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

Anterior cervical corpectomy for the treatment of spondylotic myelopathy: results of a prospective double-armed study with a three-year follow-up

BACKGROUND

Since the first description in the 1950s, cervical spondylotic myelopathy (CSM) has posed many challenges to neurosurgeons and spine surgeons. Direct comparison among different operative approaches has failed to produce valuable results due to either an insufficient number of enrolled patients or a lack of standardization of baseline conditions. This prospective double-armed non-randomized study with a 3-year follow-up involved 80 patients with degenerative cervical myelopathy surgically and conservatively treated. The primary aim was to determine the efficacy of corpectomy in mild-moderate and severe CSM and to compare the outcomes of conservative and surgical treatment.

METHODS

Eighty patients were stratified into two arms, on the basis of the mJOA score: mild-moderate (mJOA ≥12) and severe myelopathy (mJOA score <12). Each arm was subdivided into two treatment groups (operative or conservative): A1, mild-moderate myelopathy treated with corpectomy; A2, mild-moderate myelopathy treated conservatively; B1, severe myelopathy treated with corpectomy; B2, severe cervical myelopathy treated conservatively. The clinical outcome was evaluated with the modified JOA score, timed 10-meter walk, Mehalic grade, motor evoked potentials, the SF-12, and further assessed by external observers blinded to the type of treatment.

RESULTS

No significant differences in the recovery rates were found between the A1 and A2 groups at 6 months, although better results were recorded in the surgical groups (A1 and B1) at 12 months and at the final follow-up, as suggested by the significantly higher recovery rates. Multivariate analysis showed an inverse correlation between the duration of symptoms and the recovery rate (P<0.0001). Moreover, the preoperative timed 10-meter walk (P<0.004), the preoperative hypointensity on T1-weighted MR images (P<0.001), a higher Mehalic grade (P<0.02), the pre-treatment MEP (P<0.002), and the preoperative spinal canal diameter (P<0.004) significantly influenced the recovery rate.

CONCLUSIONS

This prospective double-armed non-randomized study demonstrates that corpectomy is an effective and safe treatment, especially for severe forms of myelopathy. In mild-moderate conditions, a discrepancy between neurological improvement and expressed level of satisfaction was found. The present results also show that a multiparametric evaluation is crucial for proper patient selection for corpectomy.

Anterior Cervical Corpectomy and Fusion for Degenerative Cervical Spondylotic Myelopathy: Case Presentation With Surgical Technique Demonstration and Review of Literature

Anterior cervical corpectomy and fusion (ACCF) provides an extensive decompression and provides a large surface area for fusion in patients presenting with cervical spondylotic myelopathy. Unfortunately, this procedure is a more difficult spinal surgery to perform (compared with a traditional anterior cervical discectomy and fusion) and has a higher incidence of overall complications. In literature, ACCF has functional outcomes that seem clinically equivalent to those for multilevel anterior cervical discectomy and fusion, especially when contained to 1 vertebral body level, and in cases, for which both posterior and anterior procedures would be appropriate surgical options, may provide greater long-term clinical benefit than posterior fusion or laminoplasty. In this manuscript, we summarize the indications and outcomes following ACCF for degenerative cervical spondylotic myelopathy. We then describe a case presentation and associated surgical technique with a discussion of complication avoidance with this procedure.

Anterior cervical discectomy and fusion is more effective than cervical arthroplasty in relieving atypical symptoms in patients with cervical spondylosis

BACKGROUND AND PURPOSE

Patients with cervical spondylosis often present with concurrent 'atypical symptoms' of unknown etiology that have been associated with cervical spondylotic disease, including dizziness, headache, nausea, tinnitus, blurred vision, palpitations, and memory and gastrointestinal disturbances. Few studies have addressed whether surgical intervention to treat classic symptoms of cervical spondylosis can also effectively alleviate atypical symptoms. Accordingly, the purpose of this study is to compare the ability of cervical arthroplasty (CA) and anterior cervical discectomy and fusion (ACDF) to alleviate atypical symptoms associated with cervical spondylosis.

MATERIALS AND METHODS

A retrospective analysis of 140 patients with cervical spondylosis and associated atypical symptoms was performed. Atypical symptoms were defined vertigo, headache, nausea and vomiting, tinnitus, blur vision, palpitation, hypomnesia, and gastroenteric disturbances not otherwise explained by medical comorbidities. Seventy-eight patients (55.7%) underwent ACDF and 62 (44.3%) patients underwent CA. Demographics, surgical characteristics, patient reported outcome measures (PROMs), radiographs, complication rates, and resolution in atypical symptoms were recorded and compared between groups. Atypical symptoms were assessed using a 20-point system. All the patients had a minimum of five years follow-up.

RESULTS

VAS, SF-36, JOA, and NDI scores improved significantly in all the patients (p < 0.001). At the last follow-up, the fusion rate was 97% in the ACDF group. Atypical symptoms improved in both groups (p < 0.001), although the ACDF group demonstrated greater improvement in headache and vertigo resolution compared to the CA group (p < 0.0001).

CONCLUSIONS

While both ACDF and CA are effective in alleviating atypical symptoms associated with cervical spondylosis, ACDF demonstrated greater improvements in atypical symptoms.

SEVERE CERVICAL MYELOPATHY: APPROACHES AND POSTOPERATIVE EVALUATION

ABSTRACT Objectives: To evaluate and compare the clinical evolution of surgical approaches used in patients with severe cervical myelopathy. Methods: Retrospective observational study in which 19 patients with myelopathy who underwent surgery were evaluated. Neurological assessments using the Frankel scale were conducted both preoperatively and one year following surgery, and the modified Japanese Orthopedic Association (JOA), Nurick, and Visual Analog Scale for pain (VAS) questionnaires were applied 1 year after the surgical procedure. Results: 89% of the participants were male and the average age was 63.9 years. No patient had postoperative neurological worsening, 12 patients (63.16%) had mild pain, and seven (36.84%) had moderate pain. The group with degenerative disease showed neurological improvement after surgery and the exclusively anterior approach was used in 84% of the cases, the exclusively posterior approach in 10% of the cases, and the dual approach in 6% of the cases. Conclusion: Surgical treatment has good results for inhibiting the unfavorable natural evolution of myelopathy within 1 year following surgery and promotes neurological improvement in degenerative cases, making it possible to use the anterior access route in most cases. Level of evidence III; Retrospective Study.

Change in the postoperative intervertebral space height and its impact on clinical and radiological outcomes after ACDF surgery using a zero-profile device: a single-Centre retrospective study of 138 cases

BACKGROUND

The effects of postoperative intervertebral height (IH) changes on the clinical and radiological outcomes after anterior cervical decompression and fusion (ACDF) surgery using a zero-profile device remain unclear.

METHODS

We retrospectively reviewed patients who had undergone ACDF using a zero-profile device from March 2012 to February 2016 at our institution. Based on the postoperative IH variation, the patients were divided into group A with postoperative IH 0 to 2 mm, group B with postoperative IH 2 to 4 mm, and group C with postoperative IH greater than 4 mm. Clinical efficacy was evaluated using JOA, VAS, and NDI scores in the groups. Imaging parameters including the IH, cervical lordosis, fusion rate, intervertebral foramen (IVF) diameter and complications such as subsidence, dysphagia, and ASD were also compared across the three groups.

RESULTS

The average IH increased significantly from 6.72 mm preoperatively to 10.46 mm 1 week after surgery, and then gradually decreased to 7.48 mm at the final follow-up. The fusion rate was 61.90% in group A, 63.23% in group B, 53.57% in group C at 3 months, 73.81% in group A, 79.41% in group B, 67.86% in group C at 6 months, 90.48% in group A, 95.59% in group B, 92.86% in group C 1 year after surgery, and at the last follow-up, the fusion rate of three groups was all 100%. The IVF diameter was 6.52 ± 1.80 mm in group A, 9.55 ± 2.36 mm in group B, and 9.34 ± 1.62 mm in group C. ASD at the superior and inferior levels affected 11.90 and 16.67% patients in group A, 5.88 and 7.38% in group B, and 14.28 and 10.71% in group C. Regarding the 3 groups, the subsidence rates were 7.14, 4.41, and 14.29%, respectively.

CONCLUSIONS

No clear correlation was found between IH changes and clinical efficacy within a year of surgery. However, the IH may affect various complications after ACDF. If postoperative IH changes are maintained at 2 to 4 mm after a year, a satisfactory imaging parameters and relatively low complications may be achieved after ACDF surgery using a zero-profile device.

Pattern and Rate of Functional Recovery After Surgery for Cervical Spondylotic Myelopathy: Egyptian Prospective Study

OBJECTIVE

To study pattern and rate of neurological functional recovery after surgery for cervical spondylotic myelopathy (CSM).

METHODS

This prospective study comprised 25 patients with CSM who underwent surgical decompression at our institution. Upper limb, lower limb, and sphincter functions were assessed using the modified Japanese Orthopaedic Association score (mJOA). Assessment was done before the operation and at 1 month, 3 months, and 1 year after surgery.

RESULTS

The mJOA score did not significantly increase at 1 month after surgery (P = 0.051); however, increase in mJOA score was statistically significant at 3 and 1 year after surgery (P < 0.001 and P < 0.001, respectively). Upper limb motor dysfunction improved in 65% of patients, lower limb motor dysfunction improved in 52% of patients, upper limb sensory dysfunction improved in 48% of patients, and sphincter dysfunction improved in 14.2% of patients. There was a significant positive correlation between preoperative and postoperative mJOA score at 1 month, 3 months, and 1 year after surgery.

CONCLUSIONS

Minimal improvement occurred in the first month after CSM surgery to reach a peak at 3 months after surgery and steady improvement up to 1 year after surgery. Upper limbs recovered better and earlier than lower limbs and sphincter function. Preoperative severity of CSM is one of the main predictors of postoperative neurological outcome.

Effectiveness of 2 Types of Drill Templates for Cervical Anterior Transpedicular Screw Placements: A Comparative Study

OBJECTIVE

To evaluate effectiveness of regular and modified drill templates used to guide cervical anterior transpedicular screw (ATPS) placement.

METHODS

This study included 15 adult cadaveric specimens. Computed tomography images were imported into Mimics software. Three-dimensional modeling of all cervical vertebrae was done, and the ideal trajectories were designed for ATPSs. Models of regular and modified templates were designed for every level on the left or right side randomly. After three-dimensional printing, 2 types of templates were used to guide the insertion. Postoperative computed tomography scans were used to measure deviations between real and ideal trajectories in the direction and positioning of entry points. The deviations in the 2 groups were compared using paired t test.

RESULTS

There were 120 templates and ATPSs fabricated and placed. Postoperative images showed that 7 screws perforated pedicles in the regular group, with an accuracy rate of 88.3%. Deviations between real and ideal trajectories in cranially inclined angles and extroversive angles were 1.13° ± 0.61° and 0.97° ± 0.60°, respectively, and deviations of entry point position in the x-axis and y-axis were 0.72 ± 0.38 mm and 0.95 ± 0.47 mm, respectively. In the modified group, there were 2 malposition screws with accuracy rate of 96.7%. Deviations in cranially inclined angles were 0.66° ± 0.53° and 0.66° ± 0.55° in extroversive angles, respectively, and deviations in entry point positions in the x-axis and y-axis were 0.45 ± 0.37 mm and 0.51 ± 0.34 mm, respectively. The differences in deviations between groups were statistically significant.

CONCLUSIONS

Compared with regular drill templates, modified drill templates can provide higher accuracy and stronger trajectory control in ATPS insertions.

Effect of Changes in Postoperative Intervertebral Space Height on Clinical and Radiological Outcomes After Cervical Disc Replacement

BACKGROUND

Narrowing of intervertebral space height (ISH) is an important pathological change in degenerative spinal disease, and ideal intraoperative distraction and postoperative intervertebral space maintenance is one of the most expectant goals pursued by spinal surgeons. The effect of postoperative ISH changing on the clinical and radiological outcomes after cervical disc replacement is not fully understood, however.

METHODS

In this study, the height variation and general trend of postoperative ISH in all patients were analyzed. The patients were divided into 3 groups based on the change of postoperative intervertebral space height (ISH)-group A (ISH <2 mm), group B (ISH 2-4 mm), and group C (ISH >4mm)-and the clinical and radiographic results compared among the 3 groups.

RESULTS

A total of 120 consecutive patients with symptomatic cervical disc disease were included in this study. The results showed that the mean ISH increased significantly from 0.729 mm before surgery to 1.143 mm at 1 week, then gradually decreased to 1.032 mm at 3 months, 0.980 mm at 6 months, 0.760 mm at one year, and 0.750 mm at the final follow-up. The average postoperative Neck Disability Index (NDI) was 19.73 ± 0.81, 13.74 ± 4.94, 17.19 ± 4.22, respectively, in the 3 groups at 1 year after surgery and the average range of motion (ROM) was 5.44° ± 3.85° in group A, 9.34° ± 4.38° in group B, and 6.51° ± 4.38° in group C. The mean diameter of the intervertebral foramen was 6.54 ± 1.86 mm in group A, 9.63 ± 2.38 mm in group B, and 9.31 ± 1.68 mm in group C. Degeneration at the superiorly adjacent disc level was observed in 13.51% patients in group A, 9.37% in group B, and 21.05% in group C. Degeneration at the inferiorly adjacent level was radiographically identified in 21.62% in group A, 14.06% in group B, and 26.32% in group C.

CONCLUSIONS

This study revealed that cervical disc replacement cannot maintain the intervertebral disc height obtained immediately after surgery. There is no obvious correlation between the change in intervertebral space height and clinical efficacy in the early postoperative stage. Nonetheless, the intervertebral disc height may affect the NDI index 1 year after surgery. If the postoperative intervertebral space height change can be maintained at 2-4 mm at 1 year, satisfactory ROM, intervertebral foramen diameter, and relatively low adjacent segment degeneration may be obtained after cervical disc replacement.

Cervical Spondylotic Myelopathy: When and Why the Cervical Corpectomy?

BACKGROUND

Cervical spondylotic myelopathy (CSM) is a degenerative disease that represents the most common spinal cord disorder in adults. The best treatment option has remained controversial. We performed a prospective study to evaluate the clinical, radiographic, and neurophysiologic outcomes for anterior cervical corpectomy in the treatment of CSM.

METHODS

From January 2011 to January 2017, 60 patients with CSM were prospectively enrolled in the present study. The patients were divided according to the modified Japanese Orthopaedic Association scale (mJOA) score into 2 groups: group A, patients with mild to moderate CSM (mJOA score ≥13); and group B, patients with severe myelopathy (mJOA score <13). Data were collected for each participating subject, including demographic information, symptoms, medical history, radiologic and neurophysiologic features, and functional impairment.

RESULTS

Of the 60 patients, 35 were men (58.3%) and 25 were women (41.7%). Their average age was 57.48 ± 10.60 years. The mean symptom duration was 25.33 ± 16.00 months; range, 3-57 months). Of the 60 patients, 22 had undergone single-level corpectomy and 36 multilevel corpectomy. A significant improvement in the motor evoked potentials was observed in both groups.

CONCLUSIONS

Single- and multilevel corpectomy are valid and safe options in the treatment of CSM. In the present prospective study, a statistically significant improvement in the mJOA score and neurophysiologic parameters was observed for both moderate and severe forms of CSM.

Outcome Measures and Variables Affecting Prognosis of Cervical Spondylotic Myelopathy: WFNS Spine Committee Recommendations

This study is conducted to review the literature systematically to determine most reliable outcome measures, important clinical and radiological variables affecting the prognosis in cervical spondylotic myelopathy patients. A literature search was performed for articles published during the last 10 years. As functional outcome measures we recommend to use modified Japanese Orthopaedic Association scale, Nurick’s grade, and Myelopathy Disability Index. Three clinical variables that affect the outcomes are age, duration of symptoms, and severity of the myelopathy. Examination findings require more detailed study to validate their effect on the outcomes. The predictive variables affecting the outcomes are hand atrophy, leg spasticity, clonus, and Babinski’s sign. Among the radiological variables, the curvature of the cervical spine is the most important predictor of prognosis. Patients with instability are expected to have a poor surgical outcome. Spinal cord compression ratio is a critical factor for prognosis. High signal intensity on T2-weighted magnetic resonance images is a negative predictor for prognosis. The most important predictors of outcome are preoperative severity and duration of symptoms. T2 hyperintensity and cord compression ratio can also predict outcomes. New radiological tests may give promising results in the future.

The DOWN Questionnaire: A Novel Screening Tool for Cervical Spondylotic Myelopathy

STUDY DESIGN

Case-control study.

OBJECTIVES

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord injury in adults aged over 55 years. However, since the onset is typically insidious, accurately diagnosing CSM can be challenging, often requiring referral to a subspecialist and advanced imaging. To help identify patients at risk for CSM, this case-control study compared responses to a series of 4 questions (DOWN questionnaire) in myelopathic and non-myelopathic patients.

METHODS

Ninety-two patients, 46 with and 46 without myelopathy, were recruited for the study. Each patient answered 4 questions encompassing common symptoms associated with CSM. Responses between patient groups were compared, and Cohen's κ was used to assess for agreement between responses and the diagnosis of myelopathy.

RESULTS

We found a sensitivity of 91% and a κ of 0.54 to 3 positive responses and a sensitivity of 72% and a κ of 0.61 to 4 positive responses.

CONCLUSIONS

Positive responses to 3 or more DOWN questions has high sensitivity and moderate agreement with the diagnosis of myelopathy based on history, physical exam, and review of advanced imaging by an orthopedic or neurological surgeon. The DOWN questionnaire is a potentially useful screening tool to identify patients at risk for CSM.

The Natural History of Cervical Spondylotic Myelopathy and Ossification of the Posterior Longitudinal Ligament: A Review Article

Cervical spondylotic myelopathy (CSM) is the chronic and slow deterioration of cervical spinal cord function. The pathophysiology of this condition is multifactorial, including compression, repetitive trauma, and vascular compromise of the spinal cord. Clinically, it presents as a progressive decline in patients' appendicular neurological function. The natural history of this disease varies but, it is well-known that the duration and degree of compression correlate negatively with prognosis. A mild degree of CSM tends to stabilize with potential improvement over time while more severe CSM tends to progress. Surgical intervention has shown to positively alter the natural history of the disease by halting the progression with some restoration of function. Ossification of the posterior longitudinal ligament (OPLL) is a chronic disease that results in progressive ossification of the posterior longitudinal ligament of the spine. It commonly affects the cervical spine. The etiology is multifactorial in nature, including genetic and environmental factors. The progressive nature of this condition and the resultant cervical spinal stenosis make it one of the main causes of cervical myelopathy (CM). There is no medical therapy for this disease, and surgery is reserved for patients with CM caused by spinal cord compression. In this article, we review the different aspects of the natural history of both CSM and OPLL.

Smoking is Associated With 1-year Suboptimal Patient-reported Outcomes After 2-level Anterior Cervical Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To study the impact of smoking on patient-reported outcomes after primary 2-level anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Previous studies have found suboptimal outcomes after multilevel ACDF in smoking patients. There is contrasting evidence on the negative effects of smoking in single-level ACDF, while there are no specific reports in 2-level ACDF. Adding knowledge of smoking's impact on patient-reported outcomes (PRO) will help in tailored patient counseling and preoperative education.

METHODS

Patients 18 years of age or older at a single academic institution who underwent 2-level ACDF to treat cervical radiculopathy and/or myelopathy between September 2013 and September 2015 were included. PRO was studied using the neck disability index (NDI) preoperatively, and at 3, 6, 12 months. χ test for qualitative variables, and one-way analysis of variance (ANOVA) and unpaired t test for quantitative variables were used for statistical analysis.

RESULTS

A total of 61 patients, of which 23 (37.7%) were classified as smokers were included. Demographic and clinical profile of patients was similar both groups. Preoperatively, smokers had a mean NDI of 62.8±12.7 with a 17.5%, 18.7%, and 27.7% decrease at 3, 6, and 12-months, respectively. Nonsmokers had a mean preoperative NDI of 45.9±15.3, with a 36.4%, 61.2% and 65.4% decrease at 3, 6, and 12-months, respectively. Despite higher baseline NDI in smokers, improvement in NDI reached significance at 3-months in nonsmokers. In smokers, the improvement in NDI was slower and reached significance at 12-months. The radiographic fusion status at latest follow-up was similar in smokers and nonsmokers (P=0.67).

CONCLUSIONS

Smokers had lower improvements in NDI scores compared to nonsmokers after a 2-level ACDF. Preoperative counseling before 2-level ACDF should include education about risks of inferior clinical outcomes in smokers independent of fusion status.

Clinical and Radiological Outcomes of Anterior Approach Microscopic Surgery for the Pincer Mechanism in Cervical Spondylotic Myelopathy

Objective

We aimed to evaluate the efficacy of anterior approach microscopic surgery for patients with the pincer mechanism in cervical spondylotic myelopathy.

Methods

The clinical data of pincer cervical spondylotic myelopathy that received anterior cervical decompression and fusion in our hospital from Aug 2014 to Dec 2017 were analyzed retrospectively, including 12 males and 9 females, with an average age of 64.3 years (range 46-81 years). Occupying rate, anterior occupying rate, and posterior occupying rate were measured on pre- and postoperative mid-sagittal MRIs. Pre- and postoperative Japanese Orthopedic Association (JOA) scores, intervertebral space height, and C2 to C7 Cobb's angle were analyzed.

Result

Duration of follow-up was six months. The pre- and postoperative anterior occupying rate were averagely 38.6±8.5% and 12.9±5.5%, respectively, the posterior occupying rates were averagely 27.4±7.2% and 13.1±6.6%, respectively, and Cobb's angle changed from 15.3±8.0° to 22.7±7.9°. The intervertebral space height increased from 4.6±0.4mm to 6.5±0.4mm. JOA scores improved significantly by 59.4±34.0% at six months after surgery.

Conclusion

Decompression by anterior microscopic surgery can increase spinal canal volume directly, recover intervertebral space height, and resize Cobb's angle, but decrease the posterior compression by ligament Flava indirectly. Anterior decompression under the microscope may provide an alternative surgical option for partial patients with the pincer mechanism in cervical spondylotic myelopathy.

CERVICAL SPONDYLOTIC MYELOPATHY: CLINICAL CASES AND PHYSIOTHERAPY

ABSTRACT The aims of this article are to present cervical spondylotic myelopathy, a spinal condition caused by bony, ligament and disc alterations that results in spinal cord compression leading to progressive degeneration of the spinal cord, and to describe the possible physiotherapeutic interventions. The pathology has different forms of progression and affected areas, which contributes to the diversity of clinical presentations. This work presents two evaluations of three patients diagnosed with this disease, at different times, to compare the severity, the affected regions, and the evolution of each one. Subsequently, it describes the most appropriate physiotherapeutic treatment for this illness, demonstrating its wide variability according to the signs and symptoms presented. Level of Evidence: IV. Case series.

Effect of Social Factors on Surgical Outcomes in Cervical Disc Disease

Background

Daily clinical practice shows us how diametrically different surgical outcomes can occur in particular groups of patients sharing the same diagnosis and being subjected to the same treatment. Patient-reported outcomes appear to be significantly influenced by social factors and patients’ emotional status. Data on such variables were collated and analyzed statistically with the aim of confirming our clinical observations.

Methods

We analyzed a group of 100 patients following cervical disc surgery. The clinical evaluation was based on a visual analog scale (VAS) for pain and the neck disability index (NDI). Non-clinical data comprised education status, employment status, body mass index (BMI), and history of depressive episodes in the period immediately preceding the surgery, which was investigated using the Beck Depression Inventory (BDI).

Results

Patients who had completed university or secondary school education had a significantly lower BMI and lower BDI scores and they reported less pain at 12 months postoperatively than patients with vocational or elementary school education only. Patients who were employed at the time of the study or were retired demonstrated significantly lower NDI scores both before the surgery and at 12 months postoperatively, as well as lower BDI scores compared to those who were unemployed or drew disability pensions. Factors such as age or BMI score did not exert a direct effect on treatment outcomes assessed as changes in the VAS and NDI scores.

Conclusions

Surgical treatment for the cervical disc disease decreases pain and improves patients’ quality of life. Treatment outcomes are also influenced by social factors and patients’ emotional status.

A Comparison of Cervical Disc Arthroplasty and Anterior Cervical Discectomy and Fusion in Patients with Two-Level Cervical Degenerative Disc Disease: 5-Year Follow-Up Results

OBJECTIVE

To present a long-term clinical and radiographic comparison between the Prestige LP cervical disc replacement and the Zero-P spacer cervical disc fusion in the treatment of patients with symptomatic 2-level cervical degenerative disease.

METHODS

In total, 36 patients in the anterior cervical discectomy and fusion (ACDF) group and 24 patients in the cervical disc arthroplasty (CDA) group were analyzed before surgery and at 1 week and 3, 6, 12, 24, and 60 months after surgery. Clinical assessments included the Japanese Orthopaedic Association score, visual analog scale, and Neck Disability Index scores. Radiographic assessments included cervical lordosis, range of motion (ROM) of the total cervical spine, functional spinal unit (FSU), and superior and inferior adjacent segments. Complications including heterotopic ossification and adjacent-segment degeneration (ASD) at 5-year follow-up were collected as well.

RESULTS

Mean follow-up period was 65.6 months. Both the ACDF and CDA groups showed significant clinical improvements in terms of Japanese Orthopaedic Association score, visual analog scale, and Neck Disability Index (P < 0.05), but there was no significant difference between groups at the last follow-up period. A significant increase of cervical lordosis was observed in the CDA group after surgery whereas a significant difference was not observed between groups. ROM of the total cervical spine and FSU were maintained during the follow-up, and a significant decrease was observed in the ACDF group after surgery (P < 0.05). The ROM of the superior adjacent segment did not show any difference whereas the ROM of the inferior adjacent segment in the ACDF group presented a significant increase at 6 months and 1 year after surgery and a significant decrease at the last follow-up period. A total of 8 (33.3%) patients in the CDA group had an occurrence of heterotopic ossification. ASD was observed in 2 (8.3%) patients who underwent CDA surgery and 8 (22.2%) patients who underwent ACDF surgery.

CONCLUSIONS

The use of the Prestige-LP and ZERO-P Spacer implantations is safe and effective. At 5 years after surgery, CDA with Prestige-LP is superior in terms of ROM of the total cervical spine, FSU, and inferior adjacent segment. It also has a relatively low occurrence rate of ASD. This procedure may be a suitable choice for the treatment of contiguous 2-level CDDD.

Chronic preoperative opioid use is a risk factor for increased complications, resource use, and costs after cervical fusion

BACKGROUND CONTEXT

As health-care transitions to value-based models, there has been an increased focus on patient factors that can influence peri- and postoperative adverse events, resource use, and costs. Many studies have reported risk factors for systemic complications after cervical fusion, but none have studied chronic opioid therapy (COT) as a risk factor.

PURPOSE

The objective of this study was to answer the following questions from a large cohort of patients who underwent primary cervical fusion for degenerative pathology: (1) What is the patient profile associated with preoperative COT? (2) Is preoperative COT a risk factor for 90-day systemic complications, emergency department (ED) visits, readmission, and 1-year adverse events? (3) What are the risk factors and 1-year adverse events related to long-term postoperative opioid use? (4) How much did payers reimburse for management of complications and adverse events?

STUDY DESIGN

This is a retrospective review of Humana commercial insurance data (2007-Q3 2015).

PATIENT SAMPLE

The patient sample included 29,101 patients undergoing primary cervical fusion for degenerative pathology.

METHODS

Patients and procedures of interest were included using International Classification of Diseases (ICD) coding. Patients with opioid prescriptions for >6 months before surgery were considered as having preoperative COT. Patients with continued opioid use until 1-year after surgery were considered as long-term users. Descriptive analysis of patient cohorts has been done. Multiple-variable logistic regression analyses adjusting for approach, number of levels of surgery, discharge disposition, and comorbidities were done to answer first three study questions. Reimbursement data from insurers have been reported to answer our fourth study question.

RESULTS

Of the entire cohort, 6,643 (22.8%) had preoperative COT. Preoperative COT was associated with a higher risk of 90-day wound complications (odds ratio [OR] 1.39, 95% confidence interval [CI]: 1.16-1.66), all-cause 90-day ED visits (adjusted OR 1.22, 95% CI: 1.13-1.32), and pain-related ED visits (adjusted OR 1.39, 95% CI: 1.24-1.55). Patients who had preoperative COT were more likely to receive epidural or facet joint injections within 1 year after surgery (adjusted OR 1.68, 95% CI: 1.47-1.92). These patients were also more likely to undergo a repeat cervical fusion within a year than patients who did not have preoperative COT (adjusted OR 1.21, 95% CI: 1.01-1.43). Preoperative COT had a higher likelihood of long-term use after surgery (adjusted OR 4.72, 95% CI: 4.41-5.06). Long-term opioid use after surgery was associated with a higher risk of new-onsetconstipation (adjusted OR 1.34, 95% CI: 1.22-1.48). The risk of complications and adverse events was not found to be significant in patients with <3 months of preoperative opioid use or those who stopped opioids for at least 6 weeks before surgery. The cost of additional resource use for medications, ED visits, constipation, injections, and revision fusion ranged from $623 to $27,360 per patient.

CONCLUSIONS

Preoperative opioid use among patients who underwent cervical fusion increases complication rates, postoperative opioid usage, health-care resource use, and costs. These risks may be reduced by restricting the duration of preoperative opioid use or weaning off before surgery. Better understanding and management of pain in the preoperative period with judicious use of opioids is critical to enhance outcomes after cervical fusion surgery.

Long-Term Sustainability of Functional Improvement Following Central Corpectomy for Cervical Spondylotic Myelopathy and Ossification of Posterior Longitudinal Ligament

STUDY DESIGN

Retrospective study.

OBJECTIVE

To examine predictors of long-term outcome and sustainability of initial functional improvement in patients undergoing corpectomy for cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament (OPLL).

SUMMARY OF BACKGROUND DATA

There are limited data on the predictors of outcome and sustainability of initial functional improvement on long-term follow-up after cervical corpectomy.

METHODS

We studied the functional outcome at more than 1-year follow-up after central corpectomy in 352 patients with CSM or OPLL. Functional status was evaluated with the Nurick grading system. Analysis was directed at identifying factors associated with both improvement in functional status and the achievement of a "cure" (improvement to a follow-up Nurick grade of 0 or 1). A survival analysis was performed to identify factors associated with sustained functional improvement in patients with serial follow-up evaluations.

RESULTS

Nurick grade improved from 3.2 ± 0.1 to 1.9 ± 0.1 over a mean follow-up period of 57.1 months (range 12-228 mo). On multivariate analysis, age ≥50 years (P = 0.008) and symptom duration ≥1 year (P < 0.001) were negatively associated with functional improvement by ≥1 Nurick grade. Independent factors negatively associated with "cure" after surgery included age 50 years or older (P = 0.005), preoperative Nurick grade of 4 or higher (P < 0.001) and symptom duration of 1 or more years (P < 0.001). Early improvement in functional status was maintained in 90.5% and 76.3% of patients at 5 and 10 years follow-up, respectively. On survival analysis, patients with shorter preoperative symptom duration (<1 yr) were more likely to demonstrate sustained improvement in functional status after surgery (P = 0.022).

CONCLUSION

Initial gains in functional status after central corpectomy for CSM and OPLL are maintained in more than 75% of patients at 10 years after surgery. Overall, the most favorable long-term outcomes are achieved in younger patients who present early and with good preoperative functional status.

LEVEL OF EVIDENCE

4.

Atypical symptoms in patients with cervical spondylosis: Comparison of the treatment effect of different surgical approaches

To compare the effectiveness of total disk replacement (TDR), anterior cervical discectomy and fusion (ACDF), and laminoplasty on atypical symptoms of cervical spondylosis.Patients with confirmed diagnosis of cervical spondylosis and reported atypical symptoms such as blurred vision, headache, nausea, palpitation, tinnitus, vertigo, hypomnesia, and abdominal discomfort were retrospectively included in the present study. They were treated with TDR, ACDF, or laminoplasty depending on the etiology and patient preference. Severity of the atypical symptoms before the surgery and at the end of 2-year follow-up was recorded and the degree of severity alleviation was compared between different surgical approaches.A total number of 336 patients who were treated in our institute from February 2002 to March 2011 were included in the final analysis. Atypical symptoms were significantly alleviated in most patients after surgical intervention. No significant differences were found regarding the change of severity of those symptoms among patients in different surgery groups.TDR, ACDF, and laminoplasty can equally alleviate the severity of atypical symptoms in patients with cervical spondylosis. This indicates that the neural network in the posterior longitudinal ligament may not be the cause of atypical symptoms in patients with cervical spondylosis.

No correlation between radiological and clinical outcome 1 year following cervical arthrodesis

AIM

To correlate clinical and radiological outcome following one- and two-level anterior cervical discectomy and fusion (ACDF) with stand-alone polyetheretherketone (PEEK) cages filled with demineralized bone matrix (DBM).

METHODS

We performed a retrospective review of a consecutive patient cohort with degenerative disc disease that underwent ACDF with stand-alone PEEK cages filled with demineralized bone matrix (DBM) between 2010 and 2013 with a minimum follow-up of 12 months. Changes in the operated segments were measured and compared to radiographs directly after surgery. Clinical outcome was evaluated by a physical examination, pain by visual analog scale (VAS) for arm and neck. Health-related quality of life was measured using the EuroQOL questionnaire (EQ-5D).

RESULTS

Of 282 consecutive cases, follow-up data were obtained from 194 (69%) cases. The median age at presentation was 54 years and 91 patients were male (46%). Ninety-eight and 96 patients had one- and two-level surgeries, respectively. Mean VAS pain was reduced from 5.2 ± 3.6 to 2.6 ± 2.4 (p < 0.001) and from 5.8 ± 3.3 to 2.1 ± 2.7 (p < 0.001) in the myelopathy and radiculopathy group, respectively. Fusion was achieved in 79 and 82% of segments in one- and two-level surgeries, respectively. Cervical alignment was better in 10 and 1%, similar in 68 and 76%, worse in 23 and 23% in one- and two-level surgeries, respectively. Subsidence was observed in 44 and 34% of segments in one- and two-level surgeries, respectively. Follow-up operations due to symptomatic adjacent disc disease or implant failure were needed in 13 (7%) and 15 (8%) of cases, respectively. Subsidence, adjacent disc disease, and cervical alignment all had no influence on the clinical outcome.

CONCLUSIONS

The clinical outcome after ACDF with PEEK cages filled with demineralized bone matrix is highly satisfactory. Radiological signs of non-fusion, subsidence, and cervical alignment have no influence on clinical outcome.

Age-related changes of the spinal cord: A biomechanical study

Although it is known that aging plays an important role in the incidence and progression of cervical spondylotic myelopathy (CSM), the underlying mechanism is unclear. Studies that used fresh bovine cervical spinal cord report the gray matter of the cervical spinal cord as being more rigid and fragile than the white matter. However, there are no reports regarding the association between aging an tensile and Finite Element Method (FEM). Therefore, FEM was used based on the data pertaining to the mechanical features of older bovine cervical spinal cord to explain the pathogenesis of CSM in elderly patients. Tensile tests were conducted for white and gray matter separately in young and old bovine cervical spinal cords, and compared with their respective mechanical features. Based on the data obtained, FEM analysis was further performed, which included static and dynamic factors to describe the internal stress distribution changes of the spinal cord. These results demonstrated that the mechanical strength of young bovine spinal cords is different from that of old bovine spinal cords. The gray matter of the older spinal cord was significantly softer and more resistant to rupture compared with that of younger spinal cords (P<0.05). Among the old, although the gray matter was more fragile than the white matter, it was similar to the white matter in terms of its rigidity (P<0.05). The in vitro data were subjected to three compression patterns. The FEM analysis demonstrated that the stress level rises higher in the old spinal cords in response to similar compression, when compared with young spinal cords. These results demonstrate that in analyzing the response of the spinal cord to compression, the age of patients is an important factor to be considered, in addition to the degree of compression, compression speed and parts of the spinal cord compression factor.

Clinical Outcomes Following Surgical Management of Coexisting Parkinson Disease and Cervical Spondylotic Myelopathy

BACKGROUND

Distinguishing the causes of weakness and gait instability in patients with Parkinson disease (PD) and cervical spondylotic myelopathy (CSM) is a diagnostic and therapeutic challenge due to symptomatic similarities. No study has reported outcomes following decompression in patients with PD and CSM.

OBJECTIVE

To report outcomes following cervical decompression for patients with coexisting PD and CSM.

METHODS

A retrospective matched cohort study of all patients with PD and CSM undergoing cervical decompression at a tertiary-care center between January 1996 and December 2014 was conducted. PD patients were matched to patients with CSM alone by age, gender, American Society of Anesthesiologists classification, and operative parameters. Myelopathy was assessed by Nurick and modified Japanese Orthopaedic Association (mJOA) scales. The effect of PD on mJOA was modeled using multivariable regression.

RESULTS

Twenty-one matched pairs were included. PD patients experienced poorer improvement in Nurick (0.0 vs -1.0, P < .01) and mJOA (0.9 vs 2.5, P < .01) composite scores. However, no significant changes in absolute improvement in the upper extremity motor, upper extremity sensory, or sphincter mJOA components were observed. Multivariable regression identified PD as a significant predictor of decreased improvement in mJOA (β = -0.89, P < .01) and failure to achieve a minimal clinically important difference in change in mJOA (OR 0.18, P = .03).

CONCLUSION

This study is the first to characterize outcomes following cervical decompression in patients with PD and CSM. PD patients experienced symptomatic improvement but less overall improvement in myelopathy compared to controls. However, PD patients demonstrated improvement in upper extremity motor, upper extremity sensory, and sphincter symptoms no worse than control patients.

Management of degenerative cervical myelopathy - An update

Introduction

Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction in adult patients. Patients generally present with a slow, progressive neurological decline or a stepwise deterioration pattern. In this paper, we discuss the most important factors involved in the management of DCM, including a discussion about the surgical approaches.

Method

The authors performed an extensive review of the peer-reviewed literature addressing the aforementioned objectives.

Results

Although the diagnosis is clinical, magnetic resonance imaging (MRI) is the study of choice to confirm stenosis and also to exclude the differential diagnosis. The severity the clinical symptoms of DCM are evaluated by different scales, but the modified Japanese Orthopedic Association (mJOA) and the Nürick scale are probably the most commonly used. Spontaneous clinical improvement is rare and surgery is the main treatment form in an attempt to prevent further neurological deterioration and, potentially, to provide some improvement in symptoms and function. Anterior, posterior or combined cervical approaches are used to decompress the spinal cord, with adjunctive fusion being commonly performed. The choice of one approach over the other depends on patient characteristics (such as number of involved levels, site of compression, cervical alignment, previous surgeries, bone quality, presence of instability, among others) as well as surgeon preference and experience.

Conclusion

Spine surgeons must understand the advantages and disadvantages of all surgical techniques to choose the best procedure for their patients. Further comparative studies are necessary to establish the superiority of one approach over the other when multiple options are available.

Is Decompressive Surgery for Cervical Spondylotic Myelopathy Effective in Patients Suffering from Concomitant Multiple Sclerosis or Parkinson's Disease?

A subset of patients with a demyelinating disease suffer from concurrent cervical spondylotic myelopathy, both of which evince similar symptomatology. Differentiating the cause of these symptoms is challenging, and little research has been done on patients with coexisting diseases. This review explores the current literature on the appropriate surgical management of patients with concurrent multiple sclerosis (MS) and cervical spondylotic myelopathy (CSM), and those with both Parkinson’s disease (PD) and CSM. MS and CSM patients may benefit from surgery to reduce pain and radiculopathy. Surgical management in PD and CSM patients has shown minimal quality-of-life improvement. Future studies are needed to better characterize demyelinating disease patients with concurrent disease and to determine ideal medical or surgical treatment.

Surgical treatment of severe multilevel circumferential compressive myelopathy of the cervical spine: is circumferential procedure necessary?

OBJECTIVE

To determine the necessity of circumferential decompression and fusion in patients with severe multilevel cervical spondylotic myelopathy with circumferential cord compression.

METHODS

This prospective study involved 51 patients with severe multilevel circumferential cervical myelopathy underwent two-stage circumferential procedure between July 2008 and June 2010. VAS scores, satisfaction surveys and JOA scores and imaging studies were obtained. Twenty-three patients (45.1%) underwent two-stage surgery (group A); the other 28 patients (54.9%) were satisfied with the outcomes after first-stage surgery, and the second-stage surgery was avoided (group B). Age, sex and symptom duration did not differ between the groups.

RESULTS

Patients were followed up for 3-5 years (mean, 42.5 months). In group A, VAS and JOA scores significantly improved from 63.3 and 7.9 to 38.3 and 10.4, respectively, at 3 months after the first-stage operation and 10.2 and 12.7, respectively, at 3 months after the second-stage operation. In group B, the VAS and JOA scores significantly improved from 62.7 and 7.9 to 31.1 and 11.2 respectively, at 3 months and 18.2 and 12.4, respectively at 6 months. Patient satisfaction rate significantly increased from 43.5% after the first-stage operation to 82.6% after the second-stage operation in group A. In group B, this rate was 89.3%. In group A, cervical spine lordosis increased from 12.8° preoperatively to 18.5° (p < .0001) and 19.1° (p > .05) at 3 months after the first-stage and second-stage operations, respectively. In group B, lordosis significantly increased from 12.5° preoperatively to 18.8° at 3 months. The total complication rate did not significantly differ from the rates after a single surgery (either anterior or posterior).

CONCLUSION

Only 45.1% patients required surgery via both approaches. Therefore, a two-stage procedure is a rational choice and safe procedure. If outcomes are unsatisfactory after the first-stage operation, a second-stage operation can be performed.

A progressive compression model of thoracic spinal cord injury in mice: function assessment and pathological changes in spinal cord

Non-traumatic injury accounts for approximately half of clinical spinal cord injury, including chronic spinal cord compression. However, previous rodent spinal cord compression models are mainly designed for rats, few are available for mice. Our aim is to develop a thoracic progressive compression mice model of spinal cord injury. In this study, adult wild-type C57BL/6 mice were divided into two groups: in the surgery group, a screw was inserted at T₉ lamina to compress the spinal cord, and the compression was increased by turning it further into the canal (0.2 mm) post-surgery every 2 weeks up to 8 weeks. In the control group, a hole was drilled into the lamina without inserting a screw. The results showed that Basso Mouse Scale scores were lower and gait worsened. In addition, the degree of hindlimb dysfunction in mice was consistent with the degree of spinal cord compression. The number of motor neurons in the anterior horn of the spinal cord was reduced in all groups of mice, whereas astrocytes and microglia were gradually activated and proliferated. In conclusion, this progressive compression of thoracic spinal cord injury in mice is a preferable model for chronic progressive spinal cord compression injury.

Quality of life outcomes following cervical decompression for coexisting Parkinson's disease and cervical spondylotic myelopathy

BACKGROUND CONTEXT

Coexisting Parkinson's disease (PD) and cervical spondylotic myelopathy (CSM) presents a diagnostic and therapeutic challenge due to symptomatic similarities between the diseases. Whereas CSM patients are routinely treated with surgery, PD patients face poorer outcomes following spine surgery. No studies have investigated the quality of life (QOL) outcomes following decompression in coexisting PD and CSM.

PURPOSE

The purpose of the present study was to characterize QOL outcomes for patients with coexisting PD and CSM following cervical decompression.

STUDY DESIGN/SETTING

This is a matched cohort study at a single tertiary-care center.

PATIENT SAMPLE

Patients with coexisting PD and CSM undergoing cervical decompression between June 2009 and December 2014 were included. These patients were matched to controls with CSM alone by age, gender, American Society of Anesthesiologists classification, Modified Japanese Orthopaedic Association scores, and operative parameters.

OUTCOME MEASURES

The primary outcome measure was QOL outcomes assessed by change in the EuroQol 5-Dimensions (EQ-5D), Pain Disability Questionnaire (PDQ), and Patient Health Questionnaire-9 (PHQ-9) at last follow-up (LFU). Change in QOL exceeding the minimal clinically important difference (MCID) was secondary.

METHODS

QOL data were collected using the institutional prospectively collected database of patient-reported health status measures. Simple and multivariable regressions were used to assess the impact of PD upon change in QOL.

RESULTS

Eleven PD patients were matched to 44 controls. Control patients experienced QOL improvement across all three measures, whereas PD patients only improved with respect to PDQ(89.9-80.7, p=.03). Despite no significant differences in preoperative QOL, PD patients experienced poorer QOL at LFU in EQ-5D (0.526 vs. 0.707, p=.01) and PDQ (80.7 vs. 51.4, p=.03), and less frequently achieved an EQ-5D MCID (18% vs. 57%, p=.04). However, no differences in the achievement of an MCID in PDQ or PHQ-9 were observed between cohorts. Multivariable regression identified PD as a significant independent predictor of poorer improvement in EQ-5D (β=-0.09, p<.01) and failure to achieve an EQ-5D MCID (odds ratio: 0.08, p<.01).

CONCLUSIONS

This is the first study to characterize QOL outcomes following cervical decompression for patients with coexisting PD and CSM. Although myelopathy may have been less severe among PD patients, a significant reduction in pain-related disability was observed following decompression. However, PD predicted diminished improvement in overall QOL measured by the EQ-5D.

Imaging Evaluation and Relative Significance in Cases of Cervical Disk Allografting: Radiographic Character After Total Disk Transplantation

STUDY DESIGN

The clinical and radiologic data of total disk allografting (TDA) cases were collected and analyzed to explore the correlation between neurological function improvements and imaging changes.

OBJECTIVE

The aim of the study was to assess the medium-term and long-term outcome and radiographic character after TDA, and, furthermore, to explore the significance of the changes of imaging signs after the transplantation.

SUMMARY OF BACKGROUND DATA

Spinal fusion may result in the adjacent segment degeneration. The anxiousness urged the necessity for the development of TDA to reduce the risk of adjacent segment degeneration. Both animal studies and recent clinical trials have shown promising results to support the use of intervertebral disk allograft as a natural mobile disk replacement.

METHODS

The conditions of 13 cases that underwent TDA after cervical discectomy were recorded in detail. Axial symptoms and neurological function in various periods were assessed, and, meanwhile, radiologic examination was performed for the comprehensive evaluation of the relevant indicators before and after surgery.

RESULTS

(1) There was significant improvement in the neurological function after TDA. Postoperatively, the Visual Analog Score of axial symptoms did not increase significantly. (2) Both the entire and local segment maintained a satisfactory curve after allografting. There was no obvious correlation between the neurological function recovery and the cervical curve. Besides, the motion of the cervical spine did not change postoperatively. (3) Postoperatively, the spinal cord area at the index level increased significantly, whereas the signal value of the transplanted disk decreased sharply.

CONCLUSIONS

(1) Disk allografting is one of the effective and safe methods in treating the diseases of cervical disk herniation. (2) Although some degeneration occurs in the transplanted disk, the allograft can still be alive and can successfully maintain and improve the biological characters of the cervical spine in both radiologic and practical aspects.

Revision surgery for cervical artificial disc: Surgical technique and clinical results

OBJECTIVE

Cervical artificial disc replacement (C-ADR) was developed with the goal of preserving mobility of the cervical segment in patients with degenerative disc disease. So far, little is known about experiences with revision surgery and explantation of C-ADRs. Here, we report our experience with revision the third generation, Galileo-type disc prosthesis from a retrospective study of two institutions.

PATIENTS AND METHODS

Between November 2008 and July 2016, 16 patients with prior implantation of C-ADR underwent removal of the Galileo-type disc prosthesis (Signus, Medizintechnik, Germany) due to a call back by industry. In 10 patients C-ADR was replaced with an alternative prosthesis, 6 patients received an ACDF. Duration of surgery, time to revision, surgical procedure, complication rate, neurological status, histological findings and outcome were examined in two institutions.

RESULTS

The C-ADR was successfully revised in all patients. Surgery was performed through the same anterior approach as the initial access. Duration of the procedure varied between 43 and 80min. Access-related complications included irritation of the recurrent nerve in one patient and mal-positioning of the C-ADR in another patient. Follow up revealed two patients with permanent mild/moderate neurologic deficits, NDI (neck disability index) ranged between 10 and 42%.

CONCLUSIONS

Anterior exposure of the cervical spine for explantation and revision of C-ADR performed through the initial approach has an overall complication rate of 18.75%. Replacements of the Galileo-type disc prosthesis with an alternative prosthesis or conversion to ACDF are both suitable surgical options without significant difference in outcome.

Establishment of a rat model of chronic thoracolumbar cord compression with a flat plastic screw

Previous studies of animal models of chronic mechanical compression of the spinal cord have mainly focused on cervical and thoracic lesions, but few studies have investigated thoracolumbar injury. The specific pathophysiological mechanism of chronic thoracolumbar cord injury has not yet been elucidated. The purpose of this study was to improve animal models of chronic thoracolumbar cord compression using the progressive screw. A custom-designed flat plastic screw was implanted in the spinal cord between thoracic vertebrae 12 and lumbar 1 of rats. The screw was tightened one complete turn (0.5 mm) every 7 days for 4 weeks to create different levels of chronic spinal cord compression. Following insertion of the screw, there was a significant decline in motor function of the hind limbs, and severe stenosis of micro-computed tomography parameters in the spinal cord. Cortical somatosensory evoked potential amplitudes were reduced remarkably, and latencies were prolonged at 30 minutes after surgery. The loss of motor neurons in the gray matter was marked. Demyelination and cavitation were observed in the white matter. An appropriate rat model of chronic thoracolumbar cord compression was successfully created using the progressive screw compression method, which simulated spinal cord compression injury.

Clinical and radiological outcome after anterior cervical discectomy and fusion with stand-alone empty polyetheretherketone (PEEK) cages

OBJECTIVE

To evaluate long-term results after one-, two-, and three-level anterior cervical discectomy and fusion (ACDF) with stand-alone empty polyetheretherketone (PEEK) cages.

METHODS

We performed a retrospective review of a consecutive patient cohort that underwent ACDF with stand-alone empty PEEK cages between 2007 and 2010 with a minimum follow-up of 12 months. Radiographic follow-up included static and flexion/extension radiographs. Changes in the operated segments were measured and compared to radiographs directly after surgery. Clinical outcome was evaluated by a physical examination, pain visual analog scale (VAS), and health-related quality of life (HRQL) using the EuroQOL questionnaire (EQ-5D). Analysis of associations between fusion, subsidence, cervical alignment, and clinical outcome parameters were performed.

RESULTS

Of 407 consecutive cases, 318 met all inclusion criteria. Follow-up data were obtained from 265 (83 %) cases. The mean age at presentation was 55 years and 139 patients were male (52 %). In the sample, 127, 125, and 13 patients had one-, two-, and three-level surgeries, respectively; 132 (49 %) presented with spondylotic cervical myelopathy and 133 (50 %) with cervical radiculopathy. Fusion was achieved in 85, 95, and 94 % of segments in one-, two-, and three-level surgeries, respectively. Non-fusion was associated with higher VAS pain levels. Radiographic adjacent segment disease (ASD) was observed in 20, 29, and 15 % in one-, two-, and three-level surgeries, respectively. ASD was associated with lower HRQL. Subsidence was observed in 25, 27, and 15 % of segments in one-, two-, and three-level surgeries, respectively. However, this had no influence on clinical outcome. Follow-up operations for symptomatic adjacent disc disease and implant failure at index level were needed in 16 (6 %) and four (1.5 %) cases, respectively. Younger age was associated with better clinical outcome. Multilevel surgery favored better myelopathy outcomes and fusion reduced overall pain. ASD worsened EuroQOL-Index values. Worsening of the cervical alignment induced arm pain.

CONCLUSIONS

One- and two-level ACDF with stand-alone empty PEEK cages achieved very high fusion rates and a low rate of follow-up operations. The rate of good clinical outcome is highly satisfactory. Younger age was the single most influential factor associated with better clinical outcome.

Effect of different surgical methods on headache associated with cervical spondylotic myelopathy and/or radiculopathy

BACKGROUND

Anterior cervical discectomy and fusion, total disk replacement and open door laminoplasty have been widely used to treat patients with cervical spondylotic myelopathy and/or radiculopathy. In our clinical practice, many patients with cervical spondylosis also complain of headache, and wish to know if the surgical treatment for cervical spondylosis can also alleviate this symptom. Considering that there is no literature concerning this extra benefit of surgical manipulation on cervical spondylosis, we have carried out this retrospective study.

METHODS

Among the patients treated with anterior cervical discectomy and fusion, total disk replacement and open door laminoplasty in our institute for cervical spondylotic myelopathy and/or radiculopathy between February 2002 to March 2011, 108 of whom that have complained about headache at the same time were included in this study. Those patients were followed by 25 to 145 months. Severity of headache before the surgery and at the last follow up was recorded by VAS pain scores and compared among the patients with different surgical methods using SPSS17.0 software. One way ANOVA was used to compare VAS scores between the groups, paired sample t-tests were used to compare the differences in a group at different time points.

RESULTS

Headache was significantly alleviated in all groups (P < 0.01). Respectively, 75.0% of the patients in the ACDF group, 84.6% of the patients in the TDR group and 82.2% of the patients in the laminoplasty group were significantly relieved of the headache after the surgery. No significant differences were found with the VAS score at the last follow up among the groups (P > 0.05). No significant differences were found among the groups comparing the degree of alleviation of VAS scores before and after the surgery (P > 0.05).

DISCUSSION

Considering that all the three procedures in the current study have achieved similar effect on alliviating headache in patients with cevical myelopathy, and that what they have in common was that was the decompression of spinal cord, it can be assumed that the headache associated with cervical spondylosis may be the result of compression on the spinal cord.

CONCLUSIONS

Anterior cervical discectomy and fusion, total disk replacement and open door laminoplasty can all significantly alleviate headache in patients with cervical spondylotic myelopathy and/or radiculopathy. No surgical technique is better than any other technique on alleviating cervical headache associated with cervical spondylotic myelopathy and/or radiculopathy.

A global perspective on the outcomes of surgical decompression in patients with cervical spondylotic myelopathy: results from the prospective multicenter AOSpine international study on 479 patients

STUDY DESIGN

Prospective, multicenter international cohort.

OBJECTIVE

To evaluate outcomes of surgical decompression for cervical spondylotic myelopathy (CSM) at a global level.

SUMMARY OF BACKGROUND DATA

CSM is a degenerative spine disease and the most common cause of spinal cord dysfunction worldwide. Surgery is increasingly recommended as the preferred treatment strategy for CSM to improve neurological and functional status and quality of life. The outcomes of surgical intervention for CSM have never been evaluated at an international level.

METHODS

Between October 2007 and January 2011, 479 symptomatic patients with image evidence of CSM were enrolled in the prospective, multicenter AOSpine CSM-International study from 16 global sites. Preoperative and postoperative clinical status, functional impairment, and quality of life were evaluated using the modified Japanese Orthopaedic Assessment Scale, Nurick Scale, Neck Disability Index, and Short-Form-36v2. Preoperative and 12- and 24-month postoperative outcomes were compared using mixed-model analysis of covariance for repeated measurements.

RESULTS

The study cohort consisted of 310 males and 169 females, with a mean age of 56.37 ± 11.91 years. There were significant differences in age, etiology, and surgical approaches between the regions. At 24 months postoperatively, the mean modified Japanese Orthopaedic Assessment Scale score improved from 12.50 (95% confidence interval [CI], 12.24-12.76) to 14.90 (95% CI, 14.64-15.16); the Neck Disability Index improved from 36.38 (95% CI, 34.33-38.43) to 23.20 (95% CI, 21.24-25.15); and the SF36v2 Physical Component Score and Mental Composite Score improved from 34.28 (95% CI, 33.46-35.10) to 40.76 (95% CI, 39.71-41.81) and 39.45 (95% CI, 38.25-40.64) to 46.24 (95% CI, 44.94-47.55), respectively. The rate of neurological complications was 3.13%.

CONCLUSION

Surgical decompression for CSM is safe and results in improved functional status and quality of life in patients around the world, irrespective of differences in medical systems and sociocultural determinants of health.

LEVEL OF EVIDENCE

3.

Tract-Specific Diffusion Tensor Imaging in Cervical Spondylotic Myelopathy Before and After Decompressive Spinal Surgery: Preliminary Results

PURPOSE

Diffusion tensor imaging (DTI) metrics of the cervical spinal cord in patients with cervical spondylotic myelopathy (CSM) were compared to those measured in healthy volunteers, using tract-specific region of interests (ROIs) across all cervical intervertebral disc levels.

METHODS

Magnetic resonance (MR) imaging of the cervical spinal cord was performed in four patients with CSM and in five healthy volunteers on a 3-T MR scanner. Region-specific fractional anisotropy (FA) and mean diffusivity (MD) were calculated on axial imaging with ROI placement in the anterior, lateral, and posterior regions of the spinal cord. FA and MD were also calculated on sagittal acquisitions. Nonparametric statistical tests were used to compare controls and patients before and after surgery.

RESULTS

FA values were significantly lower (p = 0.050) and MD values were significantly higher (p = 0.014) in CSM patients measured at level of maximal compression before surgery than in healthy controls in lateral and posterior ROIs, respectively. In posterior ROIs, MD values were significantly higher in patients before surgery compared to controls at all levels except C7-T1.

CONCLUSION

Patients with CSM may demonstrate region-specific changes in DTI metrics when compared to healthy controls. Changes in DTI metrics may also occur at levels remote from site of compression.

Use of multivariate linear regression and support vector regression to predict functional outcome after surgery for cervical spondylotic myelopathy

This study introduces the use of multivariate linear regression (MLR) and support vector regression (SVR) models to predict postoperative outcomes in a cohort of patients who underwent surgery for cervical spondylotic myelopathy (CSM). Currently, predicting outcomes after surgery for CSM remains a challenge. We recruited patients who had a diagnosis of CSM and required decompressive surgery with or without fusion. Fine motor function was tested preoperatively and postoperatively with a handgrip-based tracking device that has been previously validated, yielding mean absolute accuracy (MAA) results for two tracking tasks (sinusoidal and step). All patients completed Oswestry disability index (ODI) and modified Japanese Orthopaedic Association questionnaires preoperatively and postoperatively. Preoperative data was utilized in MLR and SVR models to predict postoperative ODI. Predictions were compared to the actual ODI scores with the coefficient of determination (R(2)) and mean absolute difference (MAD). From this, 20 patients met the inclusion criteria and completed follow-up at least 3 months after surgery. With the MLR model, a combination of the preoperative ODI score, preoperative MAA (step function), and symptom duration yielded the best prediction of postoperative ODI (R(2)=0.452; MAD=0.0887; p=1.17 × 10(-3)). With the SVR model, a combination of preoperative ODI score, preoperative MAA (sinusoidal function), and symptom duration yielded the best prediction of postoperative ODI (R(2)=0.932; MAD=0.0283; p=5.73 × 10(-12)). The SVR model was more accurate than the MLR model. The SVR can be used preoperatively in risk/benefit analysis and the decision to operate.

Predictors of morbidity and mortality among patients with cervical spondylotic myelopathy treated surgically

PURPOSE

The aim of this study is to report and quantify the associated factors for morbidity and mortality following surgical management of cervical spondylotic myelopathy (CSM).

METHODS

The Nationwide Inpatient Sample (NIS) database was use to retrospectively review all patients over 25 years of age with a diagnosis of CSM who underwent anterior and/or posterior cervical fusion or laminoplasty between 2001 and 2010. The main outcome measures were total procedure-related complications and mortality. Multivariate regression analysis was used to identify demographic, comorbidity, and surgical parameters associated with increased morbidity and mortality risk [reported as: OR (95% CI)].

RESULTS

A total of 54,348 patients underwent surgical intervention for CSM with an overall morbidity rate of 9.83% and mortality rate of 0.43%. Comorbidities found to be associated with an increased complication rate included: pulmonary circulation disorders [6.92 (5.91-8.12)], pathologic weight loss [3.42 (3.00-3.90)], and electrolyte imbalance [2.82 (2.65-3.01)]. Comorbidities found to be associated with an increased mortality rate included: congestive heart failure [4.59 (3.62-5.82)], pulmonary circulation disorders [11.29 (8.24-15.47)], and pathologic weight loss [5.43 (4.07-7.26)]. Alternatively, hypertension [0.56 (0.46-0.67)] and obesity [0.36 (0.22-0.61)] were found to confer a decreased risk of mortality. Increased morbidity and mortality rates were also identified for fusions of 4-8 levels [morbidity: 1.55 (1.48-1.62), mortality: 1.80 (1.48-2.18)] and for age >65 years [morbidity: 1.65 (1.57-1.72), mortality: 2.74 (2.25-3.34)]. An increased morbidity rate was found for posterior-only [1.55 (1.47-1.63)] and combined anterior and posterior fusions [3.20 (2.98-3.43)], and an increased mortality rate was identified for posterior-only fusions [1.87 (1.40-2.49)]. Although revision fusions were associated with an increased morbidity rate [1.81 (1.64-2.00)], they were associated with a decreased rate of mortality [0.24 (0.10-0.59)].

CONCLUSION

The NIS database was used to provide national estimates of morbidity and mortality following surgical management of CSM in the United States. Several comorbidities, as well as demographic and surgical parameters, were identified as associated factors.

Dynamic Compression of the Spinal Cord by Paraspinal Muscles following Cervical Laminectomy: Diagnosis Using Flexion-Extension MRI

Introduction. Flexion-extension, or kinematic, MRI has been used to identify dynamic spondylotic spinal cord compression not seen with traditional static MRI. The use of kinematic MRI to diagnose postoperative complications, specifically dynamic compression, is not as well documented. The authors describe a case of dynamic spinal cord compression by the paraspinal muscles causing worsening myelopathy following cervical laminectomy. This was only diagnosed with flexion-extension MRI. Methods. The patient was a 90-year-old male presenting to the neurosurgery clinic with functional decline and cervical spondylotic myelopathy. Results. A multilevel laminectomy was performed. Following surgery the patient had progressive weakness and worsening myelopathy. No active cord compression was seen on multiple MRIs obtained in a neutral position, and flexion-extension X-rays did not show instability. A kinematic MRI demonstrated dynamic compression of the spinal cord only during neck extension, by the paraspinal muscles. To relieve the compression, the patient underwent an instrumented fusion, with cross-links used to buttress the paraspinal muscles away from the cord. This resulted in neurologic improvement. Conclusions. We describe a novel case of spinal cord compression by paraspinal muscles following cervical laminectomy. In individuals with persistent myelopathy or delayed neurologic decline following posterior decompression, flexion-extension MRI may prove useful in diagnosing this potential complication.

Comparison of the Japanese orthopaedic association score and the Japanese orthopaedic association cervical myelopathy evaluation questionnaire scores: time-dependent changes in patients with cervical spondylotic myelopathy and posterior longitudinal ligament

Study Design

Prospective cohort study.

Purpose

To identify differences in time-dependent perioperative changes between the Japanese Orthopaedic Association (JOA) score and the JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) score in patients with cervical spondylotic myelopathy (CSM) and posterior longitudinal ligament (OPLL) who underwent cervical laminoplasty.

Overview of Literature

The JOA score does not take into consideration patient satisfaction or quality of life. Accordingly, the JOACMEQ was designed in 2007 as a patient-centered assessment tool.

Methods

We studied 21 patients who underwent cervical laminoplasty. We objectively evaluated the time-dependent changes in JOACMEQ scores and JOA scores for all patients before surgery and at 2 weeks, 3 months, 6 months, and 1 year after surgery.

Results

The average total JOA score and the recovery rate improved significantly after surgery in both groups, with a slightly better recovery rate in the OPLL group. Cervical spine function improved significantly in the CSM group but not in the OPLL group. Upper- and lower-extremity functions were more stable in the CSM group than in the OPLL group. The effectiveness rate of the JOACMEQ for measuring quality of life was quite low in both groups. In both groups, the Spearman contingency coefficients were dispersed widely except for upper- and lower-extremity function.

Conclusions

Scores for upper- and lower-extremity function on the JOACMEQ correlated well with JOA scores. Because the JOACMEQ can also assess cervical spine function and quality of life, factors that cannot be assessed by the JOA score alone, the JOACMEQ is a more comprehensive evaluation tool.

Anterior cervical discectomy and fusion versus corpectomy and fusion in treating two-level adjacent cervical spondylotic myelopathy: a minimum 5-year follow-up study

OBJECTIVE

A retrospective study was performed to compare the clinical and radiological outcomes of two-level anterior cervical discectomy and fusion (ACDF) with those of single-level anterior cervical corpectomy and fusion (ACCF) in treating two adjacent level cervical spondylotic myelopathy (CSM) with at least 5-year follow-up.

METHODS

A total of 46 consecutive patients who underwent surgery for the treatment of two-level CSM in our institution were evaluated from February 2002 to December 2007. In this series, 22 patients underwent two-level ACDF (group ACDF) and 24 received single-level ACCF (group ACCF). The operation duration, blood loss, perioperative complication, fusion rate, neural function (mJOA score) and the segmental lordosis of the surgical level were compared between the two groups.

RESULTS

The mean follow-up time was 84.5 ± 13 months in group ACDF and 86 ± 11 months in group ACCF (P = 0.723). The rates of perioperative complications were 18.2 % in group ACDF and 20.8 % in group ACCF, respectively (P > 0.05). Although there was no significant difference in neural function (mJOA score) between the two groups at the final follow-up (P > 0.05), the blood loss and the operation duration were significantly less in group ACDF than those in group ACCF (P < 0.05). The fusion rates at the 12th week after surgery were 86.4 % (19/22) in group ACDF and 87.5 % (21/24) in group ACCF (P > 0.05). According to the radiographs measurement, the segmental lordosis at the surgical segment was significantly greater in group ACDF than that in group ACCF (P < 0.05).

CONCLUSION

There were high fusion rates and excellent clinical outcomes in both ACDF and ACCF for treating two adjacent level CSM. However, there were less blood loss, less operation duration and better cervical lordosis in group ACDF than those in group ACCF.

Patient satisfaction with double-door laminoplasty for cervical compression myelopathy

BACKGROUND

Patient satisfaction with posterior laminoplasty for cervical compression myelopathy is not yet established. Moreover, postoperative patient-reported outcomes (PROs) associated with patient satisfaction remain unclear. This study aimed to investigate patient satisfaction after double-door laminoplasty for cervical compression myelopathy, and to identify the postoperative patient-reported outcomes associated with patient satisfaction.

METHODS

This retrospective study included 97 patients with cervical compression myelopathy who underwent double-door laminoplasty between 2002 and 2010 in our institution [mean follow-up: 58 months (range 12-123 months)]. We assessed postoperative PROs from questionnaires administered before surgery and at the latest follow-up. These questionnaires included the Neck Disability Index, physical and mental component summary of Short Form-36, EuroQol-5 dimension, Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and a numerical rating scale of pain or numbness in the neck, arms, and scapular lesion. Satisfaction was evaluated on the basis of a seven-point scale. Patients were divided into two groups: satisfied (very satisfied, satisfied, slightly satisfied) and dissatisfied (neither satisfied nor dissatisfied, slightly dissatisfied, dissatisfied, very dissatisfied). All PROs and the effectiveness of surgical treatment assessed by JOACMEQ were compared between both groups.

RESULTS

The satisfied group comprised 69 patients (71 %). Univariate analysis revealed a significant difference in scapular pain, Neck Disability Index, physical component summary of Short Form-36, postoperative mental component summary of Short Form-36, and improvement of lower extremity function postoperatively between both groups. Multivariate analysis revealed that there was a significantly higher proportion of patients with improved lower extremity function in the satisfied group than in the dissatisfied group.

CONCLUSIONS

In conclusion, 71 % of the patients who underwent double-door laminoplasty for cervical compression myelopathy were satisfied. The findings of this study, which examines the association between patient satisfaction and PROs, suggest that improvement in lower extremity function following surgical intervention affects patient satisfaction in those with cervical compression myelopathy.

Biomechanical evaluation of an interfacet joint decompression and stabilization system

A majority of the middle-aged population exhibit cervical spondylosis that may require decompression and fusion of the affected level. Minimally invasive cervical fusion is an attractive option for decreasing operative time, morbidity, and mortality rates. A novel interfacet joint spacer (DTRAX facet screw system, Providence Medical) promises minimally invasive deployment resulting in decompression of the neuroforamen and interfacet fusion. The present study investigates the effectiveness of the device in minimizing intervertebral motion to promote fusion, decompression of the nerve root during bending activity, and performance of the implant to adhere to anatomy during repeated bending loads. We observed flexion, extension, lateral bending, and axial rotation resonant overshoot mode (ROM) in cadaver models of c-spine treated with the interfacet joint spacer (FJ spacer) as stand-alone and supplementing anterior plating. The FJ spacer was deployed bilaterally at single levels. Specimens were placed at the limit of ROM in flexion, extension, axial bending, and lateral bending. 3D images of the foramen were taken and postprocessed to quantify changes in foraminal area. Stand-alone spacer specimens were subjected to 30,000 cycles at 2 Hz of nonsimultaneous flexion-extension and lateral bending under compressive load and X-ray imaged at regular cycle intervals for quantitative measurements of device loosening. The stand-alone FJ spacer increased specimen stiffness in all directions except extension. 86% of all deployments resulted in some level of foraminal distraction. The rate of effective distraction was maintained in flexed, extended, and axially rotated postures. Two specimens demonstrated no detectable implant loosening (<0.25 mm). Three showed unilateral subclinical loosening (0.4 mm maximum), and one had subclinical loosening bilaterally (0.5 mm maximum). Results of our study are comparable to previous investigations into the stiffness of other stand-alone minimally invasive technologies. The FJ spacer system effectively increased stiffness of the affected level comparable to predicate systems. Results of this study indicate the FJ spacer increases foraminal area in the cervical spine, and decompression is maintained during bending activities. Clinical studies will be necessary to determine whether the magnitude of decompression observed in this cadaveric study will effectively treat cervical radiculopathy; however, results of this study, taken in context of successful decompression treatments in the lumbar spine, are promising for the continued development of this product. Results of this biomechanical study are encouraging for the continued investigation of this device in animal and clinical trials, as they suggest the device is well fixated and mechanically competent.

Clinical and radiographic evaluation of cervical disk replacement: a retrospective study

Studies have shown the effectiveness of cervical disk replacement. However, clinical outcomes, particularly by radiographic assessment during the 36-month follow-up visit, have not been reported for cervical disk replacement with Mobi-C (LDR, Austin, Texas) disk prostheses. A retrospective study was conducted at 10 centers across China and included 65 patients who underwent single-level Mobi-C disk prosthesis replacement from October 2009 to July 2010. Clinical and radiographic data were collected before replacement, 7 days postoperatively, and 1, 3, 6, 12, 24, and 36 months postoperatively. Clinical and neurologic outcomes were assessed by the Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS), Neck Disability Index (NDI), and Odom's criteria. Static and dynamic radiographs were measured to determine intervertebral height and range of motion (ROM) of the cervical spine, the functional spinal unit, the treated segment, and adjacent segments. JOA, VAS, and NDI scores showed statistically significant improvement 36 months after replacement (P<.05). The ROM of the cervical spine, functional spinal unit, treated segment, and adjacent segments did not show a significant difference before and after replacement (P>.05). The intervertebral height of the treated segment increased significantly, and the intervertebral height of adjacent segments showed no statistical significance between time points and at follow-up. Clinical outcomes indicated that Mobi-C artificial cervical disk replacement is reliable. Radiographic data showed that it plays a role in reconstruction or maintenance of intervertebral height and ROM of the cervical spine, functional spinal unit, treated segment, and adjacent segments after Mobi-C cervical disk replacement.

Functional assessment of patients with cervical myelopathy who underwent surgical treatment

OBJECTIVE: Evaluate and correlate the functional response of patients with cervical myelopathy with the current clinical scores in patients who underwent surgical treatment. METHODS: We analyzed medical records of 34 patients with cervical myelopathy who underwent four different types of surgery. All patients were evaluated preoperatively and postoperatively with the application of the JOA and Nurick questionnaires. RESULTS: Functional clinical improvement was statistically significant. The mean preoperative JOA was 8.5 ± 3.06 and 10.7 ± 3.9 in the postoperative; Nurick was 3.2 ± 1.1 preoperatively and 2.8 ± 1.3 postoperatively. CONCLUSION: There is benefit with the surgical procedure in patients with cervical myelopathy. The neurological function after surgery depends on the previous function (the higher the duration of the previous symptoms, the greater the progression of the disease and, therefore, worse the neurological function) and the age is not a relevant factor of improvement, as already shown in other series. The clinical functional improvement of patients is visible with surgical treatment, regardless of surgical technique.

Evaluation of a new type of titanium mesh cage versus the traditional titanium mesh cage for single-level, anterior cervical corpectomy and fusion

STUDY DESIGN

A retrospective review of prospectively collected data in an academic institution.

OBJECTIVE

To evaluate the safety and efficacy of a new type of titanium mesh cage (TMC) in single-level, anterior cervical corpectomy and fusion (ACCF).

METHODS

Fifty-eight patients consecutive with cervical spondylotic myelopathy (CSM) from cervical degenerative spondylosis and isolated ossification of the posterior longitudinal ligament were treated with a single-level ACCF using either a new type of TMC (28 patients, group A) or the traditional TMC (30 patients, group B). We evaluated the patients for TMC subsidence, cervical lordosis (C2-C7 Cobb and Cobb of fused segments) and fusion status for a minimum of 30 months postoperatively based on spine radiographs. In addition, neurologic outcomes were evaluated using the Japanese Orthopedic Association (JOA) scores. Neck pain was evaluated using a 10-point visual analog scale (VAS).

RESULTS

The loss of height of the fused segments was less for group A than for group B (0.8 ± 0.3 vs. 2.8 ± 0.4 mm) (p < 0.01); also, there was a lower rate of severe subsidence (≥3 mm) in group A (4 %, 1/28) than in group B (17 %, 5/30) (p < 0.01). There were no differences in the C2-C7 Cobb and Cobb of fused segments between the groups preoperatively or at final follow-up (p > 0.05), but the Cobb of fused segments immediately postoperative were significantly less for group B than for group A (p < 0.01). All patients, however, had successful fusion (100 %, each). Both groups had marked improvement in the JOA score after operation (p < 0.01), with no significant differences in the JOA recovery ratio (p > 0.05). The postoperative VAS neck pain scores for group A were significantly less than that for group B (p < 0.05); severe subsidence was correlated with neck pain.

CONCLUSIONS

The new type of TMC provides comparable clinical results and fusion rates with the traditional TMC for patients undergoing single-level corpectomy. The new design TMC decreases postoperative subsidence (compared to the traditional TMC); the unique design of the new type of TMC matches the vertebral endplate morphology which appears to decrease the severity of subsidence-related neck pain in follow-up.

Is cervical disc arthroplasty superior to fusion for treatment of symptomatic cervical disc disease? A meta-analysis

BACKGROUND

As the current standard treatment for symptomatic cervical disc disease, anterior cervical decompression and fusion may result in progressive degeneration or disease of the adjacent segments. Cervical disc arthroplasty was theoretically designed to be an ideal substitute for fusion by preserving motion at the operative level and delaying adjacent level degeneration. However, it remains unclear whether arthroplasty achieves that aim.

QUESTIONS/PURPOSES

We investigated whether cervical disc arthroplasty was associated with (1) better function (neck disability index, pain assessment, SF-36 mental and physical health surveys, neurologic status) than fusion, (2) a lower incidence of reoperation and major complications, and (3) a lower risk of subsequent adjacent segment degeneration.

METHODS

We conducted a comprehensive search in MEDLINE(®), EMBASE, and Cochrane Central Register of Controlled Trials and identified 503 papers. Of these, we identified 13 reports from 10 randomized controlled trials involving 2227 patients. We performed a meta-analysis of functional scores, rates of reoperation, and major complications. The strength of evidence was evaluated by using GRADE profiler software. Of the 10 trials, six trials including five prospective multicenter FDA-regulated studies were sponsored by industry. The mean follow-ups of the 10 trials ranged from 1 to 5 years.

RESULTS

Compared with anterior cervical decompression and fusion, cervical disc arthroplasty had better mean neck disability indexes (95% CI, -0.25 to -0.02), neurologic status (risk ratio [RR], 1.04; 95% CI, 1.00-1.08), with a reduced incidence of reoperation related to the index surgery (RR, 0.42; 95% CI, 0.22-0.79), and major surgical complications (RR, 0.45; 95% CI, 0.27-0.75) at a mean of 1 to 3 years. However, the operation rate at adjacent levels after two procedures was similar (95% CI, 0.31-1.27). The three studies with longer mean follow-ups of 4 to 5 years also showed similar superiority of all four parameters of cervical disc arthroplasty compared with fusion.

CONCLUSIONS

For treating symptomatic cervical disc disease, cervical disc arthroplasty appears to provide better function, a lower incidence of reoperation related to index surgery at 1 to 5 years, and lower major complication rates compared with fusion. However, cervical disc arthroplasty did not reduce the reoperation rate attributable to adjacent segment degeneration than fusion. Further, it is unclear whether these differences in subsequent surgery including arthroplasty revisions will persist beyond 5 years.

Predictors of outcome in patients with degenerative cervical spondylotic myelopathy undergoing surgical treatment: results of a systematic review

PURPOSE

To conduct a systematic review of the literature to determine important clinical predictors of surgical outcome in patients with cervical spondylotic myelopathy (CSM).

METHODS

A literature search was performed using MEDLINE, MEDLINE in Process, EMBASE and Cochrane Database of Systematic Reviews. Selected articles were evaluated using a 14-point modified SIGN scale and classified as either poor (<7), good (7-9) or excellent (10-14) quality of evidence. For each study, the association between various clinical factors and surgical outcome, evaluated by the (modified) Japanese Orthopaedic Association scale (mJOA/JOA), Nurick score or other measures, was defined. The results from the EXCELLENT studies were compared to the combined results from the EXCELLENT and GOOD studies which were compared to the results from all the studies.

RESULTS

The initial search yielded 1,677 citations. Ninety-one of these articles, including three translated from Japanese, met the inclusion and exclusion criteria and were graded. Of these, 16 were excellent, 38 were good and 37 were poor quality. Based on the excellent studies alone, a longer duration of symptoms was associated with a poorer outcome evaluated on both the mJOA/JOA scale and Nurick score. A more severe baseline score was related with a worse outcome only on the mJOA/JOA scale. Based on the GOOD and EXCELLENT studies, duration of symptoms and baseline severity score were consistent predictors of mJOA/JOA, but not Nurick. Age was an insignificant predictor of outcome on any of the functional outcomes considered.

CONCLUSION

The most important predictors of outcome were preoperative severity and duration of symptoms. This review also identified many other valuable predictors including signs, symptoms, comorbidities and smoking status.