Anterior cervical corpectomy for cervical spondylotic myelopathy

Comparative Effectiveness of Ventral vs Dorsal Surgery for Cervical Spondylotic Myelopathy

BACKGROUND:

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction.

OBJECTIVE:

To determine the feasibility of a randomized clinical trial comparing the clinical effectiveness and costs of ventral vs dorsal decompression with fusion surgery for treating CSM.

METHODS:

A nonrandomized, prospective, clinical pilot trial was conducted. Patients ages 40 to 85 years with degenerative CSM were enrolled at 7 sites over 2 years (2007–2009). Outcome assessments were obtained preoperatively and at 3 months, 6 months, and 1 year postoperatively. A hospital-based economic analysis used costs derived from hospital charges and Medicare cost-to-charge ratios.

RESULTS:

The pilot study enrolled 50 patients. Twenty-eight were treated with ventral fusion surgery and 22 with dorsal fusion surgery. The average age was 61.6 years. Baseline demographics and health-related quality of life (HR-QOL) scores were comparable between groups; however, dorsal surgery patients had significantly more severe myelopathy (P < .01). Comprehensive 1-year follow-up was obtained in 46 of 50 patients (92%). Greater HR-QOL improvement (Short-Form 36 Physical Component Summary) was observed after ventral surgery (P = .05). The complication rate (16.6% overall) was comparable between groups. Significant improvement in the modified Japanese Orthopedic Association scale score was observed in both groups (P < .01). Dorsal fusion surgery had significantly greater mean hospital costs ($29 465 vs $19 245; P < .01) and longer average length of hospital stay (4.0 vs 2.6 days; P < .01) compared with ventral fusion surgery.

CONCLUSION:

Surgery for treating CSM was followed by significant improvement in disease-specific symptoms and in HR-QOL. Greater improvement in HR-QOL was observed after ventral surgery. Dorsal fusion surgery was associated with longer length of hospital stay and higher hospital costs. The pilot study demonstrated feasibility for a larger randomized clinical trial.

Intramedullary high signal intensity and neurological status as prognostic factors in cervical spondylotic myelopathy

PURPOSE

The neurological outcome of cervical spondylotic myelopathy (CSM) may depend on multiple factors, including age, symptom duration, cord compression ratio, cervical curvature, canal stenosis, and factors related to magnetic resonance (MR) signal intensity (SI). Each factor may act independently or interactively with others. To clarify the factors in prognosis, we prospectively analyzed the outcomes of patients with myelopathy caused by soft disc herniation in correlation with magnetic resonance imaging (MRI) findings and other clinical parameters.

MATERIALS AND METHODS

From June 2006 to July 2009, we performed surgical operations in 137 patients with CSM. Of these patients, 70 (51.1%), including 45 men and 25 women with ventral cord compression at one or two levels, underwent anterior cervical discectomy and fusion. The mean duration of follow-up was 32.7 months. We surveyed the cervical curvature index (CCI), canal stenosis (Torg-Pavlov ratio), cord compression ratio, the length of SI change on T2WI, and clinical outcome using the Japanese Orthopedic Association (JOA) score for cervical myelopathy. The MRI SI was evaluated by grade: grade 0, no change in signal intensity; grade 1, light signal change; and grade 2, bright signal change on the T2WI. Multifactorial effects were identified by regression analysis.

RESULTS

The mean preoperative and postoperative JOA scores were 10.5 ± 2.9 and 14.9 ± 2.1, respectively (p < 0.05). The mean recovery rate based on the JOA score was 70.0 ± 20.1%. The respective preoperative JOA scores and recovery ratios(%) were 11.6 ± 2.3 and 81.5 ± 17.0% in 20 patients with SI grade 0; 10.8 ± 2.3 and 70.1 ± 17.3% in 25 patients with grade 1; and 9.2 ± 3.6 and 60.7 ± 20.9% in 25 patients with grade 2, respectively. Post-surgical neurological outcome showed no significant relationship to age, symptom duration, cervical alignment, stenosis, or cord compression.

CONCLUSIONS

Among the variables tested, preoperative neurological status and intramedullary signal intensity were significantly related to neurological outcome. The better the preoperative neurological status was, the better the post-operative neurological outcome. The SI grade on the preoperative T2WI was negatively related to neurological outcome. Hence, the severity of SI change and preoperative neurological status emerged as significant prognostic factors in post-operative CSM.

Cervical Laminoplasty as a Management Option for Patients With Cervical Spondylotic Myelopathy

BACKGROUND

Cervical spondylotic myelopathy (CSM) is one of the leading causes of spinal cord dysfunction in the adult population. Laminoplasty is an effective decompressive procedure for the treatment of CSM.

OBJECTIVE

We present our experience with 40 patients who underwent cervical laminoplasty using titanium miniplates for CSM.

METHODS

We performed a retrospective review of the medical records of a consecutive series of patients with CSM treated with laminoplasty at the University of Rochester Medical Center or Rochester General Hospital. We documented patient demographic data, presenting symptoms, and postoperative outcome. Data are also presented regarding the general cost of constructs for a hypothetical 3-level fusion.

RESULTS

Forty patients underwent cervical laminoplasty; all were available for follow-up. The mean number of levels was 4. All patients were myelopathic, and 17 (42.5%) had signs of radiculopathy preoperatively. Preoperatively, 62.5% of patients had a Nurick grade of 2 or worse. The average follow-up was 31.3 months. The median length of stay was 48 hours. On clinical evaluation, 36 of 40 patients demonstrated an improvement in their myelopathic symptoms; 4 were unchanged. Postoperative kyphosis did not develop in any patients.

CONCLUSION

The management of CSM for each of its etiologies remains controversial. As demonstrated in our series, laminoplasty is a cost-effective, decompressive procedure for the treatment of CSM, providing a less destabilizing alternative to laminectomy while preserving mobility. Cervical laminoplasty should be considered in the management of multilevel spondylosis because of its ease of exposure, ability to decompress, effective preservation of motion, maintenance of spinal stability, and overall cost.

Quality of life assessment after central corpectomy for cervical spondylotic myelopathy: comparative evaluation of the 36-Item Short Form Health Survey and the World Health Organization Quality of Life-Bref

OBJECT

In this study, the authors assessed the construct validity and the reliability of the World Health Organization Quality of Life-Bref (WHOQOL-Bref) questionnaire in patients with cervical spondylotic myelopathy (CSM) and compared the performance of the WHOQOL-Bref and the 36-Item Short Form Health Survey (SF-36) in assessing quality of life (QOL) in patients with CSM.

METHODS

In this prospective study, 70 patients with CSM were assessed preoperatively and again 1 year after central corpectomy using the Nurick scale, the SF-36, and the WHOQOL-Bref. Construct validity and reliability of the WHOQOL-Bref, its responsiveness compared with that of the SF-36, and the correlations between the 2 scales were studied.

RESULTS

The WHOQOL-Bref was found to be valid (p < 0.001, Cuzick test for trend between the physical domain of the WHOQOL-Bref and Nurick grade) and reliable (Cronbach alpha > 0.7). It had smaller floor and ceiling effects (ranges 1.4-7.1% and 0-7.1%, respectively) than the SF-36 (ranges 2.9-71.4% and 0-14.1%, respectively). There was significant postoperative improvement in patient scores on all the SF-36 scales (p < 0.001) and the physical, psychological, and environment domains of the WHOQOL-Bref (p < 0.001). The SF-36 scales were more responsive to change (relative efficiency range 0.24-1) than the WHOQOL-Bref domains (relative efficiency range 0.002-0.73). Among scales measuring similar concepts, only the physical functioning and bodily pain scales of the SF-36 had a moderate correlation (r = 0.57 and 0.53, respectively; p < 0.001) with the physical domain of WHOQOL-Bref. Many of the scales of these 2 QOL instruments unexpectedly had a fair correlation with one another (r range = 0.2-0.4).

CONCLUSIONS

The WHOQOL-Bref, like the SF-36, is valid and reliable in assessing outcome in patients with CSM. It measures impairment in CSM in a more uniform manner than the SF-36, but its domains are less responsive to postoperative changes. Because the WHOQOL-Bref measures different constructs and has additive value, it should be used along with the SF-36 for QOL assessment in patients with CSM.

Surgical Management of Cervical Spondylotic Myelopathy

Cervical spondylosis is a common degenerative condition that is a significant cause of morbidity. This review discusses the pathophysiology and natural history of cervical spondylotic myelopathy and focuses on the current literature evaluating the clinical management of these patients.

Prevention, identification, and treatment of perioperative spinal cord injury

OBJECT

In this report, the authors suggest evidence-based approaches to minimize the chance of perioperative spinal cord injury (POSCI) and optimize outcome in the event of a POSCI.

METHODS

A systematic review of the basic science and clinical literature is presented.

RESULTS

Authors of clinical studies have assessed intraoperative monitoring to minimize the chance of POSCI. Furthermore, preoperative factors and intraoperative issues that place patients at increased risk of POSCI have been identified, including developmental stenosis, ankylosing spondylitis, preexisting myelopathy, and severe deformity with spinal cord compromise. However, no studies have assessed methods to optimize outcomes specifically after POSCIs. There are a number of studies focussed on the pathophysiology of SCI and the minimization of secondary damage. These basic science and clinical studies are reviewed, and treatment options outlined in this article.

CONCLUSIONS

There are a number of treatment options, including maintenance of mean arterial blood pressure > 80 mm Hg, starting methylprednisolone treatment preoperatively, and multimodality monitoring to help prevent POSCI occurrence, minimize secondary damage, and potentially improve the clinical outcome of after a POSCI. Further prospective cohort studies are needed to delineate incidence rate, current practice patterns for preventing injury and minimizing the clinical consequences of POSCI, factors that may increase the risk of POSCI, and determinants of clinical outcome in the event of a POSCI.

Two-level anterior cervical discectomy versus one-level corpectomy in cervical spondylotic myelopathy

STUDY DESIGN

A retrospective investigation of clinical and radiologic outcomes after surgical treatment for 2-level cervical spondylotic myelopathy (CSM).

OBJECTIVE

The study was undertaken to compare the outcomes of 2 different anterior approach types for 2-level CSM. Specifically, 2-level anterior cervical discectomy and fusion (ACDF) was compared with 1-level anterior cervical corpectomy and fusion (ACCF).

SUMMARY OF BACKGROUND DATA

The optimal surgical approach for 2-level CSM has not been defined, and thus, the relative merits of 2-level ACDF and 1-level ACCF remain controversial. However, few comparative studies have been conducted on these 2 surgical approaches.

METHODS

The authors reviewed the case histories of 31 patients that underwent surgical treatment for 2-level CSM from 2002 to 2006. Cases of myelopathy because of cervical ossification of posterior longitudinal ligament were excluded. Thirty-one patients (16 men and 15 women) of mean age 54.45 +/- 11.6 years (28 approximately 77) were included. The average follow-up period was 26.23 +/- 15.0 months (12 approximately 63). The authors compared perioperative parameters (hospital stays, bleeding amounts, operation times, complications), clinical parameters (Japanese Orthopedic Association scores, Visual Analog Scale scores for neck and arm pain), and radiologic parameters (total cervical range of motion, segmental range of motion, segmental height, cervical lordosis, fusion rate).

RESULTS

Of these above parameters, operation time (P = 0.001) and bleeding amount (P = 0.001) were significantly greater in the ACCF group, whereas segmental height (P = 0.018) and postoperative cervical lordosis (P = 0.009) were significantly lower in the ACCF group. However, other parameters were not significantly different in the 2 groups.

CONCLUSION

Surgical managements of 2-level CSM using ACDF or ACCF were found to be similar in terms of clinical outcomes. However, 2-level ACDF was found to be superior to 1-level ACCF in terms of operation times, bleeding amounts, and radiologic results.

Outcomes for combined anterior and posterior surgical approaches for patients with multisegmental cervical spondylotic myelopathy

Corpectomy is widely used to treat cervical spondylotic myelopathy (CSM). However, when this technique alone is performed at 1 or 2 levels for a multisegmental involvement (3 or more vertebrae), the incidence of post-operative complications is high. The optimal treatment for multisegmental CSM is still debatable. The aim of this study was to assess clinical and radiological outcomes for patients with multisegmental CSM who underwent combined anterior and posterior (AP) surgical approaches. Forty adults (17 women and 23 men; age range, 41-76 y) treated at our center between 2004 and 2007 were reviewed retrospectively. Their neurological function was assessed at different times using the Nurick classification (Grades 0 [root symptoms only] to 5 [wheelchair- or bed-bound]). Patients' satisfaction with the surgery was evaluated using Odom's criteria (poor, fair, good, or excellent). Pre-operatively, 20% of patients were assessed as Nurick Grade 0, 60% as Grade 1, and 20% as Grade 2. At the 1-year follow-up, only 10% of patients were assessed as Grade 1. At 1 year after surgery, 85% of patients rated their satisfaction with the operation as "excellent" and 15% rated it as "good". These outcomes suggest that, when surgery is indicated and patients with multisegmental CSM are carefully selected, the combined AP approach yields symptom relief comparable to that of corpectomy alone and a lower incidence of post-operative complications.

Cervical Corpectomy: Complications and Outcomes

Objective:

Previously, information on cervical corpectomy complication rates has been obtained from retrospective analysis of single-institution data. The aim of this study was to report 30-day mortality and complication rates after cervical corpectomy using multicenter prospective data from the Veterans Affairs National Surgical Quality Improvement Program database.

Methods:

The National Surgical Quality Improvement Program database was used to identify 1560 patients who underwent cervical corpectomy in United States Veterans Affairs hospitals from 1997 to 2006. Multivariate analysis was performed to analyze the effects of patient and hospital characteristics on morbidity and mortality rates.

Results:

A total of 1560 patients underwent corpectomy, with an overall in-hospital mortality rate of 1.6%, a complication rate of 18.4%, and a mean length of stay of 6 days. Multivariate analysis identified age older than 80 years (odds ratio [OR], 21.24), history of Type 1 diabetes (OR, 2.36), American Society of Anesthesiologists class greater than 3 (OR, 6.93), and dependent functional status (OR, 3.17) as the most significant preoperative predictors of complications. Three or more corpectomy levels (OR, 2.46) and operative duration longer than 6 hours (OR, 3.45) were also found to be significant predictors of postoperative complications. Patients who underwent 3 or more levels of corpectomy had a return-to-operating room rate of 17.9% and a graft/instrumentation failure rate of 5.4% compared with those who underwent single-level corpectomy, who had rates of 6.2 and 1.87%, respectively. Patients who were returned to the operating room had significantly higher mortality rates (7.0 versus 1.2%) and accounted for 39.9% of the total number of complications. Multivariate analysis identified age, American Society of Anesthesiologists class, history of disseminated cancer, and diabetes as the most significant predictors of mortality. Patients with Type 1 diabetes had 4-fold higher mortality rates compared with patients with no history of diabetes or diet-controlled diabetes.

Conclusion:

We have analyzed the morbidity and mortality data on the largest series of corpectomy reported to date. We have demonstrated the impact of age, American Society of Anesthesiologists class, and number of operated levels on complication rates. Type 1 diabetes was established as a strong risk factor for 30-day mortality after cervical corpectomy.

[Evaluation of the clinical and radiological results of cervical longitudinal median somatotomy without graft]

OBJECTIVES

To evaluate the clinical and radiological results of cervical longitudinal median somatotomy without graft, used for the treatment of cervical myelopathy and radiculopathy, and compare it to techniques with graft and to laminectomies.

MATERIAL AND METHOD

Thirty-four patients (25 males and nine females), with a mean age over 60 years, were included in a study comparing pre- and postoperative clinical status on the Japanese Orthopaedic Association (JOA) functional scale and radiological status with evaluation of the cervical curve on plain films and dynamic tests in flexion and extension.

RESULTS

No significant difference was found with the clinical and anatomical results published in the literature concerning median somatotomies performed with graft and/or osteosynthesis and laminectomies and their variants.

CONCLUSIONS

The cervical longitudinal median somatotomy without graft is an easy and reliable technique that can be proposed as first-line treatment for cervical spondylotic myelopathy related to anterior compression. It decreases the cost and the duration of the surgical procedure, it protects the patient from the complications and sequelae related to graft harvesting and the use of implants. It should be limited to patients without preoperative kyphosis who are over 50 years old.

Prospective study of anterior cervical microforaminotomy for cervical radiculopathy

Cervical radiculopathy caused by a posterolateral disc herniation or spondylosis is a common pathology. Decompression of a stressed cervical nerve root is a routine neurosurgical procedure. To determine the safety and effectiveness of anterior cervical microforaminotomy (ACM), we prospectively studied patients undergoing this treatment at our institution to determine the efficacy of the approach for the treatment of unilateral cervical spondylotic or discogenic radiculopathy. Twenty-five patients were treated with ACM and were followed up for 15-40 months. Clinical signs, neurological results, and complications were recorded. Radiological imaging studies for measurement of post-operative changes were performed to evaluate spinal stability and effectiveness of the ACM procedure. We used MRI, axial cervical CT and reconstructive sagittal cervical CT to assess foraminal decompression. Eight men and 17 women (mean age 51.8 years) were included in this study. Nineteen patients had a single ACM, and six underwent procedures at adjacent 19 levels. The ACM procedure involves microsurgical removal of the lateral portion of the uncinate process to identify the nerve root. Post-operatively, none of the patients' conditions had worsened symptomatically or neurologically. A positive outcome at last follow-up examination was achieved in all patients. The visual analoge scale pain rating was 6.36 pretreatment and 0.64 after 1 year (p<0.0001). ACM appears to be a good alternative procedure, and a good non-fusion disc-preserving technique. Disc and bone resections are minimal in carefully selected patients with unilateral cervical radiculopathy. This method avoids osteoarthrodesis or arthroplasty with disc prostheses.

Anterior cervical corpectomy and fusion accelerates degenerative disease at adjacent vertebral segments

BACKGROUND

Anterior cervical corpectomy provides the most direct and thorough surgical approach for anterior decompression when spinal cord compression is found directly behind the vertebral body. However, anterior cervical fusion has been shown to be associated with the development of new degenerative changes at levels immediately adjacent to the fused segments. Th e incidence of adjacent segment disease (ASD) following anterior cervical corpectomy has not been widely reported. We set out to determine the incidence of clinical ASD following anterior cervical corpectomy.

METHODS

We retrospectively reviewed all available medical charts and radiographic studies of all cases of anterior cervical corpectomy performed at the Barrow Neurological Institute over a 4-year period with a minimum 24-month follow-up. Factors assessed included the success of arthrodesis, the presence of degenerative changes on serial follow-up radiographs, and the development of new neurological symptoms.

RESULTS

Seventy-six patients met the criteria for inclusion: 54 had undergone a 1-level corpectomy, 18 underwent a 2-level corpectomy, and 4 underwent a 3- or 4-level corpectomy. Arthrodesis was performed with either allograft or autograft and anterior cervical plating. All patients achieved successful fusion. Follow-up was available for a minimum of 2 years in all cases, with a mean length of 3.6 years. Sixteen patients (21%) eventually developed radiological and clinical evidence of degenerative changes at adjacent levels. In 10 of 11 patients who developed clinical symptoms within 2 years, the changes represented progression of pre-existing, asymptomatic degenerative disease. Five patients developed degenerative changes more than 5 years after surgery; these were all associated with an unrelated new insult to the cervical spine such as trauma.

CONCLUSIONS

Anterior cervical corpectomy with fixation can accelerate degenerative changes identified preoperatively at adjacent, asymptomatic levels of the cervical spine.

LEVEL OF EVIDENCE

Retrospective cohort study (level 2b).

Anterior corpectomy with iliac bone fusion or discectomy with interbody titanium cage fusion for multilevel cervical degenerated disc disease

STUDY DESIGN

Clinical and radiologic study evaluating the outcome after anterior corpectomy with iliac bone fusion compared with discectomy with interbody titanium cage fusion for multilevel cervical degenerated disc disease.

OBJECTIVES

To investigate the safety and effectiveness of interbody titanium cage with plate fixation in multilevel postdiscectomy fusion.

SUMMARY OF BACKGROUND DATA

The operation for segmental multilevel cervical degenerated disc disease remains controversial. Data on safety and efficacy of titanium cages in multilevel postdiscectomy fusion are rarely available. We investigated the safety and effectiveness of interbody fusion cages with plate fixation and compared the clinical and radiographical results between anterior corpectomy and iliac bone fusion with plate fixation and multilevel discectomy and cage fusion with plate fixation.

METHODS

Sixty-two patients were treated with either a multilevel discectomy and cage fusion with plate fixation (27 patients, group A) or an anterior corpectomy and iliac graft fusion with plate fixation (35 patients, group B). We evaluated the patients for cervical lordosis, fusion status, and stability 24 months postoperatively on the basis of spine radiographs. The patients' neurologic outcomes were assessed by the Japanese Orthopedic Association (JOA) scores. Neck pain was graded using a 10-point visual analog scale.

RESULTS

Both groups A and B demonstrated a significant increase in the JOA scores (preoperatively 11.1+/-2.1 and 10.4+/-3.5, postoperatively 14.3+/-2.4 and 13.9+/-2.1, respectively) and a significant decrease in the visual analog pain scores (preoperatively 8.5+/-1.1 and 8.7+/-1.5, postoperatively 2.9+/-1.8 and 3.0+/-2.0, respectively). However, there was no significant difference between groups A and B. Both groups A and B showed a significant increase in the cervical lordosis after operation and reached satisfactory fusion rates (96.3% and 91.4%, respectively). Three patients (two 2-level corpectomies and one 3-level corpectomy) had construct failures that required a second operation. Eight of 35 patients who underwent iliac bone fusion had donor site pain. The hospital stay in group A was significantly shorter than that in group B (P=0.022).

CONCLUSIONS

Either a multilevel discectomy and cage fusion with plating or a corpectomy and iliac bone fusion with plating provides good clinical results and similar fusion rates for cervical degenerative disc disease. However, absence of donor site complications and construct failures and shorter hospital stay make the multilevel discectomy and cage fusion with plate fixation better than corpectomy and strut graft fusion with plate fixation.

Transient long segment spinal cord hyperintensity after anterior cervical discectomy

A 69-year-old man was admitted to our hospital with progressive numbness in both feet and gait disturbance. MR imaging revealed a large cervical disc herniation resulting in significant spinal cord compression with hyperintensity of the spinal cord on T2-weighted images at C-5/6. Immediately after undergoing anterior cervical discectomy, the patient developed severe weakness of his left hand and lower extremities. MR imaging obtained 5 days after surgery revealed a long segment hyperintensity between C-3 and T-2 on T2-weighted images. This long segment hyperintensity disappeared after 2 weeks of steroid administration. We suspect that the persistent, localised, patchy C-5/6 cord hyperintensity represents spinal cord degeneration due to ischaemia and trauma resulting from the disc herniation. However, the transient long segment hyperintensity may represent oedema, probably due to minor trauma of an already compromised cord, during the decompression surgery. Clinicians should be aware that even careful surgery can result in a significant change in radiological studies and neurological condition.

Analysis of five specific scores for cervical spondylogenic myelopathy

The ability to compare various results that measure clinical deficits and outcome is a necessity for successful worldwide discussion about cervical spondylogenic myelopathy (CSM) and its treatment. There is hardly any information in literature how to value and compare outcome assessed by different scores. In a retrospective study we objectively evaluated the Nurick-score, Japanese-orthopaedic-association-score (JOA-Score), Cooper-myelopathy-scale (CMS), Prolo-score and European-myelopathy-score (EMS) using the data of 43 patients, all of whom showed clinical and morphological signs of CSM and underwent operative decompression. The scores were assessed pre- and postoperatively. The correlation between the score-results, anamnesis, clinical and diagnostic data was investigated. All the scores show a statistically significant correlation and measure postoperative improvement. With exception of the Prolo-score all scores reflect clinical deficits of CSM. The Prolo-score rates the severity of CSM on the state of the economic situation above clinical symptoms. The main differences of the scores are shown in the number of patients showing postoperative improvement, varying between 33% (Nurick-score) and 81% (JOA-score). The recovery-rates, as a measure of the cumulative improvement of all the symptoms, show less variation (23-37%). The differences of the recovery-rate were only statistically significant between JOA-score, Nurick-score and EMS (P < 0.05), whereas all the other scores showed no significant differences. To assess the postoperative successes, the evaluation of the recovery-rate is essential. There is no significant difference in the recovery-rate amongst the majority of the scores, which allows a good comparison of the results from different studies. Nevertheless, it is always important to differentiate the therapy results of CSM published worldwide.

Patient perceived outcome after central corpectomy for cervical spondylotic myelopathy

BACKGROUND

Patient perception of outcome after decompressive surgery for CSM is infrequently reported. We evaluated a simple, quantitative patient-reported assessment of outcome after CC for CSM by comparing it with the NGRR.

METHODS

In a prospective study between 1994 and 2004, patients who underwent CC for CSM were asked to quantify the outcome (relative to their preoperative status) on a scale of 0 to 100. Patient perceived outcome score was compared with the NGRR (preoperative grade - postoperative grade / preoperative grade x 100) at the same follow-up.

RESULTS

A total of 208 patients with a follow-up ranging from 6 to 72 months (mean, 16.3 months) were evaluated. There was a good positive correlation between PPOS and NGRR for the whole group (Pearson correlation coefficient, 0.62; P < .001), good-grade patients (preoperative Nurick grade of 1-3) (Pearson correlation coefficient, 0.52; P < .001), and poor-grade patients (Pearson correlation coefficient, 0.79; P < .001); the correlation was strongest in the poor-grade group of patients. kappa statistic revealed moderate agreement between the 2 scores in the whole group (kappa = 0.45), substantial agreement in the poor-grade patients (kappa = 0.61), and fair agreement in the good-grade patients (kappa = 0.34). In 28 of the 208 patients (13.5%), there was no agreement between the 2 scores with a significantly greater proportion (24/28), reporting an improvement in spite of no change in their Nurick grade (McNemar chi(2) test, P = .0002).

CONCLUSIONS

Although there was good agreement and a positive correlation between PPOS and NGRR, the disagreement in 13.5% of patients suggests that the 2 scores are evaluating some dissimilar functional domains; therefore, PPOS provides additional independent data in the assessment of the results of decompressive surgery for CSM. Patient-reported outcome should be included in reporting outcome of decompressive surgery for CSM.

Multilevel Oblique Corpectomies: Surgical Indications and Technique

Objective:

We describe extensively the multilevel oblique corpectomy technique with its advantages, disadvantages, indications, and biomechanical effects. This procedure is an alternative to the anterior corpectomy.

Methods:

Multilevel oblique corpectomy can be indicated in spondylotic myelopathy, whether or not it is associated with unilateral radiculopathy. Certain conditions must be fulfilled: anterior compression must be predominant, the spine must be kyphotic or straight, preoperative instability has to be excluded, and intervertebral discs have to be dehydrated and collapsed.

Results:

The lateral aspect of the cervical spine is reached and the vertebral artery is controlled through a lateral approach. The lateral part of the pathological intervertebral discs is removed. Then, the lateral portion of the vertebral body is drilled to create an 8-mm wide vertical trench. When the posterior cortical bone as well as the superior and inferior end plates are reached, the microscope is moved obliquely to extend the drilling horizontally as long as required, up to the contralateral pedicle if necessary. Next, the posterior cortical bone and the posterior longitudinal ligament are removed to completely decompress the spinal cord. In the case of radiculopathy, the ipsilateral foramen can be completely opened by taking away the uncovertebral joint after its lateral aspect has been separated from the vertebral artery.

Conclusion:

The multilevel oblique corpectomy technique allows wide anterior decompression of the spinal cord and complete unilateral nerve root decompression. Using this technique, the spinal stability is preserved and osteoarthrodesis is not required. Spinal motions are preserved and appear close to normal.

Cervical corpectomy with preserved posterior vertebral wall for cervical spondylotic myelopathy: a randomized control clinical study

STUDY DESIGN

Cervical corpectomy with preserved posterior vertebral wall (CPW) had been performed by the senior author (Y.W.) since 1999. A prospective study had been conducted to evaluate the efficacy of CPW since 2001.

OBJECTIVE

To validate the clinical outcome of CPW against conventional corpectomy (CC).

SUMMARY OF BACKGROUND DATA

Anterior surgical managements of cervical spondylotic myelopathy (CSM) include discectomy and corpectomy. Both have significant disadvantages, including low fusion rates and residual symptoms. A procedure incorporating multilevel discectomy, corpectomy with preserved posterior vertebral wall, autograft and plating was described. By keeping the posterior vertebral wall (PW), infringement of the vein plexus and spinal canal was avoided and more fusion site was available.

METHODS

From March 2001 to March 2004, 178 cases of CSM were randomized to undergo CPW (n = 89) or CC (n = 89). Arthrodesis was done with autogenous iliac bone graft or titanium cage supplemented with anterior self-lock plates in both groups. Operation time, blood loss, days of hospitalization, the numbers and types of complications, and preoperative and postoperative JOA scores were recorded. Fusion rate, segmental lordosis, and disc height were assessed by roentgenography. Three-dimensional reconstructions of CT scan were used to confirm fusion evidence.

RESULTS

Average operation time and blood loss decreased significantly in the CPW group (98.06 +/- 19.42 minutes, and 131.69 +/- 62.41 mL) as compared with those in the CC group (108.45 +/- 22.35 minutes, and 181.57 +/- 82.10 mL) (P < 0.05). There were 2 cases of epidural bleeding and 1 case of CSF leak in the CC group. Other complications were minor. JOA improvement scores were similar in both groups. Roentgenograms showed that the fusion rate was 100% at 6 months postoperatively in both groups. CT scans showed that PW fused with grafts and bone dust in cages. Improvement in segmental lordosis and disc height was similar in both groups.

CONCLUSION

CPW is a feasible procedure for anterior decompression and fusion, with safety, complete decompression, and high fusion rate, as long as indicative patients are selected.

Biomechanical comparison of instrumented and uninstrumented multilevel cervical discectomy versus corpectomy

STUDY DESIGN

In vitro flexibility test comparing biomechanics of cervical corpectomy versus discectomy with and without instrumentation.

OBJECTIVES

To evaluate whether the additional effort required to perform multilevel discectomies instead of corpectomies is worthwhile biomechanically.

SUMMARY OF BACKGROUND DATA

Both cervical corpectomy and discectomy have been shown to be effective clinically. No previous biomechanical comparison exists.

METHODS

Fourteen human cadaveric cervical spines were studied: 1) intact, 2) after discectomy and wedge grafting at C4-C5, C5-C6, and C6-C7 (Group 1) or corpectomy and strut grafting of C5 and C6 (Group 2), 3) after attaching a locking metal plate from C4-C7, and 4) after adding posterior locking lateral mass screw/rod instrumentation across C4-C7. Non-constraining, nondestructive torques induced flexion, extension, lateral bending, and axial rotation (maximum, 1.5 Nm) while angular motion was measured stereophotogrammetrically.

RESULTS

Discectomy and grafting did not alter the range of motion (ROM) significantly from normal during any loading mode (P > 0.11). Corpectomy and grafting allowed a significantly greater range of motion than normal during flexion, lateral bending, and axial rotation (P < 0.05). Addition of an anterior plate reduced ROM to significantly less than normal during all loading modes in both groups (P < 0.005). Addition of posterior instrumentation further reduced ROM significantly in both groups (P < 0.01). There was no significant difference in ROM between corpectomy and discectomy groups in any loading mode whether uninstrumented (P > 0.18), anteriorly plated (P > 0.33), or anteriorly and posteriorly instrumented (P > 0.30).

CONCLUSIONS

Less difference in stability was observed than was predicted between specimens receiving multilevel discectomy versus multilevel corpectomy, regardless of whether specimens were left unplated, plated anteriorly, or fixated with combined anterior/posterior instrumentation.

In vivo evaluation of biomechanical anterior cervical plate failure

Anterior cervical plate (ACP) failure is rarely addressed in the literature. In this retrospective, observational, longitudinal, cohort study, the objectives were to (1) identify incidences of in vivo biomechanical failure in commercially available, US Food and Drug Administration-approved ACP systems, (2) describe modes of failure, (3) suggest structural explanations for system failure, and (4) discuss complications and treatment of patients with failed ACP systems. Investigators retrospectively identified patients who underwent anterior cervical procedures followed by use of ACP as a fusion adjunct and showed evidence of ACP failure on plain radiographs. Components of the ACP system that led to failure were identified and examined. A total of 240 patients received ACP supplementation of anterior cervical fusion constructs during the 9.5-y study period. Evidence of ACP failure was noted in 7 patients (3.3%), and an eighth patient was referred for evaluation after ACP failure. Screw-plate interface failure occurred in all 8 cases. The biomechanical method by which the bone screw head was secured into the vertebral body, or against the ACP, the use of hybrid systems, the surgical technique selected, and host factors were used to determine the rate of failure. Concern for esophageal or other tissue injury often necessitated ACP removal. Screw-plate interface failure, which was found to be the most common mode of biomechanical ACP failure, may occur in hybrid constructs and in systems that do not create a rigid interface between the screw head and the ACP. Surgical technique and patient host factors may also influence the rate of biomechanical construct failure.

Neurological recovery after surgical decompression in patients with cervical spondylotic myelopathy - a prospective study

Cervical spondylotic myelopathy is a common clinical problem. No study has examined the pattern of neurological recovery after surgical decompression. We conducted a prospective study on the pattern of neurological recovery after surgical decompression in patients with cervical spondylotic myelopathy. Patients suffering from cervical spondylotic myelopathy and requiring surgical decompression from January 1995 to December 2000 were prospectively included. Upper limbs, lower limbs and sphincter functions were assessed using the Japanese Orthopaedic Association (JOA) score. Assessment was done before the operation, at 1 week, 2 weeks, 1 month, 3 months, 6 months, 1 year and then yearly after surgery. Results were analysed with the t-test. Differences with P-values less than 0.05 were regarded as statistically significant. Fifty-five patients were included. The average follow-up period was 53 months. Thirty-nine patients (71%) had neurological improvement after the operation with a mean recovery rate of 55%. The JOA score improved after surgery, reaching statistical significance at 3 months and a plateau at 6 months. Thirty-six patients (65%) had improvement of upper limb function. Twenty-four patients (44%) had improvement of lower limb function. Eleven patients (20%) had improvement of sphincter function. The recovery rate of upper limb function was 37%, of lower limb function was 23% and of sphincter function was 17%. Surgical decompression worked well in patients with cervical spondylotic myelopathy. Seventy-one percent of patients had neurological improvement after the operation. The neurological recovery reached a plateau at 6 months after the operation. The upper limb function had the best recovery, followed by lower limb and sphincter functions.

Comparison of multisegment anterior cervical fixation using bone strut graft versus a titanium rod and buttress prosthesis: analysis of outcome with long-term follow-up and interview by independent physician

STUDY DESIGN

A retrospective study of 73 consecutive patients who underwent cervical corpectomy and anterior strut fixation over 3 or more disc levels between July 1989 and May 1999.

OBJECTIVE

To compare the efficacy of cervical spine fixation by autologous strut graft from iliac crest or fibula versus a titanium prosthesis without bone graft.

SUMMARY OF BACKGROUND DATA

Strut grafting after multilevel anterior cervical corpectomy remains a challenging procedure, with published dislocation rates from 0% to 71%, and nonunion from 0% to 54%. This paper describes a quicker and easier alternative to the use of a bone strut, imparting a very high degree of immediate spinal stability, and osseous integration equivalent to bone fusion.

METHODS

Thirty-eight bone-graft operations and 38 titanium prosthesis operations were performed on 73 patients between July 24, 1989 and May 20, 1999. Average follow-up was 53.2 months (range 19.8-134).

RESULTS

The group of patients who received the prosthesis was significantly older than the bone-grafted group and required significantly more segments excised, but operation times were significantly shorter than for the bone strut operation. The titanium prosthesis had a lower incidence of dislodgement in the early postoperative period (1/38 vs. 4/38 for bone struts) but a higher rate of late reoperation (4/38 vs. 1/38 for bone struts). The SF-36 scores in the domain of Physical Function (only) were significantly higher in the bone-grafted group (P = 0.016, Mann Whitney), consistent with the difference in mean ages of the 2 groups. The groups were indistinguishable by Odom criteria, patient verdict, pain scores, analgesic intake, length of hospital stay, radiologic fusion rate, and residual symptoms.

CONCLUSION

A titanium rod and buttress prosthesis may be a faster and easier alternative to conventional iliac crest/fibula autograft after multisegmental cervical vertebral corpectomy.

ANTERIOR CERVICAL APPROACH FOR THE TREATMENT OF CERVICAL MYELOPATHY

COMPRESSION OF THE spinal cord by the degenerating cervical spine tends to lead to progressive clinical symptoms over a variable period of time. Surgical decompression can stop this process and lead to recovery of function. The choice of surgical technique depends on what is causing the compression of the spinal cord. This article reviews the symptoms and assessment for cervical spondylotic myelopathy (clinically evident compression of the spinal cord) and discusses the indications for decompression of the spinal cord anteriorly.

Indications for circumferential surgery for cervical spondylotic myelopathy

BACKGROUND CONTEXT

The surgical management of patients with cervical spondylotic myelopathy (CSM) remains challenging.

PURPOSE

To review the indications, techniques, and results of circumferential fusion for CSM.

CONCLUSION

Circumferential decompression and stabilization with instrumentation is a viable option to treat selected complex cervical spine disorders. It provides immediate stabilization of the spine, decreases anterior graft and instrumentation failure, and can obviate the need for postoperative halo immobilization.

Functional outcome after central corpectomy in poor-grade patients with cervical spondylotic myelopathy or ossified posterior longitudinal ligament

OBJECTIVE

We studied the long-term functional outcome in poor-grade patients (Nurick Grades 4 and 5) with cervical spondylotic myelopathy (CSM) or ossified posterior longitudinal ligament after central corpectomy (CC). We sought to determine whether there were any prognostic factors that could predict functional outcome in these patients.

METHODS

Functional outcome data were collected for 72 patients (68 men and 4 women; mean age, 49.7 yr; range, 30-67 yr) with CSM (60 patients) or OPLL (12 patients) of Nurick Grades 4 (55 patients) and 5 (17 patients). Uninstrumented CC was performed at 1 level in 12 patients, at 1 level combined with a discoidectomy at another level in 4 patients, at 2 levels in 50 patients, and at 2 levels plus a discoidectomy in 5 patients. The age at presentation (< or =50 yr or >50 yr), grade before surgery (4 or 5), the number of levels operated (1 or >1), diagnosis (CSM or ossified posterior longitudinal ligament), and duration of myelopathic symptoms (< or =12 mo or >12 mo) were studied for their effect on the functional outcome noted at the last follow-up. Functional outcome was graded as poor (no change in Nurick grade), fair (improvement of one Nurick grade), good (improvement of two Nurick grades), and cure (follow-up Nurick grade of 0 or 1).

RESULTS

The follow-up ranged from 9 to 104 months (mean, 36.3 mo). One patient died 3 weeks after CC after surgery for a perforated duodenal ulcer. There was transient operative morbidity in 12 patients (16.9%). The mean Nurick score improved from 4.24 to 2.47 (P < 0.001). Of the 54 patients (76%) who improved in their Nurick grade, the functional outcome was graded as fair in 13 patients (18.3%), good in 24 patients (33.8%), and cure in 17 patients (23.9%). The functional outcome was poor in 17 patients (23.9%). Functional improvement after CC was uniformly correlated with myelopathic symptoms of 12 months' duration or shorter. The other favorable prognostic indicators for improvement after CC were a diagnosis of CSM and preoperative Nurick Grade 5; however, patients with a preoperative Nurick grade of 4 were more likely to experience a cure.

CONCLUSION

More than three-fourths of patients with poor-grade CSM improve in their functional status after CC, with nearly 24% of patients obtaining a cure. Because patients with a duration of myelopathic symptoms of 12 months or less had the best functional outcome, early decompressive surgery should be offered to patients with poor-grade CSM.

Dynamic anterior cervical plates for multilevel anterior corpectomy and fusion with simultaneous posterior wiring and fusion: efficacy and outcomes

STUDY DESIGN

To prospectively evaluate major complications associated with the application of dynamic ABC plates (Aesculap, Tuttlingen, Germany) to multilevel Anterior Corpectomy/Fusion (ACF) followed by posterior fusion (C2-C7 PF).

OBJECTIVES

To determine whether dynamic ABC (Aesculap, Tuttlingen, Germany) plates would minimize major complications (plate/graft extrusion, pseudarthrosis) while maximizing neurological outcomes in 40 consecutive patients undergoing simultaneous multilevel ACF/PF with halo application.

SETTING

USA.

METHODS

Patients averaged 53 years of age and preoperatively exhibited severe myeloradiculopathy (Nurick Grade 3.9). MR/CT studies documented marked ossification of the posterior longitudinal ligament/spondylostenosis. Surgery included two to four level ACF utilizing fibula strut allograft and ABC plates. Posterior spinous process wiring/fusions utilized braided titanium cables. The average operative time was 8.9 h. Fusion was confirmed on dynamic X-rays/CTs (3-12 months postoperatively). The average follow-up interval was 2.7 years. Outcomes (3 months-2 years postoperatively) were assessed utilizing Odom's Criteria, Nurick Grades, and SF-36 questionnaires.

RESULTS

Major complications included one pseudarthrosis requiring secondary PWF. Minor complications in six patients included two pulmonary emboli (PE), two tracheostomies, and five superficial wound infections. At 1 year postoperatively, marked improvement was observed in all patients utilizing Odom's criteria (38 excellent/good), Nurick Grades (mild radiculopathy 0.4), and the SF-36 (3 Health Scales; Role Physical (12.5-38.6), Bodily Pain (39.9-65.5), and Role Emotional (53.8-75.8)]. The 2-year postoperative data showed minimal additional improvement. The average time to fusion was 6.3 months.

CONCLUSION

Patients undergoing multilevel ACF/PF demonstrated marked neurological improvement (SF-36), and only one of 40 developed a delayed pseudarthrosis.

Cervical spondylotic myelopathy: 10 years of prospective outcome analysis of anterior decompression and fusion

BACKGROUND

Fifty-one patients with cervical spondylotic myelopathy (CSM) treated by anterior cervical corpectomy with fusion (ACWF) at our institution were included in a study during a period of 10 years to evaluate neurological, anatomical, and functional outcomes including satisfaction levels.

METHODS

We have completed a prospective evaluation of 39 patients with spondylotic myelopathy submitted to ACWF during the period of 1989-2000. The data were analyzed for age, duration of symptoms, severity of preoperative neurological deficit, and single-level or multilevel compressive status looking for possible association with prognostic surrogate data and clinical outcome that were evaluated with the Nurick score and a survey of level of satisfaction.

RESULTS

Of the 51 patients, 39 fullfilled the intended follow-up being 28 men (71.8%) and 11 women (28.2%). The average age was 63.5 years. Duration of symptoms ranged from 1 to 240 months (mean, 38.1 months). The mean preoperative Nurick scale score was 2.97; the mean postoperative score was 2.1. The most frequently involved vertebral body was C5 (71.7%). The follow-up period was longer than 18 months for all patients. Postoperative nonneurological complications occurred in 8 patients (15.6%). The mortality rate was 1.9% (n = 1). Postoperative results showed improvement in 25 patients (64.1%), no change in 13 (33.3%), and worsening in 1 (2.6%). The correlation coefficient of preoperative and postoperative Nurick scores was 0.733 (R(2) = 0.53). Of the 39 patients, 31 answered the questionnaire for quality of life-19 (61.2%) were very satisfied, 6 were satisfied (19.35%), and 6 were not satisfied (19.35%).

CONCLUSION

Most patients (80.6%) were very satisfied or satisfied with the outcome and would decide again for the surgery (87%) if the results were previously known. Anterior cervical corpectomy with fusion was a reliable and rewarding procedure for CSM, with functional improvement in most patients. Excellent long-term outcome results in cervical fusion can be achieved without the use of hardware instrumentation.

[The results of surgical treatment for cervical spondylotic myelopathy]

OBJECTIVE

Cervical spondylotic myelopathy is th emost serious consequence of cervical intervertebral disc degeneration. The purpose of this study is to evaluate functional results of surgical treatment of patients with cervical spondylotic myelopathy who underwent anterior or posterior decompressive operations.

METHODS

we prospectively analyzed 57 patients with cervical spondylotic myelopathy who were operated in Institut for Neurosurgery in Belgrade (1995-2002). The severity of myelopathy is graded by Nurick myelopathy grading system. The average foloow-up period was 20 months.

RESULTS

Postoperative improvement schowed 75% of patients and 21% remained unchanged. Myelopathy worsening was observed in two patients, 4%. We didn't have serious operative complications. Selection of surgical approach was not significantly correlated with surgical outcome.

CONCLUSION

surgical decompression of cervical medulla is safe treatment that gives good chances for functional recovery in patients with cervical spondylotic myelopathy.

Rapid opening and closing of the hand as a measure of early neurologic recovery in the upper extremity after surgery for cervical spondylotic myelopathy

OBJECTIVE

To compare the results of a simple bedside test with the Jebsen-Taylor hand function test, in the assessment of early improvement of neurologic function after surgery for cervical spondylotic myelopathy (CSM).

DESIGN

Case series comparing the bedside test with the Jebsen-Taylor test of hand function as the criterion standard in a blinded comparison.

SETTING

Referral center, institutional practice, hospitalized care.

PARTICIPANTS

One hundred referent subjects and 26 consecutive patients undergoing surgery for CSM.

INTERVENTION

Decompressive cervical spine surgery. Main outcome measures Complete, rapid opening and closing of the hand was timed for 20, 40, and 60 repetitions, the Rapid Hand Flick Time (RHFT), preoperatively and in the first week postoperatively. The results of this test were correlated with the Jebsen-Taylor test.

RESULTS

There was a 40% to 50% prolongation in the RHFT compared with age-matched referent subjects. Postoperatively, there was a 3.84-second mean improvement in the RHFT for 20 repetitions in the right hand and 2.8 seconds in the left hand. A paired-samples t test, comparing the preoperative and postoperative day 1 and day 7 timings, showed a statistically significant improvement (P<.001). There was no significant change from postoperative day 1 to day 7. In the Jebsen-Taylor test, patients showed a significant postoperative improvement (P<.01) in the writing test, in simulated feeding, and in transfer of small objects in both hands. Pearson correlation coefficient testing for correlation between the RHFT and the Jebsen-Taylor subtests were low, which indicates that, although they both record an improvement after surgery, they probably do not test the same aspects of hand function.

CONCLUSIONS

The RHFT is a simple and reliable method of assessing early improvement in hand function and spasticity in patients after surgery for CSM.

Results of surgical treatment for degenerative cervical myelopathy: anterior cervical corpectomy and stabilization

STUDY DESIGN

This retrospective study involves 26 patients with degenerative cervical myelopathy who were surgically treated by anterior corpectomy, titanium mesh cage (TMC) filled with autogenous bone, and anterior plate +/- posterolateral plate and fusion.

OBJECTIVES

This study was conducted to determine the indications, efficacy, and complication rate associated with performing corpectomy to achieve anterior decompression of neural elements or for removing anterior lesions.

SUMMARY OF BACKGROUND DATA

This retrospective study involves patients with degenerative cervical myelopathy who were surgically treated by > or =2-level anterior corpectomy, TMC filled with autogenous bone, and anterior plate +/- posterolateral plate and fusion. The purpose was to evaluate and compare the results in terms of neurologic recovery and function and effectivity of TMC as a structural support.

METHODS

Twenty-six patients with degenerative cervical myelopathy who had surgical treatment and average 30 months (range, 24-52 months) follow up were included. The mean age was 64.9 years (range, 55-74 years) and average period between myelopathic symptoms and surgery was 2.8 years (range, 6 months-5 years). Preoperative evaluation of every patient consisted of anterior-posterior, lateral, bilateral oblique, flexion, and extension radiographs, computed tomography reconstructions and magnetic resonance imaging of the cervical spine, Doppler ultrasound of the carotid arteries, vertebral artery magnetic resonance angiography, neurologic examination, and electromyography. Degree of pre- and postoperative myelopathy was determined according to the scoring systems developed by Nurick and Japanese Orthopedic Association (JOA). Twelve patients had a mild balance problem and difficulty while walking but were able to perform their daily activities. Fourteen patients had spastic quadriparesis ambulating on either crutches or with wheelchairs. Of these, 11 experienced bladder disturbance as well. Surgical treatment in 18 patients consisted of anterior decompressive corpectomy, structural TMC, and anterior plate stabilization in 14 patients who had 2-level corpectomy. Posterior plate stabilization without laminectomy was added to this procedure in another 4 patients who had 3- or more level corpectomy. The remaining 8 patients had first laminectomy and posterolateral plate, then anterior corpectomy, TMC, and anterior plate on the same stage. Corpectomy levels were between C3 and T1, and anterior corpectomy, structural TMC, and anterior plating was the procedure that all patients had in common.

RESULTS

Mean sagittal Cobb angle (C2-C7) was 9 degrees (range, 0-23 degrees) before surgery, 17.1 degrees (range, 11-22 degrees) on the third postoperative month, and 16.9 degrees (range, 10-22 degrees) at last follow-up. The difference in sagittal alignment on the third month and last follow up was not statistically significant (P > 0.05). Average preoperative Nurick score was 3.5 (range, 2-5) and JOA score was 7 (range, 1-14). Major and statistically significant neurologic recovery was within the first 3 months, and average Nurick and JOA scores at 3 months were 2 (range, 0-3) and 11 (range, 8-17) (P < 0.001), respectively. All patients had improved neurologic status at final follow up. As confirmed by plain radiographs and computed tomography reconstructions, solid fusion was achieved across the TMC with no settling or migration, and we had no implant-related complication or failure. As major complications, 1 (3.8%) early deep posterior infection developed but responded to early debridement and antibiotics. Also, 3 patients (11.5%) had transient C5 nerve root injury. At final follow up, all patients were able to ambulate without support and maintain their daily activities.

CONCLUSIONS

Anterior decompression provides good neurologic recovery in patients with degenerative cervical myelopathy. TMC provides good structural support, and solid fusion can be achieved with TMC and anterior plate (for < or =2-level corpectomy) and/or posterior plate (> or =3-level corpectomy). There is increased risk of C5 nerve root injury when first laminectomy and posterolateral plate stabilization are performed.

The incidence of C5?C6 radiculopathy as a complication of extensive cervical decompression: own results and review of literature

This retrospective study aims to discuss and compare our results with those previously mentioned in the literature with regard to C5-C6 radiculopathy that occurs after decompression carried out for cervical spondylotic myelopathy. There are few reports in the literature referring to the incidence of the C5-C6 radiculopathy following cervical decompression procedures. Some authors believe that the postoperative cord shift is the most likely cause. From January 1994 to November 2002, 121 patients underwent cervical corpectomies for cervical spondylotic myelopathy. The preoperative and the postoperatively discovered paresis have been assessed according to the criteria of the British Medical Council. The Nurick Scale was used to grade the severity of the myelopathic changes. The follow-up period varied from 4 to 111 months with an average of 50 months. Symptoms of C5 and/or C6 radiculopathy appeared in 10 patients (8.2%) postoperatively. Aggravation of a preoperative C5 and/or C6 radiculopathy was seen in 3 patients, while 7 patients developed a new C5 and/or C6 radiculopathy in the immediate postoperative period. These motor deficits resolved completely in 7 patients within 7 months of surgery, whereas a residual motor weakness remained in the other 3 patients. The postoperative C5 motor deficit is not infrequently associated with partial involvement of the C6 root. The lesions can be either unilateral or bilateral with a statistically average frequency of 8%. The prognosis is generally favorable. Our results did not support the hypothesis that the claimed cord shift phenomenon is a possible aetiology.

Circumferential cervical surgery for ossification of the posterior longitudinal ligament: a multianalytic outcome study

STUDY DESIGN

Three outcome measures, Nurick grades, Odom's criteria, and the Short Form (SF-36) were analyzed following circumferential cervical surgery in 47 patients.

OBJECTIVES

To analyze three outcome measures following circumferential surgery.

SUMMARY OF BACKGROUND DATA

Few studies use multiple outcome criteria to assess circumferential surgery.

METHODS

Patients averaged 54 years of age and exhibited severe myelopathy (Nurick grade 3.6). Corpectomies of 2.6 vertebrae (on average) were followed by posterior fusions (C2-T1) with halo stabilization. Initial fixed-plates (n = 28) and subsequent dynamic ABC plates (Aesculap, Tuttlingen, Germany) (n = 19) were applied, Fusion was confirmed on dynamic radiographs and two-dimensional CT studies 3, 6, and up to 12 months after surgery. Nurick grades and Odom's criteria were evaluated 1 and 2 years after surgery. Results of SF-36 questionnaires, obtained before surgery, 6 weeks, 3 months, 6 months, 1 year, 2 years after surgery, were calculated.

RESULTS

Neurodiagnostic studies confirmed fusion on average 5.0 months after surgery. One and 2 years after surgery, mean Nurick grades were 0.8 (+2.8 points) and 0.4 (+3.2 points), respectively. One year (2 years) postoperative Odom's criteria revealed excellent 26 (30), good 14 (11), fair 6 (5), and poor 1 (1) patient outcomes. Comparing preoperative with 1-year postoperative SF-36 questionnaires revealed moderate improvement on 5 health scales: Social Function (+19.9), Bodily Pain (+19.6), Role-Physical (+18.8), Physical Function (+12.5), and Role-Emotional (+11.1). Minimal additional improvement occurred over the second year: Role-Physical (+21.6), Social Function (+16.4), Bodily Pain (+13.4), Physical Function (+12.8), and Role Emotional (+9.5).

CONCLUSION

Based on three outcome measures, the greatest improvement occurs 1 year following circumferential surgery.

Prolonged and severe dysphagia following anterior cervical surgery

While mild swallowing difficulties are commonly reported transiently following anterior cervical surgery, marked dysphagia is unusual. The authors report a patient who experienced severe and prolonged dysphagia following elective cervical corpectomies with iliac grafting and anterior plate fusion for multilevel cervical canal stenosis. The literature is reviewed and discussed.

Biomechanical comparison of cervical spine reconstructive techniques after a multilevel corpectomy of the cervical spine

STUDY DESIGN

An in vitro biomechanical study of several reconstructive techniques after a two-level cervical corpectomy.

OBJECTIVES

To evaluate, compare, and quantitate the stability of several reconstructive strategies (anterior, posterior, or anterior/posterior with or without instrumentation) after a multilevel cervical corpectomy.

SUMMARY OF BACKGROUND DATA

Several clinical and biomechanical studies have questioned the stability of stand-alone long-segment anterior plate fixation after a multilevel (>or=2) corpectomy. The large cantilever forces generated within the stabilized construct, particularly at the caudal screw-bone interface, have led to plate and screw dislodgement and the need for further surgical intervention. The addition of posterior segmental instrumentation has been shown to improve overall stability and decrease local stresses on the anterior fusion construct (graft and plate).

MATERIALS AND METHODS

Seven fresh-frozen cadaveric human cervical spines (C1-T1) were harvested. The C1-C2 and C7-T1 vertebral bodies were embedded in poly-methylmethacrylate (PMMA). Three VICON cameras tracked three-dimensional segmental motions at the ends of the fusion construct after a two-level corpectomy and placement of a strut graft with or without instrumentation. Pure moments (flexion/extension, lateral bending, and axial rotation) were applied to the C1 level of each specimen. The motion segments were loaded to a maximum of 2 Nm using dead weights. Testing was first performed on the intact specimens. Then, a two-level corpectomy at the C4 and C5 levels was performed. A PMMA strut graft was then placed into the corpectomy site. Biomechanical testing was then repeated among three different reconstruction techniques: 1) anterior cervical locking plate (PEAK; Depuy-Acromed, Raynham, MA) with dual unicortical screw fixation at C3 and C6; 2) posterior cervical instrumentation (Summit; Depuy-Acromed) using a 3.0-mm rod with segmental lateral mass screw fixation from C3 to C6; and 3) a combined anterior-posterior instrumentation using the anterior PEAK plate and posterior Summit rod system.

RESULTS

In all pure moments tested (flexion/extension/lateral bending/axial rotation) the combined anterior-posterior instrumentation reconstruction model and the posterior-only instrumentation model were significantly more rigid than the anterior-only instrumentation model (P < 0.05). Interestingly, no statistically significant difference was noted between the combined anterior plate/posterior instrumentation model and the posterior instrumentation-only model.

CONCLUSION

The biomechanical results obtained suggest that posterior segmental instrumentation confers significant stability to a multilevel cervical corpectomy regardless of the presence or absence of anterior instrumentation. In cases in which the stability of a multilevel reconstruction procedure is tenuous, the surgeon should strongly consider the placement of segmental posterior instrumentation to significantly improve the overall stability of the fusion construct.

Anterior decompression for cervical spondylotic myelopathy

Cervical spondylotic myelopathy is a clinical entity that manifests itself due to compression and ischemia of the spinal cord. The goal of treatment is to decompress the spinal cord and stabilize the spine in neutral, anatomical position. Since the obstruction and compression of the cord are localized in front of the cord, it is obvious that an anterior surgical approach is the preferred one. The different surgical procedures, complications, and outcome are discussed here.

Surgery for postarthrodesis adjacent–cervical segment degeneration

Anterior cervical decompression and fusion has gained popularity because of its applicability to a variety of cervical spine disorders. The authors of long-term follow-up studies have demonstrated the development of degenerative changes in segments adjacent to fusion. So-called adjacent-segment disease causes symptomatic deterioration in up to 25% of the patients who have undergone anterior cervical decompression and fusion for cervical spondylotic myelopathy. The causes of this condition are debated in the literature. The authors provide a review of the available literature on the pathogenesis, prevention, and treatment of postarthrodesis adjacent-segment degenerative disease.

Cervical arthroplasty in the management of spondylotic myelopathy

Cervical spinal cord compression managed via an anterior approach with an arthrodesis is associated with a decreased range of motion and accelerated adjacent segment degeneration. Artificial cervical disc replacement may address these problems. A series of seven cases (three women, two men; age 31-55 years) of anterior cervical decompression and placement of an artificial disc prosthesis is presented. A total of nine Bryan cervical disc prostheses (Spinal Dynamics Corp., Mercer Island, WA) were placed. Clinical and radiologic follow-up was performed at 24 hours, 6 weeks, 3 months, 6 months, and then yearly (mean follow-up period 6.29 months, range 1-17 months). There were no complications. There was an improvement in Nurick grade by 0.72 grade (P < 0.05) and Oswestry Neck Disability Index score by 51.4 points (P < 0.0001). Motion was preserved. Improvement in lordosis occurred in 29% of cases. The spinal cord was decompressed on postoperative imaging. Cervical arthroplasty after anterior cervical decompression at one or more levels represents an exciting tool in the management of spinal cord compression secondary to spondylotic disease or acute disc prolapse. This is the first study that looks specifically at cervical arthroplasty for cervical myelopathy. Longer follow-up will reveal any delayed problems with artificial disc implantation, but in the short term, this technique offers an excellent outcome.

Fixed vs dynamic plate complications following multilevel anterior cervical corpectomy and fusion with posterior stabilization

STUDY DESIGN

Comparison of fixed vs dynamic plate complications in cervical surgery.

SETTING

: New York, USA.

METHODS

Anterior cervical plate-related complications were evaluated following 66 anterior cervical corpectomy and fusion (ACF) with posterior stabilization (PWF) procedures performed in patients with ossification of the posterior longitudinal ligament (OPLL). Clinical data were comparable for both patient populations. Patients averaged between 52 and 53 years of age. The male to female ratio was approximately 2:1. Surgery addressed MR and CT documented multilevel OPLL in all patients accompanied by spondylosis and stenosis. Preoperatively average Nurick Grades ranged from 3.6 to 3.7. Anterior cervical corpectomies included an average of 2.6-3.0 vertebral bodies, while PWF covered seven levels. Fixed plates were applied in the initial 38 patients, while the latter 28 patients had dynamic plates (ABC, Aesculap, Tuttlingen, Germany) applied. Halo devices were used until fusion was documented on both X-ray and 2D-CT studies. Patients were followed-up for an average of 5.4 years in the fixed-plated groups, and 2.7 years in the dynamic-plated population.

RESULTS

CT and dynamic X-ray confirmed that fusion occurred an average of 4.5-4.9 months postoperatively. Five (13%) fixed plates (Medtronic, Sofamor Danek, Memphis, TN, USA) failed warranting secondary surgery, while only one (3.6%) dynamic-plated patient developed a pseudarthrosis and required secondary posterior fusion.

DISCUSSION/CONCLUSION

Higher failure rates follow multilevel ACF as compared with anterior diskectomy and fusion required to resect multilevel OPLL. Vaccaro et al observed a 9% failure rate following two-level ACFs and 50% failure rate following three-level ACFs performed with fixed plates. In this series, the plate extrusion rate was reduced to 3.6% when dynamic plates were applied.

Long-term outcome for surgically treated cervical spondylotic radiculopathy and myelopathy

Long-term follow-up results were examined to verify the efficacy of anterior osteophytectomy for cervical spondylotic myelopathy and radiculopathy, in particular the outcome for patients with developmentally narrow cervical canals and patients with associated ossification of the posterior longitudinal ligament (OPLL). One hundred thirty-nine patients who had undergone anterior osteophytectomy with interbody fusion between 1976 and 1990 were followed up for 1 to 22.5 years (mean 11.4 years). Overall results evaluated by the neurosurgical cervical spine scale scoring and grading showed significant improvement in both improvement score (2.7 +/- 2.3) and improvement rate (52.3 +/- 45.7%). Lower extremity motor function improved in 66.1% of patients, upper extremity motor function in 82.0%, and sensory/pain function in 70.5%. Improvement ranged from one to three grades. Severely affected patients showed good recovery. Outcome for patients with narrow cervical canals (41 patients, 29.5%) did not differ significantly from that for patients with normal canals (98, 70.5%). Patients with associated OPLL (32 patients, 23.0%) had approximately the same outcomes as those with only spondylosis (107, 77.0%). Fifteen patients (10.8%) underwent reoperation because of myelopathy due to disc degeneration adjacent to the fused level (11 patients) or OPLL (4 patients). Anterior osteophytectomy with interbody fusion can achieve good outcomes in patients with cervical spondylotic myelopathy and radiculopathy, regardless of the size of the spinal canal and association with OPLL.

Changes in cervical spine curvature after uninstrumented one- and two-level corpectomy in patients with spondylotic myelopathy

OBJECTIVE

We studied changes in the cervical spine curvature in patients with cervical spondylotic myelopathy who underwent one- or two-level central corpectomy and iliac bone grafting without the use of instrumentation.

METHODS

Curvature of the fused segment and of the whole cervical spine was evaluated on preoperative and follow-up x-rays in 93 patients (30 underwent one-level corpectomy, and 63 underwent two-level corpectomy). In 59 patients, the changes in the cervical spine curvature were studied using one follow-up x-ray; in the other 34 patients, the changes were studied on x-rays obtained at two or more follow-up visits. The sagittal alignment of the fused segment was categorized as lordotic (>+5 degrees), straight (+5 to -5 degrees) or kyphotic (>-5 degrees). The whole spine curvature also was recorded as lordotic, straight, or kyphotic.

RESULTS

At a mean follow-up of 22.2 months (range, 6-71 mo), there was a mean change of -10.4 degrees in the segmental curvature (P < 0.001). The fused segment sagittal alignment also worsened (lordotic angles becoming straight or kyphotic and straight angles becoming kyphotic) in 44 patients (47%)(P < 0.001). However, serial studies in 34 patients (mean first and last follow-ups, 11.9 and 30.8 mo, respectively) did not demonstrate significant worsening of the kyphotic angle or the sagittal alignment over time (P = 0.9). Whole spine curvature worsened in 33 (35%) of the 93 patients (P < 0.001); serial studies did not reveal a significant change (P = 0.9). Patients improved in their functional status from a preoperative mean Nurick grade of 2.9 (range, 1-5) to a follow-up mean Nurick grade of 1.5 (range, 0-4) (P < 0.001). Patients with a kyphotic change in their whole spine curvature (n = 33) and those without such change (n = 60) had a similar functional outcome (mean change in Nurick grade, 1.5 and 1.4, respectively).

CONCLUSION

Cervical spine curvature tended to undergo a kyphotic change at the fused segment in 47% of patients and a kyphotic change of the whole spine curvature in 35% of patients who underwent one- or two-level uninstrumented central corpectomy. This kyphotic change in the cervical spine, which stabilizes within 1 year after surgery, is not progressive, and it does not affect neurological outcome in these patients.

Partial corpectomy for cervical spondylosis

STUDY DESIGN

A retrospective review was performed of a single surgeon's experience with partial corpectomy over a 9-year period. The measures evaluated included fusion rate, complications, and neurologic symptoms.

OBJECTIVE

To demonstrate the safety and efficacy of partial corpectomy for multilevel cervical spondylosis.

SUMMARY OF BACKGROUND DATA

Strategies for the surgical management of cervical spondylosis have included laminectomy, multilevel corpectomy, and multilevel discectomy. All have significant disadvantages, including high nonunion rates and late deformity. A procedure incorporating multilevel discectomy, partial corpectomy, strut graft, and plating is described. By removal of the anterior two thirds of the intervening vertebral body, visualization of the interface between the dura and the disc or PLL is enhanced, and osteophytes can be easily removed. Fusion rates are improved.

METHODS

All partial corpectomy cases with a 2-year follow-up evaluation managed by the senior author for multilevel cervical spondylosis from 1991 to June 1999 were reviewed for the number of levels decompressed, graft source, use of plating, fusion success, and neurologic status.

RESULTS

Most of the patients (n = 97) were managed with two-level discectomies, with 42 requiring treatment of three levels and 5 requiring treatment of four or more levels. Allograft was used in 60%. The remainder received iliac crest bone graft. The majority (81%) were plated. Of the cases with 2-year follow-up evaluation, the fusion rate was 95.8%, independent of the number of levels fused. Among the 11% who had continued problems, most had improved. Nonunions were higher in smokers.

CONCLUSIONS

Partial corpectomy is an effective strategy for treating multilevel cervical disc disease. It is associated with a high fusion rate. In addition, partial corpectomy facilitates a complete decompression by providing excellent visualization of the dural interface.

Effects of surgical treatment for cervical spondylotic myelopathy in patients > or = 70 years of age: a retrospective comparative study

The objective of this study was to compare efficacy of cervical surgery for myelopathy in patients > or = 70 and < or = 60 years of age. Forty patients > or = 70 years and 50 patients < or = 60 years of age with MRI and CT proven myelopathy were neurologically assessed using the JOA score. Three operative procedures were performed: anterior spinal fusion, laminoplasty, and laminectomy. Postoperatively, patients exhibited comparable outcomes irrespective of age or operative procedure performed. The only exception was the increase in postoperative neurologic complications noted for the older individuals with greater comorbidities.