Treatment options and results in cervical myelopathy

Improvement of postural stability and gait velocity after cervical decompression surgery in patients with cervical spondylotic myelopathy

OBJECTIVE

Cervical spondylotic myelopathy (CSM) is a progressive degenerative condition that can lead to significant neurological deficits, including gait instability. Biomechanical alterations of gait and its various components are poorly understood. The goal of the current study was to determine how spatiotemporal gait parameters, as well as postural and dynamic stability, change after surgery in CSM patients.

METHODS

A total of 47 subjects were included, with 23 test subjects and 24 controls. Baseline measurements were made for both cohorts. In the CSM cohort, repeat measurements were made at 3 and 6 months postoperatively. To record spatiotemporal and dynamic stability parameters, subjects performed walking trials over force plates on a 15-m runway. To assess postural stability, standing balance trials were conducted on a floor-mounted force plate. Three-dimensional motion analysis cameras and gait modeling software were used to quantify and visually represent results. Statistical analysis was completed using repeated-measures ANOVA and paired t-tests. Significance was set at p < 0.05.

RESULTS

CSM patients had significantly increased gait velocity at the 6-month follow-up (mean 0.948 ± 0.248 m/sec/leg length) versus baseline (mean 0.852 ± 0.257 m/sec/leg length) (p = 0.039). The tilted ellipse area was significantly decreased at the 6-month follow-up compared with baseline (mean 979.8 ± 856.7 mm2 vs 598.0 ± 391.1 mm2, p = 0.018). Angular momentum excursion was not significantly different between baseline and the 3- and 6-month follow-ups.

CONCLUSIONS

CSM patients displayed significant improvement in gait velocity and postural stability parameters after decompressive surgery. Dynamic stability parameters did not change significantly during the study period.

A Comparison of Multilevel Anterior Cervical Discectomy and Corpectomy in Patients With 4-level Cervical Spondylotic Myelopathy: a Minimum 2-year Follow-up Study: Multilevel Anterior Cervical Discectomy

STUDY DESIGN

Retrospective clinical series.

OBJECTIVES

To compare perioperative parameters, clinical outcomes, radiographic parameters, and complication rates of segmental anterior cervical corpectomy and fusion (sACCF) plus preservation of middle vertebrae with those of multilevel anterior cervical discectomy and fusion (mACDF) in 70 patients with 4-level cervical spondylotic myelopathy (CSM).

METHODS

Between July 2006 and May 2011, 70 consecutive patients [49 males and 21 females; mean age 56.8 y (range, 38-72 years)] with 4-level CSM were enrolled in this study and divided into sACCF (n=39) group and mACDF (n=31) group. The study compared perioperative parameters, complication rates, clinical parameters, and radiologic parameters.

RESULTS

No significant differences between the groups were found in demographic, baseline disease characteristics, operation time, hospital stay, and follow-up time. Significant improvements of clinical outcome were seen from preoperative to postoperative in both groups. Satisfaction was rated as excellent or good by 79.5% of the sACCF group and 80.6% of the mACDF group, which was not a significant difference. Mean postoperative cervical lordosis was significantly greater in the mACDF group than in the sACCF group. Blood loss was significantly greater in the sACCF group than in the mACDF group and instrumentation-related and/or graft-related complication rate significantly lower for the mACDF group. Both sACCF and mACDF groups achieved solid fusion rates (87.1% and 90.3%, respectively).

CONCLUSIONS

Both mACDF and sACCF provide satisfactory clinical outcomes and fusion rates for 4-level CSM. However, mACDF is associated with better radiologic parameter, less blood loss, and lower instrumentation-related and/or graft-related complication rate.

Surgical technique: Hemilaminectomy and unilateral lateral mass fixation for cervical ossification of the posterior longitudinal ligament

BACKGROUND

Surgical approaches for cervical ossification of the posterior longitudinal ligament (OPLL) include anterior, posterior, or combined decompression with or without fusion. The goal of surgery is to decompress the spinal cord while maintaining the stability and sagittal alignment of the cervical spine. C5 palsy has been reported as a postoperative complication of cervical laminectomy or laminoplasty characterized as motor weakness of the muscles supplied with C5 nerve roots. Several studies have shown this phenomenon was partially attributable to posterior shift of spinal cord.

DESCRIPTION OF TECHNIQUE

The rationale for choosing hemilaminectomy is to control postoperative posterior shift of the spinal cord and afford more stability by preserving ligamentous attachments and posterior bony elements as much as possible. After a fixation system of lateral mass screws and rods is installed unilaterally, laminae are removed from the underlying dura using a high-speed burr and Kerrison laminectomy rongeur on the other side. The spinous processes are preserved.

PATIENTS AND METHODS

Patients with multilevel continuous/mixed cervical OPLL are good candidates for this technique. We retrospectively reviewed 146 patients who had multilevel continuous/mixed cervical OPLL and underwent surgery from January 2006 to January 2010. Neurologic condition was evaluated using the improvement ratio (IR) of the Japanese Orthopaedic Association (JOA) score for cervical myelopathy.

RESULTS

The mean JOA score increased from 10 points before surgery to 14 points at last followup. The mean IR of neurologic function (JOA score) was 59%. C5 palsy was not observed in any patient after decompression, and cervical lordosis changed from 8.7° preoperatively to 9.1° at last followup.

CONCLUSIONS

For patients with multilevel continuous/mixed cervical OPLL without fixed kyphosis, multilevel hemilaminectomy with unilateral lateral mass fixation is an effective alternative technique.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Evaluation of the rate of decompression in anterior cervical corpectomy using an intra-operative computerized tomography scan (O-Arm system)

OBJECT

The purpose of this study was to evaluate the efficacy of intra-operative computerized tomography (CT) scanning in the analysis of bone removal accuracy during anterior cervical corpectomy, in order to allow any necessary immediate correction in the event of inadequate bone removal.

METHODS

From September 2009 to December 2010 we performed an intra-operative (CT) scan using the O-Arm(™) Image system to assess the rate of central and lateral decompression in all patients treated for cervical spondylotic myelopathy by anterior cervical corpectomy and fusion.

RESULTS

Out of a population of 187 patients admitted to our department, with a diagnosis of myelopathy due to spondylotic degenerative cervical stenosis, 15 patients underwent a surgical treatment with anterior cervical corpectomy and fusion. There were nine males (60%) and six females (40%); the mean age was 52.4 years, ranging from 41 to 57 years. The pre-operative radiologic investigations (MRI and CT scans) revealed in the nine patients (60%) the extent of the compression to one vertebral body (C4 one case, C5 four cases, C6 four cases), while in the six cases (40%) the compression regarded two vertebral body (C3 and C4 one case, C4 and C5 two cases, C5 and C6 three cases). During surgery, when the decompression was judged completely, a CT scan was performed: in 11 cases (73.3%) the decompression was considered adequate, while in four cases (26.7%) it was deemed insufficient and the surgical strategy was changed in order to optimize the bone removal. In these cases an additional scan was taken to prove the efficacy of decompression, achieved in all patients.

CONCLUSION

Intra-operative CT scan performed during cervical corpectomy is a really useful tool in helping to ensure complete bone removal and the adequacy of surgery. The O-arm(™) Image system grants optimal image quality, allowing correctly assessing the rate of decompression and, in any case of doubt, allows an intra-operative evaluation of the final correct positioning of the graft.

Cervical compression myelopathy: is fusion the main prognostic indicator?

Object

A variety of factors may affect the neurological improvement in patients with cervical compression myelopathy (CCM) after surgery. The aim of this study was to report and discuss the prognostic factors in a group of patients with insufficient decompression of the spinal canal.

Methods

A prospective follow up and analysis of 20 consecutive patients with CCM treated between 2000 and 2002 was performed. All patients were surgically treated via an anterior approach, either by anterior cervical discectomy and fusion with instrumentation or by cervical corpectomy and fusion with instrumentation. The surgical results were examined using the modified Japanese Orthopaedic Asssociation disability scale, with reference to the findings of magnetic resonance imaging, computed tomography, and radiography. Seventeen patients (85%) experienced a 50% or more recovery rate as calculated using the Hirabayashi formula during the follow-up period (mean 32.5 months), despite a persistently narrow spinal canal and permanent or increased intramedullary high-intensity signal after surgery.

Conclusions

Results of the study showed that patients with CCM benefited from anterior cervical discectomy and fusion with instrumentation or cervical corpectomy and fusion with instrumentation procedures despite insufficient decompression of the spinal canal. Fusion of the affected level(s) might be the reason for the acquired high recovery rates. The authors also conclude that the neurological improvement is not correlated with the reversal of or decrease in the intramedullary high-intensity signal change after surgery.

Surgical management of cervical myelopathy: indications and techniques for laminectomy and fusion

BACKGROUND

Cervical spondylotic myelopathy (CSM) is a commonly encountered surgical disease that may be approached through a variety of operative techniques. Operative goals in the treatment of CSM include effective neural element decompression and maintaining spinal stability to avoid delayed deformity progression and neurologic compromise. Determining the most appropriate operative approach requires careful consideration of the patient's clinical presentation and radiographic imaging.

PURPOSE

To review the indications and techniques for multilevel laminectomy and fusion in the treatment of CSM.

CONCLUSIONS

When indications permit, a multilevel laminectomy is an effective and safe method of neural element decompression. Recognizing the potential for spinal instability is essential to prevent neurologic compromise and intractable axial neck pain caused by deformity progression. A variety of techniques have been described to supplement the posterior tension band after laminectomy; however, lateral mass fixation has evolved into the preferred stabilization technique. Although clinical success is well documented, a successful outcome is dependent on a comprehensive, individualized evaluation of each patient presenting with CSM.