Novel C-arm-based planning robotic spinal surgery in a cadaver model using quantitative accuracy assessment methodology.

BACKGROUND: This preclinical study emulating the clinical environment quantitatively analysed the accuracy of pedicle screw insertion using a navigated robotic system. METHODS: Pedicle screws were placed from T7 to L5 in the whole-body form of a cadaver. After the insertion of multiple artificial markers into each vertebra, errors between the planned insertion path and the inserted screw were quantified using the Gertzbein-Robbins system (GRS) and offset calculation. RESULTS: A total of 22 screws were placed. Almost all (95.45% [21/22]) were classified as GRS A or B, while one (4.55%) was GRS C. The mean and standard deviations of entry, tip, and angular offset were 1.78 ± 0.94 mm, 2.30 ± 1.01 mm, and 2.64 ± 1.05°, respectively. CONCLUSIONS: This study demonstrated that pedicle screw insertion using a navigated robotic system had high accuracy and safety. A future clinical study is necessary to validate our findings.

Association of frailty with regional sagittal spinal alignment in the elderly.

The degenerative changes in the spine of the frail elderly gradually exacerbate the alignment of the spine as the degeneration progresses. This study was conducted to assess the relationship between frailty and spine sagittal alignment measured in terms of global, cervical, thoracic, and lumbo-pelvic parameters. In total, 101 patients aged 75 years and older hospitalized for spine surgery were prospectively enrolled. We evaluated spinal sagittal parameters by dividing them into global (C7 sagittal vertical axis [SVA] and T1 pelvic angle [T1PA]), cervical (the C2-7 Cobb angle, Jackson line, and C2-7 plumb line), thoracic (thoracic kyphosis [TK]), and lumbo-pelvic (pelvic tilt [PT] and pelvic incidence minus lumbar lordosis value [PI-LL]). Patient characteristics; the Fatigue, Resistance, Ambulation, Illness, Loss of Weight (FRAIL) scale; and sagittal spinal parameters were included in the analysis. Multiple regression analysis was performed to identify associations between the FRAIL scale and sagittal spinal parameters. The FRAIL scale showed correlations with global sagittal parameters (C7 SVA [ß = 0.225, p = 0.029] and T1PA [ß = 0.273, p = 0.008]) and lumbo-pelvic parameters (PT [ß = 0.294, p = 0.004] and PI-LL [ß = 0.323, p = 0.001). Cervical and thoracic parameters were not directly associated with the FRAIL scale. LL and PI-LL were associated with TK, and TK was associated with cervical parameters (the C2-7 Cobb angle, Jackson line and C2-7 plumb line). In conclusion, frailty status could be an important factor that influences sagittal spinal alignment in the elderly. In this study, it was found that frailty mainly affected the balance of lumbo-pelvic alignment, and consequently affected the balance of the whole spine.

Cervical disc arthroplasty: What we know in 2020 and a literature review.

Cervical disc arthroplasty (CDA) is a safe and effective option to improve clinical outcomes (e.g., NDI, VAS, and JOA) in degenerative cervical disc disease and compressive myelopathy. CDA's two main purported benefits have been that it maintains physiologic motion and thereby minimizes the biomechanical stresses placed on adjacent segments as compared to an ACDF. CDA might reduce the degeneration of adjacent segments, and the need for adjacent-level surgery. Reoperation rates of CDA have been reported to range from 1.8% to 5.4%, with a minimum 5-year follow-up. As the number of CDA procedures performed continues to increase, the need for revision surgery is also likely to increase. When performed skillfully in appropriate patients, CDA is an effective surgical technique to optimize clinical outcomes and radiological results. This review may assist surgical decision-making and enable a more effective and safer implementation of cervical arthroplasty for cervical degenerative disease.

Predictors of neurologic outcome after surgery for cervical ossification of the posterior longitudinal ligament differ based on myelopathy severity: a multicenter study.

OBJECTIVE: The purpose of this retrospective multicenter study was to compare prognostic factors for neurological recovery in patients undergoing surgery for cervical ossification of the posterior longitudinal ligament (OPLL) based on their presenting mild, moderate, or severe myelopathy. METHODS: The study included 372 consecutive patients with OPLL who underwent surgery for cervical myelopathy between 2006 and 2016 in East Asian countries with a high OPLL prevalence. Baseline and postoperative clinical outcomes were assessed using the Japanese Orthopaedic Association (JOA) myelopathy score and recovery ratio. Radiographic assessment included occupying ratio, cervical range of motion, and sagittal alignment parameters. Patient myelopathy was classified as mild, moderate, or severe based on the preoperative JOA score. Linear and multivariate regression analyses were performed to identify patient and surgical factors associated with neurological recovery stratified by baseline myelopathy severity. RESULTS: The mean follow-up period was 45.4 months (range 25-140 months). The mean preoperative and postoperative JOA scores and recovery ratios for the total cohort were 11.7 ± 3.0, 14.5 ± 2.7, and 55.2% ± 39.3%, respectively. In patients with mild myelopathy, only age and diabetes correlated with recovery. In patients with moderate to severe myelopathy, older age and preoperative increased signal intensity on T2-weighted imaging were significantly correlated with a lower likelihood of recovery, while female sex and anterior decompression with fusion (ADF) were associated with better recovery. CONCLUSIONS: Various patient and surgical factors are correlated with likelihood of neurological recovery after surgical treatment for cervical OPLL, depending on the severity of presenting myelopathy. Older age, male sex, intramedullary high signal intensity, and posterior decompression are associated with less myelopathy improvement in patients with worse baseline function. Therefore, myelopathy-specific preoperative counseling regarding prognosis for postoperative long-term neurological improvement should include consideration of these individual and surgical factors.

Prediction of angular kyphosis after cervical laminoplasty using radiologic measurements.

Angular kyphosis is an important complication after cervical laminoplasty. Previous reports have suggested that T1 slope (T1s) and extension function (EF) have key roles in kyphosis, and no different radiologic measuments which affects postoperative kyphosis were seen between ossification of the posterior longitudinal ligament (OPLL) or cervical spondylotic myelopathy (CSM). We tried to find preoperative radiologic measurements predicting angular kyphosis after laminoplasty according to disease entities. We retrospectively analyzed 133 patients with OPLL or CSM who underwent expansive laminoplasty. Preoperative neutral and extension C2-7 cobb angle (CA), T1s, C2-7 sagittal vertical axis, and C2-7 slope angle (SA) were measured. EF of C2-7 CA and C2-7 SA was defined as extension CA/SA minus neutral CA/SA. Significant angular kyphosis was defined as LCL less than -10° after surgery. Mean loss of lordosis was -3.23, and 16.5% of patients showed significant kyphosis. Preoperative EF-CA, EF-SA, and T1s were found to be predictive for angular kyphosis by Pearson correlation analysis. The receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) of radiologic measurements could not reach 0.7. In patients with OPLL, the AUC of preoperative neutral CA was 0.716. However, in patients with CSM ROC curve analysis revealed that EF-CA and EF-SA could predict the significant angular kyphotic changes. Examining OPLL and CSM separately, preoperative radiologic measurements were found to influence postoperative cervical kyphosis, respectively. However, preoperative C2-7 neutral CA in OPLL patients and both EF-CA and EF-SA in CSM patients could predict significant angular kyphosis after cervical laminoplasty.

Novel C-arm based planning spine surgery robot proved in a porcine model and quantitative accuracy assessment methodology.

BACKGROUND: We assessed pedicle screw accuracy utilizing a novel navigation-based spine surgery robotic system by comparing planned pathways with placed pathways in a porcine model. METHODS: We placed three mini screws per vertebra for accuracy evaluation and used a reference frame for registration in four pigs (46 screws in 23 vertebrae). We planned screw paths and performed screw insertion under robot guidance. Using C-arm and CT images, we evaluated accuracy by comparing the 3D distance of the placed screw head/tip from the planned screw head/tip and 3D angular offset. RESULTS: Mean registration deviation between the preoperative 3D space (C-arm) and postoperative CT scans was 0.475 ± 0.119 mm. The average offset from preoperative plan to final placement was 4.8 ± 2.0 mm from the head (tail), 5.3 ± 2.3 mm from the tip and 3.9 ± 2.4 degrees of angulation. CONCLUSIONS: Our spine surgery robot showed good accuracy in executing an intended planned trajectory and screw path. This faster and more accurate robotic system will be applied in future studies, first in cadavers and subsequently in the clinical field.

Clinical and radiological outcomes of multilevel cervical laminoplasty versus three-level anterior cervical discectomy and fusion in patients with cervical spondylotic myelopathy.

BACKGROUND: Cervical spondylotic myelopathy (CSM) is one of the most common causes of spinal cord impairment in elderly patients. However, a consensus has yet to be reached on the ideal method of surgical intervention. In this study, we investigated serial changes of radiological findings after three-level anterior cervical discectomy and fusion (ACDF) and multilevel laminoplasty and attempted to identify the radiological parameters affecting long-term clinical outcomes in CSM. METHODS: Of the 152 patients with multilevel CSM treated with three-level ACDF and multilevel laminoplasty, 42 had complete radiological parameters both before and 2 years after surgery (three-level ACDF, 22 patients; multilevel laminoplasty, 20 patients). Radiological parameters included spinal cord signal intensity (SI) changes on magnetic resonance imaging (MRI). Clinical outcomes including the Japanese Orthopaedic Association (JOA) score, neck disability index (NDI), Oswestry disability index (ODI), and 36-Item Short Form Health Survey score were measured. RESULTS: The ACDF group showed significant restoration of segmental lordosis postoperatively (preoperatively: 2.21°, 6 months: 8.37°, P=0.026), and segmental and cervical range of motion (ROM) was markedly reduced and well maintained until the final follow-up (preoperatively: 25.48°, 24 months: 4.35°, P<0.001; preoperatively: 41.71°, 24 months: 20.18°, P<0.001). The recovery rates of the JOA score were 42.85% and 57.40% in the ACDF and laminoplasty groups, respectively, although this difference was not statistically significant. Multivariate regression analysis demonstrated that signal change on MRI significantly affected the recovery rate (P=0.003). The visual analog scale (VAS) score and NDI decreased considerably only in the laminoplasty group, and device complications were confirmed only in the ACDF group (incidence rate =36.5%). CONCLUSIONS: Multilevel laminoplasty showed better radiological and similar clinical outcomes. ACDF had more surgical complications. Spinal cord SI change on preoperative MRI was the independent risk factor for poor clinical outcomes. We recommend laminoplasty instead of three-level ACDF to treat multilevel CSM.

Comparison of the effectiveness and safety of bioactive glass ceramic to allograft bone for anterior cervical discectomy and fusion with anterior plate fixation.

Recently, a bioactive glass ceramic (BGC) has been developed for use as intervertebral cages for anterior cervical discectomy and fusion (ACDF). However, the effectiveness and safety of BGC cages remain to be evaluated. We completed a retrospective comparison of the radiological and clinical outcomes of 36 patients (52 levels) who underwent ACDF with a BGC cage and 35 patients (54 levels) using allograft bone. The following variables were compared between the two groups: the visual analog (VAS) neck and arm pain score and the neck disability index (NDI), measured before surgery and 1 year after; the change in Cobb's angle, between the C2 and C7 vertebrae, the global sagittal angle, and disc height compared from before surgery to 1 year after; and the rate of spinal fusion and cage subsidence at 1 and 2 years after surgery. The VAS and NDI scores were not different between the two groups. Similarly, the spinal fusion rate was not different between the BGC and allograft bone group at 1 year (73% and 87%, respectively; p = 0.07) and 2 years (94% and 91%, respectively; p = 0.54) after surgery. However, the rate of cage subsidence was higher in the allograft bone (43%) than the BGC (19%) group (p = 0.03), as was the rate of instrument-related failure (p = 0.028), with a specifically higher incidence of implant fracture or failure in the allograft bone group (p = 0.025). Overall, our findings indicate that BGC cages provide a feasible and safe alternative to allograft bone for ACDF.

Upper Cervical Surgery, Increased Signal Intensity of the Spinal Cord, and Hypertension as Risk Factors for Dyspnea After Multilevel Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective study. OBJECTIVE: To investigate the associated risk factors for acute respiratory distress after multilevel anterior cervical discectomy and fusion (ACDF) with a focus on the subjective symptom, dyspnea. SUMMARY OF BACKGROUND DATA: Acute respiratory distress after ACDF is a relatively common adverse event, the cause of which is usually soft tissue swelling or hematoma. It can result in serious morbidity and requires careful, focused treatment. METHODS: We reviewed the records of 532 patients (from January 2014 to August 2018) who had undergone multilevel ACDF surgery. Acute respiratory distress was defined as a complaint of dyspnea within 5 postoperative days. We investigated the patients' demographic parameters, comorbidities, and surgical procedure details. We also investigated radiologic parameters, including magnetic resonance imaging (MRI), with special attention to the prevertebral soft tissue thickness at C3 and C6. Statistical analysis was performed using the Student's t test and multiple logistic regression analysis. RESULTS: Out of a total of 484 patients studied after exclusion criteria were applied, 31 patients (6.6%) experienced dyspnea after surgery. We selected 92 patients from the non-dyspnea group and compared them with 31 patients from the dyspnea group. On univariate analysis, upper cervical surgery involving C3, increased cord signal intensity on T2-weighted imaging (T2WI) magnetic resonance imaging (MRI), hypertension, smoking, and prevertebral soft tissue swelling at C3 level on postoperative day 1 were statistically significant factors associated with dyspnea. On logistic regression analysis, upper cervical surgery involving C3, increased cord signal intensity on T2WI MRI, and hypertension were found to be statistically significant variables (P < 0.05). CONCLUSION: Patients undergoing upper cervical surgery involving C3, and having increased cord signal intensity on T2WI MRI and hypertension need to be monitored more carefully for acute respiratory distress after multilevel ACDF. LEVEL OF EVIDENCE: 4.

Evaluating the differences between 1D, 2D, and 3D occupying ratios in reflecting the JOA score in cervical ossification of the posterior longitudinal ligament.

BACKGROUND: To compare the differences between the one-dimensional (1D) length, two-dimensional (2D) area, and three-dimensional (3D) volume occupying ratios, and to assess the difference between the central and peripheral types of ossification of the posterior longitudinal ligament (OPLL). METHODS: In total, 60 patients were included in this study, and 1D and 2D occupying ratios were obtained using Centricity PACS (GE Healthcare), while a 3D model was created using MIMICS® (Materialise, Leuven, Belgium). Clinical symptoms were measured preoperatively by the modified Japanese Orthopedic Association (JOA) score, short-form health survey (SF-36), and neck disability index. The increased signal intensity (ISI) in T2-weighted MRI was divided into three groups: grade 0, none; grade1, limited to one disc level; or grade2, beyond one disc level. The axial view of spinal canal in CT was vertically divided into three equal parts. Then, the OPLL was categorized by central and peripheral type according to the location of most protruded tip. RESULTS: The 1D, 2D, and 3D occupying ratios had a significantly negative relationship with JOA score (r=-0.503; -0.506; -0.516, respectively). There was little difference in the JOA score between the central and peripheral types (17.15 vs. 17.12, P=0.785). The relationship with MR ISI, according to the central and peripheral type, showed no significant difference. In each multiple regression analysis, the 1D, 2D, and 3D occupying ratios were determined to have more influence on the JOA score (Beta: -0.364, -0.411, -0.462, respectively) than age, sex, most severe level, OPLL type, location type, and MR ISI. CONCLUSIONS: There was no difference between 1D, 2D, and 3D occupying ratios in reflecting the JOA score in cervical OPLL. Also, it is sufficient to reflect the occupying ratio in the clinical outcome without distinguishing between central and peripheral type.

Surgical Management of Gorham-Stout Disease in Cervical Compression Fracture with Cervicothoracic Fusion: Case Report and Review of Literature.

BACKGROUND: Gorham-Stout disease (GSD) or "vanishing bone" disease is characterized by progressive osteolysis with intraosseous lymphangiomatosis (hemangiomatosis). Given its rarity, with about 300 reported cases, its pathophysiology, etiology, and treatment guidelines are not established yet. CASE DESCRIPTION: A 22-year-old man was admitted to Severance Hospital with the chief complaint of neck pain from an injury due to falling. Initial cervical radiography showed a C4 burst fracture, and cervical magnetic resonance imaging revealed diffuse osteolytic lesions with coarse trabeculation with T2 hyperintensity and T1 enhancement in the entire cervical and upper thoracic area. He had a previous history of chylothorax that was still noticeable on a chest radiograph at the time of admission. A 2-stage operation was conducted. First, anterior corpectomy of C4 and anterior plate fixation of C3-5 were performed. Second, a week later, posterior fixation of C3-5 was performed. Thereafter, the patient was discharged without any neurologic complications. However, during the 1-month follow-up, asymptomatic progressive kyphosis was detected via radiography, and posterior cervical fusion of C2-T4 was performed. A minimal postoperative symptom of an intermittent left arm pain of 4-5 on the visual analog scale was experienced. No further deformity progression was noted until the last outpatient follow-up. CONCLUSIONS: Spinal GSD can cause severe deformity and neurologic deficits such as paralysis. Although treatment for GSD is not established, surgical treatment is recommended in severe deformity or aggravated neurologic deficit. The appropriate timing of surgery is after the arrest of osteolysis. Magnetic resonance imaging could be helpful in determining stable GSD.

Vertebral Reconstruction with Customized 3-Dimensional-Printed Spine Implant Replacing Large Vertebral Defect with 3-Year Follow-up.

BACKGROUND: Destruction of the spine is a huge complication of infectious spondylitis and surgical intervention is required. However, vertebral defect is a major problem after surgical intervention and numerous methods have been researched to solve this problem. There are known methods that use variously designed, patient-customized 3-dimensional (3D)-printed implants in various medical fields. The use of 3D-printed implants has also been attempted in treating defects in the spine. We present a case of failure of expandable titanium cage fusion after infection, treated using a 3D-printed implant. CASE DESCRIPTION: The patient had undergone reconstruction surgery with expandable titanium cage due to infectious spondylitis and needed reoperation owing to recurrence of infections and failure of bone fusion. The problem we faced in this operation was a large vertebral defect, for which we used a 3D-printed implant. After 3 years of follow-up, the implant and bone fusion were intact and infection or mechanical complications were not seen. CONCLUSIONS: A 3D-printed implant could be an acceptable and alternative treatment option for replacing a large vertebral defect.

Analysis of Risk Factors Associated with Hospital Readmission Within 360 Days After Degenerative Lumbar Spine Surgery in Elderly Patients.

OBJECTIVE: There is a paucity of studies on readmission rates in elderly patients over a period of 360 days after spinal surgery. METHODS: We identified 1248 patients older than 70 years who underwent degenerative lumbar spinal surgery from November 2005 to April 2015. We reviewed the patients who were readmitted within 360 days and compared them by univariate and multivariate analysis with the nonreadmitted patients for each period of 0-30, 30-90, 90-180, and 180-360 days postoperatively to determine risk factors for hospital readmission. RESULTS: A total of 1248 patients (733 female, 58.7%) were enrolled in the study. The number of readmitted patients was 37 (2.96%), 94 (7.53%), 145 (11.62%), 182 (14.58%), and 213 (17.07%) at 30, 90, 180, 270, and 360 days, respectively. Surgical site-related problems decreased gradually in the first 0-90 days and slightly increased after then. Non-surgical site-related problems gradually increased with time. Logistic multiple regression analysis showed that electrocardiographic abnormalities, male sex, low hemoglobin levels, asthma, heart disease, intensive care unit admission, low alanine aminotransferase level, high body mass index, and high platelet level were risk factors for readmission. CONCLUSIONS: We found that electrocardiographic abnormalities, male sex, low hemoglobin levels, asthma, heart disease, intensive care unit admission, low aspartate aminotransferase level, high body mass index, and high platelet level were risk factors for readmission. As the postoperative observational period became longer, the reasons for readmission tended to be more related to non-surgical site-related problems than to surgical-related problems.

Clinical Efficacy and Safety of Trans-Sacral Epiduroscopic Laser Decompression Compared to Percutaneous Epidural Neuroplasty.

Percutaneous epidural neuroplasty (PEN) is an effective and safe procedure for herniated lumbar disc (HLD). Although PEN has an advantage of adhesiolysis, this procedure cannot decompress the protruded disc. Recently, trans-sacral epiduroscopic laser decompression (SELD) for HLD has been introduced as a promising alternative methodology. This study evaluated the clinical efficacy and safety of SELD compared to PEN, as well as the change in protruded disc volume after SELD through pre- and postoperative magnetic resonance imaging (MRI), in patients with HLD. Thirty consecutive patients underwent SELD (SELD group), and 45 patients underwent PEN (PEN group). The Visual Analog Scale (VAS) for leg pain; Oswestry Disability Index (ODI); 12-Item Short-Form Health Survey (SF-12); preoperative and postoperative 4-, 12-, and 24-week Macnab criteria; and preoperative and 24-week postoperative lumbar spinal MRIs after SELD were obtained. There was no significant difference in age, sex, duration of symptoms, and the distributions of disc level between the two groups (all P > 0.05). Between the SELD and PEN groups, preoperative VAS, ODI, and SF-12 scores had no significant differences. However, the VAS, ODI, and SF-12 scores improved significantly after the procedures by postoperative week 24 in each group (all P < 0.05). Furthermore, improvements of VAS, ODI, SF-12, and success rate of Macnab criteria in the SELD group were better than those in the PEN group (all P < 0.05). The protruded disc volume after SELD decreased significantly (P=0.034). All clinical and functional outcomes of patients undergoing SELD and PEN for HLD improved following the procedures. Notably, SELD was superior to PEN regarding the degree of improvement in clinical and functional outcomes. Therefore, we suggest that SELD can be used as an effective alternative to PEN to provide improved clinical and functional outcomes in patients with HLD.

Impact of H3.3 K27M Mutation on Prognosis and Survival of Grade IV Spinal Cord Glioma on the Basis of New 2016 World Health Organization Classification of the Central Nervous System.

BACKGROUND: Spinal cord glioma grade IV is a rare, diffuse midline glioma. H3 K27M-mutant was classified in a different entity in the 2016 World Health Organization (WHO) classification recently. No reports about prognosis of spinal cord glioma grade IV are available yet. OBJECTIVE: To analyze the prognostic factors for spinal cord glioma grade IV. METHODS: Twenty-five patients with spinal cord glioma of grade IV who underwent surgery in a single institute were selected. All grade IV spinal cord glioma histologically confirmed as glioblastoma or "diffuse midline glioma with H3 K27M-mutant" by the 2016 WHO classification of the central nervous system were included. Basic demographics, treatment modalities, and pathological tumor molecular profiles were investigated for prognosis. RESULTS: Mean age was 39.1 yr; male to female ratio was 18 : 7. Tumor was located in thoracic cord (53.3%), cervical cord (40%), and lumbar area (6.7%). Median overall survival was 37.1 mo; median disease-free survival was 18.5 mo. Treatment modality showed no statistical difference. Only K27M profile showed significant prognostic value, 20 patients (80%) showed K27M mutation positive, K27M mutation patients showed longer overall survival (40.07 mo) than K27M negative patients (11.63 mo, P < .0001), and disease-free survival (20.85 vs 8.72 mo, P = .0241). CONCLUSION: This study is the first and largest report of the prognosis of primary spinal cord grade IV glioma using the new WHO classification. This study reported survival analysis and prognostic factors, and revealed that H3.3 K27M mutation is not a major poor prognostic factor. Further studies to explore K27M mutations needed for risk stratification and therapy optimization.

Treatment outcomes of 17 patients with atypical spinal meningioma, including 4 with metastases: a retrospective observational study.

BACKGROUND CONTEXT: Because of the scarcity of atypical spinal meningioma, there is a lack of research on this type of tumor or its associated metastases. PURPOSE: The aim of this study was to investigate the biological behavior of atypical spinal meningioma and identify its prognostic factors by reviewing surgical and clinical outcomes of patients with these tumors. STUDY DESIGN: A retrospective chart review was performed. PATIENT SAMPLE: We retrospectively reviewed the data from all patients who underwent spinal cord tumor excision between 1994 and 2017. Seventeen patients were pathologically proven to have atypical spinal meningioma. OUTCOME MEASURES: We examined patients' neurologic status by determining their Nurick scores before and after surgery. Moreover, imaging studies, laboratory data, and the employed surgical method were analyzed retrospectively, as was the Ki-67 index and prognosis following postoperative radiation therapy. METHODS: The ranges, locations, and pathologic diagnoses of the tumors were extracted from the radiological and pathological records of each patient. The extent of surgery and progression of disease were confirmed using postoperative enhanced magnetic resonance imaging. Patients were divided into two atypical spinal meningioma groups: primary and metastatic. The demographics, age, sex, presenting symptom duration, tumor location, Simpson resection grade, Ki-67, radiotherapy, recurrence, overall survival, and progression-free survival of patients in both groups were compared. RESULTS: Seventeen patients were included in the analysis, of whom 12 (70%), 4 (24%), and 1 (6%) had tumors in the thoracic, cervical, and sacral regions, respectively. Complete and subtotal resections were achieved in 15 (88%) and 2 (12%) patients, respectively. Overall and progression-free survival rates in patients who underwent complete resection were longer than those in patients who underwent subtotal resection (p<.001). Four patients (24%) had metastatic meningiomas in the brain, among whom three were administered adjuvant radiotherapy after surgery. Two patients with intramedullary atypical spinal meningioma had metastatic tumors and experienced poorer prognoses. The 5-year overall and progression-free survival rates were 84.4% and 85.2%, respectively. The Simpson resection grade, Ki-67 index, and preoperative neurologic status were found to be important prognostic factors on univariate Cox regression analysis (p<.05). CONCLUSIONS: Complete resection should be considered as a primary treatment modality for individuals with atypical spinal meningioma. If subtotal resection is performed, adjuvant therapy can be administered.

Factors associated with surgical outcomes of cervical ossification of the posterior longitudinal ligament.

To investigate factors associated with surgical outcomes of cervical ossification of the posterior longitudinal ligament (OPLL). This retrospective study included patients (662 males and 251 females; mean age 55.8 years) with symptomatic OPLL. All patients had been diagnosed with OPLL based on cervical magnetic resonance imaging and computed tomography scans. Demographic, surgical outcome was measured using visual analog scale (VAS) and Japanese Orthopedic Association (JOA) scale scores. The results of our study indicated radicular pain was more common in segmental and circumscribe OPLL subtypes (P < 0.05). An anterior approach was favored in patients with less than 3 involved vertebral levels (P < 0.05). All surgical methods showed good outcomes (P < 0.05). Continuous and mixed OPLL subtypes showed worse surgical outcome with higher VAS and JOA scores (P < 0.05). Laminoplasty and anterior cervical discectomy and fusion were significantly associated with a higher recovery rate (P < 0.05). Among these patients, there were more complications with the anterior approach (P < 0.05). Male gender, open door laminoplasty ipsilateral, and ipsilateral-to-symptom-side opening were associated with postoperative C5 palsy (P < 0.05). Cervical OPLL may cause myelopathy, surgery is a safe and effective treatment for OPLL. There were no differences in clinical outcome according to surgical type, but complication rates varied depending on sex and surgical approach to symptom.

Prevalence, Incidence, Comorbidity, and Mortality Rates of Ossification of Posterior Longitudinal Ligament in the Cervical Spine: A Nested Case-Control Cohort Study.

OBJECTIVE: To evaluate prevalence, incidence, morbidity, and mortality rates of cervical ossification of posterior longitudinal ligament (OPLL) using data from a 12-year national cohort of 1,025,340 Korean people. METHODS: A nested case-control cohort study was performed from 2002 to 2013 using the insurance claims database provided by the National Health Insurance Service. We examined prevalence and incidence of cervical OPLL. Age- and sex-matched control subjects were randomly extracted, with 10 times the number of OPLL cases. Differences in sex, comorbidity, and relative survival rate compared with control subjects were assessed. RESULTS: Cumulative prevalence was 20,960 per 1,025,340 people for 12 years. Annual incidence was approximately 199-371 per 1 million people. Overall crude mortality rate was 7.64%. Relative survival rate of OPLL cases was not significantly different from control cases. Diabetes, hypertension, cardiovascular disease, and cerebrovascular disease, except renal disease, correlated significantly with OPLL compared with control cases (P < 0.001). Additionally, between dead and surviving patients among OPLL cases, all comorbidities correlated more significantly with death (P < 0.001). Furthermore, between surgery and nonsurgery cases of OPLL, diabetes, hypertension, and renal disease (P < 0.05) were significantly associated with surgery. CONCLUSIONS: Annual incidence of OPLL was 199-371 per 1,025,340 people for 10 years. Diabetes, hypertension, cardiovascular disease, and cerebrovascular disease, except renal disease, correlated significantly with OPLL compared with control cases. Especially, diabetes, hypertension, and renal disease were associated with patients with OPLL who underwent surgery.

Anatomical variations of vertebral artery and C2 isthmus in atlanto-axial fusion: Consecutive surgical 100 cases.

VA anomalies in extra- and intraosseous regions of the craniovertebral junction (CVJ) is considered very carefully during the posterior screw fixation for the atlantoaxial instability (AAI). This study aims to compare the incidence and variations of VA anomalies, isthmus and pedicle size of C2 in 100 patients with AAI due to congenital skeletal anomaly (CSA) and acquired disease by using three-dimensional CT angiograms (3D CTA) before surgery. The CSA group contained 48 patients and the acquired disease group consisted of 52. In the CSA group, Os odontoideum was the major cause with 43 patients. The causes of acquired disease were RA in 16 patients and OA in 36 patients. Five patients had the anomalous VA in only CSA group; fenestration 2 patients and persistent first intersegmental (PFIS) artery 3 patients. Between CSA and acquired disease groups, no significant differences were found in the isthmus height, internal height, and pedicle width of C2 except the right internal height that is bigger in CSA group. The high-riding VA (isthmus height <4 mm or internal height <2 mm) had no significant difference between CSA group (27.1%) and acquired disease group (34.6%). However, in acquired disease group, patients with rheumatoid arthritis had smaller left internal height (4.21 ±â€¯1.63 vs. 5.51 ±â€¯1.83 mm) and pedicle width (4.11 ±â€¯1.05 vs. 5.05 ±â€¯1.66 mm) of C2 than those of patients with degenerative osteoarthritis. Therefore, in the case of atlantoaxial fusion, we should contemplate VA anomaly and the high-riding VA, especially in patients with CSA and RA.

Feasibility of a Modified E-PASS and POSSUM System for Postoperative Risk Assessment in Patients with Spinal Disease.

OBJECTIVE: This retrospective case control study aimed to evaluate the feasibility of using Estimation of Physiological Ability and Surgical Stress (E-PASS) and Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity (POSSUM) systems in patients undergoing spinal surgical procedures. Degenerative spine disease has increased in incidence in aging societies, as has the number of older adult patients undergoing spinal surgery. Many older adults are at a high surgical risk because of comorbidity and poor general health. METHODS: We retrospectively reviewed 217 patients who had undergone spinal surgery at a single tertiary care. We investigated complications within 1 month after surgery. Criteria for both skin incision in E-PASS and operation magnitude in the POSSUM system were modified to fit spine surgery. We calculated the E-PASS and POSSUM scores for enrolled patients, and investigated the relationship between postoperative complications and both surgical risk scoring systems. To reinforce the predictive ability of the E-PASS system, we adjusted equations and developed modified E-PASS systems. RESULTS: The overall complication rate for spinal surgery was 22.6%. Forty-nine patients experienced 58 postoperative complications. Nineteen major complications, including hematoma, deep infection, pleural effusion, progression of weakness, pulmonary edema, esophageal injury, myocardial infarction, pneumonia, reoperation, renal failure, sepsis, and death, occurred in 17 patients. The area under the receiver operating characteristic curve (AUC) for predicted postoperative complications after spine surgery was 0.588 for E-PASS and 0.721 for POSSUM. For predicted major postoperative complications, the AUC increased to 0.619 for E-PASS and 0.842 for POSSUM. The AUC of the E-PASS system increased from 0.588 to 0.694 with the Modified E-PASS equation. CONCLUSIONS: The POSSUM system may be more useful than the E-PASS system for estimating postoperative surgical risk in patients undergoing spine surgery. The preoperative risk scores of E-PASS and POSSUM can be useful for predicting postoperative major complications. To enhance the predictability of the scoring systems, using of modified equations based on spine surgery-specific factors may help ensure surgical outcomes and patient safety.