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.

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.

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.

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.

Atomistic weak interaction criterion for the specificity of liquid metal embrittlement.

Liquid metal embrittlement (LME) occurs in some solid-liquid metal elements' couples (e.g., Fe-Zn and Al-Ga), called specificity. Although some material parameters like solubility and bonding energy were suggested as controlling factors, none could be attributed satisfactorily. Here we have unveiled the primary factor that governs the specificity of LME. From first-principles calculations compared with a systematic surveillance test result, we found that the grain-boundary (GB) adsorption energy shows near-zero values in all embrittling couples; the interaction between solid and liquid metal atoms is weak when an atom from the liquid state penetrates the grain boundary of the solid. Furthermore, we found that the calculated surface adsorption energy that promotes bond-breaking does not correlate to the specificity. Therefore, we consider that the penetration of a liquid metal atom surrounded by weakly interacting solid metal atoms is necessary before the bond-breaking assisted by surface adsorption occurs at a microcrack tip. This mechanism is also applicable for transgranular cracking along low-energy boundaries and crystal planes. While liquid metal atoms penetrate and diffuse into solid GB macroscopically before cracking, liquid metal's surface adsorption stronger than GB adsorption should promote the bond-breaking of solid metal. In conclusion, the atomistic penetration precedes the surface-adsorption-assisted bond-breaking and controls the specificity of LME.

[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.

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.

Diagnosis and Surgical Treatment of Thoracic Dorsal Arachnoid Web: A Report of Two Cases.

INTRODUCTION: An arachnoid web (AW) is a relatively rare disease and shows clinical symptoms and radiological findings similar to those of an arachnoid cyst (AC) or spinal cord herniation (SCH). Since the operative procedures for an AW are generally different from those intrathecal disorders, correct preoperative differential diagnosis is important. The purposes of this study were to report the usefulness of magnetic resonance imaging (MRI) and computed tomography (CT) myelography for diagnosing AW and to show the histological findings and clinical results. Case Description. Two patients, a 79-year-old man and a 43-year-old woman, are presented. The primary diagnoses were AC with ossification of the ligamentum flavum and epidural hematoma, respectively, in previous hospitals. They were finally diagnosed by the characteristic MRI and CT myelogram finding called the "scalpel sign." Histological findings showed epithelial cells and fibrous tissue derived from arachnoid tissues and microcalcifications. After surgery, the scalpel sign has vanished, and aggravation of their symptoms was prevented. CONCLUSION: An AW is refractory, but early detection by MRI and CT myelography and early treatment improve outcomes after surgery.

[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.

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.

Theoretical Calculation and Experimental Verification for Dislocation Reduction in Germanium Epitaxial Layers with Semicylindrical Voids on Silicon.

Reduction of threading dislocation density (TDD) in epitaxial germanium (Ge) on silicon (Si) has been one of the most important challenges for the realization of monolithically integrated photonics circuits. The present paper describes methods of theoretical calculation and experimental verification of a novel model for the reduction of TDD. The method of theoretical calculation describes the bending of threading dislocations (TDs) based on the interaction of TDs and non-planar growth surfaces of selective epitaxial growth (SEG) in terms of dislocation image force. The calculation reveals that the presence of voids on SiO2 masks help to reduce TDD. Experimental verification is described by germanium (Ge) SEG, using an ultra-high vacuum chemical vapor deposition method and TD observations of the grown Ge via etching and cross-sectional transmission electron microscope (TEM). It is strongly suggested that the TDD reduction would be due to the presence of semicylindrical voids over the SiO2 SEG masks and growth temperature. For experimental verification, epitaxial Ge layers with semicylindrical voids are formed as the result of SEG of Ge layers and their coalescence. The experimentally obtained TDDs reproduce the calculated TDDs based on the theoretical model. Cross-sectional TEM observations reveal that both the termination and generation of TDs occur at semicylindrical voids. Plan-view TEM observations reveal a unique behavior of TDs in Ge with semicylindrical voids (i.e., TDs are bent to be parallel to the SEG masks and the Si substrate).

Surgical treatment of complete fifth lumbar osteoporotic vertebral burst fracture: A retrospective case report of three patients.

BACKGROUND: Due to its rarity, surgical treatments for a complete fifth lumbar osteoporotic vertebral burst fracture (L5 OVBF) have yet to be well documented as compared to that for osteoporotic vertebral fractures of the thoracolumbar spine. The current case report discusses details of the surgical outcomes following posterior decompression and fusion for a complete L5 OVBF. CASE DESCRIPTION: Three women, ranging in age from 69 years to 82 years, were surgically treated for a complete L5 OVBF. Two of these patients were being treated for rheumatoid arthritis. Surgery was performed using the L5 shortening osteotomy or vertebroplasty, with one- or two-level posterior lumbar interbody fusion, and posterior spinal fixation for the L2 or L3 to the pelvis. Although the spinal alignment parameters, which included lumbar lordosis (LL), pelvic incidence-lumbar lordosis, T1 pelvic angle, and sagittal vertical axis, were better as compared to that observed before the surgery, these worsened at the final follow-up due to clinical fractures that occurred at the adjacent vertebral body and proximal junctional kyphosis. Compared to preoperative Japanese Orthopaedic Association (JOA) scores, postoperative JOA scores were improved and maintained at the final follow-up. CONCLUSION: Posterior surgery of a complete L5 OVBF led to improvement of both the JOA score and spinal alignment after the surgery. Despite a worsening of the spinal alignment parameters, the JOA score was maintained at the final follow-up.

Comparison of Posterior Lumbar Interbody Fusion and Microendoscopic Muscle-preserving Interlaminar Decompression for Degenerative Lumbar Spondylolisthesis With >5-Year Follow-up.

STUDY DESIGN: Retrospective analysis of prospectively collected observational multicenter data. OBJECTIVE: To compare the clinical results and rates of revision surgery after posterior lumbar interbody fusion (PLIF) and microendoscopic muscle-preserving interlaminar decompression (ME-MILD) in patients with single-level, mild degenerative lumbar spondylolisthesis (DLS) and follow-up of at least 5 years. SUMMARY OF BACKGROUND DATA: Surgery for symptomatic DLS remains controversial. Evaluating long-term results may reveal problems such as adjacent segmental diseases of the PLIF and decreased quality of life because of slippage and restenosis of the ME-MILD. METHODS: We enrolled 116 patients who underwent PLIF (79 patients) or ME-MILD (37 patients). Operative times, blood losses, surgical complications, Short-Form 36 (SF-36), Japanese Orthopedic Association (JOA) score, the JOA Back Pain Questionnaire (JOABPEQ), visual analog scales (VAS), and Zurich Claudication Questionnaire (ZCQ) were evaluated. RESULTS: PLIF was observed to require significantly longer operative times and entailed greater operative blood losses than did ME-MILD (151.1 vs. 119.9 min; 202.2 vs. 6.4 mL, respectively). Surgery-related complications were identified in 3 cases in the PLIF group and 2 cases in the ME-MILD group. Seventy-eight patients (50 and 28 patients in the PLIF and ME-MILD groups, respectively) were successfully followed-up for >5 years. The follow-up rate was 67.2%. No significant differences between the groups were found in terms of preoperative and postoperative JOA scores, postoperative JOABPEQ, VAS, or ZCQ. Significant improvements in JOA scores were observed in both groups. Significant improvements in the SF-36 were observed in all subscales except in role physical, general health, vitality, and mental health in the ME-MILD group. Revision surgical procedures were performed in 2 patients in the ME-MILD group and 4 patients in the PLIF group. CONCLUSIONS: PLIF and ME-MILD resulted in equivalent improvements in SF-36 and JOA scores. There were no differences in revision surgery rates among patients with single-level, mild DLS. LEVEL OF EVIDENCE: Level III-a retrospective analysis.

Hydrocephalus after foramen magnum decompression for Chiari I malformation successfully treated with the aspiration of pseudomeningocele: a case report.

BACKGROUND: Pseudomeningocele or cerebrospinal fluid leakage is one of the most common complications of foramen magnum decompression with duraplasty for Chiari I malformation. Usually, cerebrospinal fluid leakage is treated with lumbar drainage and/or secondary suture. However, if hydrocephalus occurs, spinal drainage may cause brain herniation. CASE PRESENTATION: A 54-year-old Japanese woman presented to our hospital with a 10-month history of bilateral finger extension weakness and clumsiness. Magnetic resonance imaging showed displacement of her cerebellar tonsils below the foramen magnum level, with syringomyelia presenting from the C4 to T8 level. Suboccipital craniectomy and C1 laminectomy with duraplasty were performed under general anesthesia. At 1 month after discharge, she again presented to our hospital due to severe headache and nausea. Magnetic resonance imaging of her cervical spine showed pseudomeningocele compressing her cerebellum and spinal cord. Magnetic resonance imaging of her brain also showed ventriculomegaly. Pseudomeningocele aspiration was performed, with 25 ml of fluid removed under X-ray control. Immediately after aspiration her headache and nausea decreased, and she reported improvement in her symptoms with increasing bilateral finger extension strength and decreasing bilateral upper extremity numbness at her 1-year follow-up. CONCLUSIONS: Although there is a considerable risk of meningitis with the aspiration procedure of pseudomeningocele, an aspiration procedure may be an easy and effective treatment option for postoperative hydrocephalus after suboccipital craniotomy with duraplasty in a patient treated for Chiari I malformation.

Sacropelvic Fixation With S2 Alar Iliac Screws May Prevent Sacroiliac Joint Pain After Multisegment Spinal Fusion.

STUDY DESIGN: A retrospective study. OBJECTIVE: To examine the postoperative incidence of sacroiliac joint pain (SIJP) at the lower fusion level following multisegment fusion. SUMMARY OF BACKGROUND DATA: Recently, multisegment fusion is being increasingly performed. While proximal junctional kyphosis (PJK) commonly develops following multisegment fusion, SIJP also commonly occurs following this surgery. In surgery for adult spinal deformity, fixation is often extended to the pelvis to include the sacroiliac joint. Therefore, the question of whether SIJP occurs in such cases is interesting. Here, we examined postoperative incidence of SIJP at the lower fusion level, including the incidence of PJK, and postoperative lumbopelvic alignment. METHODS: Participants included 77 patients who underwent corrective fusion (≥3 segments). Patients were divided into three groups based on the lower fixation end: L5 (L5), S (sacrum), and P (pelvis). In the P group, an S2 alar iliac screw was used. Postoperative incidence of SIJP and PJK in each group was examined along with lumbopelvic parameters. RESULTS: SIJP incidence was 16.7%, 26.1%, and 4.2% in the L5, S, and P groups, respectively, indicating the highest value in the S group and a significantly lower value in the P group. PJK incidence was 23.3%, 30.4%, and 29.2% in the L5, P, and S groups, respectively, with no significant differences. Regarding postoperative lumbopelvic parameters, there was no significant difference between the groups; however, lumbar lordosis tended to be better in the P group. CONCLUSION: SIJP incidence was extremely high with fixation to the sacrum, and in the group with fixation to the pelvis, there was hardly any SIJP. Sacropelvic fixation using S2 alar iliac screws could prevent SIJP onset following multisegment fusion. LEVEL OF EVIDENCE: 3.

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.

Integrated contrast-transfer-function for aberration-corrected phase-contrast STEM.

We describe the optical conditions that are essentially necessary for phase-contrast imaging with aberration-corrected scanning transmission electron microscopy (STEM), whose depth of field has reached almost comparable to the specimen thickness. For such state-of-the-art STEM, contrast-transfer-function (CTF) should be defined not solely for the projected potential but multiply for each wavefront during the beam propagation across the specimen thickness; an integration of multiple CTFs (iCTF). We show that the iCTF concept explains fairly well characteristic annular-bright-field (ABF) imaging behaviors of heavy/light atom sites against the defocus changes, and also provide notable concerns on possible artifacts that arise from different imaging-depth dependences between the heavy/light atom sites.