Cervical endplate bone density distribution measured by CT osteoabsorptiometry and direct comparison with mechanical properties of the endplate.

PURPOSE: Intervertebral device subsidence is one of the complications of anterior cervical discectomy and fusion. The biomechanical properties of vertebral bony endplate may be related to device subsidence. The aim of this study is to measure the cervical endplate bone density distribution using a novel 3D measurement method. METHODS: Eight human cadaver cervical spines were obtained and levels C3-C7 were dissected and CT scanned. Three-dimensional (3D) CT model was created with the same 3D coordinates of the original DICOM dataset. The regional strength and stiffness of the endplate were determined by indentation testing. The indentation points were recorded by a photograph and the location of the indentation points was projected to the 3D CT model. Three-dimensional coordinates of the indentation point was obtained in the 3D space determined by the DICOM dataset. The area underneath the indentation point was calculated by a trilinear interpolation method directly. Data in HU and correlations with the indentation strength and stiffness were analysed. RESULTS: A positive correlation was found between HU and strength (r = 0.52) and between HU and stiffness (r = 0.41). Overall, mechanical strength and stiffness and HU in the superior endplate of the caudal vertebra were lower than those in the inferior endplate of the cranial vertebra in the same intervertebral disc. CONCLUSIONS: The mechanical properties and the HU were found to be significantly correlated, which employed a novel 3D HU measurement method, thus demonstrating potential to predict cervical endplate failure risk in a clinical setting.

Proximal junctional fracture and kyphosis after long spinopelvic corrective fixation for adult spinal deformity.

BACKGROUND: Proximal junctional fractures (PJFx) are the main cause for proximal junctional kyphosis (PJK), a complication of adult spinal deformity surgery. This study investigated risk factors for PJFx when performing long spinopelvic corrective fixation with lateral interbody fusion from T9 to ilium. METHODS: This was a retrospective study of 43 patients with a minimum follow-up of 2 years. Radiographic measurements including thoracic kyphosis (TK), sagittal vertical axis (SVA), T1 pelvic angle (TPA), proximal junctional angle (PJA), lumbar lordosis (LL), lower LL, and pelvic tilt were measured preoperatively, one-month postoperatively, and at final follow up. TK and LL were also measured in a fulcrum backward-bending position preoperatively. RESULTS: At final follow-up, PJK was found in 30/43 patients (69.8%); 20.9% of the cases had PJFx (9 patients). TPA (preoperative, and one-month postoperative) was significantly higher in the PJFx group than in the other groups. The differences in TPA, TK, and PJA between preoperative and one-month postoperative measurements in the PJFx group were significantly higher than those in the other groups. At final follow up, SVA was significantly higher in the PJFx group than in the "PJK without PJFx" group. TPA and TK were significantly higher in the PJFx group than in the other groups. PJA was significantly different between all groups. CONCLUSION: Preoperative large TPA was the only risk factor for PJFx. Preoperative flexibility of the thoracolumbar spine and overcorrection of sagittal deformity were not related to PJFx or PJK.

[Posterior Lumbar Decompression:Variations and Pitfalls].

Lumbar canal stenosis is the most common pathological condition causing spinal degeneration. Symptomatic patients who fail conservative treatment are considered candidates for surgical treatment. Many types of minimally invasive procedures for lumbar decompression have been proposed, most of which are effective and have shown good long-term results. However, in special cases, a second operation may be needed for spondylolisthesis caused by degeneration of the same segment. Two major minimally invasive approaches are available for bilateral decompression of lumbar canal stenosis: unilateral approach and midline approach. The unilateral approach is used to preserve midline structures, the contralateral facet joint, and the contralateral paravertebral muscle. The midline approach is used to preserve the left and right facet joints and the enthesis of the paravertebral muscle. These two approaches are suitable for specific situations based on their own concepts. Nevertheless, it is important to understand the advantages and disadvantages of each procedure. In this article, the varieties of lumbar decompressive methods and the pitfalls of decompression procedures will be discussed.

[How to Treat Osteoporotic Vertebral Fracture?]

In very elderly patients with low back pain, we must consider the possibility of osteoporotic vertebral fracture (OVF). In most patients with OVF, improvement can be observed without surgical intervention. However, even after providing the best possible conservative treatment, symptom recovery is not observed in some patients, and such patients experience delayed neurological deficits due to neural compression with the proceeding deformity of the vertebral body. Moreover, it is well known that once patients have OVF, the risk of another osteoporotic fracture in them increases. The clinical course of such patients eventually results in the loss of healthy life and increased mortality. Therefore, we should initiate medical treatment for osteoporosis at the earliest possible when OVF is detected in a patient. Patients who remain symptomatic even after undergoing adequate conservative therapy are candidates for balloon kyphoplasty. However, this minimally invasive surgery has some pitfalls. Furthermore, occasionally, we have to select instrumentation surgery for patients with delayed neurological deficits. In this "super-aged society," neurosurgeons also encounter patients with OVF not only in surgical situations but also in outpatient clinics. Thus, we should be aware about the clinical options for the management of osteoporosis.

Androgen receptor expression is useful to predict the therapeutic effect in HER2-positive breast carcinoma.

PURPOSE: Although HER2-positive (HER2+) invasive breast carcinomas (BC) have a different clinical therapeutic responsiveness according to estrogen and progesterone receptor expression, the relationship with androgen receptors (AR), which are the same family of steroid hormones, is poorly understood. We investigated the relationship between AR expression in HER2 BCs and therapeutic responsiveness and prognosis in this study. METHODS: We evaluated patients with HER2 (H) + invasive BC undergoing surgery after neoadjuvant chemotherapy (± HER2-targeted therapies) from 2007-2017, classified as hormone receptor-positive (Allred score: 2-8) (luminal B: LH) and receptor-negative groups (Allred: score 0) (non-luminal: NLH). AR expression was assessed by immunostaining pre-neoadjuvant chemotherapy biopsy specimens, positive with Allred score ≥ 4. The pathological complete response, disease-free survival, and overall survival rates were compared between AR-positive and AR-negative groups. RESULTS: We classified 82 patients with HER2 + invasive BC into LH (n = 45, 54.9%) and NLH groups (n = 37, 45.1%), and AR + was observed in 43 patients (52.4%) (LH: 23, 51.1%; NLH: 20, 54.1%; p = 0.79). Quasi-pathological complete response was observed in 40 patients (48.8%) (LH: 18, 40%; NLH: 22, 59.5%; p = 0.08) overall, and in 31 AR + patients (72.1%) (LH: 15, 34.9%; NLH: 16, 37.2%), significantly higher than in the AR - group for both subgroups (p < 0.001). Regarding prognosis, disease-free survival was relatively better in the AR + group in all HER2 + BCs (p = 0.085), and overall survival was significantly better in the AR + group for NLH (p = 0.029). CONCLUSIONS: High AR expression may be a useful predictor of therapeutic effects and prognosis in both subgroups of HER2 + BCs.

[Analysis of a Spontaneous Spinal Epidural Hematoma Mimicking Cerebral Infarction:A Case Report and Review of the Literatures].

Spontaneous spinal epidural hematoma is a rare disease, and the critical form may mimic cerebral infarction in the acute stage. Consequently, misdiagnosis of a cerebral infarction may result in unnecessary antithrombotic therapy. The present study investigated 19 cases of spontaneous spinal epidural hematoma first diagnosed as cerebral infarctions and treated with antithrombotic therapy. Of these, 16 cases(84.2%)presented with pain in the neck, shoulder, and back on admission, 19 cases(100%)with hemiplegia not including the face, 7 cases(36.8%)with limb sensory disturbance, and all 19 cases(100%)underwent MRI findings for definite diagnosis. After diagnosis, 6 of the 19 cases(31.6%)were treated with recombinant tissue-type plasminogen activator(rt-PA)administration, 13 cases(68.4%)with surgical treatment, and 9 cases(47.4%)were without after effect and showed good progress. MRI is effective in detecting spontaneous spinal epidural hematoma, however, CT is also used for this diagnosis. The most common site of spontaneous spinal epidural hematoma is the cervicothoracic spine junction or thoracolumbar spine junction, but occurrence in the upper cervical vertebra may present with hemiplegia similar to cerebral infarction. Pathognomonic symptoms include pain in the neck, shoulder, and back, however, symptoms such as hemiplegia not including the face, cervical spine, and cervical cord lesion may be important indicators. Although, some cases may not present with pain and sensory disturbance symptoms, therefore an initial misdiagnosis of cerebral infarction may be made and subsequent antithrombotic therapy can result in increased bleeding and serious after-effects. In particular, 4 of the 6 cases(66.7%)treated with hyperacute phase thrombolytic therapy(rt-PA treatment)in this study required surgical treatment, and the time until definite diagnosis was shorter compared with other antithrombotic agents, presumably due to the rapid increase in hematoma. Therefore, the possibility of spinal cord epidural hematoma should be considered before beginning rt-PA therapy with careful examination to confirm the presence of lesions in the cervical spine and cervical cord.

Activities of daily living and patient satisfaction after long fusion for adult spinal deformity: a retrospective study.

PURPOSE: Spinal instrumented arthrodesis improves health-related quality of life (HRQOL), although mobility is impaired. This study evaluates activities of daily livings after thoracolumbosacroiliac arthrodesis for adult spinal deformity and patient satisfaction. METHODS: Fifty patients who underwent surgery filled self-administered questionnaires (1-year preoperative and postoperative conditions), and 36 patients (3 men and 33 women; mean age 71.4 years) participated in the study. Twenty-five activities, including weeding, snow shoveling, toilet activities, and sleeping postures, were examined. Spinal alignment with Scoliosis Research Society (SRS)-Schwab classification, HRQOL with SRS-22, complications, and patient satisfaction were evaluated. Pre- and postoperative conditions were statistically compared. RESULTS: Spinal alignment improved postoperatively. Comparison data revealed that strenuous activities, such as weeding and farm work, significantly deteriorated postoperatively in 42.1-87.5% patients. Other basic activities, excluding Western toilet usage, sleeping supine, laundry and kitchen chores, and changing jacket/pants, also significantly deteriorated in 21-88% patients. Only activities such as sleeping supine, standing upright, vacuuming, doing laundry, and reaching for objects placed at heights became possible with significant difference postoperatively among activities that could not be performed preoperatively. Light activities were continued, but strenuous activities were restricted. Nevertheless, the patient satisfaction rate was 70%. Six patients exhibited complications; however, none were dissatisfied with surgery outcomes. Instrumentation or proximal junctional failures were associated with at least one strenuous work activity. CONCLUSIONS: Thoracolumbosacroiliac arthrodesis does not always improve activities postoperatively. Therefore, surgical indication for patients who continue activities preoperatively should be carefully decided. LEVEL OF EVIDENCE: Level 3. These slides can be retrieved under Electronic Supplementary Material.

Probing Single Pt Atoms in Complex Intermetallic Al13Fe4.

The atomic structure of a 0.2 atom % Pt-doped complex metallic alloy, monoclinic Al13Fe4, was investigated using a single crystal prepared by the Czochralski method. High-angle annular dark-field scanning transmission electron microscopy showed that the Pt atoms were dispersed as single atoms and substituted at Fe sites in Al13Fe4. Single-crystal X-ray structural analysis revealed that the Pt atoms preferentially substitute at Fe(1). Unlike those that have been reported, Pt single atoms in the surface layers showed lower activity and selectivity than those of Al2Pt and bulk Pt for propyne hydrogenation, indicating that the active state of a given single-atom Pt site is strongly dominated by the bonding to surrounding Al atoms.

[Dissecting Aneurysm of the Distal Middle Cerebral Artery Formed the Out Pouch during Long-term Follow-up:A Case Report].

A 40-year-old man with a rare case of dissecting aneurysm of the distal middle cerebral artery(MCA, M2 segment)presented with ischemic stroke, manifesting as headache, nausea, and visual disorder. Computed tomography(CT)scan revealed cerebral infarction, and three-dimensional CT angiogram revealed stenotic change at the M2 segment. The patient was conservatively treated and remained neurologically stable. Ten months later, CT scan and magnetic resonance imaging(MRI)revealed outpouching of the M2 segment at the location of the initial stenosis. Angiogram revealed pearl and string sign at the M2 segment of the inferior trunk. The preoperative diagnosis was spontaneous dissecting aneurysm of the right distal MCA. The patient was treated with direct surgery for aneurysm resection and revascularization using the superficial temporal artery. The brain surface in contact with the dissecting aneurysm was colored xanthochromic, so minor bleeding from the dissecting aneurysm was highly suspected. Previously, 19 cases of dissecting aneurysm of the distal MCA have been reported. Distal dissecting aneurysms seem to rupture more frequently in the MCA than in the proximal segment. Long-term follow-up MRI and angiogram might be important, not only in the acute stage in patients with atypical caliber changes in the distal MCA. Immediate direct surgery is indicated to avoid hemorrhagic stroke if dilatation of the major trunk at the dissection is suspected.

Limaprost or Pregabalin: Preoperative and Postoperative Medication for Pain due to Lumbar Spinal Stenosis.

PURPOSE: We aimed to evaluate the incidence of (and risk factors for) postoperative pregabalin and/or limaprost to treat persistent numbness and/or pain of the lower extremities after lumbar spinal stenosis (LSS) surgery. METHODS: Medical records of 329 patients (168 men, 161 women; average age 70 years) were retrospectively reviewed for data on the duration of LSS diagnosis; LSS disease; preoperative medication (limaprost, pregabalin, or combined limaprost/pregabalin; duration); symptoms; preoperative/postoperative intermittent claudication (IC); operation type; and postoperative medication and period. RESULTS: Limaprost, pregabalin, and combined limaprost/pregabalin were prescribed preoperatively for 43%, 7%, and 5% of patients, respectively. At an average of 21 months postoperatively, limaprost, pregabalin, and combined therapy were prescribed in 11%, 8%, 4% of patients, respectively. Medication requirement was significantly lower postoperatively than preoperatively (P < 0.0001). Significant risk factors for required postoperative medication were required preoperative medication (odds ratio [OR] 3.088, 95% confidence interval [CI] 1.679 to 5.681]; postoperative period (OR 1.063, 95% CI 1.031 to 1.096); and postoperative IC (OR 3.868, 95% CI 1.481 to 10.103). A negative impact from postoperative medication was seen in patients who had undergone decompression surgery (OR 0.589, 95% CI 0.377 to 0.918). CONCLUSIONS: Overall, 23% of LSS patients required medication for pain and/or numbness at 21 months postoperatively. Significant factors portending required postoperative medication were preoperative medication, longer postoperative period, and postoperative IC. A negative influence from postoperative medication was seen in patients who had undergone decompression surgery without fusion.

A Diagnostic Scoring System for Sacroiliac Joint Pain Originating from the Posterior Ligament.

Objective: Sacroiliac joint (SIJ) pain originating from the posterior ligament manifests in not only the buttocks but also the groin and lower extremities and thus may be difficult to discern from pain secondary to other lumbar disorders. We aimed to develop a simple clinical diagnostic tool to help physicians distinguish between patients with SIJ pain originating from the posterior ligament and those with lumbar disc herniation (LDH) or lumbar spinal canal stenosis (LSS). Design: Prospective case-control study. Patients and Methods: We evaluated 62 patients with SIJ pain originating from the posterior ligament and 59 patients with LDH and LSS. Pain areas, pain increasing positions, provocation test, and tenderness points were investigated. A scoring system based on multivariate logistic regression equations using the investigated items was developed. Results: Two pain areas (the posterosuperior iliac spine (PSIS) detected by the one-finger test and groin), pain while sitting on a chair, provocation test, and two tenderness points (PSIS and the sacrotuberous ligament) had high odds ratios (range, 25.87­1.40) and were used as factors in the scoring system. An integer score derived from the regression coefficient and clinical experience was assigned to each identified risk factor. The sum of the risk score for each patient ranged from 0­9. This scoring system had a sensitivity of 90.3% and a specificity of 86.4% for a positivity cutoff point of 4. Conclusion: The scoring system can help distinguish between patients with SIJ pain originating from the posterior ligament and those with LDH and LSS.

[Opioid combination of transdermal fentanyl and oral oxycodone for pain in a patient with giant-cell tumor of the sacrum].

We describe successful pain control in a patient suffering from severe pain, using an opioid combination of transdermal fentanyl and oral oxycodone. A woman in her 40s with a giant-cell tumor of the sacrum suffered from refractory 4-5/5 pain on the Wong-Baker faces pain rating scale in her sacrum, feet and legs. Despite administration of fentanyl (2,520 microg day(-1)), she could not sleep in the supine position due to pain and dysesthesia. We gradually changed her medication from transdermal fentanyl to oral oxycodone. However, the patient complained of constant drowsiness after the complete switch to oral oxycodone (120 mg x day(-1)). Hence, we reduced the oral oxycodone dose and began a combination of transdermal fentanyl and oral oxycodone in addition to increasing doses of pregabalin. With the combination of transdermal fentanyl (25 microg x hr(-1)) and oral oxycodone (60 mg x day(-1)) her pain decreased to 1-3/5 on the faces pain rating scale. Our experience suggests that an opioid combination may provide favorable pain control in patients with severe pain, while minimizing the side effects of each drug.

Chain-Level Analysis of Reinforced Polyethylene through Stretch-Induced Crystallization.

Herein, we propose a large-scale simulation approach to perform the stretch-induced crystallization of entangled polyethylene (PE) melts. Sufficiently long (1000 ns) united-atom molecular dynamics (UAMD) simulations for 16000 chains of 1000 consecutive CH2 united-atom particles under periodic boundary conditions were performed to achieve the crystallinity observed in experiments. Before the isothermal crystallization process, we applied uniaxial stretching as pre-elongation to the embedded strain memory on the entangled PE melts. We confirmed significant differences in the morphologies of crystal domains and scattering patterns for pre-elongation ratios of 400% and 800%. The obtained scattering patterns were consistent with the experimental results. Uniaxial stretching MD simulations revealed that the elastic modulus at 800% pre-elongation was stronger than that at 400% pre-elongation. From this observation, we can derive the structure-property relationship, wherein the magnitude of the pre-elongation governs the crystal domain structures and mechanical properties.

Comparison of Postoperative Results With Prognostic Nutritional Index for Lumbar Disc Herniation.

INTRODUCTION: The prognostic nutritional index (PNI) is an immune-nutritional index simply provided by a blood test. We retrospectively compared the postoperative outcomes of patients with lumbar disc herniation divided into two groups according to the PNI. MATERIALS AND METHODS: Seventy-three patients who underwent surgery at our hospital were included in the study. All patients had herniation between one of the L3/4, L4/5, or L5/S intervertebral discs and underwent one posterior lumbar interbody fusion. These patients were divided into two groups: patients with a PNI of <50 (poorly nourished (PN) group) and patients with a PNI of ≥50 (well-nourished (WN) group). Evaluation items included patient background characteristics, operative time, blood loss, postoperative complications, and length of hospital stay. RESULTS: The results showed that the body mass index was significantly higher in the WN group than in the PN group (p=0.0221). The rates of collagen disease, steroid use, and postoperative complications were significantly higher (p=0.0475, p=0.0073, and p=0.0211, respectively) and the length of hospital stay was significantly longer (p=0.021) in the PN group than in the WN group. CONCLUSION: In conclusion, this study indicates that postoperative complications and the length of hospital stay are significantly worse in PN patients than in WN patients.

Implications of DNA Methylation Classification in Diagnosing Ependymoma.

BACKGROUND: Ependymoma is a central nervous system (CNS) tumor that arises from the ependymal cells of the brain's ventricles and spinal cord. The histopathology of ependymomas is indistinguishable regardless of the site of origin, and the prognosis varies. Recent studies have revealed that the development site and prognosis reflect the genetic background. In this study, we used genome-wide DNA methylation array analysis to investigate the epigenetic background of ependymomas from different locations treated at our hospital. METHODS: Four cases of posterior fossa ependymomas and 11 cases of spinal ependymomas were analyzed. RESULTS: DNA methylation profiling using the DKFZ methylation classifier showed that the methylation diagnoses of the 2 cases differed from the histopathological diagnoses, and 2 cases could not be classified. Tumor that spread from the brain to the spinal cord was molecularly distinguishable from other primary spinal tumors. CONCLUSIONS: Although adding DNA methylation classification to conventional diagnostic methods may be helpful, the diagnosis in some cases remains undetermined. This may affect decision-making regarding treatment strategies and follow-up. Further investigations are required to improve the diagnostic accuracy of these tumors.

Posterior-approach vertebral replacement with rectangular parallelepiped cages (PAVREC) for the treatment of osteoporotic vertebral collapse with neurological deficits.

STUDY DESIGN: A retrospective clinical study. OBJECTIVE: To assess the efficacy of a new spinal reconstruction technique (posterior-approach vertebral replacement with rectangular parallelepiped cages: PAVREC) for the treatment of osteoporotic late vertebral collapse with neurological deficits. SUMMARY OF BACKGROUND DATA: Poor bone quality and medically complicated situations obfuscate precise treatment for paraplegia caused by osteoporotic vertebral collapse. Recently, posterior-approach corpectomy and replacement with a cylindrical cage have been proposed. However, postoperative cage subsidence and kyphosis progression frequently occurs. METHODS: Surgical invasiveness, perioperative complications, and clinical and radiographic outcomes in a total of 19 consecutive patients with osteoporosis (7 men and 12 women; mean age, 75 y) who underwent PAVREC with a mean follow-up period of 45.6 months (range, 16-79 mo) were reviewed. The affected vertebral levels ranged from T12-L4. The mean bone mineral density of the femoral neck was 0.611±0.077 g/cm(2) (mean±SD). RESULTS: Mean operative time was 261 minutes (range, 155-326 min). Mean blood loss was 664 mL (range, 197-1595 mL). There were no reported surgical complications. Neurological deficits evaluated with the Frankel grading score improved >1 grade after surgery in all patients. Mean preoperative visual analog scale scores for back or leg pain (7.2; range, 6-9) significantly improved after surgery (1.4; range, 0-2) (P<0.05). Local kyphosis improved from a mean of 24.6 degrees before surgery to a mean of 1.5 degrees after surgery (P< 0.05), and it was maintained at a mean of 2.5 degrees at the final follow-up. Although screw loosening, cage subsidence, and subsequent vertebral fracture were seen in several cases, no additional surgeries were needed. Solid bony fusion was confirmed in all cases. CONCLUSIONS: PAVREC provided a satisfactory clinical and radiologic outcome without severe complications. This procedure can be a treatment option for osteoporotic vertebral collapse and an alternative to an anterior-approach or single posterior-approach reconstruction with a cylindrical cage.

Electron microscopy of quasicrystals -where are the atoms?

Quasicrystals represent aperiodically ordered form of solids with symmetries long thought forbidden in nature. Since their discovery, the fundamental key question has been "where are the atoms?" in these novel aperiodic solids, and electron microscopy has indeed provided images of real atomic arrangements in quasicrystals. In this tutorial review, we describe the microscopic view of quasicrystals using state-of-the-art scanning transmission electron microscopy, providing intriguing details that had never been unveiled by the early diffraction-based structural analyses.

Surgical technique of spine-shortening vertebral osteotomy for adult tethered cord syndrome: a case report and review of the literature.

BACKGROUND: Miyakoshi et al. reported three cases of tethered cord syndrome treated by spine-shortening vertebral osteotomy, which provided relief of the patients' symptoms with no complications. Although the details of these cases were described in a previous report, the surgical technique was not thoroughly explained. In the present report, we describe the details of our procedure with reference to a fourth case. CASE PRESENTATION: A 47-year-old Asian woman was admitted to our hospital with a 1-year history of worsening leg numbness and urinary dysfunction. Magnetic resonance imaging revealed a low-lying conus medullaris extending to the level of S2 and surrounded by fat tissue at that level. We diagnosed her condition as adult tethered cord syndrome, and spine-shortening vertebral osteotomy was planned. The target level for the osteotomy was L2. Bilateral pedicle screw implants were placed at L1 and L3 using an anterior-posterior image intensifier. In this procedure, it is essential to use monoaxial screws inserted exactly parallel to the rostral endplates of each vertebral body; this ensures appropriate alignment between the L1 caudal endplate and the L2 osteotomy surface. The upper one-third of the lamina of L2 was resected, and the bilateral two-thirds of the pedicle of L2 was removed with a surgical air drill. After exposure of the lateral side of the L1-2 disc, discectomy was performed with a knife and curette. Following complete discectomy of L1-2, the upper vertebral body of L2 was removed with a surgical air drill. After complete removal of the vertebral body, a straight rod was connected to two screws and applied pressure between the screws. Two polyethylene tapes were applied to the L2 lamina and bilateral rods. CONCLUSION: Spine-shortening osteotomy that preserves the caudal one-third of the pedicle and lamina with one-above and one-below instrumentation successfully reduced the spinal cord tension without causing neural damage.

A Comparison of Hidden Blood Loss Between Multilevel Posterior Lumbar Interbody Fusion and Lateral Lumbar Interbody Fusion in Adult Spinal Deformity Patients.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: This study aimed to compare transfusion and blood loss volumes, particularly hidden blood loss volume, in adult spinal deformity patients undergoing lateral lumbar interbody fusion (LLIF) and posterior lumbar interbody fusion (PLIF). Corrective surgery for adults with spinal deformity patients can be performed via the traditional posterior approach (PLIF) or minimally invasive lateral approach (LLIF). LLIF is associated with longer or comparable operation times and lower intraoperative blood loss. However, hidden blood loss has not been compared between the two procedures. METHODS: We compared hidden blood loss and other blood loss volumes, transfusion volume, operation time, and radiographic surgical outcomes between LLIF patients (n = 71) and PLIF patients (n = 33) who underwent surgery in our institution from September 2011 to June 2018. All patients provided informed consent in accordance with the Declaration of Helsinki. Institutional ethics committee conducted this study approval was obtained. RESULTS: Transfusion volume and intraoperative and total blood loss volumes were significantly higher in the PLIF group. Operation time and HBL did not significantly differ. The hidden blood loss-to-intraoperative blood loss ratio was significantly higher in the LLIF group (113% vs 60%; P = .004). Radiographic measures of outcome were significantly better after surgery than before in both groups. CONCLUSIONS: Although intraoperative blood loss was less with LLIF than PLIF, HBL was similar between the approaches. Patients undergoing LLIF should be followed closely for postoperative anemia even if intraoperative blood loss is low.

Direct imaging of hydrogen-atom columns in a crystal by annular bright-field electron microscopy.

Enhancing the imaging power of microscopy to identify all chemical types of atom, from low- to high-atomic-number elements,would significantly contribute for a direct determination of material structures. Electron microscopes have successfully provided images of heavy-atom positions, particularly by the annular dark-field method, but detection of light atoms was difficult owing to their weak scattering power. Recent developments of aberration-correction electron optics have significantly advanced the microscope performance, enabling identification of individual light atoms such as oxygen, nitrogen, carbon, boron and lithium. However, the lightest hydrogen atom has not yet been observed directly, except in the specific condition of hydrogen adatoms on a graphene membrane. Here we show the first direct imaging of the hydrogen atom in a crystalline solid YH(2), based on a classic 'hollow-cone' illumination theory combined with state-of-the-art scanning transmission electronmicroscopy. The optimized hollow-cone condition derived from the aberration-corrected microscope parameters confirms that the information transfer can be extended to 22.5 nm(-1), which corresponds to a spatial resolution of about 44.4 pm. These experimental conditions can be readily realized with the annular bright-field imaging in scanning transmission electron microscopy according to reciprocity, revealing successfully the hydrogen-atom columns as dark dots, as anticipated from phase contrast of a weak-phase object.