Nurick Grade Research Articles

Microsurgical Experience with Pedicle-Sparing Transfacet Approach for Thoracic Disk Herniation.

Thoracic disk herniation (TDH) is relatively uncommon. The surgical approach differs from lumbar or cervical disk herniations because serious complications are associated with the posterior approach in TDH. Various different approaches have been tried for the surgical removal of TDH, but most of them are cumbersome surgeries such as thoracotomy or thoracoscopic or anterior approaches with or without instrumentation. The requirement for a simplified, familiar, and less morbid surgery has motivated some new approaches. A pedicle-sparing transfacet approach (PSTA) was first described in 1995, but to date no sufficient clinical series has been presented in the literature to report on its feasibility and applicability along with complication and morbidity rates. Our objective was to assess the feasibility of the PSTA under microscopic visualization in a cumulative clinical series. Twenty-eight consecutive patients with no response to medical/physical treatment with and without motor weakness of their lower extremities underwent the surgery for TDH via the PSTA under microscopic visualization by a senior neurosurgeon. Preoperative and postoperative low extremity muscle strength, sensation, reflex status, and visual analog scores (VAS), Nurick grades, and complications were recorded. Postoperative MRI within 24 hours was performed. The median follow-up period was 33 months. The patients consisted of 16 men and 12 women. The disk levels ranged from T8 to T12-L1. All but one patient received one-level surgery. One patient was operated on two levels. A total of 21 patients had paracentral disk herniations; the other 7 had central disk herniations. Postoperative MRI showed satisfactory removal of disk herniation in all but one patient. There was no infection, wrong level surgery, or incidental durotomy. Median VAS levels significantly improved after the operation from 7.4 to 2.3. The Nuric grades decreased from 2.7 to 1.6 after surgery. The microsurgical PSTA is a safe and feasible technique with a significantly shorter surgeon's learning curve. The approach offers a wide surgical window; moreover, it can by increased by tilting the surgical table allowing satisfactory decompression of TDH. After PSTA, segmental instrumentation is not required.

Foot Tapping Test as Part of Routine Neurologic Examination in Degenerative Compression Myelopathies: A Significant Correlation between 10-sec Foot-tapping Speed and 30-m Walking Speed.

Introduction Leg spasticity in degenerative compression myelopathy causes impairment of fast and rapid repetitive movements, which tends to appear despite the disproportionate paucity of clinical weakness. As clinically useful measures used to quantify the slowness of voluntary leg movements in this pathological condition, we compared the foot tapping test (FTT) with the simple walking test, which is now considered the gold standard in this field. Methods We compared the FTT with the simple walking test, the grip-and-release test, and the functional scales of Nurick and the Japanese Orthopedic Association (JOA) in 77 patients with cervical compression myelopathy and 56 age-matched healthy subjects. The FTT was conducted on both sides separately, and the subject, while being seated on a chair, moved his/her toes up and down repeatedly to tap the floor as fast and as vigorously as possible for 10 sec with his/her heels planted on the floor. Results The number of 10-sec foot tapping in the patient group significantly correlated with the Nurick grades (r = −0.566; P < 0.0001), the JOA scores (r = 0.520; P < 0.0001), and the grip-and-release rates (r = 0.609; P < 0.0001). It also significantly correlated with the 30-m walking time (r = −0.507; P < 0.0001) and the number of steps taken (r = −0.494; P < 0.0001). Assessments of wheelchair-dependent patients and side-to-side comparison, in which the simple walking test plays no role, revealed significantly fewer FTT taps in wheelchair-bound patients than in the ambulatory patients and a significant trend for cervical compression myelopathy to dominantly affect the upper and lower limbs on the same side. Conclusions This study contributes to the reassessment of the currently underutilized FTT as part of a routine neurologic examination of degenerative compression myelopathy.

Role of Decompressive Laminectomy without Instrumentation in the Management of Nurick Grade 4 and 5 Cervical Compressive Myelopathy.

Introduction:Cervical laminectomy is a very well-known posterior decompressive procedure for cervical compressive myelopathy (CCM). Our objective is to evaluate the functional effect of posterior decompressive laminectomy for poor grade CCM.Methods:This study was an observational retrospective study carried out on patients with poor-grade CCM who underwent decompressive laminectomy from January 2010 to December 2015. Patients with Nurick Grades 4 and 5 (walking with support or bedbound) were included in the study. Clinical data and radiological information were collected from medical records, and objective scales were applied to compare the surgical outcome between preoperative score and postoperative score.Results:A total of 69 patients who underwent decompressive laminectomy for poor grade CCM were included. The mean age was 54.9 years, and the male-to-female ratio was 5.3:1. Ossified posterior longitudinal ligament comprised 52.6% cases. The follow-up data of at least 6 months’ duration after surgery was available for 57 (82.6%) cases. On comparing with preoperative Nurick grade at follow-up, 40 of the 57 patients (70.2%) were found to have improvement following surgery by at least one grade. The remaining 17 (29.8%) had either remained the same or had deteriorated further. The mean preoperative modified Japanese Orthopedic Association score was 8.4 ± 2.8, and the mean follow-up score was 11.8±0.3 (P = 0.0001). On multivariate analysis, the number of levels of laminectomy, postoperative deterioration, and anesthesia grade were predictors of outcome.Conclusion:Decompressive laminectomy for poor grade myelopathy is effective in improving functional outcome.

Haemodynamic changes during prone positioning in anaesthetised chronic cervical myelopathy patients.

Background and Aims:Anaesthetised patients, when positioned prone, experience hypotension and reduction in cardiac output. Associated autonomic dysfunction in cervical myelopathy patients predisposes them to haemodynamic changes. The combined effect of prone positioning and autonomic dysfunction in anaesthetised patients remains unknown.Methods:Thirty adult chronic cervical myelopathy patients, aged 18-65 years with Nurick grade ≥2 were recruited in this prospective observational study. Heart rate, mean blood pressure, cardiac output, stroke volume, total peripheral resistance and stroke volume variation were measured using NICOM® monitor. Data were collected in supine before anaesthetic induction (baseline), 2 minutes after induction, 2 minutes after intubation, before and after prone positioning and every 5 minutes thereafter until skin incision. Repeated measures analysis of variance (ANOVA) was used to analyse the haemodynamic parameters across the time points. Bivariate Spearman's correlation was used to find factors associated with blood pressure changes. A P value <0.05 was kept significant.Results:Cardiac output during the entire study period remained stable (P = 0.186). Sixty percent of the patients experienced hypotension. At 15 and 20 minutes after prone positioning, mean blood pressure decreased (P = 0.001), stroke volume increased (P = 0.001), and heart rate and total peripheral resistance decreased (P < 0.001, P = 0.001, respectively). These changes were significant when compared to pre-prone position values. Number of levels of spinal cord compression positively correlated with the incidence of hypotension.Conclusion:Cervical myelopathy patients experienced hypotension with preserved cardiac output in prone position due to a reduction in total peripheral resistance. Hypotension correlated with the number of levels of spinal cord compression.

Vertico-horizontal atlantoaxial index (VHAI): A new craniovertebral radiographic index

ObjectiveThe purpose of this study was to develop a new index that can reliably quantify the reduction of basilar invagination with atlantoaxial dislocation. Patients and methodsBetween May 2012 and September 2017, 40 patients with congenital basilar invagination and atlantoaxial dislocation as well as 100 sex-and age-matched control subjects were recruited for this study. All patients underwent direct posterior reduction and fixation. Mid-sagittal computerized tomography scan films were obtained before and after surgery as well as the vertico-horizontal atlantoaxial index (VHAI) was measured in all patients -before and after surgery- and controls. Additionally, the pre-and postoperative Japanese Orthopedic Association (JOA) scores, Nurick grading, European Myelopathy Score (EMS) and Prolo Scale score were used to evaluate the cervical myelopathy. ResultsThe mean follow-up was 24.75 months with a range of 6–60 months. The mean value of VHAI in the control group was 87.86 ± 24.98 mm2, while the mean values of VHAI before and after surgery were 209.45 ± 96.80 mm2 and 95.08 ± 66.95 mm2, respectively. Additionally, in the patient group, a negative correlation was observed between JOA, EMS, Prolo Scale scores and VHAI. On the other hand, a positive correlation was found between the Nurick grading and VHAI. ConclusionThe VHAI can be an excellent measurement tool to evaluate the reduction of basilar invagination with atlantoaxial dislocation. There was a negative correlation between VHAI and JOA, EMS and Prolo Scale scores, and a positive correlation with Nurick grading; which indicates the effectiveness of this index.

Clinical and radiological outcomes following open door laminoplasty: a single center evolution of the technique.

The aim of the present study was to compare and describe clinical and radiological outcomes after two different variants of open door laminoplasty for cervical spondylotic myelopathy (CSM). Fifty-five patients underwent cervical laminoplasty for CSM. Between 2005 to 2009, 32 patients underwent open-door laminoplasty (Group A) performed with a monolateral exposure with contralateral "green stick" laminar fracture. A technical variant consisting in bilateral exposure, spinous process removal and symmetrical muscular closure was applied in the other 23 (Group B), from 2009 to 2016. A retrospective analysis of surgical results between the two groups was performed. In group B, the mean operative time was longer, and the mean volume of intraoperative blood loss was much higher than in group A. Both differences were not significant (P=0.1601 and P=0.0884, respectively). The average hospitalization was non-significantly longer in group B (7.3±1.8 vs. 6.5±1.6 d; P=0.0947). Postoperatively, axial neck pain was more severe in group A at last follow-up than preoperatively (P>0.05). mJOA scores and Nurick grades improved significantly in both groups at last follow-up; in group A, the mean recovery rates were 41.5% by mJOA scores and 29.4% by Nurick grades, whereas in group B they were 52.7% and 36.8%, respectively. Applying some few variations to a standard monolateral approach, although slightly more time and blood consuming, could reduce the incidence of long-term axial symptoms and, in our experience, are not burdened by worsening of outcomes. A prospective, multicentric study with a longer follow-up should be conducted in order to confirm our findings.

Hemilaminectomy for Spinal Cord Intradural Tumors: An Institutional Experience.

Introduction:Laminectomy is the workhorse of spinal cord tumor surgery. This procedure is not without the debilitating sequelae of postoperative pain and delayed kyphosis. Hemilaminectomy is an alternate option to laminectomy which offers the advantage of preserving the posterior supporting structures of the spine on the contralateral side. In this study, we analyze the outcome of hemilaminectomy clinically with improvement in pain scores and Nurick's grade as well as radiologically by assessing for the development of delayed kyphosis. We also discuss the technique and operative nuances of hemilaminectomy in intradural extramedullary tumors of the spinal cord.Materials and Methods:All patients with intradural spinal cord tumors were included in the study. All patients underwent unilateral hemilaminectomy (UHL) depending on the laterality of the tumor on the preoperative magnetic resonance imaging. Preoperative neurologic status was assessed with Nurick's grade for tumors involving the cervicothoracic region tumors, and visual analog scale scores were recorded for tumors of Thoracic, Lumbar and Lumbosacral regions. The postoperative outcomes were assessed by improvement in respective scales on follow-up. The occurrence of delayed spinal deformity was assessed by follow-up X-rays. Any complications whether intraoperative or postoperative were recorded.Results:There were a total of 34 cases of intradural extramedullary tumors in this study. Patient population consisted of 11 males and 23 females. Total excision was achieved in 31 patients. In three patients, we were unable to achieve complete removal through UHL. In these patients the procedure was converted to total laminectomy. They were excluded from analysis. The distribution of the tumors was in cervical, cervicothoracic, thoracic, lumbar, and lumbosacral region. All patients presented with pain or varying degrees or neurologic deficits. Sixteen patients underwent UHL from the right side, while 18 from the left. There were no intraoperative complications. The neurological status and pain scores of all patients improved postoperatively at 3 and 6 months of follow-up. There was no radiological evidence of kyphosis of the involved segment.Conclusion:With a small learning curve, UHL is a good corridor for the removal of intradural extramedullary spinal cord tumors. This approach offers the advantage of less postoperative pain and no postoperative deformity.

The strategy and results of percutaneous endoscopic surgery for cervical disc herniation

Objective To evaluate the strategy and clinical effects of percutaneous endoscopic surgery for cervical disc herniation. Methods Fifty-one patients with cervical disc herniation were treated with percutaneous endoscopic surgery from June 2015 to March 2017, including 32 men and 19 women, with an average age of 52.2 years (range, 28-66 years). Radicular symptoms were present in all patients, while 23 patients had mild myelopathy (Nurick Grade: 0-3) and 3 patients of multilevel stenosis had severe myelopathy (Nurick Grade: 4-5). According to axial image of preoperative magnetic resonance imaging (MRI), 31 patients had lateral herniation that was located lateral to the edge of spinal cord, 20 patients had central herniation that was located within the lateral edge of spinal cord. Among them, 48 patients had soft herniation and 3 patients had ossified lateral herniation combined with foraminal stenosis. All surgery was carried out under general anesthesia, while posterior and anterior percutaneous endoscopic surgeries were performed for lateral herniation and central herniation respectively. Posterior endoscopic surgery was performed with keyhole fenestration at V point (the junction of lateral edge of lamina space and inner edge of facet). Lateral edge of thecal sac and nerve root were exposed and decompressed, soft herniation was explored and removed. Anterior endoscopic surgery was performed through puncture and 4mm tube between the visceral sheath and vascular sheath. The tube was inserted through disc to the base of herniation under fluoroscopy. The herniation was removed until the dura sac was exposed and relaxed. One stage open-door laminoplasty was performed for 3 patients with severe multiple segmental stenosis and huge central herniation. The operative time and blood loss were recorded, and patients were followed-up (range, 6-18 months, average 12.1 months) to evaluate the clinical efficacy. Results The mean operative time of posterior endoscopic surgery was 90 min (range, 45-150 min). The nerve root was not well exposed, and the fenestration was too lateral in 1 patient, with partial relieve of symptoms; and simple nerve root decompression was performed for 3 patients of ossified herniation combined with foraminal stenosis. Herniated or sequestered nucleus pulposus was removed for 27 patients, one of them had transient paralysis ipsilateral limb and 2 of them had linkage of cerebrospinal fluid. The Visual Analogue Score (VAS) score improved form preoperative 8.9±1.6 to 0.5±0.4, and the Oswestry Disability Index (ODI) score improved form 32.8±4.2 to 2.3±1.9 at final follow-up. For anterior percutaneous endoscopic surgery, the mean operative time was 80 min (range, 45–120 min). Herniated or free nucleus was successfully removed for all patients. The thecal sac was lacerated due to unclear exposure in 1 case. The VAS score improved form preoperative 6.9±2.3 to 0.9±0.8, and the ODI score improved form 40.1±8.6 to 5.6±3.0 at final follow-up, with improvement of myelopathy at least one Nurick Grade. During follow-up, the alignment of cervical spine was well preserved without kyphosis for two groups, while the height of intervertebral space decreased with 0.4±0.3 mm and 0.9±0.6 mm in posterior and anterior surgery respectively. Conclusion Percutaneous endoscopic surgery provides minimally invasive alternatives for some cervical disc herniation with predominant radicular pain. Posterior endoscopic surgery is suitable for lateral herniation, and anterior endoscopic discectomy is suitable for some central soft herniation without obvious collapse and instability. However, the long-term results of disc space collapsed after anterior approach remains unclear. Key words: Cervical vertebrae; Intervertebral disc displacement; Endoscopy; Surgical procedures, minimally invasive

OPEN DOOR CERVICAL LAMINOPLASTY FOR OSSIFICATION OF POSTERIOR LONGITUDINAL LIGAMENT; A TERTIARY CARE EXPERIENCE FROM KARACHI, PAKISTAN

Background and Objectives: To analyze the functional outcome of open doorlaminoplasty (ODL) for the treatment of Cervical Ossified Posterior Longitudinal Ligament(OPLL). Study Design: Case series study. Setting: Civil Hospital Karachi. Period: 05 years,2013 to 2017. Material &amp; Methods: 18 patients (15 Male, 3 Female) underwent ODL for cervicalOPLL, over a period of 5 years. Pre-operative &amp; post- operative degree of myelopathy wasassessed using Nurick grading score. Patients with Nurick grade &gt; 2 were included in study.MRI compatible titanium micro plates &amp; screws were used. Instability was assessed by X-rayCervical Spine obtained 6 weeks post-operatively. Results: Mean age of presentation was 52years. 2 to 3 levels were involved in most cases. Mean operative time was 2 hours 30 minutes.Following Nurick grading 94.4% (n=17) improved by grade 1 or more, while in only 5.6%(n=1) it remained same. No instability or kyphotic deformity was seen on follow up X-rays.Conclusion: ODL is a safe &amp; effective procedure for the treatment of multiple level OPLL. Itcan avoid complications related to the anterior approach (like unintentional durotomy &amp; spinalcord injury) and diminished the possibility of instability &amp; kyphotic deformity associated withlaminectomy alone.

CERVICAL LAMINOPLASTY;

Background and Objectives: To analyze the functional outcome of open doorlaminoplasty (ODL) for the treatment of Cervical Ossified Posterior Longitudinal Ligament(OPLL). Study Design: Case series study. Setting: Civil Hospital Karachi. Period: 05 years,2013 to 2017. Material &amp; Methods: 18 patients (15 Male, 3 Female) underwent ODL for cervicalOPLL, over a period of 5 years. Pre-operative &amp; post- operative degree of myelopathy wasassessed using Nurick grading score. Patients with Nurick grade &gt; 2 were included in study.MRI compatible titanium micro plates &amp; screws were used. Instability was assessed by X-rayCervical Spine obtained 6 weeks post-operatively. Results: Mean age of presentation was 52years. 2 to 3 levels were involved in most cases. Mean operative time was 2 hours 30 minutes.Following Nurick grading 94.4% (n=17) improved by grade 1 or more, while in only 5.6%(n=1) it remained same. No instability or kyphotic deformity was seen on follow up X-rays.Conclusion: ODL is a safe &amp; effective procedure for the treatment of multiple level OPLL. Itcan avoid complications related to the anterior approach (like unintentional durotomy &amp; spinalcord injury) and diminished the possibility of instability &amp; kyphotic deformity associated withlaminectomy alone.

Friday, September 28, 2018 4:05 PM–5:05 PM abstracts: cervical myelopathy and deformity: 259. The influence of cervical spondylolisthesis on clinical presentation and surgical outcome in patients with degenerative cervical myelopathy: analysis of a global cohort

BACKGROUND CONTEXT Cervical Spondylolisthesis (CS) presents in ∼12% of patients with Degenerative Cervical Myelopathy (DCM). However, its impact on clinical presentation and surgical outcome have not been well-described. Using a prospective and multicenter cohort, we compare patients with and without CS on MRI undergoing surgical treatment for DCM. PURPOSE To determine the influence of cervical spondylolisthesis in patients with DCM. STUDY DESIGN/SETTING Retrospective review of prospectively collected data from multiple global sites. PATIENT SAMPLE A total of 458 patients with MRIs and clinical data. OUTCOME MEASURES The modified Japanese Orthopedic Association score (mJOA), Nurick grade, SF-36 Mental and Physical Component Scores, and the Neck Disability Index. METHODS A total of 458 MRIs from the AOSpine North America and International Studies were reviewed. Patient demographics and baseline neurological and functional status were also obtained. CS was identified using T2 MRI. Patients with DCM were divided into two cohorts, those with CS and those without. Patient demographics, neurological and functional status at baseline and outcome at 2-year follow-up were compared using independent t-tests, chi square tests, Fischer exact tests, and multivariate analysis. RESULTS In comparison to the nonspondylolisthesis cohort (n=404), CS patients (n=54) were on average 8.8 years older (p CONCLUSIONS CS patients are older and present with worse neurological and functional impairment. Furthermore, they receive surgery on more levels and more commonly from the posterior. CS may indicate a more advanced state of DCM pathology and is more likely to result in a suboptimal surgical outcome.

Clinical Comparison of Surgical Constructs for Anterior Cervical Corpectomy and Fusion in Patients With Cervical Spondylotic Myelopathy or Ossified Posterior Longitudinal Ligament: A Systematic Review and Meta-Analysis.

This is a systematic review and meta-analysis. To examine the differences in outcomes among current constructs and techniques for anterior cervical corpectomy and fusion (ACCF) in patients with single or multiple level cervical myelopathy (CM) secondary to cervical spondylosis or ossified posterior longitudinal ligament. The natural history of CM can be a progressive disease process. In such cases, where surgical decompression is indicated to halt the progression, ACCF is typically chosen for pathology located posterior to the vertebral body. Numerous studies have shown that decompression with appropriate stabilization not only halts progression, but also improves patient outcomes. However, several constructs are available for this procedure, all with variable outcomes. A systematic review was conducted using Cochrane Database, Medline, and PubMed. Only studies with a minimum patient population of 10, reporting on CM because of cervical spondylosis or ossified posterior longitudinal ligament were included; a minimum follow-up period of 12 months and 1 clinical and/or radiographic outcome were required. Studies examining patients with cervical trauma/fracture, tumor, and infection or revision cases were excluded. Data analysis was carried out with Microsoft Excel. A total of 30 studies met the inclusion criteria for qualitative analysis, while 26 studies were included for quantitative analysis. Constructs that were reported in these studies included titanium mesh cages, nano-hydroxyapatite/polyamide 66 composite struts, bone graft alone, expandable corpectomy cages, and polyetheretherketone cages. Clinical outcomes included Japanese Orthopaedic Association and modified Japanese Orthopaedic Association scores, Visual Analog Scale scores, Neck Disability Index scores, and Nurick grades. Radiographic outcomes included C2-C7 and segmental Cobb angles and pseudarthrosis rates. Each construct type had variable and unique benefits and shortcomings. ACCF is a common surgical option for CM, despite carrying certain risks expected of any anterior cervical approach. Several constructs are available for ACCF, all with variable clinical and radiographic outcomes.

Clinico-Radiological Outcome Analysis in Craniovertebral Junction Diseases: An Institutional Experience of 38 Patients in a Tertiary Care Centre

Craniovertebral junction diseases, although considered rare, are common in northern parts of India. This study was conducted to evaluate the clinico-radiologic and surgical outcome of patients with a minimum follow-up of 1 year. Our study also compared bony fusion among various techniques of posterior fusion. This retrospective study was performed with 38 patients who met the inclusion criteria for analysis. These patients were contacted by telephone and letters, and their clinical examination and radiologic investigations were performed at a follow-up visit. The preoperative, postoperative, and follow-up clinical evaluations of the patients were done using the Nurick grading system. The age range was 4-60 years with an average of 20.5 years. There were 31 male and 7 female patients, with a male:female ratio of 4.43:1. There were 13 cases of fixed atlantoaxial dislocation (AAD), 17 cases of mobile AAD, 6 cases of traumatic AAD, and 2 cases of postinfective AAD. The majority of these patients (n= 29; 76.31%) had neck pain and cerebellovestibular disturbances (n= 27; 71.1%). Sphincter disturbances were observed in 9 patients. An increase in craniovertebral angle was observed in postoperative period in all patients. Initially, 84% of the patients had a poor Nurick grade; this was reduced to 28% after the surgical intervention. One hundred percent bony fusion was attained in patients who underwent rigid fixation technique, and 80% was attained using a semirigid fixation technique. The key to successful management of craniovertebral junction disease is individualized selection of judicious surgical intervention from various available techniques.

The Impact of Surgical Treatment on Survival in Patients With Cervical Spine Metastases.

ObjectiveTo compare overall survival (OS) in patients with cervical spine metastases between initial radiotherapy followed by surgery and initial surgery followed by radiotherapy. MethodsThe medical records of 36 patients with cervical spine metastases from January 2007 to December 2015 were retrospectively analyzed. These patients were divided into 2 groups. Group 1 included patients who underwent initial radiotherapy followed by surgery, while group 2 included patients who underwent initial surgery followed by radiotherapy. Clinical outcomes, OS, OS after cervical spine metastasis, and OS after surgery were analyzed in both groups. We evaluated whether primary tumor type, initial treatment modality, the modified Tomita score, Eastern Cooperative Oncology Group performance status, Karnofsky performance status, Japanese Orthopedic Association (JOA) score, Nurick grade, Frankel classification, and preoperative symptoms were associated with OS after cervical spine metastasis. ResultsBoth groups exhibited improvement in the postoperative visual analogue scale, but only group 2 showed a significant improvement in postoperative JOA score (p=0.03). OS did not differ significantly between groups. However, OS after cervical spine metastasis was only 7.0 months (95% confidence interval [CI], 4.8–9.3) in group 1 versus 15.8 months (95% CI, 8.8–24.0) in group 2, which represented a significant difference (p<0.05). Factors related to OS after cervical spine metastasis were primary tumor type, initial treatment modality, and preoperative symptoms (p<0.05). Patients who presented with only preoperative pain had approximately 3 fold longer OS after cervical spine metastasis than patients with preoperative motor weakness, even in group 2 (p<0.05). ConclusionSurgical treatment prior to the onset of motor weakness or radiotherapy may be a good decision in case of cervical spine metastasis.

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

Retrospective study. 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). There are limited data on the predictors of outcome and sustainability of initial functional improvement on long-term follow-up after cervical corpectomy. 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. 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). 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. 4.

Postoperative Resolution of Magnetic Resonance Imaging Signal Intensity Changes and the Associated Impact on Outcomes in Degenerative Cervical Myelopathy: Analysis of a Global Cohort of Patients.

Subanalysis of the prospective AOSpine CSM North America and International studies. To describe the postoperative changes in magnetic resonance imaging (MRI) spinal cord signal intensity in degenerative cervical myelopathy (DCM) patients and to investigate the impact of its postoperative resolution on clinical outcomes. When examining the spinal cord, hyperintensity found in MRI T2-weighted images and hypointensity in T1-weighted images are known to correlate with preoperative severity of DCM and to predict postoperative neurological recovery. However, the clinical importance of these signal intensity changes in postoperative images has not been established. Among 757 surgical DCM patients enrolled in two prospective multicenter studies, postoperative MRI images obtained between 6 and 24 months after the operation were examined with a focus on T2 hyper- and T1 hypointensity in the spinal cord. The 2-year postoperative Nurick grade, modified Japanese Orthopaedic Association score and modified Japanese Orthopaedic Association recovery rate (RR) were analyzed between patients with or without resolution of signal intensity changes. A total of 167 patients with preoperative T2 hyperintensity were included with complete postoperative MRI images. Of these patients, 11% showed resolution of signal intensity changes, 70% retained T2 hyperintensity only, and 19% showed both T2 hyper- and T1 hypointensity postoperatively. There was a stepwise trend toward worse postoperative outcomes, with the no signal intensity change group showing the best outcome and the T1 hypointensity group showing the worst (mean RR: 72% vs. 51% vs. 36%, P = 0.02). Patients who exhibited resolution of T2 hyperintensity showed better outcomes than those who retained it (RR: 72% vs. 47%, P = 0.04), but the resolution of T1 hypointensity was not associated with improved outcomes (RR: 38% vs. 26%, P = 0.36). Postoperative resolution of T2 hyperintensity in patients with DCM was associated with the best clinical outcomes, whereas those with T1 hypointensity showed the worst. 3.

T91. Factors predicting the successful generation of baseline motor evoked potentials in patients undergoing spine surgery

Introduction The purpose of this study was to search for clinical factors predicting the successful generation of baseline muscle motor evoked potentials (mMEPs) in patients undergoing spine surgery and to determine the relationship with postoperative functional outcome. Methods From July 2014 to June 2015, a total of 345 patients underwent spine surgery with intraoperative mMEPs monitoring and were consecutively included in this study. Their demographic features, clinical parameters, and mMEPs recording results were reviewed retrospectively. Results Two hundred and fifty-three (73%) patients showed the successful generation of baseline mMEPs at all recording muscles, and 92 (27%) patients failed to record baseline mMEPs at one or more limb muscles. When we compared the preoperative clinical parameters of the two groups, the latter group (“Failure group”) significantly had a higher male ratio, lower MRC grades, higher Nurick grades, more often cervical/cervicothoracic segment involvement, higher proportion of the presence of spine surgery history, motor deficits, sensory symptoms, bladder/bowel dysfunction, T2-weighted high signal intensity (HSI) of cord at spine MRI compared to the former group (“Success group”) and were older. Among these factors, male sex, cervical/cervicothoracic lesion location the presence of T2-weighted HSI of cord, preoperative Nurick grade, and MRC grade showed a significant contribution for predicting the successful generation of mMEPs. When analyzing predictors for postoperative poor functional outcomes, the success rate of mMEPs recording and lesion etiology were significantly related factors for the aggravation of the Nurick grades before and after surgery. Conclusion Various clinical parameters including lesion location, abnormal cord signal on MRI, preoperative motor power, and functional status were revealed to have a significant relationship with the successful generation of baseline mMEPs. Additionally, the successful generation of mMEPs was one of the indicators for predicting the long-term functional outcome.

Endoscopic Anterior Approach for Cervical Disc Disease (Disc Preserving Surgery)

To report our experience of endoscopic disc removal by anterior approach for management of cervical myelopathy in 210 patients. A retrospective study of 187 cases of single- and 23 cases of double-level disc disease was performed. Cases of myelopathy with or without unilateral or bilateral radiculopathy and unilateral radiculopathy with either soft or hard disc prolapse were included. Patients with ≥3 disc levels, unstable spine, infections, trauma, significant posterior compression, congenital canal stenosis, disc extending more than half the vertebral body height, and prior surgery at the same level were excluded. C5-6 (n= 119 patients), C6-7 (n= 58 patients), C4-5 (n= 49 patients), C3-4 (n= 6 patients), and C2-3 (n= 1 patient) levels were represented. Visual analog scale and Nurick grading system were used to assess severity of neck and arm pain and functional outcomes, respectively. Preoperative mean visual analog scale scores for arm and neck pain were 6.7 and 3.2, respectively, which improved to 1.7 and 1.1 at 3 months after surgery. The average preoperative Nurick grade improved from 2.64 to0.81 at 6 months postoperatively. Follow-up was 6-54months. Endoscopic anterior discectomy (disc preserving surgery) is an effective and safe alternative in cervical disc disease. Although there was reduction in disc height, clinical outcome was good at an average 29 months of follow-up. Long-term follow-up is required to assess any progressive disc degeneration and clinical results.

Correlation between the severity of myelopathy and cervical morphometric parameters on dynamic magnetic resonance imaging.

To compare morphometric factors of cervical spine in the cervical stenosis on dynamic and static magnetic resonance imaging. To analyse the relationship between the severity of myelopathy and morphometric parameters. Patients with cervical canal stenosis scanned with MRI in neutral (N), flexion (F) and extension (E) positions were retrospectively reviewed. All cases were evaluated in Nurick and Muhle grades. Following parameters were measured: anterior and posterior length of the cervical cord (aLCC, pLCC), mid-cord distance (L value), cervical cord angle (CCA), cervical lordosis, spine/cord (S/C) angle ratio, spinal cord (SC) area, cerebrospinal fluid (CSF) area, and CSF reserve ratio (CSF/CSF plus SC). Univariate multiple regression for Nurick grade as dependent factor was used. Sixty-three patients and 34 men, with the mean age of 58.2 ± 11years, were analysed. Significant differences were found for pLCC, SC area, C lordosis and CCA. The difference between F and E for C lordosis angle was 42.80° ± 14.4 and for CC angle 30.42° ± 9.6. The mean S/C angle ratio was calculated for 1.4 ± 1.3. Nurick grade positively correlated with age (p = 0.041) and S/C angle ratio (p = 0.011), negatively with SC area (p = 0.006) and flexion-extension difference of L value (0.004). Severity of myelopathy correlates with age, spinal cord area on extension and reduced mobility of spinal cord. An association between spine/cervical cord angle mismatch and Nurick grade was found.

Cervical Spine and Cord Angle Mismatch in the Pathogenesis of Myelopathy

Cervical myelopathy is a complex pathology and dynamic compression of the tethered cervical cord, which may be responsible for clinical symptoms. Patients with cervical canal stenosis who had magnetic resonance imaging in flexion and extension positions were retrospectively reviewed. All cases were evaluated in Nurick grade. The cervical parameters-cervical cord (CC) angle, cervical lordosis, and spine/cord (S/C) angle ratio-were measured on the magnetic resonance imaging. Mean values of these parameters were compared between nonmyelopathic (Nurick grade 0) and myelopathic groups (Nurick grades 1-5). A multinomial ordinal logistic regression was used to predict outcome for Nurick grade using the CC angle, the cervical lordosis angle, and the S/C angle ratio as independent variables. A total of 65 patients (35 men) with the mean age of 58.6 ± 11.4 years were analyzed. A comparison of means between Nurick grade 0 against each of myelopathic grades 1-5 revealed significant differences only for the S/C angle ratio. A cumulative comparison between nonmyelopathic and myelopathic grades for the S/C angle ratio showed significant difference of 0.29 (1.16 ± 0.5 vs. 1.45 ± 0.6, respectively; P < 0.05). Cumulative comparison for the CC angle difference in flexion and extension lordosis did not show substantial differences. The S/C angle ratio was the only significant parameter in the prediction of the Nurick grade with an odds ratio of 2.63 (95% confidence interval 2.11-2.79). A positive correlation between Nurick grade and cervical spine and cord angle mismatch was found.