. This is
relatively safe with a minimal persistent complication rate. Furthermore, in
experienced hands these techniques do not add substantial time to the duration
of the surgery [7,9].
Despite a long-lasting interest in the various techniques, the clinical
superiority of one method over the other has never been established. To our
knowledge, a randomized controlled trial comparing laminectomy with or without
fusion has never been performed.
References
1. Shedid D, Benzel EC: Cervical spondylosis anatomy: pathophysiology
and biomechanics. Neurosurgery 2007, 60 S: S1-7-S1-13.
2. Henderson FC, Geddes JF, Vacarro AR, Woodard E, Berry KJ: Stretch -
associated injury in cervical spondylotic myelopathy: new concept and review.
Neurosurgery 2005, 56: 1101-1113.
3. Fehlings MG, Skaf G: A review of the pathophysiology of cervical
spondylotic myelopathy with insights for potential novel mechanisms drawn from
traumatic spinal cord injury. Spine 1998, 23: 2730-2736.
4. Baptiste DC, Fehlings MG: Pathophysiology of cervical myelopathy.
Spine J 2006, 6: 190S-197S.
5. Baron EM, Young WF: Cervical spondylotic myelopathy: a brief review
of its pathophysiology, clinicical course, and diagnosis. Neurosurgery 2007,
60S: S35-S41.
6. Mazanec D, Reddy A: Medical management of cervical spondylosis.
Neurosurgery 2007, 60S: S43-S59.
7. Wiggins GC, Shaffrey CI: Dorsal surgery for myelopathy and
myeloradiculopathy. Neurosurgery 2007, 60S: S71-S81.
8. LaRocca H: Cervical spondylotic myelopathy: natural history. Spine
1988, 13: 854-855.
9. Houten JK, Cooper PR: Laminectomy and posterior cervical plating
for multilevel cervical spondylotic myelopathy and ossification of the
posterior longitudinal ligament: effects on cervical alignment, spinal cord
compression, and neurological outcome. Neurosurgery 2003, 52: 1081-1087.
10. Benzel EC, Lancon J, Kesterson L, Hadden T: Cervical laminectomy
and dentate ligament section for cervical spondylotic myelopathy. J Spinal
Disord 1991, 4: 286-295.
11. Cheung WY, Arvinte D, Wong YW, Luk KD, Cheung KM: Neurological
recovery after surgical decompression in patients with cervical spondylotic
myelopathy - a prospective study. Int Orthop 2007, Jan 19: epub.
12. Ware J, Sherbourne D: The MOS 36 - item short-form health survey.
Med Care 1992, 30: 473-483.
13. Jankowitz BT, Gerszten PC: Decompression for cervical myelopathy.
Spine J 2006, 6: 317S-322S.
Study objective
Cervical myelopathy is caused by static components like stenosis, and probably
worsened by movement. From this point of view, decompression with fusion will
have better clinical results when compared to decompression solely. In
literature, indications in this direction are found. This randomised controlled
trial has been developed to compare laminectomy without dorsal fusion versus
laminectomy with dorsal instrumented fusion.
Hypothesis
Patients that are surgically treated for signs and symptoms due to a stenosis
of the cervical spinal canal have a better clinical outcome when a dorsal
fusion is performed in addition to a laminectomy compared to those that have
solely a laminectomy.
At the end of the study, the quality of life, complications, and the costs will
be evaluated comparing these two treatment groups.
Study design
multi center, randomised controlled trial
Intervention
Surgical technique
Cervical laminectomy of the compressed levels is performed. Previous to the
laminectomy a dorsal fusion is done. Dorsal fusion includes lateral mass screws
from C2 to C6. In C2, C7 and the upper thoracic spine levels, pedicle screws
will be placed. The screws are connected by rods or plates. Transverse
connectors are used when indicated. In order to keep the posterior tension band
intact, the fusion will extend from one level above the planned most cranial
laminectomy level to at least one level below the most caudal planned
laminectomy site. If the lowest level of fusion would include C7 or lower
extension of the fusion to the upper thoracic spine (Th2 or Th3) is
recommended. This extension of the fusion is thought to prevent junction
disease at the cervicothoracic junction. For example, if the laminectomy
includes the levels C4 to C6, the fusion would be from C3 to C7. Because C7 is
the lowest fusion level , incorporation of Th1 is recommended.
Study burden and risks
We do not expect any extra burden or risks for the patient, since it are
standard procedures. An exception is filling in the SF 36 questionnaires.
R.Postlaan 4
6500 HB Nijmegen
NL
R.Postlaan 4
6500 HB Nijmegen
NL
Listed location countries
Age
Inclusion criteria
In - and exclusion criteria
Patients with a minimal age of 60 years are included (Table 1). At neurologic examination myelopathic changes must be apparent. At magnetic resonance imaging, concordant stenotic alterations at the cervical level(s) must be present. At the plain sitting lateral radiograph a lordotic spine must be shown. The shape of the cervical spine is lordotic when the vertebral bodies of C3 to C6 are in front of a line drawn from a point of the posterior inferior part of C2 to a point at the posterior superior part of C7 (Figure 1).
Only patients that sign the informed consent after some time of reflection (1 week) are included.
Exclusion criteria
Exclusion
Previous cervical surgery for myelopathic signs and symptoms
Solely radiculopathy, or most important complaint
Unable to undergo MRI
Life expectancy less than 1 year
Other diseases interfering with neurologic symptoms and signs, for example spinal cord glioma, thoracic herniated disc with spinal cord compression, multiple sclerosis etc.
Rheumatoid arthritis
Trauma to the neck in history
Diseases interfering with rehabilitation, for example severe cardiac congestive disease.
Participation in another study
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL16633.091.07 |