Analysis of intradiscal cement leakage during percutaneous vertebroplasty: multivariate study of risk factors emphasizing preoperative MR findings.

OBJECTIVE: Previous reports have shown that intradiscal cement leakage during percutaneous vertebroplasty (PVP) is related to several risk factors. The purpose of this study was to evaluate preoperative MRI scans for such risk factors. METHODS: The study retrospectively analyzed 136 patients (aged 43-93 years; 234 vertebral bodies) with osteoporotic compression fractures. All patients underwent both MRI and PVP. There were 28 men (20.59%) and 108 women (79.41%). Age, gender, bone mineral density (BMD) score, endplate cortical disruption, abnormal T2-weighted hyperintensity in adjacent discs, presence of Kümmell's disease, linear body fracture with extension to endplate, level of treated vertebral body and injected cement volume were considered risk factors for intradiscal cement leakage. RESULTS: Of the 234 vertebral bodies, 55 bodies from 42 patients with no endplate cortical disruption showed no adjacent intradiscal cement leakage. Of 179 bodies from 95 patients with endplate cortical disruption, 54 (30.17%) showed intradiscal cement leakage. Of the other possible risk factors, abnormal T2 hyperintensity in adjacent discs was significantly related to intradiscal cement leakage (P = 0.016). The other possible factors (age, gender, BMD score, Kümmell's disease, linear body fracture extending to the endplate, level of treated vertebral body and injected cement volume) were not related to intradiscal cement leakage. CONCLUSION: There was no adjacent intradiscal cement leakage without endplate cortical disruption. Abnormal T2 hyperintensity in adjacent discs may be related to intradiscal cement leakage, but only in the presence of endplate cortical disruption. Also, not having Kümmell's disease did not prevent intradiscal cement leakage. Thus, given these circumstances, careful cement injection is needed to reduce intradiscal cement leakage.

Postoperative survival after lumbar instrumented surgery for metastatic spinal tumors: a nationwide population-based cohort analysis.

BACKGROUND: It is difficult to predict the expected survival after lumbar instrumented surgery for metastases owing to the difference among different cancer origins and the relatively short survival after surgery. AIMS: The aim of this study is to analyze the postoperative survival period of lumbar spinal metastasis patients who underwent lumbar instrumented surgery. METHODS: Data were collected from the Korean National Health Insurance Review and Assessment Service database. Patients who underwent lumbar spinal surgery with instrumentation between January 2011 and December 2015 for metastatic lumbar diseases were reviewed. The mean postoperative survival period of patients with metastatic lumbar cancer according to each primary cancer type was evaluated. RESULTS: A total of 628 patients were enrolled and categorized according to primary cancer type. The overall median survival rate was 1.11±1.30 years. The three most prevalent primary cancer groups were lung, hepatobiliary, and colorectal cancers, presenting relatively short postoperative survival rates (0.93±1.25, 0.74±0.75 and 0.74±0.88 years, respectively). The best postoperative survival period was observed in breast cancer (2.23±1.83 years), while urinary tract cancer showed the shortest postoperative survival period (0.59±0.69 years). CONCLUSION: The postoperative survival period of patients with lumbar metastatic spinal tumors according to different primary cancers after instrumented fusion was ˃1 year overall, with differences according to different primary origins. This result may provide information regarding the expected postoperative survival after instrumented surgery for lumbar spinal metastases.

Long-term outcomes following anterior foraminotomy for one- or two-level cervical radiculopathy.

PURPOSE: Anterior foraminotomy (AF) is a surgical treatment for unilateral cervical radiculopathy that avoids fusion-related complications, but its long-term outcome has yet to be investigated. To clarify the efficacy of AF, the author retrospectively collected long-term data regarding the results of this technique. METHODS: Of 50 patients who underwent AF between November 1999 and June 2005, those who were followed for more than 6 years (n = 44) were enrolled in this study. The parameters studied included the number of revisions, additional surgeries, VAS/NDI, and Odom's criteria. Plain radiographs were also obtained pre- and postoperatively. RESULTS: At discharge, 98% of patients reported improvement, although 20 % temporarily experienced some residual symptoms. There were no other major postoperative complications. At final follow-up (FU, mean of 8.8 years), an excellent or good outcome was achieved in 39 patients (89%). There was no index level reoperation required, but two additional operations for symptomatic adjacent-segment degeneration were needed (4.5%). Six patients suffered from shoulder pain on the same side after surgery (mean onset: 3.6 years). At final FU, significant degeneration at the operated level was demonstrated on plain radiographs, resulting in a decreased range of motion. However, loss of lordosis of the segment was minimal. Radiographically, adjacent segment degeneration was noted in only 6 and 11% at the cranial and caudal segments, respectively. CONCLUSIONS: In this retrospective study, patients who underwent AF for one- or two- level cervical radiculopathy showed a good long-term outcome with minimal adjacent segment degeneration. However, more data should be collected to clarify possible associations with these findings, such as delayed shoulder problems and aggravation of degeneration at the operated level.

Radiologic risk factors associated with development of myelopathy in patients with ossification of the posterior longitudinal ligament of the cervical spine.

STUDY DESIGN: Retrospective Cohort Study OBJECTIVE: Myelopathy following ossification of the posterior longitudinal ligament (OPLL) is one of the devastating clinical features in these patients, while we still know little about which factors are associated with development of myelopathy. We evaluated the difference of radiologic measurements between OPLL patients with or without myelopathy and searched for the clinical significance with emphasis on the impact of dynamic motion. METHODS: 305 patients diagnosed of OPLL were enrolled for retrospective review. They were divided into two groups according to the coexistence of radiographic evidence of myelopathy. Demographic data as well as radiologic measures including the presence of disc degeneration (DD), anterior-posterior diameter (APD) of central canal, canal compromise (CC) ratio, global and segmental range of motion (gROM and sROM), OPLL type (morphologic classification) and K-line were collected. RESULTS: APD (odds ratio (OR); 0.411), CC ratio (OR; 1.100) and sROM (OR; 1.371) were significantly associated with the presence of myelopathy in the multivariate analysis. While the statistically significant factors were same in OPLLs with CC larger than 50%, presence of DD (OR; 4.509) and sROM (OR; 1.295) were significantly associated with myelopathy but not the CC itself in OPLLs with CC smaller than 50%. CONCLUSIONS: We discovered that the APD, CC ratio and sROM had significant association with development of myelopathy in OPLLs. And the presence of dynamic factors had significant association with myelopathy in OPLLs with smaller CC ratios. This observation and its clinical significance on development of myelopathy might enhance our understanding of OPLL.

Use of prophylactic perioperative antibiotics for lumbar spinal fusions: A nationwide population-based cohort study.

BACKGROUND: Perioperative prophylactic antibiotic (PPA) use in spine surgery is known to reduce the rate of surgical site infections. In the past decade, several evidence-based guidelines have been published and surveillance systems to monitor the proper use of antimicrobials had been adapted by many institutes. OBJECTIVE: To report the trends of PPA prescription in lumbar fusion surgeries nationwide in the Republic of Korea. METHODS: This is a nationwide registry study. Using the population-based data from the Republic of Korea provided by the Korean Health Insurance Review and Assessment Service, data of all lumbar spinal fusion surgeries performed between 2010 and 2018 in adult patients (age ≥19 years) were reviewed. RESULTS: The most frequently used antibiotics were first-generation cephalosporins, which accounted for 38.2 % of total PPA prescriptions and were prescribed in 58.96 % of lumbar fusion surgeries. A gradual increase in prescription trends was observed. The second most frequently used PPAs were second-generation cephalosporins, which showed decrease in use from 2016. The frequency of vancomycin prescriptions gradually increased over the observation period and showed an almost four-fold increase in 2018 compared to 2010. First- and second-generation cephalosporins were prescribed less frequently to patients with renal disease. CONCLUSION: The pattern of PPA use has changed remarkably over the observation period. Furthermore, specific differences in PPA prescriptions were observed among patients with certain co-morbidities.

Characteristics of Sagittal Spinopelvic Alignment Changes After Symptom Relief After Simple Lumbar Decompression.

BACKGROUND: Sagittal spinopelvic alignment (SSPA) parameters are essential for the diagnosis of adult spinal deformities (ASDs) and their progression. Certain clinical symptoms that occur in patients with lumbar spinal stenosis (LSS) and herniated nucleus pulposus (HNP) may distort the SSPA and mimic ASD. OBJECTIVE: To differentiate SSPA in symptomatic patients from asymptomatic patients within 10 minutes in the standing position. METHODS: This retrospective cohort study evaluated changes in SSPA after simple lumbar decompression surgery in patients with LSS and HNP. Relative sagittal alignment (RSA), relative pelvic version, relative lumbar lordosis (RLL), Lordosis Distribution Index (LDI), and global alignment and proportion (GAP) values were calculated using the conventional Schwab classification method. First, the preoperative and postoperative SSPA parameters were compared. Second, patients were subgrouped into symptomatic within 10 minutes of standing (SP group) and other symptoms of LSS and HNP as controls. Changes in SSPA parameters after symptom relief after simple lumbar decompression surgery were compared between the two groups. RESULTS: Overall, all SSPA parameters improved after surgery. However, after subgrouping, patients in the control group did not show significant SSPA alterations, except for LDI, whereas patients in the SP group significantly improved in terms of their RSA, RLL, LDI, and GAP values after symptom relief after surgery. CONCLUSION: Patients with pain on standing within 10 minutes showed significant correction in RSA, RLL, and GAP values after simple lumbar decompression. Therefore, it is important to observe such clinical symptoms to avoid misdiagnosis of ASD.

Elucidating the effect of mechanical stretch stress on the mechanism of ligamentum flavum hypertrophy: Development of a novel in vitro multi-torsional stretch loading device.

OBJECTIVE: We developed a novel multi-torsional mechanical stretch stress loading device for ligamentum flavum cells and evaluated its influence on the development of ligamentum flavum hypertrophy, a common cause of lumbar spinal canal stenosis. MATERIALS AND METHODS: Stretch strength of the device was optimized by applying 5% and 15% MSS loads for 24, 48, and 72 h. A cytotoxicity assay of human ligamentum flavum cells was performed and the results were compared to control (0% stress). Inflammatory markers (interleukin [IL]-6, IL-8), vascular endothelial growth factor [VEGF], and extracellular matrix (ECM)-regulating cytokines (matrix metalloproteinase [MMP]-1, MMP-3 and MMP-9, and tissue inhibitor of metalloproteinase [TIMP]-1 and TIMP-2) were quantified via enzyme-linked immunosorbent assay. RESULTS: Using our multi-torsional mechanical stretch stress loading device, 5% stress for 24 hour was optimal for ligamentum flavum cells. Under this condition, the IL-6 and IL-8 levels, VEGF level, and MMP-1, MMP-3, and TIMP-2 were significantly increased, compared to the control. CONCLUSION: Using the novel multi-torsional mechanical stretch stress loading device we confirmed that, mechanical stress enhances the production of inflammatory cytokines and angiogenic factors, and altered the expression of ECM-regulating enzymes, possibly triggering ligamentum flavum hypertrophy.

The effects of anterior cervical discectomy and fusion with stand-alone cages at two contiguous levels on cervical alignment and outcomes.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) using stand-alone cages is an effective method of treating degenerative disease. However, stand-alone cages are reported to have a relatively high incidence of implant subsidence with secondary kyphotic deformity particularly after multilevel ACDF. The purpose of our article was to investigate clinical and radiological outcomes after ACDF using stand-alone cages, at two contiguous levels, with a particular focus on changes in regional alignment and the correlation between alignment of the operated cervical levels and the entire cervical spine. METHODS: Twenty-seven patients with 54 levels and a mean age of 50.8 years were enrolled between January 2005 and August 2006. They underwent ACDF using polyetheretherketone cages packed with demineralized bone matrix without plate fixation at two contiguous levels. Mean follow-up period was 25.5 months (range, 13-60). Clinical outcome was evaluated using two Visual Analog Scales and the Neck Disability Index (NDI). We assessed fusion, regional alignment (RA) of the operated levels and cervical global alignment (GA) preoperatively in the immediate 1-week postoperative period and at the final follow-up. An interspinous distance ≥2 mm was used as an indicator of pseudoarthrosis at each level. FINDINGS: All patients showed improvements in clinical outcome, with 96% of patients showing mild NDI scores (<14). Radiological solid fusion was obtained at 48 of 54 levels (88.9%) and in 21 of 27 patients (77.8%). Lower cervical levels were significantly more vulnerable to pseudoarthrosis (100%). Fusion rate had no significant correlation with outcome (p > 0.05). RA of the operated levels was improved at the final follow-up compared with preoperatively in 76% of patients, although it had decreased compared with the immediate postoperative period due to subsidence in 84% of patients. In total, 80.8% of patients showed improvements in GA. Furthermore, improvements in RA showed a significant positive correlation with those in GA (p = 0.001), although improvement in RA and GA did not correlate significantly with clinical outcome (p > 0.05). CONCLUSIONS: Though some degree of subsidence occurred in most cases, RA had improved at the last follow-up compared with preoperatively, which contributed to the significant improvement in GA. However, improvement of RA and GA was not correlated with outcomes.

A New Classification for Cervical Ossification of the Posterior Longitudinal Ligament Based on the Coexistence of Segmental Disc Degeneration.

OBJECTIVE: Classification systems for cervical ossification of the posterior longitudinal ligament (OPLL) have traditionally focused on the morphological characteristics of ossification. Although the classification describes many clinical features associated with the shape of the ossification, including the concept of spondylosis seems necessary because of the similarity in age distribution. METHODS: Patients diagnosed with OPLL who presented with increase signal intensity (ISI) on magnetic resonance imaging were surgically treated in our department. The patients were divided into two groups (pure versus degenerative) according to the presence of disc degeneration. RESULTS: Of 141 patients enrolled in this study, more than half (61%) were classified into the degenerative group. The pure group showed a profound male predominance, early presentation of myelopathy, and a different predilection for ISI compared to the degenerative group. The mean canal compromise ratio (CC) of the ISI was 47% in the degenerative group versus 61% in the pure group (p<0.0000). On the contrary, the global and segment motions were significantly larger in the degenerative group (p<0.0000 and p=0.003, respectively). The canal diameters and global angles did not differ between groups. CONCLUSION: Classifying cervical OPLL based on the presence of combined disc degeneration is beneficial for understanding the disorder's behavior. CC appears to be the main factor in the development of myelopathy in the pure group, whereas additional dynamic factors appear to affect its development in the degenerative group.

Nonsurgical treatment outcomes for surgical candidates with lumbar disc herniation: a comprehensive cohort study.

Physicians often encounter surgical candidates with lumbar disc herniation (LDH) who request non-surgical management even though surgery is recommended. However, second opinions may differ among doctors. Therefore, a prospective comprehensive cohort study (CCS) was designed to assess outcomes of nonsurgical treatment for surgical candidates who were recommended to undergo surgery for LDH but requested a second opinion. The CCS includes both randomized and observational cohorts, comprising a nonsurgery cohort and surgery cohort, in a parallel fashion. Crossover between the nonsurgery and surgery cohorts was allowed at any time. The present study was an as-treated interim analysis of 128 cases (nonsurgery cohort, n = 71; surgery cohort, n = 57). Patient-reported outcomes included visual analogue scores for the back (VAS-B) and leg (VAS-L), the Oswestry Disability Index, the EuroQol 5-Dimension instrument, and the 36-Item Short-Form Health Survey (SF-36), which were evaluated at baseline and at 1, 3, 6, 12, and 24 months. At baseline, age and SF-36 physical function were significantly lower in the surgery cohort than in the nonsurgery cohort (p < 0.05). All adjusted outcomes significantly improved after both nonsurgical and surgical treatment (p < 0.05). The nonsurgery cohort showed less improvement of VAS-B and VAS-L scores at 1 month (p < 0.01), but no difference between cohorts was observed thereafter for 24 months (p > 0.01). Nonsurgical management may be a negotiable option even for surgical candidates in the shared decision-making process.

Extra-domain B of fibronectin as an alternative target for drug delivery and a cancer diagnostic and prognostic biomarker for malignant glioma.

Extra-domain B of fibronectin (EDB-FN) is an alternatively spliced form of fibronectin with high expression in the extracellular matrix of neovascularized tissues and malignant cancer cells. In this study, we evaluated the practicality of using EDB-FN as a biomarker and therapeutic target for malignant gliomas (MGs), representative intractable diseases involving brain tumors. Methods: The microarray- and sequence-based patient transcriptomic database 'Oncopression' and tissue microarray of MG patient tissue samples were analyzed. EDB-FN data were extracted and evaluated from 23,344 patient samples of 17 types of cancer to assess its effectiveness and selectivity as a molecular target. To strengthen the results of the patient data analysis, the utility of EDB-FN as a molecular marker and target for MG was verified using active EDB-FN-targeting ultrasmall lipidic micellar nanoparticles (~12 nm), which had a high drug-loading capacity and were efficiently internalized by MG cells in vitro and in vivo. Results: Brain tumors had a 1.42-fold cancer-to-normal ratio (p < 0.0001), the second highest among 17 cancers after head and neck cancer. Patient tissue microarray analysis showed that the EDB-FN high-expression group had a 5.5-fold higher risk of progression than the EDB-FN low-expression group (p < 0.03). By labeling docetaxel-containing ultrasmall micelles with a bipodal aptide targeting EDB-FN (termed APTEDB-DSPE-DTX), we generated micelles that could specifically bind to MG cells, leading to superior antitumor efficacy of EDB-FN-targeting nanoparticles compared to nontargeting controls. Conclusions: Taken together, these results show that EDB-FN can be an effective drug delivery target and biomarker for MG.

Coronavirus Disease (COVID-19) Outbreak and Its Impact on Spinal Daily Practice : Preliminary Report from a Single (Regional) University Hospital in Republic of Korea.

OBJECTIVE: Since the first discovery of the 2019 novel coronavirus (COVID-19), rapid and wide spread of the disease has been reported and the World Health Organization announced that a 'pandemic' has started. Up to date there is little known regarding the impact of this outbreak on spinal specialists' daily clinical practice. We intended to evaluate how COVID-19 has affected the number of spinal disease patients we meet and operate in daily practice. METHODS: The de-identified data regarding number of patients visiting the spine clinic at a tertiary referral hospital and a secondary level hospital from January, February and March of 2017 to 2020 were retrospectively reviewed. The number of out-patient department (OPD) visits, number of emergency room (ER) visits as well as number of surgeries performed during the reviewed period were collected and analyzed, comparing 2020 to the previous 3 years. RESULTS: The number of daily OPD visits showed a steady decrease starting from January, and presented a statistically significant decrease by early March 2020, compared to the previous 3 years. During the same period, decrease in number of daily ER visits was statistically significant as well. The number of elective surgeries or number of surgeries for patients admitted via ER during COVID-19 outbreak remained similar to that of 2017-2019 suggesting, despite the decrease of patients visiting the hospital for spinal diseases, those whom required surgery still visited the hospital. The results were consistant among other hospital level. CONCLUSION: The outbreak of COVID-19 affected our daily practice as OPD and ER visits reduced but did not affect the number of surgeries. We believe that this report will be informative to spinal specialists worldwide fighting the COVID-19 pandemic.

A prospective study of non-surgical versus surgical treatment for lumbar spinal stenosis without instability.

OBJECTIVE: Even if analyzed through meta-analyses or systemic reviews ensued lately, we could say that at least it is inconclusive which of the surgical or non-surgical treatment to lumbar spinal stenosis is better particularly in short to intermediate-term. This study compared non-surgical and surgical outcomes in surgical candidates for lumbar spinal stenosis (LSS). METHODS: Surgical candidates for LSS were prospectively screened. Patients were offered the option to be enrolled in a randomized cohort, an observational cohort, or not to participate. Patient-reported outcomes were evaluated at baseline, and at 1, 3, 6, and 12 months. The primary outcomes were measures of pain and functional outcomes such as the Korean version of the Oswestry Disability Index (K-ODI), the EuroQol 5-Dimension instrument (EQ-5D), and 36-Item Short-Form Health Survey (SF-36). RESULTS: One hundred and ten patients were enrolled in the randomized cohort and 37 patients in the observational cohort. Among them, 97 patients received non-surgical treatment, and 50 patients underwent surgical treatment. At 12 months, the non-surgical treatment group had less improvements in the primary outcome measures of back pain (mean change: non-surgery, 2.34 vs. surgery, 3.99), leg pain (2.92 vs. 3.40), K-ODI (5.12 vs. 8.31), EQ-5D utility index (0.19 vs. 0.25), and EQ-5D VAS (9.68 vs. 16.0). Most SF-36 section parameters also showed less improvement in the non-surgical treatment group than in the surgical treatment group throughout the 12-month follow-up. CONCLUSIONS: In LSS patients without instability, non-surgical treatment resulted in less pain improvement and functional recovery through 1 year.

Korean guideline development for the evaluation of permanent impairment of the spine: proposal by the Korean Academy of Medical Sciences Committee.

The criteria for the evaluation of spinal impairment are diverse, complex, and have no standardized form. This makes it difficult and somewhat troublesome to accurately evaluate spinal impairment patients. A standardized guideline was studied for the evaluation of spinal impairment, based on the American Medical Association (AMA) Guides and the McBride method. This guideline proposal was developed by specialty medical societies under the Korean Academy of Medical Sciences. In this study, the grades of impairment were assessed by dividing patients into three different categories: spinal cord impairment, spinal injury impairment and spinal disorder impairment. The affected regions of the spine are divided into three: the cervical region, the thoracic region, and the lumbosacral region. The grade of impairment was differentially evaluated according to the affected region. The restricted range of motion was excluded in the evaluation spinal impairment because of low objectivity. Even though the new Korean guideline for the evaluation of spinal impairment has been proposed, it should be continuously supplemented and revised.

Comparison of Operating Conditions, Postoperative Pain and Recovery, and Overall Satisfaction of Surgeons with Deep vs. No Neuromuscular Blockade for Spinal Surgery under General Anesthesia: A Prospective Randomized Controlled Trial.

We aimed to investigate operating conditions, postoperative pain, and overall satisfaction of surgeons using deep neuromuscular blockade (NMB) vs. no NMB in patients undergoing lumbar spinal surgery under general anesthesia. Eighty-three patients undergoing lumbar fusion were randomly assigned to receive deep NMB (n = 43) or no NMB (n = 40). In the deep-NMB group, rocuronium was administered to maintain deep NMB (train-of-four count 0, post-tetanic count 1-2) until the end of surgery. In the no-NMB group, sugammadex 4 mg/kg at train-of-four (TOF) count 0-1 or sugammadex 2 mg/kg at TOF count ≥2 was administered to reverse the NMB 10 min after placing the patient prone. Peak inspiratory airway pressure, plateau airway pressure, lumbar retractor pressure significantly were lower in the deep-NMB group. Degree of surgical field bleeding (0-5), muscle tone (1-3), and satisfaction (1-10) rated by the surgeon were all superior in the deep-NMB group. Pain scores, rescue fentanyl consumption in post-anesthesia care unit (PACU), and postoperative patient-controlled analgesia consumption were significantly lower in the deep-NMB group, and this group had a shorter length of stay in PACU. Compared to no NMB, deep NMB provides better operating conditions, reduced postoperative pain and higher overall satisfaction in lumbar spinal surgery.

Inflammation by activated macrophage-like THP-1 cells increases human dura mater cell adhesion with alteration of integrin α2 ß1 and matrix metalloproteinase.

This study was designed to investigate (i) extracellular matrix to specify adhesive substrates to human dura mater cell (hDMC); (ii) the alteration on adhesion-related molecules in hDMC; and (iii) secreted matrix metalloproteinases (MMPs) linked with extracellular matrix remodeling after exposure to inflammation. The hDMC was cultured from human dura mater tissue, and the studies were performed with hDMC after co-culturing with macrophage like THP-1 cells (Mϕ). The adhesion of co-cultured hDMC through collagen I increased 6.4-fold and through collagen IV increased 5.0-fold compared with the adhesion of naïve cells (p < 0.001). Integrin subtype α2 ß1 expression was increased 6.3-fold (p < 0.001) and α1 expression was decreased 2.0-fold (p < 0.001) in the co-cultured cells compared with the naïve cells. Co-culturing induced significant increases in MMP-1 (13.9-fold, p < 0.01), MMP-3 (7.6-fold, p < 0.01), and VEGF (VEGF: 3.8-fold, p < 0.05) expression and decreases in MMP-9 (0.1-fold, p < 0.01) compared with the sum of naïve hDMC and Mϕ values. Increased hDMC adhesion under inflammatory conditions is caused by an increased cellular affinity for collagen I and IV mediated by increased hDMC levels of integrin subtype α2 ß1 and environmental MMP-1, -3 and decreased MMP-9. Selective integrin subtype α2 ß1 inhibition assay showed 37.8% and 35.7% reduction in adhesion of co-cultured hDMC to collagen I (p < 0.001) and IV (p = 0.057), respectively. The present study provides insight into the pathological conditions related to dura mater adhesion in inflammation. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 9999:1-11, 2019.

Surgical consideration of the intraspinal component in extradural dumbbell tumors.

BACKGROUND: The dumbbell tumor is considered a distinct group of tumors of the spinal nerve sheath owing to its intriguing clinical and radiological characteristics. More than half of dumbbell tumors are completely restricted to the extradural space, although preoperative MRI in some cases suggests the presence of intradural/extradural tumors. The aim of this retrospective investigation is to elucidate the clinical features and to suggest the surgical strategy to reduce the operating time and prevent additional complications in extradural type. METHODS: The medical records and radiological studies of 7 consecutive cases (4 male, 3 female, mean age 40.4 years) who underwent removal of the intraspinal component of their extradural dumbbell tumors between January 1996 and December 2005 were analyzed. Diagnosis and preoperative evaluation were performed with MRI and myelogram/CTs. RESULTS: The relationship of the tumor mass to dural sac in preoperative MRIs was so indistinct as to suggest an intradural mass in 5 cases. We found that extradural portion was covered with an attenuated dura and that the dural ring was invaginated into the intradural portion in these cases. Therefore, the author began with the epidural removal of the intraspinal and extraspinal component, followed by carefully extracting the intradural-like mass. CONCLUSIONS: In conclusion, we suggest that invagination of the dural ring is the anatomical feature that may be confused with an intradural/extradural tumor during operations for extradural dumbbell tumors. Initial epidural mass removal, extraction of intradural/extradural tumors subsequent to dural opening, and affirmation of presence of intradural tumor remnant could save time during dumbbell tumor surgery.

Decompression with Lateral Pediculectomy and Circumferential Reconstruction for Unstable Thoracolumbar Burst Fractures: Surgical Techniques and Results in 18 Patients.

OBJECTIVE: To introduce our technique and results of retropleural/peritoneal lateral pediculectomy for the decompression of thoracolumbar fractures and reconstruction using an expandable titanium cage and circumferential fixation at a single stage. METHODS: Eighteen patients who had single unstable, burst thoracolumbar fracture were treated by this technique between January 2014 and December 2016 (T12: n = 9, L1: n = 7, L2: n = 2). They were reviewed retrospectively in terms of radiologic outcomes (computed tomography [CT] scan and radiograph), clinical outcomes, and complications. The results were compared with another cohort of thoracolumbar fractures treated by posterior-only surgery. RESULTS: There were no radiologic complications implying pseudoarthrosis or instrument failure on the postoperative 6-month CT scan. There was also no neurologic deterioration or infection during the same period. Two patients (11.1%) of iatrogenic injury and 1 patient of trauma-related injury of the dura were secured without any delayed complications. Three patients (16.7%) with transient weakness in left hip flexion immediately after operation were observed and recovered within 2 weeks in all cases. Six patients (33.3%) complained of dysesthesia and/or hypoesthesia on the incision site. CONCLUSIONS: In this study, we suggest lateral pediculectomy as a distinct anatomic landmark to access and remove bony fragments effectively and safely in unstable thoracolumbar burst fractures. This provides a more straightforward access to the burst fragment and helps the surgeon to make better intraoperative decompression strategies. Moreover, this circumferential instrumentation with anterior support and fusion revealed better restoration of the thoracolumbar spine alignment compared with posterior-only surgery, with acceptable complications rates.

Depletion of ATP and release of presynaptic inhibition in the CA1 region of hippocampal slices during hypoglycemic hypoxia.

Transient recovery (TR) of evoked synaptic potentials and ATP depletion during the late stage of hypoxic hypoglycemic insults were investigated in rat hippocampal slices. TR was observed not only in the late stage of insult, but also during recovery. The concentration of ATP corresponded to the appearance (27% of control) and disappearance (15% of control) of TR. Paired pulse studies showed the presynaptic nature of the release of inhibition of synaptic transmission during TR. Both N- and P/Q-type voltage-dependent calcium channels were involved in the appearance of TR. This evidence suggests that underlying mechanisms of TR appearance during hypoxic hypoglycemic insult might be related to ATP depletion and release of A1 adenosine receptor mediated inhibition of presynaptic voltage-dependent calcium channels.

Arterial cerebral air embolism at the site of a spontaneous pontine hemorrhage in a patient receiving erroneous continuous positive pressure ventilation.

We report the case of a 48-year-old male with iatrogenic arterial cerebral air embolism at the site of a spontaneous pontine hemorrhage. The patient inadvertently received continuous positive pressure ventilation without exhalation for a few minutes, resulting in pneumothorax, interstitial emphysema, pneumoperitoneum, and arterial cerebral air embolism at the site of the intracerebral hemorrhage. This is the first report of pneumocephalus without head trauma or previous surgery in which the air embolism occurs at the site of a spontaneous intracerebral hemorrhage. We hypothesize that air preferentially leaked into the brain parenchyma through the weakened perforating pontine artery that caused the intracerebral bleeding.