Analysis of postoperative dysphagia after anterior cervical decompression and fusion.

Purpose: To investigate the incidence and risk factors of postoperative dysphagia after anterior cervical decompression and fusion (ACDF) in terms of demographic, procedural and anaesthetic perspectives.Materials and methods: Medical records and radiologic data of patients who underwent anterior cervical surgery performed by two surgeons in a single centre between January 2012 and December 2015 were retrospectively analysed. Patients with spinal tumours, infective spondylitis and traumatic cervical pathologies were excluded. Patients with preoperative dysphagia and previous history of anterior cervical surgery were also excluded. Finally, 127 patients were enrolled. Bazaz dysphagia score was used for the diagnosis of postoperative dysphagia.Results: The incidence of postoperative dysphagia was 10.2% at six weeks after ACDF. Nine patients showed mild dysphagia that fully recovered at three months after ACDF. Four patients showed moderate dysphagia that also recovered fully at six months after surgery. The incidence of postoperative dysphagia increased significantly in cases of C4 or C5 level involvements. Age, sex, hypertension, body mass index, postoperative soft tissue swelling, intubation difficulty and intubation tools were not significant risk factors of ACDF. Diabetes mellitus, two surgical levels, the use of plate, long anaesthetic and operative time and large intubation tube size were causative factors of postoperative dysphagia in multivariable analysis (p < 0.05).Conclusions: The incidence of postoperative dysphagia after ACDF was relatively low, and the prognosis was good.

Long-term recurrence rates after the removal of spinal meningiomas in relation to Simpson grades.

PURPOSE: Simpson grade II removal (coagulation of the dural attachment after gross total removal) of spinal meningioma is considered an acceptable alternative, but increased recurrence after more than 10 years has been reported. More attention must be paid to the long-term surgical outcomes after Simpson grade II removal. METHODS: A retrospective review was performed for 20 patients (M:F = 5:15; age, 59 ± 9 years) with Simpson grade II removal (mean follow-up period, 12.9 years; range 10.0-17.5). Magnetic resonance (MR) imaging was conducted in 17 patients at 88 ± 52 months (range 12-157). During the same period, Simpson grade I removal (removal of the dural origin) was performed in 21 patients (follow-up, 89 ± 87 months; range 9-316). Radiological recurrence was defined as a visible tumor on a follow-up MR image, and clinical tumor recurrence was defined as the recurrence of symptoms. RESULTS: At the final follow-up, neurological symptoms had improved in 16/20 patients and remained stable in 4/20. A recurrent tumor was detected in one patient due to increased back pain at 92 months postoperative, but the symptom was stable without surgery until the last follow-up (124 months). The radiological and clinical recurrence-free survival periods were 150 ± 7 months (95 % CI 136-163) and 204 ± 6 months (95 % CI 193-215), respectively. There was no recurrence after Simpson grade I removal, whereas neurological deterioration occurred in two patients after surgery. CONCLUSIONS: Simpson grade II removal may be an alternative option if the risk of complications with Simpson grade I removal is expected to be high.

Highly unstable cervical spine injury in an infant: a case report.

UNLABELLED: Although the rate of surgical intervention for pediatric cervical spine injuries has risen, none of these instrumentation techniques has been reported in children less than 1 year of age. Additional consideration with placement of wires or cables is not safe because of the presence of cartilaginous bone and poor bone strength. The authors report a technique of internal fixation without fusion using nonabsorbable synthetic suture in an infant with unstable cervical injury. METHODS: A 5-month-old girl was transported to emergency department and computed tomography showed severe distraction injury at the C6-7 level with total disruption of the facet joints bilaterally. To improve her general condition, she was placed in a customized occipito-cervical brace until surgical stabilization could be performed. After 1 month, surgical fixation was performed. After removing all soft tissues at the appropriate level, a hole was made in the center of the superior articular process of C6. A nonabsorbable suture (2-0 Ethibond; Ethicon, Somerville, NJ, USA) was passed from the superior articular process to the facet joint. The suture was passed into the spinous process of the lower level, and it was progressively tightened and radiographs were taken until anatomic reduction was achieved. RESULTS: After surgery, solid fusion was achieved. She was able to sit up in a stroller after 6 months. CONCLUSION: As surgical treatment of pediatric cervical spine injuries is unsuitable for infants, the Ethibond sutures are strong enough to hold and stabilize the spine. This suturing technique can be used as an alternative treatment for cervical injury in infants.

Synovial sarcoma of the spine: a case involving paraspinal muscle with extensive calcification and the surgical consideration in treatment.

INTRODUCTION: Synovial sarcoma is a rare malignant tumor of the spine. This tumor may present as a painless mass of the spine or slowly enlarge, causing pain or neurologic deficits. As it is difficult to differentiate this lesion from other soft tissue tumors, synovial sarcoma requires histologic confirmation for definite diagnosis. Thus, the treatment strategy is often planned in the final step depending on the pathologic results. Despite its rare incidence, a few cases of primary or metastatic synovial sarcoma involving the spinal cord, foramen, vertebral body, or paraspinal muscles have been reported in the literature. MATERIALS AND METHODS: We present the case of a 29-year-old man with a synovial sarcoma in the paraspinal muscle of the cervical spine. The patient was evaluated radiologically and histologically. Plain radiography, computed tomography, and magnetic resonance imaging were performed as part of the preoperative workup, and immunohistochemical and cytogenetic studies were additionally performed to identify the histologic features of the tumor. The patient underwent marginal resection followed by adjuvant radiation therapy. The patient has been followed up for 2 years. CONCLUSIONS: This article highlights the features of synovial sarcoma of the spine via a comprehensive review. Synovial sarcoma of the spine is uncommon, but it is a challenging issue in both diagnostic and therapeutic aspects. The currently available evidence suggests the use of a multidisciplinary approach in the treatment of synovial sarcoma, which includes complete resection and radiation therapy.

Analysis of the predictive role and new proposal for surgical strategies based on the modified Tomita and Tokuhashi scoring systems for spinal metastasis.

BACKGROUND: We sought to identify preoperative factors significantly correlated with survival. We also aimed to evaluate the validity of the prognostic scores in the Tomita and Tokuhashi systems and discuss several aspects to improve the predictive accuracy of these systems. Moreover, we suggest modified criteria for selecting treatment strategies. METHODS: In total, the outcomes of 112 patients with spinal metastasis who underwent surgery between January 2006 and June 2011 were retrospectively reviewed. The validity of the prognostic scores was assessed on the basis of their correlation with survival. For various primary malignancies, new scoring criteria were applied in each system according to the survival results obtained in this study. Each revised scoring system was adjusted with a similar principle of scoring as described previously. Patient survival according to each preoperative factor was analyzed by the Kaplan-Meier method. The predictive value of each scoring system was evaluated by the log-rank test and Cox regression analysis. RESULTS: The interval from the diagnosis of the primary malignancy to that of spinal metastasis (p = 0.023) and the interval from the diagnosis of spinal metastasis to surgery (p = 0.039) were significantly correlated with survival. Regarding Tokuhashi scores, the correlation coefficient was 0.790 before adjustment (p = 0.001) and 0.853 after adjustment (p < 0.001). For Tomita scores, the correlation coefficient was -0.994 (p < 0.001) both before and after adjustment. CONCLUSIONS: Tomita scores more accurately predicted survival than Tokuhashi scores. It is helpful to evaluate both scoring systems with adjustment for primary malignancy depending on the clinical setting. Patients with Tomita scores less than or equal to 8 and Tokuhashi scores greater than or equal to 6 are recommended to undergo surgical management.

Clinical and radiographic analysis of c5 palsy after anterior cervical decompression and fusion for cervical degenerative disease.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: To present the cases of 6 patients who developed C5 palsy after anterior decompression and discuss the mechanism of C5 palsy development, especially with respect to radiographic change. SUMMARY OF BACKGROUND DATA: C5 palsy has been reported to be a major complication of both anterior and posterior decompression procedures. Although several mechanisms of injury have been proposed, few reports have been issued on C5 palsy after anterior decompression surgery. METHODS: A retrospective medical record review was performed on 134 patients who underwent anterior decompression and fusion in our hospital from 2008 to 2011. C5 paralysis was defined as deterioration in muscle power of the deltoid or biceps brachii by at least 1 grade by manual muscle testing. Clinical features and radiologic parameters were evaluated to identify predisposing factors. RESULTS: Six patients (4.3%) suffered postoperative paralysis in the upper extremities (C5 radiculopathy). C5 palsy did not occur in 30 patients with radiculopathy. Excluding patients with cervical radiculopathy, the rate of C5 palsies was 5.8% for myelopathy patients. Three of 76 (3.95'%) cervical spondylotic myelopathy cases, one of 6 (16.7%) cervical spondylotic radiculomyelopathy patients, and 2 of 22 (9%) patients with ossification of the posterior longitudinal ligament showed C5 palsy. In 2 of the 6, C5 palsy developed after anterior cervical corpectomy, in 3 patients after anterior cervical discectomy and plate fusion, and in 1 after a standalone cage. Two patients underwent reoperation for foraminal decompression. Of the 4 treated conservatively, 3 fully recovered and the other almost fully improved (grade 4). Of 2 patients treated surgically, 1 showed full improvements. The other had no improvement. Radiographic measurements of these 6 patients showed that lordosis at operated segments increased postoperatively (mean, 6 degrees), and that overall sagittal alignments of the cervical spine (C3-C7) also increased (mean, 8.2 degrees). CONCLUSIONS: This study suggests that improved lordosis of the cervical spinal column can result in traction injury to the spinal cord and C5 nerve roots and that reoperation does not always produce good results. Methods of preventing and treating C5 palsy after anterior decompression and fusion require more evaluation.

Comparison of surgical outcomes after cervical laminoplasty: open-door technique versus French-door technique.

STUDY DESIGN: A retrospective case series. OBJECTIVE: To compare the surgical outcomes of open-door and French-door cervical laminoplasty for decompressing multilevel cervical spinal cord compressions. SUMMARY OF BACKGROUND DATA: Cervical laminoplasty is an effective method for decompressing multilevel cervical spinal cord compressions. Laminoplasty is usually classified as an open-door or French-door technique, but it is still unclear whether laminoplasty affects cervical alignment and clinical outcomes. METHODS: Fifty-one patients underwent cervical laminoplasty over a 2-year period for cervical spondylotic myelopathy, ossification of the posterior longitudinal ligament, or for a mixed-type condition. The following criteria were evaluated and compared retrospectively for open-door laminoplasty (group A) and French-door laminoplasty (group B): Nurick grades, Japanese Orthopedic Association (JOA) scores, neck disability index, and visual analog scale scores for axial neck pain and radiating pain. During radiologic evaluations, changes in cervical lordotic angles and range of motion were measured at C2-C7. RESULTS: Postoperatively, radiating pain improved significantly in both groups (P<0.05), but axial neck pain was more severe in both groups at last follow-up than preoperatively (P>0.05). Mean neurological improvement was 12.5% according to Nurick grades and 28% according to JOA scores in all study subjects. In particular, the mean Nurick grades showed significant improvement in group A (P<0.05), and the recovery rate was higher in group A than in group B according to Nurick grades (23.5% vs. 6.3%; P<0.05) and JOA scores (44.4% vs. 13%; P<0.05). In contrast, radiologically, cervical lordotic angle and range of motion were more significantly decreased in group B (P<0.05). CONCLUSIONS: Although open-door and French-door laminoplasty techniques were found to be effective for treating cervical compressive myelopathy, the open-door technique seems to be superior with respect to clinical and radiologic outcomes.

Uncovertebral hypertrophy is a significant risk factor for the occurrence of heterotopic ossification after cervical disc replacement: survivorship analysis of Bryan disc for single-level cervical arthroplasty.

OBJECTIVES: The purpose of this study is to investigate the incidence of heterotopic ossification (HO) in the Bryan cervical arthroplasty group and to identify associations between preoperative factors and the development of HO. METHODS: We performed a retrospective review of clinical and radiological data on patients who underwent single-level cervical arthroplasty with Bryan prosthesis between January 2005 and September 2007. Patients were postoperatively followed-up at 1, 3, 6, 12 months and every year thereafter. The clinical assessment was conducted using Odom's criteria. The presence of HO was evaluated on the basis of X-ray at each time-point according to the McAfee classification. In this study, we focused on survivorship of Bryan prosthesis for single-level arthroplasty. The occurrence of ROM-affecting HO was defined as a functional failure and was used as an endpoint for determining survivorship. RESULTS: Through the analysis of 19 cases of Bryan disc arthroplasty for cervical radiculopathy and/or myelopathy, we revealed that ROM-affecting HO occurs in as many as 36.8% of cases and found that 37% of patients had ROM-affecting HO within 24 months following surgery. The overall survival time to the occurrence of ROM-affecting HO was 36.4 ± 4.4 months. Survival time of the prosthesis in the patient group without preoperative uncovertebral hypertrophy was significantly longer than that in the patient group with preoperative uncovertebral hypertrophy (47.2 months vs 25.5 months, p = 0.02). Cox regression proportional hazard analysis illustrated that preoperative uncovertebral hypertrophy was determined as a significant risk factor for the occurrence of ROM-affecting HO (hazard ratio = 12.30; 95% confidential interval = 1.10-137.03; p = 0.04). CONCLUSION: These findings suggest that the condition of the uncovertebral joint must be evaluated in preoperative planning for Bryan cervical arthroplasty.

Intraosseous schwannoma with ancient change on the lumbar spine.

A 65-year-old male was admitted for progressive lower back pain. The preoperative revealed an osteolytic expansile mass with a sclerotic margin involving the right lamina and pedicle of L2. The histopathology revealed an ancient schwannoma. We report a rare case of an intraosseous ancient schwannoma involving lumbar vertebra along with its imaging findings and surgical aspects.

Significance of interfacet distance, facet joint orientation, and lumbar lordosis in spondylolysis.

The aim of this study is to reveal the association between lumbar spondylolysis and several radiologic parameters, which had been suggested to be significant. The authors examine interfacet distance (IFD), facet joint orientation (FJO), and lumbar segmental lordosis (LSL) all together on the basis of lumbar computed tomography (CT) scan of 35 patients with L5 spondylolysis and 36 unaffected control groups. Thirty-five Korean military recruits, aged 19-23 (mean 20.9 years), were diagnosed as L5 spondylolysis by lumber CT scans. As a control group, 36 male Korean military recruits, aged 18-25 (mean 21.3 years), were reconfirmed as not affected by lumbar spondylolysis by CT scan when they visited our hospital complaining of back pain. This study compares IFD, FJO, and LSL for each lumbar segment between the spondylolytic and unaffected groups. We also propose the use of normal mean data of IFD, FJO, and LSL of lumbar vertebrae from 36 Korean young military recruits because each measurement has power as an absolute value, like data from an osteologic collection in other studies. Comparison of IFD between spondylolytic and unaffected individuals reveals significant differences at the L3, L4, and L5 level (P = 0.0384, P = 0.0219, and P < 0.0001, respectively). In the group of spondylolysis, the increase of IFD from L4 to S1 was less pronounced (P < 0.0001) and the LSL at L5-S1 was more lordotic (P = 0.0203). Interfacet distance and lumbar lordosis were significantly different between patients with L5 spondylolysis and individuals without pars defect on L5. In the spondylolysis group, and the increase of IFD from L4 to S1 was less pronounced and the LSL at L5-S1 was more lordotic.

Incidence of deep vein thrombosis after spinal cord injury: a prospective study in 37 consecutive patients with traumatic or nontraumatic spinal cord injury treated by mechanical prophylaxis.

BACKGROUND: Patients with spinal cord injury (SCI) are at particular risk for deep vein thrombosis (DVT) during their hospital course. In most researches on the prevention of thromboembolic events after SCI, the cause of SCI was usually limited to traumatic origin, and pharmaco-prophylaxis was usually started immediately after SCI irrespective of the presence of DVT. For this reason, it is difficult to determine the exact incidence of DVT after SCI from all possible causes in the absence of anticoagulation treatment. We sought to determine the incidence of DVT and the effect of mechanical treatments without chemical prophylaxis. METHODS: From November 2009 to October 2010, 37 consecutive patients were admitted to our institute for SCI regardless of causes. Patient data including age, sex, types of injury in motor completeness, causes of SCI, and results of color Doppler ultrasonography (DUS) were collected. Routine mechanical prophylaxis for DVT was performed in all patients; pharmacologic prophylaxis was not used to avoid the potential consequences that may have confounded their benefits. All patients were routinely checked for DVT of lower limbs. Examinations were usually performed within 1 week of injury and repeated fortnightly until any medications for DVT were started in cases of a positive DUS result. RESULTS: In total, 16 of the 37 (43%) patients with acute SCI routinely given mechanical prophylaxis without anticoagulation were found to have DVT in the lower extremities by color DUS. Ten patients showed new thrombosis by DUS within 7 days after injury, three patients after 2 weeks to 3 weeks, and three patients at more than 1 month after injury. The majority of DVT occurred in the distal leg vein (81.2%, soleal vein). The incidence of DVT in patients with traumatic SCI was not different from that of patients with nontraumatic SCI in this study (p>0.05). Age, sex, type of motor impairment, and cause of SCI were not found to be significantly related to the occurrence of DVT. CONCLUSIONS: The incidence of DVT in patients with SCI routinely given mechanical prophylaxis without anticoagulation was higher when compared with those reported in the setting of routine pharmaco-prophylaxis. Anticoagulation should not be excluded from initial DVT prophylaxis measures in the SCI patients unless there is any ongoing bleeding or severe coagulopathy. Further studies will be necessary to get a more precise data and to understand the clinical relevance of these results.

The impact of sagittal balance on clinical results after posterior interbody fusion for patients with degenerative spondylolisthesis: a pilot study.

BACKGROUND: Comparatively little is known about the relation between the sagittal vertical axis and clinical outcome in cases of degenerative lumbar spondylolisthesis. The objective of this study was to determine whether lumbar sagittal balance affects clinical outcomes after posterior interbody fusion. This series suggests that consideration of sagittal balance during posterior interbody fusion for degenerative spondylolisthesis can yield high levels of patient satisfaction and restore spinal balance METHODS: A retrospective study of clinical outcomes and a radiological review was performed on 18 patients with one or two level degenerative spondylolisthesis. Patients were divided into two groups: the patients without improvement in pelvic tilt, postoperatively (Group A; n=10) and the patients with improvement in pelvic tilt postoperatively (Group B; n=8). Pre- and postoperative clinical outcome surveys were administered to determine Visual Analogue Pain Scores (VAS) and Oswestry disability index (ODI). In addition, we evaluated full spine radiographic films for pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), thoracic kyphosis (TK), lumbar lordosis (LL), sacrofemoral distance (SFD), and sacro C7 plumb line distance (SC7D) RESULTS: All 18 patients underwent surgery principally for the relief of radicular leg pain and back pain. In groups A and B, mean preoperative VAS were 6.85 and 6.81, respectively, and these improved to 3.20 and 1.63 at last follow-up. Mean preoperative ODI were 43.2 and 50.4, respectively, and these improved to 23.6 and 18.9 at last follow-up. In spinopelvic parameters, no significant difference was found between preoperative and follow up variables except PT in Group A. However, significant difference was found between the preoperative and follows up values of PT, SS, TK, LL, and SFD/SC7D in Group B. Between parameters of group A and B, there is borderline significance on preoperative PT, preoperative LL and last follow up SS.Correlation analysis revealed the VAS improvements in Group A were significantly related to postoperative lumbar lordosis (Pearson's coefficient=-0.829; p=0.003). Similarly, ODI improvements were also associated with postoperative lumbar lordosis (Pearson's coefficient=-0.700; p=0.024). However, in Group B, VAS and ODI improvements were not found to be related to postoperative lumbar lordosis and to spinopelvic parameters. CONCLUSION: In the current series, patients improving PT after fusion were found to achieve good clinical outcomes in degenerative spondylolisthesis. Overall, our findings show that it is important to quantify sagittal spinopelvic parameters and promote sagittal balance when performing lumbar fusion for degenerative spondylolisthesis.

Progressive atlanto-axial subluxation in Behcet's disease.

Behcet's disease is a chronic inflammatory condition involving several organs, such as the skin, mucous membranes, eyes, joints, intestines, lungs and central nervous system. It rarely affects the spinal column. We describe a case of progressive atlanto-axial subluxation in a 44-year-old woman with Behcet's disease. The patient started complaining of posterior neck pain 10 years after the diagnosis of her Behcet's disease. Initial radiographs showed no abnormal finding, but follow-up radiographs 6 month later demonstrated atlanto-axial subluxation. To the best of our knowledge, this is the second reported case in the worldwide literature of an atlanto-axial instability in a patient with Behcet's disease.

Subtotal resection of cervical schwannomas and growth rate of residual tumors.

OBJECTIVEThe objective of this study was to elucidate the features and surgical outcomes of cervical schwannomas.METHODSThe authors retrospectively reviewed the records of 90 patients who underwent surgically treated cervical schwannomas from January 1995 to December 2017, with an emphasis on MRI findings such as tumor location, tumor size, extent of tumor resection, and growth of a residual tumor.RESULTSThis study included 51 men (56.7%) and 39 women (43.3%) with a mean age of 44.5 years (range 7-77 years). Dumbbell-shaped tumors comprised 62 (68.9%) of 90 cases and gross-total resection (GTR) was achieved in 59 (65.6%) of 90 cases. All nondumbbell tumors (n = 28) underwent GTR. Only 1 case of recurrence in the GTR group showed a gradual increase in size (by 8.9 mm) during the 150-month follow-up period. For the regrowth patients in the subtotal resection group, the mean percentage increase in tumor size was 47.5% ± 33.1% and the mean growth rate was 5.8 ± 4.6 mm/year during the 20.3-month follow-up period. However, the size of residual tumor spontaneously decreased by a mean of 8.3% ± 11.1% during the 48.4-month follow-up period in the nonregrowth group.CONCLUSIONSThese findings suggested that frequent MRI follow-up examinations are required for residual schwannomas in the cervical spine for at least 2 years, and continuous MRI follow-ups are also required thereafter.

Subtotal Resection of Cervical Dumbbell Schwannomas: Radiographic Predictors for Surgical Considerations.

OBJECTIVE: Currently, radiologic predictors for the resectability of cervical dumbbell schwannomas remain unknown. To identify radiologic predictors for resectability, we retrospectively reviewed data from 72 patients. METHODS: From January 1995 to June 2017, 72 patients who underwent surgical treatment for cervical dumbbell schwannomas were enrolled. We focused on the relationship between preoperative magnetic resonance imaging (MRI) features and the extent of tumor removal. The MRI features evaluated were tumor size, tumor level, Eden classification, degree of vertebral artery (VA) involvement, and signal intensity (SI) on T2-weighted images (WIs). RESULTS: Among the 72 patients, gross total resection (GTR) and subtotal resection (STR) were achieved in 37 (51.4%) and 35 (48.6%) patients, respectively. Mean maximal tumor size (P = 0.011), mean size of foraminal and extraforaminal portion (P = 0.017), tumor level (P < 0.001), VA involvement (P < 0.001), and SI on T2-WIs (P = 0.006) were significantly different between the GTR and STR groups. Univariate analyses demonstrated that maximal tumor size (odds ratio [OR]: 0.93, P = 0.012), high cervical level (OR: 11.37, P < 0.001), pushed VA (OR: 0.11, P = 0.002), encased VA (OR: 0.02, P < 0.001), and hyper-SI on T2-WIs (OR: 12.46, P = 0.020) were significant predictors for GTR. In the multivariate analysis, only high cervical level (OR: 5.48, P = 0.033) and encased VA (OR: 0.07, P = 0.014) were significant predictors for GTR. CONCLUSIONS: The resectability of cervical dumbbell schwannomas may be predicted by MRI features, including tumor size, tumor level, and degree of VA involvement.

Predicting Survival of Patients with Spinal Ependymoma Using Machine Learning Algorithms with the SEER Database.

OBJECTIVE: This study was conducted to understand the clinical and demographic factors influencing the overall survival (OS) of patients with spinal ependymoma and to predict the OS with machine learning (ML) algorithms. METHODS: We compiled spinal ependymoma cases diagnosed between 1973 and 2014 from the Surveillance, Epidemiology, and End Results (SEER) registry. To identify the factors influencing survival, statistical analyses were performed using the Kaplan-Meier method and Cox proportional hazards regression model. In addition, we implemented ML algorithms to predict the OS of patients with spinal ependymoma. RESULTS: In the multivariate analysis model, age ≥65 years, histologic subtype, extraneural metastasis, multiple lesions, surgery, radiation therapy, and gross total resection (GTR) were found to be independent predictors for OS. Our ML model achieved an area under the receiver operating characteristic curve (AUC) of 0.74 (95% confidence interval [CI], 0.72-0.75) for predicting a 5-year OS of spinal ependymoma and an AUC of 0.81 (95% CI, 0.80-0.83) for predicting a 10-year OS. The stepwise logistic regression model showed poorer performance by an AUC of 0.71 (95% CI, 0.70-0.72) for predicting a 5-year OS and an AUC of 0.75 (95% CI, 0.73-0.77) for predicting a 10-year OS. CONCLUSIONS: With SEER data, we reaffirmed that therapeutic factors, such as surgery and GTR, were associated with improved OS. Compared with statistical methods, ML techniques showed satisfactory results in predicting OS; however, the dataset was heterogeneous and complex with numerous missing values.

Analysis of Multimodal Intraoperative Monitoring During Intramedullary Spinal Ependymoma Surgery.

OBJECTIVE: To evaluate the validity of intraoperative somatosensory-evoked potential (SSEP) and motor-evoked potential (MEP) monitoring according to 2 different warning criteria during 6 months from intramedullary spinal ependymoma surgery. METHODS: Twenty-six patients who underwent intramedullary spinal ependymoma surgery with intraoperative monitoring from January 2010 to June 2017 were retrospectively analyzed. We examined the sensitivity, specificity, positive predictable value, negative predictable value, and diagnostic odds ratio of SSEP and MEP monitoring for each extremity according to 2 warning criteria: 50% decline and all-or-none. The postoperative motor deficit was evaluated using the Medical Research Council scale. The postoperative neurologic deficit was followed up during 6 months. RESULTS: Eighty-six extremities were evaluated. The success rates of SSEP and MEP monitoring were 84.9% and 83.7%, respectively. Indeterminate cases were 1 in SSEP and 6 in MEP. All-or-none criterion in SSEP and MEP monitoring showed greater specificity, positive predictable value, and diagnostic odds ratio than 50% decline criterion during 6 months. The validity of SSEP was high in the upper extremity, whereas that of MEP was high in the lower extremity. During the follow-up, 37 of 38 extremities (97.4%) and 18 of 29 extremities (62.1%) showed improvement in sensory and motor deficit, respectively. Seven indeterminate cases also showed good clinical outcomes. CONCLUSIONS: Many false-positive and false-negative results of SSEP and MEP monitoring occurred during the immediate postoperative period. All-or-none criterion was more beneficial for assessing postoperative neurologic status than 50% decline criterion. This trend was maintained until 6 months after surgery.

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

OBJECTIVE: To compare overall survival (OS) in patients with cervical spine metastases between initial radiotherapy followed by surgery and initial surgery followed by radiotherapy. METHODS: The 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. RESULTS: Both 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). CONCLUSION: Surgical treatment prior to the onset of motor weakness or radiotherapy may be a good decision in case of cervical spine metastasis.

Thermal-Induced Osteonecrosis of Adjacent Vertebra after Intradiscal Electrothermal Therapy.

A 42-year-old man was admitted to our hospital with complaints of low back pain and intermittent right thigh pain. Twelve weeks before admission, the patient received intradiscal electrothermal therapy (IDET) at a local hospital. The patient still reported low back pain after the procedure that was managed with narcotic analgesics. Follow-up magnetic resonance imaging (MRI) was performed, and his referring physician thought the likely diagnosis was spondylodiscitis at the L4-5 spinal segment with a small epidural abscess. At admission to our department, the patient reported aggravated low back pain. Blood test results, including the erythrocyte sedimentation rate and C-reactive protein levels, were slightly elevated. Biopsy samples of the L4, L5 vertebral bodies and disk were obtained. The material underwent aerobic, anaerobic, fungal, mycobacterial cultures and histologic examination. Results of all cultures were negative. Histologically, necrosis of the bone was evident from the number of empty osteocyte lacunae. In addition, there was no evidence of infection based on biopsy results. No antibiotic treatment was administered on discharge. Repeat computed tomography and MRI performed 12 months after IDET showed a bony defect in the L4 and L5 vertebral bodies, and a decrease in the size of the L4-5 intervertebral disc lesion. We report a case of lumbar vertebral osteonecrosis induced by IDET and discuss etiology and radiologic features.