Total stabilization of the cervical spine in patients with cervical spondylotic myelopathy

Cervical spondylotic myelopathy: functional and radiographic long-term outcome after laminectomy and posterior fusion

OBJECTIVE

To evaluate the long-term efficacy of cervical laminectomy with posterior lateral mass fusion/fixation in the treatment of patients with cervical spondylotic myelopathy (CSM).

METHOD

Twenty-five patients treated for CSM by laminectomy and lateral mass fusion at the Division of Neurosurgery at The Ohio State University between 1989 and 1994 were studied retrospectively. Only patients with longer than 2-year postoperative follow-up durations were included. At follow-up examination, each patient completed an SF36 questionnaire, underwent a physical examination, underwent plain radiography showing the spinal curvature with plate and screw position, and underwent magnetic resonance imaging of the cervical spine, which evaluated dural sac decompression and spinal cord abnormalities. Patient-generated data were used for outcome measurements.

RESULTS

The mean follow-up duration was 47.5 months. Good outcome was defined by the presence of three criteria: ability to walk unassisted (Grade IIIA or better), ability to write unassisted, and ability to manage buttons and/or zippers unassisted. The inability to meet these criteria was defined as a poor outcome. Two patients (8%) experienced complications that resulted from the surgery. There was no instability or progression to significant kyphosis. Lesions that were hyperintense on magnetic resonance images did not correlate with outcome. Eighty percent of the patients achieved good outcomes, and 76% had improved myelopathy scores. None of the patients had late neurological deterioration. Patients with better neurological statuses at the time of surgery (Grade IIIA or better) were more likely to improve (P < 0.0001); the likelihood of a change in status for those starting with poorer grades (IIIB or worse) was not statistically significant (P < 0.08).

CONCLUSION

Cervical laminectomy with posterior fusion/fixation proved useful in the treatment of patients with CSM with straight or lordotic spines and multilevel compression. This therapy addresses the dynamic and compressive forces that are important in the pathogenesis of CSM, resulting in minimal complications and possible improvement in long-term outcomes.

Evaluation of prognostic factors following expansive laminoplasty for cervical spinal stenotic myelopathy

BACKGROUND

Expansive laminoplasty of several types has been proposed for patients with cervical multisegmental stenotic myelopathy to reduce postlaminectomy complications. Its effectiveness has not been fully explored by evaluating long-term results and magnetic resonance imaging (MRI) findings before and after surgery.

METHODS

We conducted a 5-year follow-up study of 22 patients with cervical spondylotic myelopathy and/or ossification of the posterior longitudinal ligament surgically treated with expansive laminoplasty. The operative results were examined using the Japanese Orthopedic Association (JOA) disability scale, with reference to the findings of MRI, computed tomography, and radiography.

RESULTS

Postoperative improvement was observed in 18 (81.8%) of the 22 patients. In 11 patients the percentage recovery of the JOA score was higher than 50% (average: 83.1%), while in the remaining 11 patients it was lower than 50% (average: 20.1%). Factors contributing to incomplete recovery appear to be related mainly to cord degeneration with atrophy (depicted as a T2-high intensity area) and to specific factors such as long symptom duration, age higher than 70 years, deterioration due to trauma, severe cord compression, radiculopathy, and kyphotic cervical curvature.

CONCLUSIONS

In cervical myelopathy, patients with multisegmental stenosis, expansive laminoplasty can be expected to provide a favorable outcome by providing sufficient cord decompression and stabilization of the cervical spine, when the stenotic cervical canal is enlarged to the normal range (over 12 mm residual anteroposterior diameter and 200 mm2 residual canal area). The efficacy can be restricted by various factors, especially irreparable cord degeneration.

Wire fixation techniques of the cervical facets

STUDY DESIGN

The changes in the biomechanical responses of the cervical spine altered by multilevel laminectomy to various facet wiring techniques were evaluated.

OBJECTIVE

To determine the effectiveness of various proposed techniques of cervical facet wiring used to offer rigid internal fixation after multilevel laminectomy.

METHODS

Eight human cadaveric spine segments from C2-11 underwent combined flexion-compression loading. After testing intact and three-level laminectomy (C4-C6) preparations, two techniques of facet wiring fixation were evaluated in an identical manner. Force, displacement, and kinematics data at every level of the column were obtained.

RESULTS

The mean stiffness of the intact column was significantly greater than the mean stiffness for laminectomized specimens. Individual facet wiring to the bone graft and through the spinous process below the laminectomy failed to restore stiffness to the laminectomized preparations, whereas the Luque rectangle method restored the stiffness to that found in the intact column. The increases in segmental and overall sagittal rotations resulting from multilevel laminectomy were not decreased significantly by the individual facet wiring technique, but the Luque rectangle technique demonstrated a reduction of sagittal rotations compared with laminectomy without fixation.

CONCLUSIONS

The significant increases in total column flexibility and segmental flexural rotations after multilevel laminectomy were not corrected by techniques that depend on individual facet wires secured to an overlying strut, including wiring to the inferior intact segment. Crosslinking of the facet wire fixation above and below the laminectomized segments, as exemplified by the Luque rectangle technique, restored column stiffness and reduced segmental sagittal rotations.

Transdural approach to the anterior spinal canal in patients with cervical spondylotic myelopathy and superimposed central soft disc herniation

We present seven patients with multilevel cervical spondylotic myelopathy and superimposed midline soft disc herniation who were treated by decompressive laminectomies of the spondylotic segments followed by transdural excision of the anteriorly located disc extrusion. There was no perioperative neurological morbidity or mortality associated with this operation, and no patients have developed postoperative kyphotic deformity with an average follow-up of 50.1 months (range, 24 to 87 mo). Two patients had full neurological recovery, whereas five patients had improvement in their preoperative neurological status. We conclude that a posterior transdural approach may offer an alternative surgical option for select patients with multilevel cervical spondylosis with superimposed midline soft disc herniation in whom multiple segment decompression plus access to the anterior spinal canal is necessary.

The treatment of spondylotic cervical myelopathy by ventral discectomy. Long term results on 121 patients

The pathophysiology of spondylotic cervical myelopathy is still a matter of discussion. This paper presents a series of 126 patients operated on using a ventral approach. In 47% of the patients only a spondylotic narrowing of the spinal canal was present and in 35% an additional disc herniation was found. In 13% of the cases however a soft disc without spondylotic spures was found and in 5% a dislocation of vertebral bodies. We found a marked male preponderance of 77%, mean age was 51.6 years, ranging from 25-50 years. Most patients were operated on at the levels of C4/5 and C5/6. Observation time covered a period of 3-10 years. The outcome was rated relatively to the preoperative degree of disablement using a questionnaire for the patients and their family doctors. We found a marked difference in the answers, especially in rating deterioration, which was stated by patients in 34%, by physicians only in 12%. Another finding was the time-related outcome. We found best results with 75% improvement and 5% deterioration between 3-6 months postoperatively, with increasing time the results decreased to 33% improvement, 33% identical statys and in 33% a deterioration related to the preoperative status must be noted.

Central corpectomy for cervical spondylotic myelopathy: a consecutive series with long-term follow-up evaluation

Since 1984, a consecutive series of patients with cervical spondylotic myelopathy has been treated by central corpectomy and strut grafting. This report focuses on 40 cases operated on between 1984 and 1987 and followed from 2 to 5 years. The perioperative complication rate was 47.5%, with a 7.5% incidence of persistent sequelae: severe C-5 radiculopathy in one patient, swallowing dysfunction in one, and hypoglossal nerve palsy in one. No single factor (age, duration of symptoms, or severity of myelopathy) was absolutely predictive of outcome; however, syndromes of short duration had the best likelihood of cure. Similar outcomes were associated, individually, with long duration of symptoms, age over 70 years, and severe myelopathy. After factoring a 5% regression of improvement, the long-term cure rate was 57.5% and the failure rate was 15%. Myelopathy worsening was not documented.

Surgical and conservative treatment of cervical spondylotic radiculopathy and myelopathy

One hundred and fourteen patients were admitted to our department for evaluation of their cervical spondylogenetic symptoms, including local cervical pain, radiculopathy and myelopathy. This retrospective study gives the results, expressed as improved, unchanged or worse, of anterior surgery, posterior surgery and conservative treatment. Local cervical pain improved in about half of the patients, without any difference between the groups. The effect of surgery on radiculopathy was superior to that of conservative treatment, 71 percent and 74 percent respectively, being improved after anterior and posterior surgery, compared to 19 percent in the conservatively treated group. The majority of patients with myelopathy were treated with posterior surgery and 69 percent had improved. The results were not influenced by the patients age or the duration of symptoms. It is argued that the positive effects of surgery on the radiculopathy are due to a segmental stabilisation rather then to decompression. The immediate post-operative improvement of the myelopathy is undoubtedly caused by the decompression while the long-termed improvement cannot with certainty be attributed to the operation.