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Trials guidance: The Abstract should not exceed 350 words. Please minimize the use of abbreviations and do not cite references in the abstract. The abstract must include the following separate sections: • Background: No studies have compared the clinical outcome and radiographic outcome between window and non-window three-dimensional titanium (3D-Ti) cages. Therefore, well designed a randomized controlled trial (RCT) is needed. This multicenter, prospective RCT will compare the outcomes of window and non-window 3D-Ti cage in lumbar interbody fusion surgery. • Methods: Study participants will be randomly assigned to the active intervention group or control intervention group in a 1:1 ratio and undergone a one-level posterior lumbar interbody fusion (PLIF) for degenerative lumbar disease. The window type 3D-Ti cage will be used in the participants assigned to the control intervention group. And the non-window type 3D-Ti cage will be used in the participants assigned to the active intervention. The clinical and radiographic outcomes between two groups will be compared serially until postoperative 12-months. • Discussion: This trial designated for evaluating the equivalence of the clinical outcome between window and non-window 3D-Ti cage and will provide data on the effectiveness and safety of non-window type 3D-Ti cage. • Trial registration: Clinical Research Information Service (cris.nih.go.kr) (KCT 0005793). Registered on 19 January 2021

Primary central nervous system lymphoma is a rare form of extranodal non-Hodgkin lymphoma, and primary T-cell lymphoma of the cauda equina is extremely rare. We describe a case involving a 56-year-old female who presented with low back pain and radiating leg pain for 4 months. MRI of the lumbar spine revealed an elongated, multinodular intradural lesion of approximately 10 cm from the L4 body to the S2 body level with iso-signal intensity on T1-weighted imaging, heterogeneous iso- and high-signal intensity on T2-weighted imaging, and a heterogeneous intense enhancement on gadolinium contrast-enhanced T1-weighted imaging. A peripheral T-cell lymphoma of the cauda equina was diagnosed on the basis of immunohistochemical and T-cell receptor gamma gene rearrangement analysis after intradural biopsy of the mass.

Despite its high incidence rate, vertebral fragility fracture (VFF) is frequently underdiagnosed due to the absence of marked symptoms. This study evaluated the diagnostic accuracy of our suggested physical examinations and compared them with that of plain radiographs. Patients over 65 years of age with sudden back pain within the preceding 3 weeks were enrolled. Physical examinations in three different positions and a closed-fist percussion test were performed, and the presence of VFF was evaluated through confirmatory radiographic tools. We assessed the diagnostic accuracy of each physical examination and compared them with the interpretation of plain radiographs and examined the patient-reported pain locations based on the VFF level. A total of 179 patients were enrolled. The forward bending in supine (FB-SU) test demonstrated superior diagnostic values (sensitivity: 90.6%, specificity: 71.2%), which outperformed those of plain radiographs (sensitivity: 68.9%, specificity: 71.9%). The location of patient-reported pain was generally close to or lower than the index fracture level. FB-SU showed the highest diagnostic accuracy and was more valuable than plain radiographs in diagnosing acute VFF. FB-SU is a simple and affordable screening test. If positive, physicians should highly suspect VFF even when based on vague evidence of acute fracture provided by plain radiographs.

Background Biportal endoscopic surgery has recently been performed in lumbar discectomy, with advantages over conventional surgery, such as less skin scarring and muscle damage. However, the clinical results have not been established. Although previous studies reported no difference between the biportal endoscopic and microscopic discectomy clinical results, the evidence was weak. Therefore, this study aims to evaluate the efficacy and safety of the biportal endoscopic discectomy versus the microscopic discectomy. Methods This prospective multicenter randomized controlled equivalence trial is designed to compare the efficacy and safety outcomes of patients who underwent lumbar discectomy using biportal endoscopy or microscopy. We will include 100 participants (50 per group) with a lumbar herniated disc. The primary outcome will be the Oswestry Disability Index (ODI) score 12 months after surgery based on a modified intention-to-treat strategy. The secondary outcomes will include the visual analog scale score for low back and lower extremity radiating pain, the ODI score, the Euro-Qol-5-Dimensions score, surgery satisfaction, walking time, postoperative return to daily life period, postoperative surgical scar, and surgery-related variables, such as postoperative drainage, operation time, admission duration, postoperative creatine kinase, and implementation status of conversion to open surgery. Radiographic outcomes will also be analyzed using magnetic resonance imaging (MRI) or computed tomography (CT) and simple radiographs. Safety will be assessed by evaluating all adverse and severe adverse events and surgery-related effects. The participants will be assessed by a blinded assessor before surgery (baseline) and 2 weeks and 3, 6, and 12 months after surgery. Discussion This trial will be the first prospective, multicenter, randomized controlled trial to analyze the efficacy and safety of biportal endoscopic discectomy in lumbar herniated disc. This trial is designed for evaluating the equivalence of the results between biportal endoscopic and microscopic discectomy including adequate sample size, blinded analyses, and prospective registration to reduce bias. This trial will provide enough data on the effectiveness and safety of biportal endoscopic surgery and will be an important study that allows clear conclusions. Trial registration Clinical Research Information Service (cris.nih.go.kr.) (KCT0006191). Registered on 27 March 2021

To analyze the effects of direct vertebral rotation (DVR) on radiologic outcomes in the treatment of thoracic adolescent idiopathic scoliosis after selective thoracic fusion with pedicle screw instrumentation.Adolescent idiopathic scoliosis patients with single thoracic curves (n = 110) treated by selective thoracic fusion with a minimum of 2 years of follow-up were retrospectively analyzed. The patients were separated into 2 groups: non-DVR (n = 63) and DVR (n = 47).There was a significant difference in fused segments between the non-DVR and DVR groups (P0.001). There was also a significant difference in main thoracic curve postoperatively (P = 0.001) and at the last follow-up (P = 0.006) between the non-DVR and DVR groups. However, there was no significant difference in proximal thoracic and lumbar curves postoperatively (proximal thoracic curve: P = 0.186; lumbar curve: P = 0.155) and at the last follow-up (proximal thoracic curve: P = 0.250; lumbar curve: P = 0.060) between the 2 groups. Significant improvements in the lowest instrumented vertebra tilt and disc angle were noted but then slight deteriorations in such were observed during the follow-up period in the non-DVR group. The prevalence of unsatisfactory results was 20.6% (13 of 63) in the non-DVR group and 19.1% (9 of 47) in the DVR group, with no significant difference (P = 0.522).For correcting single thoracic adolescent idiopathic scoliosis by selective thoracic fusion with pedicle screw instrumentation, the addition of DVR to the surgical procedure showed comparable radiologic outcomes compared with non-DVR procedures.

To analyze postoperative outcomes after arthroscopic transosseous triangular fibrocartilage complex (TFCC) foveal repair and identify factors affecting the clinical outcomes.This study retrospectively enrolled patients who were treated for TFCC foveal tears by arthroscopic transosseous TFCC foveal repair. The diagnosis of TFCC foveal tear was made based on medical history, physical examination, and magnetic resonance imaging, with confirmation via arthroscopic examination. Outcome evaluation was completed at a minimum of 2 years postoperatively, and patients were classified into 2 groups according to the minimal clinically important difference of the Patient-Rated Wrist Evaluation. Various factors including age, sex, trauma history, body mass index, symptom duration, hand dominance, ulnar variance, subluxation of the distal radioulnar joint, preoperative pain score, and functional status, as well as the cross-sectional area (CSA) of the pronator quadratus (PQ) muscle, were retrospectively analyzed using both univariate and multivariate analyses.During the study period, 42 patients were treated for TFCC foveal tears. The functional status significantly improved after surgery. Overall, 27 and 15 patients showed good and poor functional outcomes, respectively, which were assessed according to the minimal clinically important difference of the Patient-Rated Wrist Evaluation. On univariate analysis, clinical outcomes were better in male patients (P = .035), younger patients (P = .022), and those with higher CSAs of the PQ muscles (P.001). However, on multivariable logistic regression analysis, only a higher CSA of the PQ muscle was identified as an independent prognostic factor affecting clinical outcome after TFCC foveal repair (P = .004).Arthroscopic transosseous TFCC complex foveal repair led to satisfactory results. However, lower PQ muscle CSA on magnetic resonance imaging was the most independent prognostic factor negatively affecting clinical outcomes.Level III, retrospective comparative study.

There are few clinical studies evaluating the relationship between lunate cysts and symptomatic ulnar impaction syndrome (UIS). The purpose of this study was to investigate the prevalence and relationship between lunate cysts and UIS by comparing data from patients with UIS against those without.From March 2012 to January 2015, 375 patients who had undergone MRI or CT for reasons other than ulnar-sided wrist pain were classified into the 'asymptomatic group' (Group I). Thirty three patients who had been diagnosed with UIS were classified in the 'UIS group' (Group II). We determined whether any differences were present between the two groups and evaluated prognostic factors for lunate cysts.The prevalence of lunate cysts was significantly higher in Group II but only reached just above 50% (10.4% vs. 57.6%, p 0.001]. Dorsal-side lunate cysts were more frequent than palmar side in Group I, while Group II had more cysts on the palmar side (74.4% vs. 52.6%, p = 0.001). Logistic regression analysis revealed that UIS and patient age was a significant factor for the presence of lunate cysts (odds ratio: 11.692, p 0.001; odds ratio: 1.063, p 0.001, respectively). However, positive ulnar variance or duration of symptom in Group II was not a predisposing factor for lunate cysts (odds ratio: 1.035, p = 0.598; odds ratio: 1.007, p = 0.877, respectively).Since positive ulnar variance or duration of symptom did not affect the formation of the lunate cyst and only slightly more than 50% (57.6%) of patients with UIS had a lunate cyst, it seems unlikely that these cysts are a pathognomonic finding. Surgeons can obtain some evidence from lunate cysts on radiographic exams, but care must be taken that this diagnosis is not made hastily or without due consideration.

STUDY DESIGN This was a retrospective comparative study. OBJECTIVE To evaluate long-term outcomes of selective thoracic fusion (STF) using both rod derotation (RD) and direct vertebral rotation (DVR) with pedicle screw instrumentation (PSI) in the treatment of thoracic adolescent idiopathic scoliosis (AIS) with a minimum 10-year follow-up. SUMMARY OF BACKGROUND DATA Postoperative compensation and maintenance of the unfused lumbar curve after STF is very important factor for the satisfactory results in the treatment of thoracic AIS. PATIENTS AND METHODS Sixty-five patients with thoracic AIS treated with STF from the neutral vertebra (NV) to NV or NV-1 with RD and DVR were retrospectively analyzed with a minimum 10-year follow-up. Patients were divided into 2 groups: satisfactory (n=52) and unsatisfactory groups (n=13). Unsatisfactory results were defined as an adding-on, a lowest instrumented vertebra (LIV) tilt of >10 degrees, or coronal balance >15 mm. RESULTS No significant differences were observed in the main thoracic curve between the satisfactory and unsatisfactory groups postoperatively (P=0.218) and at the last follow-up (P=0.636). Significant improvements of LIV tilt and disk angle were observed in both groups, but these improvements deteriorated during the follow-up period in the unsatisfactory group. Significant differences of apical vertebra (AV) and end vertebra (EV) were observed postoperatively (AV: P=0.001, EV: P=0.001) and at the last follow-up (AV: P

The accuracy of radiographic criteria for determining anterior cervical fusion remains controversial, and inconsistency in the literature makes a comparison of published clinical results problematic. The descriptions of bridging bone are still lacking and subjective, and the interpretation of images can be influenced by the type of graft or cage used.To assess and validate the diagnostic accuracies of four radiographic fusion criteria using the results of surgical exploration.Retrospective, radiographic, and comparative study.This study included patients who required anterior or posterior exploration of a previous anterior cervical arthrodesis level(s) ranging from C3-C4 to C7-T1 for suspected pseudarthrosis or adjacent-segment pathologies. They underwent radiologic examinations to determine the four fusion criteria. We included patients whose images were taken at least 1 year after the index surgery, and 82 patients with 151 cervical segments were enrolled.The inter- and intra-rater reliabilities and validity that correlated with the results of surgical exploration for the four fusion criteria were assessed using data (fusion or not) that were collected by two raters.The four published radiographic fusion criteria were interspinous motion (ISM)1 mm and superjacent ISM ≥ 4 mm, seen on dynamic radiographs; conventional bridging bone, as seen on computed tomography (CT) scans; and extra-graft bridging bone (ExGBB) and intragraft bridging bone (InGBB), observed on multi-axial reconstructed CT scans. The criteria were evaluated by two raters (spine surgeons with 5 and 7 years of experience). The raters evaluated each criterion twice at two different time points, 3 to 4 weeks apart. First, ISM and conventional bridging bone on CT scans were evaluated, followed by ExGBB and InGBB, with a time interval of 4 months. This Research was supported by the Chung-Ang University Research Grants (less than 5,000 US dollars) in 2016.The inter- and intra-rater reliability values of the ExGBB (0.887-0.933) criteria were the highest, followed by those for the ISM (0.860-0.906), bridging bone (0.755-0.907), and InGBB (0.656-0.695) criteria. The validity values that correlated with the exploration results were the highest for the ExGBB criteria (k=0.889), followed by the ISM (k=0.776), bridging bone (k=0.757), and InGBB (k=0.656) criteria and ExGBB showed the highest sensitivity (91.7%) and specificity (98.4%). Regarding the graft materials that were used, all criteria had the highest values in the auto-cortical group and lowest values in the cage group. Of note, sensitivity and specificity of ExGBB were 100% in autocortical group. In the cage group, the validity values for the ExGBB (k=0.663) and ISM (k=0.666) criteria were higher than those for the bridging bone (k=0.504) and InGBB (k=0.308) criteria CONCLUSION: The presence of ExGBB (anterior, posterior, or lateral to the graft or cage) correlated the best with surgical exploration. The ISM criteria demonstrated a similar accuracy to that of conventional bridging bone criteria on CT scans. In arthrodesed segments with auto-cortical bone, criteria showed the highest validity values. In cage group, ISM and ExGBB had acceptable accuracy, but the conventional bridging bone and InGBB were worse than guessing. We recommend that ISM and ExGBB criteria should be used to increase accuracy in patients who undergo arthrodesis with cages.

Objective To evaluate the distribution of multiple anterior bridging bone (ABB) patterns using a newly designed interbody cage with 4 anterior holes that enable communication between the inside and outside of the cage and to estimate its mechanical effect by finite element analysis (FEA). Methods Patients underwent single-level lumbar interbody fusion using ABB cages. Two raters evaluated the distribution patterns of ABB on computed tomography scans 1 year after surgery. We defined the term H-fusion as the presence of complete anterior extracage and intracage bone bridging, with ≥1 ABBs between them. We performed finite element analysis to investigate the effect of ABB on maximal stiffness. Results The study enrolled 98 patients. ABB was most frequently observed in the medial hole of the cages (73.7%). The mean number of ABBs was 3.65, and H-fusion was observed at 135 levels (34%). Postoperative improvement in the Oswestry Disability Index was significantly higher in patients who achieved interbody fusion and H-fusion than in patients who did not. As ABB was added, the increment in the relative maximal stiffness was most affected under flexion and extension forces. Conclusions We observed an average of 3.65 complete ABBs. Finite element analysis demonstrated that ABB could increase the stability in fused segments, especially under flexion and extension stress. Our results suggest that the ABB cage, which allows communicating cross-bridging between inside and outside of the cage, may facilitate a more stable fusion process than a conventionally designed cage.

Study Design: Prospective observational study. Objectives: We aimed to analysis the distributional patterns of the intra- and extra-cage bridging bone (InCBB and ExCBB) and the significance of ExCBB using suggested lumbar interbody fusion criterion. Methods: This study included the patients with planned single-level transforaminal lumbar interbody fusion. We divided bridging bone into InCBB (in void of right or left cage) and ExCBB (outside of cages; anterior, posterior, intermediate, right, or left) and graded bridging scores from 0 to 2 on postoperative 1-year computed tomography. The fusion was defined as at least having one or more graded 2 and the evaluation were conducted twice by 2 raters. Results: Sixty-five patients were enrolled. All values of intra- and inter-rater reliability in left InCBB, anterior, and posterior ExCBB showed good agreements (≥0.75). Both InCBBs showed similar mean bridging scores (Rt:1.43 vs Lt:1.48), and in ExCBBs, the anterior was the highest (1.43), followed by the posterior (1.14); the right and left were the lowest (0.49 and 0.52 respectively). In subjects determined as fusion (85.4%), complete bridging was observed more in ExCBB (88.8%) than in InCBB (69.9%). Conclusions: Given the higher bridging scores in both InCBBs and Ant. ExCBB, bone grafting is important promoting factor to increase the interbody bridging bone regardless of outside or in void of cages. Based on our suggested criterion, ExCBB has a greater proportion compared to InCBBs for determining the fusion and extra-cage bone grafting should be considered as important procedures for interbody fusion.

Background Vertebral fragility fracture (VFF) is a common fracture related to osteoporosis. However, VFF might be asymptomatic and often occurs in patients without osteoporosis. Therefore, we investigated the characteristics of age-related VFF and their correlation with bone mineral density (BMD). Furthermore, we analyzed other factors affecting VFF Methods Medical records from a single center were retrospectively reviewed for 2,216 patients over 50 years old with vertebral fractures conservatively treated from 2005 to 2016. Patients' age, gender, body mass index (BMI), BMD, fracture level, previous vertebral fractures, and anti-osteoporosis medications were obtained. Patients were divided into fragility/non-fragility groups and age sub-groups. The odds ratio for VFF in relation to BMD was evaluated. We also identified other predictive factors for VFF by age groups. Results The fragility group had a higher women ratio, older age, lower BMI, lower BMD, and greater incidence of previous vertebral fractures than the non-fragility group. VFFs were seen in 41.18% of normal BMD patients aged 50–59 and 67.82% of those aged 60–69. The proportion of VFFs increased with age in all WHO osteoporosis classifications. Patients with osteopenia and osteoporosis were 1.57 and 2.62 fold more likely to develop VFFs than normal BMD. In the younger group (under 70), age, women, BMD, and previous vertebral fracture were significant factors affecting VFF, and in the older group (70 and over), age, women, and BMD were factors. In the fragility group, anti-osteoporosis medication rates were 25.08% before and 45.96% after fracture. Conclusion Considerable VFFs occurred in the younger age groups without osteoporosis and age itself was another important predictor of VFF especially in older age groups. The discrepancy between the incidence of VFF and BMD suggests the necessity of supplemental screening factors and anti-osteoporosis treatment guidelines using only BMD should be reconsidered., Graphical Abstract

To fabricate a multi-layered structure for maximizing oxygen production, oxygen transport membrane (OTM) ceramics need to be joined or sealed hermetically metal supports for interfacing with the peripheral components of the system. Therefore, in this study, Ag–10 wt% CuO was evaluated as an effective filler material for the reactive air brazing of dense Ce0.9Gd0.1O2–δ–La0.7Sr0.3MnO3±δ (GDC–LSM) OTM ceramics. Thermal decomposition in air and wetting behavior of the braze filler was performed. Reactive air brazing was performed at 1050 °C for 30 min in air to join GDC–LSM with four different commercially available high temperature-resistant metal alloys, such as Crofer 22 APU, Inconel 600, Fecralloy, and AISI 310S. The microstructure and elemental distribution of the ceramic-ceramic and ceramic-metal interfaces were examined from polished cross-sections. The mechanical shear strength at room temperature for the as-brazed and isothermally aged (800 °C for 24 h) joints of all the samples was compared. The results showed that the strength of the ceramic-ceramic joints was decreased marginally by aging; however, in the case of metal-ceramic joints, different decreases in strengths were observed according to the metal alloy used, which was explained based on the formation of different oxide layers at the interfaces.

Several studies have reported incidence and risk factors for the development of proximal junctional kyphosis (PJK) in patients with adolescent idiopathic scoliosis (AIS). However, there is little information regarding long-term follow-up after pedicle screw instrumentation (PSI) with rod derotation (RD) and direct vertebral rotation (DVR). Sixty-nine AIS patients who underwent deformity correction using PSI with RD and DVR were retrospectively analyzed in two groups according to the occurrence of PJK, with a minimum five-year follow-up, including a non-PJK group (n = 62) and PJK group (n = 7). Radiological parameters were evaluated at preoperative, postoperative, and last follow-up. Incidence for PJK was 10.1% (7/69 patients), with a mean 9.4-year follow-up period. The thoracolumbar/lumbar curve (TL/L curve) was proportionally higher in the PJK group. The proximal compensatory curve was significantly lower in the PJK group than in the non-PJK group preoperatively (p = 0.027), postoperatively (p = 0.001), and at last follow-up (p = 0.041). The development of PJK was associated with the TL/L curve pattern, lower preoperative proximal compensatory curve, and over-correction of the proximal curve for PSI with RD and DVR. Therefore, careful evaluation of compensatory curves as well as of the main curve is important to prevent the development of PJK in the treatment of AIS.

Pedicle screw instrumentation (PSI) through posterior approach has been the mainstay of deformity correction for adolescent idiopathic scoliosis (AIS). However, changes in the quantity of paraspinal muscles after AIS surgery has remained largely unknown. The aim of this study was to investigate long-term follow-up changes in paraspinal muscle volume in AIS surgery via a posterior approach. Forty-two AIS patients who underwent deformity correction by posterior approach were analyzed through a longitudinal assessment of a cross-sectional area (CSA) in paraspinal muscles with a minimum five-year follow-up. The CSA were measured using axial computed tomography images at the level of the upper endplate L4 by manual tracing. The last follow-up CSA ratio of the psoas major muscle (124.5%) was significantly increased compared to the preoperative CSA ratio (122.0%) (p &lt, 0.005). The last follow-up CSA ratio of the multifidus and erector spine muscles significantly decreased compared to the preoperative CSA ratio (all p &lt, 0.005). The CSA ratio of the erector spine muscle was correlated with the CSA ratio of the psoas major (correlation coefficient = 0.546, p &lt, 0.001). Therefore, minimizing the injury to the erector spine muscle is imperative to maintaining psoas major muscle development in AIS surgery by posterior approach.

Concurrent knee osteoarthritis (KOA) and degenerative lumbar spinal disease (LSD) has increased, but the total knee arthroplasty (TKA) effect on degenerative LSD remains unclear. The aim of this study was to retrospectively analyze to compare radiological and clinical outcomes between spinal fusion only and preoperative TKA with spinal fusion for the patients with concurrent KOA and degenerative LSD. A total of 72 patients with concurrent KOA and degenerative LSDs who underwent spinal fusion at less than three levels were divided in two groups: non-TKA group (n = 50) and preoperative TKA group (n = 22). Preoperative lumbar lordosis (LL) was significantly lower in the preoperative TKA group than the non-TKA group (p &lt, 0.05). Significantly higher preoperative pelvic incidence (PI), PI/LL mismatch, and pelvic tilt (PT) occurred in preoperative TKA group than non-TKA group (all p &lt, 0.05). There was significant improvement of postoperative Oswestry Disability Index and leg Visual Analog Scale in the preoperative TKA group (all p &lt, 0.01). Preoperative TKA could be a benefit for in proper correction of sagittal spinopelvic alignment by spinal fusion. Therefore, preoperative TKA could be considered a preceding surgical option for patients with severe sagittal spinopelvic parameters in concurrent KOA and degenerative LSD.

Objective We have reported the surgical outcomes of an anterior column support procedure, the intravertebral cage augmentation technique for the osteoporotic spine. Methods A total of 10 consecutive osteoporotic patients with severely collapsed plana-type vertebrae, causing delayed neurologic deficits, were enrolled in cohort manner. They underwent intravertebral cage augmentation using a single posterior approach. The postoperative follow-up period was >2 years. The patients were divided into 2 groups: group I, fractured index vertebra at the thoracolumbar; and group II, fractured index vertebra at the lower lumbar. The radiographic analysis included the restored ratio of anterior vertebral height, local kyphotic angle, thoracolumbar kyphosis, and lumbar lordosis. The radiographic and clinical results, ambulatory status, and Oswestry disability index were evaluated. Results Compared with preoperatively, the average restored ratio of the anterior vertebral height was 2.98 and 2.35 times greater, and the local kyphotic angle had been corrected from an average of 20.3° and 14.8° to an average of 3.0° and 0.2° at the final follow-up visit in groups I and II, respectively. The thoracolumbar kyphosis in group I had been corrected from an average of 32.9° to 19.7° and the lumbar lordosis in group II had improved from an average of −15.8° to −32.3° at the final follow-up visit. All patients who could not independently ambulate preoperatively became able to walk, except for 2 patients who required a cane. Also, all the patients showed significant improvement in the Oswestry disability index (group I: average, from 38.2 to 12.8; group II, from 37.3 to 19.3). Conclusions The introduced technique is a valuable surgical option for obtaining anterior column support in osteoporotic patients with severely collapsed Kummel disease who require decompression and stabilization procedures using only a posterior approach.

Objective We sought to compare the radiologic outcomes for different distal fusion levels in a rigid curve with major thoracolumbar and lumbar (TL/L) adolescent idiopathic scoliosis (AIS) using rod derotation (RD) with direct vertebral rotation (DVR) after pedicle screw instrumentation (PSI). Methods This study finally enrolled 28 patients who were diagnosed with AIS in rigid curve with major TL/L curves, treated by PSI with RD and DVR and with a minimum 2-year follow-up. Patients were divided into 2 groups, L3 and L4, on the basis of the distal fusion level at the lowest instrumented vertebra (LIV) of L3 or L4. Results There was no significant difference in TL/L curve, thoracic (minor), and compensatory (caudal) curves between the L3 and L4 groups either postoperatively (P = 0.162, 0.426, and 0.762, respectively) or at the last follow-up (P = 0.952, 0.620, and 0.562, respectively). The overall prevalence of unsatisfactory results was 42.9% (12/28 patients). The prevalence of unsatisfactory results was 61.1% (11/18) in the L3 group and 10% (1/10) in the L4 group, which was significantly different (P Conclusions Unsatisfactory results occurred more often in the L3 group than in the L4 group, and unsatisfactory results had significant influence on progression of TL/L and distal compensatory curves. Such progression was closely correlated with deteriorating LIV disk angle in the L3 group. Therefore if the curve is rigid, LIV should be extended to L4 to avoid the adding-on phenomenon in the treatment of major TL/L AIS using RD with DVR after PSI.

This study examined the joining of dense Ce0.9Gd0.1O2 − δ–La0.6Sr0.4Co0.2Fe0.8O3 − δ (GDC–LSCF) ceramics to high temperature metal alloys for the fabrication of multilayered oxygen transport membrane (OTM) stacks. Reactive air brazing using a silver-based paste was performed at 1050 °C for 30 min in air to join GDC–LSCF/high temperature alloys, such as AISI 310S, Inconel 600 and Crofer 22 APU. The effects of the various filler materials, including CuO, GDC, LSCF, and GDC–LSCF mixture, in the Ag paste were also examined. The Ag–10 wt% CuO braze filler ensured in a reliable and compact joining without the formation of cracks and voids at the joining interface, while the addition of other ceramic fillers resulted in incomplete joining. Although none of the GDC–LSCF/metal alloy joints showed gas leakage at room temperature, the GDC–LSCF/Crofer joint only maintained the gas-tightness up to 800 °C under pressurized air up to 7 bars, which was explained by the microstructural rigidness of the oxide layer formed on the filler/alloy interface at high temperatures. This was supported by the minimal decrease in shear strength of the GDC–LSCF/Crofer joint, which was 91.1 and 88.3 MPa for the as-brazed and isothermally aged joint at 800 °C for 24 h in air, respectively. Keywords: Joining, Reactive air brazing, Oxygen transport membrane, Shear strength

Twenty-eight rats were randomized into two groups: a control group comprising a collagen sheet with only cast BMP-2; and an experimental group comprising a collagen sheet with BMP-2 photo-immobilized using azidophenyl gelatin. Micro-computed tomography analysis revealed that there was more regenerated bone in experimental group at both 4 and 8 weeks. Immunohistochemical analysis revealed that the positively expressed cellular ratio in RUNX2-stained cells were significantly higher in experimental group. These results demonstrate that BMP-2 photo-immobilized using Az-Gel on a collagen sheet shows promising bone regeneration, and the sheet is a good candidate of BMP-2 carrier.

The osteogenetic potential of photo-immobilized azdiophenyl (Az)-natural polymers as a carrier of bone morphogenetic protein-2 (BMP-2) was assessed in 56 rats randomized to four groups. The control group comprised implanted collagen sheet with BMP-2. In the three experimental groups, the implant comprised collagen sheet with photo-immobilized BMP-2 on Az-gelatin (Az-Gel), Az- O -carboxymethyl chitosan (Az-OMC), or Az‑ O ‑carboxymethyl low molecular chitosan (Az-LMC). Micro-computed tomography analysis revealed more regenerated bone in Az-Gel at 8 weeks. Immunohistochemical analysis at 4 weeks revealed that the positively expressed cellular ratio in RUNX2-stained cells was significantly higher in Az-Gel and Az-OMC groups. At 8 weeks, only the Az-Gel group showed higher positively expressed cellular ratio compared with the control group. These results demonstrate the superior osteogenetic potential of photo-immobilized BMP-2 using Az-Gel carrier in a rat calvarial defect model compared with control group. Photo-immobilization of BMP-2 using Az-gelatin could be a more effective carrier system of BMP-2 than a chitosan-based carrier system.

A 50-year-old male presented with acutely progressed paraplegia. His magnetic resonance imaging demonstrated two well-demarcated components with opposite signals in one cystic lesion between the T1- and T2-weighted images at the T1 spine level. The patient showed immediately improved neurological symptoms after surgical intervention and the histopathological exam was compatible with a neurenteric cyst. On operation, two different viscous drainages from the cyst were confirmed. A unique similarity of image findings was found from a review of the pertinent literature. The common findings of spinal neurenteric cyst include an isointense or mildly hyperintense signal relative to cerebrospinal fluid for both T1- and T2-weighted images. However, albeit rarer, the signals of some part of the cyst could change into brightly hyperintensity on T1-weighted images and hypointensity on T2-weighted images due to the differing sedimentation of the more viscous contents in the cyst.

Study DesignRetrospective cohort.ObjectiveTo clarify the sensitivity of C3–C2 spinolaminar line test as a screening tool for the stenosis of C1 space available for the cord (SAC).MethodsSpine clinic records from April 2005 to August 2011 were reviewed. The C1 SAC was measured on lateral radiographs, and the relative positions between a C1 posterior arch and the C3–C2 spinolaminar line were examined and considered “positive” when the C1 ring lay ventral to the line. Computed tomography (CT) scans and magnetic resonance imaging (MRI) were utilized to measure precise diameters of C1 and C2 SAC and to check the existence of spinal cord compression.ResultsFour hundred eighty-seven patients were included in this study. There were 246 men and 241 women, with an average age of 53 years (range: 18 to 86). The mean SAC at C1 on radiographs was 21.2 mm (range: 13.5 to 28.2). Twenty-one patients (4.3%) were positive for the spinolaminar line test; all of these patients had C1 SAC of 19.4 mm or less. Eight patients (1.6%) had C1 SAC smaller than C2 on CT examination; all of these patients had a positive spinolaminar test, with high sensitivity (100%) and specificity (97%). MRI analysis revealed that two of the eight patients with a smaller C1 SAC had spinal cord compression at the C1 level.ConclusionAlthough spinal cord compression at the level of atlas without instability is a rare condition, the spinolaminar line can be used as a screening of C1 stenosis.

To photo-immobilize bone morphogenetic protein-2 (BMP-2), UV light-reactive gelatin (azidophenyl gelatin, Az-gel), which is introduced with an N-(4-azidobenzoyloxy) succinimide-containing an azide group, was prepared as a carrier of BMP-2. Characterization of the photo-reactivity of Az-gel was evaluated by the curing ratio and it was micropatterned using a photomask. The cross-linking ratio and an enzyme-linked immunosorbent assay, enzymelinked immunospecific assay (ELISA)-based BMP-2-release test were used to determine the optimal density of Azgel (1, 3, and 5%) and UV treatment time (10, 30, 60 s) of the BMP-2 carrier in collagen matrix. The results showed that 5% Az-gel with 60 s of UV treatment was the most efficient condition for cross-linking. Cytotoxicity assays using the C2C12 mouse myoblast cell line showed that there were no cytotoxic effects of Az-gel. Alkaline phosphatase activity and calcium ion detection assays to evaluate the osteoinductive activities were conducted in assumed optimal condition of Az-gel (5% and 60 s UV treatment) 14 days post-treatment. In our study, the osteoinductive activities were the highest in cells treated with BMP-2 and the photo-reactive Az-gel carrier compared to BMP-2 alone or untreated control cells in collagen matrix at all time points (3, 7, and 14 days).

Background: Failed back surgery syndrome (FBSS) is a frequently encountered disease entity following lumbar spinal surgery. Although many plausible reasons have been investigated, the exact pathophysiology remains unknown. Various medications, reoperations, interventions such as spinal cord stimulation, epidural adhesiolysis or epidural injection, exercise therapy, and psychotherapy have been suggested treatment options. However, the evidence of the clinical outcome for each treatment has not been clearly determined. Objectives: To evaluate the outcomes of each treatment modality and to present treatment guidelines for patients with FBSS. Study Design: A systematic review of each treatment regimen in patients with FBSS. Methods: The available literature regarding each modality for the treatment of refractory back pain or radiating pain for FBSS was reviewed. The quality assessment and the level of evidence were analyzed using the “Methodology Checklist” of SIGN (Scottish Intercollegiate Guidelines Network). Data sources included relevant English language literature identified through searches of Pubmed, EMBASE, and Cochrane library from 1980 to Feb 2016. The primary outcome measure was pain relief of back pain or radiating pain for at least 3 months. Secondary outcome measures were improvement of the patient’s functional status, health-related quality of life, return to work, and reduction of opioid use. Results: Twenty-three articles were finally identified and reviewed. Based on our analysis, epidural adhesiolysis showed a short-term (6 to 24 months) effect (grade A) and spinal cord stimulation showed a mid-term (2 or 3 years) effect (grade B). Epidural injections showed a short-term (up to 2 years) effect (grade C). However, other treatments were recommended as grade D or inconclusive. Limitations: The limitations of this systematic review included the rarity of relevant literature. Conclusions: Epidural adhesiolysis or spinal cord stimulation can be effective in order to control chronic back pain or leg pain due to FBSS, and its recommendation grades are A and B, respectively. Other treatments showed poor or inconclusive evidence. Key words: Failed back surgery syndrome, post spinal surgery syndrome, chronic low back pain, post lumbar surgery syndrome, epidural adhesiolysis, spinal cord stimulation, epidural injection, revision

Study Design Retrospective evaluation of prospectively collected data. Objective To compare preoperative and postoperative neck pain following laminoplasty using the Neck Disability Index (NDI). Methods Seventy-two patients undergoing laminoplasty from 2006 to 2009 at a single institution were identified. Thirty-four patients with a minimum 1-year follow-up who completed preoperative, 6-week, and 1-year postoperative NDI questionnaires were enrolled. Demographic data and surgical data including estimated blood loss (EBL), length of surgery, number of laminoplasty levels, complications, and length of hospitalization were collected. Results Mean age was 62 years (range: 34 to 88), mean follow-up was 17 months (range: 12 to 31), and there were 21 men and 13 women. Diagnoses were cervical spondylotic myelopathy ( n = 26), ossification of the posterior longitudinal ligament ( n = 6), and central cord syndrome ( n = 2). Mean EBL was 120 mL (range: 50 to 200), and mean surgical time was 152 minutes (range: 70 to 240). Average number of laminoplasty levels was 3 (range: 1 to 5). The open door technique was used, and 24/34 (71%) did not have laminoplasty at C3 and C7. No intraoperative complications were noted, and average hospital stay was 1.6 days (range: 1 to 7). Significant improvement in NDI total score was noted at 1 year ( p Conclusions Patients having laminoplasty experienced significant improvement in NDI pain subscore and NDI total scores at a minimum of 1 year postoperatively.

To evaluate the differences of cervical alignment between standing cervical lateral radiograph and whole-spine lateral radiograph with clavicle position. We prospectively evaluated 101 asymptomatic adults from whom standing cervical lateral radiograph with hands on both side followed by whole-spine lateral radiographs with clavicle position were obtained from April 2012 to December 2013. On two radiographs, cervical sagittal alignment from C2 to C7 was analyzed by Gore angle (GA) and Cobb angle (CA); head position was evaluated using the translation distance (TD, distance of the anterior tubercle of C1 compared with the vertical line through the posterior-inferior body of C7) and McGregor angle (MA, angle between the McGregor and horizontal lines). T1-slope was also evaluated. Cervical alignment on the cervical radiograph (GA −13.59° [−15.58 to −11.60], CA −9.76° [−11.65 to −7.86]) was significantly more lordotic than that on whole-spine radiographs (GA −6.28° [−8.65 to −3.91] and −4.14° [−6.40 to −1.89]). TD and MA on cervical radiographs (TD 34.98 mm [33.22–36.75]; MA 7.20° [6.35–8.35]) were meaningfully higher than those on whole-spine radiographs (TD 31.31 mm [29.47–33.16]; MA 6.32° [5.25–7.39]), but the MA values were not significant (p = 0.064). T1-slope was significantly lower in whole-spine radiographs (20.11° [18.88–21.35]) than in cervical radiographs (24.37° [23.14–25.6]). Values are expressed as mean (95 % confidence interval). Clavicle position during whole-spine radiograph caused a substantial decrease in the T1-slope; head position posteriorly translated followed by the cervical sagittal alignment became more hypo-lordotic, with slight downward gazing in comparison with the cervical radiograph.