Effects of bone cement augmentation for uppermost instrumented vertebra on adjacent disc segment degeneration in lumbar fusions.

OBJECTIVE: We investigated the long-term effects of bone cement-augmented instrumentation in multilevel lumbar fusions in a retrospective cohort study. The use of cement-augmented screws is one of the techniques used to reduce early mechanical failure in treating multilevel lumbar fusion, especially in the elderly. However, little information is available regarding the long-term effects. METHODS: A total of 51 patients who had undergone ≥3 levels of lumbar fusion were divided into two groups according to the use of bone cement-augmented screw fixation involving the upper instrumented vertebra: 22 patients in the cement-augmented group (group I) and 29 patients in the non-cement-augmented group (group II). Analysis of radiographic adjacent disc segment degeneration (ASD) revealed patients with lumbosacral fusion with a similar degree of osteoporosis. Radiologic ASD was defined as progression of >2 UCLA (University of California, Los Angeles) grades at 2 years postoperatively. Other sagittal parameters and the preoperative magnetic resonance imaging Pfirrmann grades at the adjacent levels, possibly related to ASD, were also analyzed. RESULTS: No significant differences were present in the preoperative demographic and radiographic parameters between the 2 groups. However, the postoperative kyphotic changes at 3 months were greater for the non-cement-augmented group. In terms of the long-term effects, the incidence of radiologic ASD (group I, n = 20 [95.2%]; vs group II, n = 15 [53.6%]) was significantly higher in the cement-augmented group. Logistic regression analysis of radiologic ASD, including other clinical and radiologic parameters, postoperative pelvic incidence-lumbar lordosis mismatch (odds ratio, 5.201; 95% confidence interval, 1.123-24.090; P = 0.035), and cement augmentation (odds ratio, 20.193; 95% confidence interval, 2.195-185.729; P = 0.008) showed a significant correlation with the development of radiologic ASD at 2 years postoperatively. CONCLUSIONS: Although bone cement-augmented screw implantation can prevent kyphotic deformation at the proximal junction of upper instrumented vertebra in the early postoperative stages of multilevel lumbar fusion, a careful selection of patients is required because of possibly accelerated degeneration of adjacent segments.

Transition Metal Ion Doping on ZIF-8 Enhances the Electrochemical CO2 Reduction Reaction.

The electrochemical reduction of CO2  to diverse value-added chemicals is a unique, environmentally friendly approach for curbing greenhouse gas emissions while addressing sluggish catalytic activity and low Faradaic efficiency (FE) of electrocatalysts. Here, zeolite-imidazolate-frameworks-8 (ZIF-8) containing various transition metal ions-Ni, Fe, and Cu-at varying concentrations upon doping are fabricated for the electrocatalytic CO2 reduction reaction (CO2 RR) to carbon monoxide (CO) without further processing. Atom coordination environments and theoretical electrocatalytic performance are scrutinized via X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations. Upon optimized Cu doping on ZIF-8, Cu0.5 Zn0.5 /ZIF-8 achieves a high partial current density of 11.57 mA cm-2 and maximum FE for CO of 88.5% at -1.0 V (versus RHE) with a stable catalytic activity over 6 h. Furthermore, the electron-rich sp2 C atom facilitates COOH* promotion after Cu doping of ZIF-8, leading to a local effect between the zinc-nitrogen (Zn-N4 ) and copper-nitrogen (Cu-N4 ) moieties. Additionally, the advanced CO2 RR pathway is illustrated from various perspectives, including the pre-H-covered state under the CO2 RR. The findings expand the pool of efficient metal-organic framework (MOF)-based CO2 RR catalysts, deeming them viable alternatives to conventional catalysts.

Production of H2-Free Carbon Monoxide from Formic Acid Dehydration: The Catalytic Role of Acid Sites in Sulfated Zirconia.

The formic acid (CH2O2) decomposition over sulfated zirconia (SZ) catalysts prepared under different synthesis conditions, such as calcination temperature (500-650 °C) and sulfate loading (0-20 wt.%), was investigated. Three sulfate species (tridentate, bridging bidentate, and pyrosulfate) on the SZ catalysts were characterized by using temperature-programmed decomposition (TPDE), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The acidic properties of the SZ catalysts were investigated by the temperature-programmed desorption of iso-propanol (IPA-TPD) and pyridine-adsorbed infrared (Py-IR) spectroscopy and correlated with their catalytic properties in formic acid decomposition. The relative contributions of Brønsted and Lewis acid sites to the formic acid dehydration were compared, and optimal synthetic conditions, such as calcination temperature and sulfate loading, were proposed.

Rational Design of Pomegranate-like Base-Acid Bifunctional ß Zeolite by Steam-Assisted Crystallization for the Tandem Deacetalization-Knoevenagel Condensation.

A highly crystalline pomegranate-like base-acid bifunctional beta zeolite was successfully synthesized by the steam-assisted crystallization method using a basic nitrided N-beta as the starting material. The secondary crystal growth of a beta zeolite generating acid functionality occurred over the outer surface and intercrystalline void spaces of the N-beta zeolite. The pomegranate-like N-beta@H-beta zeolite had a high surface area and base-acid dual functionality because of the well-connected framework topologies of the H-beta and N-beta crystallites. The N-beta@H-beta zeolite exhibited a superior yield of benzylidenemalononitrile during the tandem deacetalization-Knoevenagel condensation of benzaldehyde dimethyl acetal and malononitrile compared to H-beta, N-beta, and their physical mixture. This is likely due to the isolated and balanced activity of the base- and acid-catalyzed reactions.

Immobilization of Radioiodine via an Interzeolite Transformation to Iodosodalite.

We described a technology for immobilizing radioiodine in the sod-cages by the interzeolite transformation of iodine-containing LTA (zeolite A) and FAU (zeolites X and Y) into a sodalite (SOD) structure. The immobilization of iodine in the sod-cage was confirmed using diverse characterization methods including powder XRD, elemental analysis, SEM-EDS, 127I MAS NMR, and I 3d XPS. Although both zeolites A (Na-A) and X (Na-X) were well converted into SOD structure in the presence of NaI and AgI, the iodide anions were fixed in the sod-cages only when NaI was used. The ability to adsorb methyl iodide (CH3I) was evaluated for zeolites A and X in which Na+ and/or Ag+ ions were exchanged, and Ag+ and zeolite X showed better adsorption properties than Na+ and zeolite A, respectively. However, when both CH3I adsorption ability and the successive immobilization of iodine by interzeolite transformation were considered, Na-X was determined to be the best candidate of adsorbent among the studied zeolites. More than 98% of the iodine was successfully immobilized in the sod-cage in the SOD structure by the interconversion of Na-X following CH3I adsorption, although the Na-X zeolite exhibited half the CH3I adsorption capacity of Ag-X.

Incidence and Risk Factors of Gastrointestinal and Hepatobiliary Complications after Spinal Fusion Surgery: a Retrospective Cohort Study.

BACKGROUND: Spinal surgery holds a higher chance of unpredicted postoperative medical complications among orthopedic surgeries. Several studies have analyzed the risk factors for diverse postoperative medical complications, but the majority investigated incidences of each complication qualitatively. Among gastrointestinal complications, reports regarding postoperative ileus were relatively frequent. However, risk factors or incidences of hepatobiliary complications have yet to be investigated. The purpose of this study was to examine the incidence of gastrointestinal complications after spinal surgery, quantitatively analyze the risk factors of frequent complications, and to determine cues requiring early approaches. METHODS: In total, 234 consecutive patients who underwent spinal fusion surgery performed by one senior doctor at our institute in one-year period were retrospectively enrolled for analyses. The primary outcomes were presence of paralytic ileus, elevated serum alanine transaminase (ALT) and aspartate transaminase (AST) levels, and elevated total bilirubin levels. Univariate logistic regression analyses of all variables were performed. In turn, significant results were reanalyzed by multivariate logistic regression. The variables used were adjusted with age and gender. RESULTS: Gastrointestinal complications were observed in 15.8% of patients. Upon the risk factors of postoperative ileus, duration of anesthesia (odds ratio [OR], 1.373; P = 0.015), number of fused segments (OR, 1.202; P = 0.047), and hepatobiliary diseases (OR, 2.976; P = 0.029) were significantly different. For elevated liver enzymes, men (OR, 2.717; P = 0.003), number of fused segments (OR, 1.234; P = 0.033), and underlying hepatobiliary (OR, 2.704; P = 0.031) and rheumatoid diseases (OR, 5.021; P = 0.012) had significantly different results. Lastly, risk factors for total bilirubin elevation were: duration of anesthesia (OR, 1.431; P = 0.008), number of fused segments (OR, 1.359; P = 0.001), underlying hepatobiliary diseases (OR, 3.426; P = 0.014), and thoracolumbar junction involving fusions (OR, 4.134; P = 0.002) compared to lumbar spine limited fusions. CONCLUSION: Patients on postoperative care after spinal surgery should receive direct attention as soon as possible after manifesting abdominal symptoms. Laboratory and radiologic results must be carefully reviewed, and early consultation to gastroenterologists or general surgeons is recommended to avoid preventable complications.

Effects of Restoration of Sagittal Alignment on Adjacent Segment Degeneration in Instrumented Lumbar Fusions.

STUDY DESIGN: Retrospective case-control study. OBJECTIVE: To investigate the effects of postoperative sagittal alignment on radiographic adjacent segment degeneration (ASD) after lumbar fusion surgery. SUMMARY OF BACKGROUND DATA: ASD is one of inherent problems with fusion surgery. Many confounding factors are related to the development of ASD. Recently, sagittal alignment has been emphasized for its significance on ASD. METHODS: Seventy-three patients who underwent four-level lumbar fusion surgery (L2-S1) were divided into two groups according to postoperative sagittal alignment (pelvic incidence-lumbar lordosis [PI-LL] ≥ or <9°): 44 patients (matched group, including 10 patients who underwent pedicle subtraction osteotomy [PSO] at L4) and 29 patients (mismatched group). The general demographics, radiographic parameters, and clinical outcomes were recorded. Preoperative disc degeneration at L1-2 was evaluated by Pfirrmann grade and Kellgren-Lawrence (K-L) grade. Disc degeneration at L1-2 was evaluated by the K-L grade on 2-year postoperative X-rays. RESULTS: The incidence of radiographic ASD (11 [25%] vs. 16 patients [55%], P = 0.02) and Oswestry Disability Index (ODI) scores (36.9 ±â€Š19.9 vs. 49.4 ±â€Š20.7, P = 0.015) at postoperative 2 years were significantly higher in the mismatched group. There were no significant differences in other demographic and radiographic parameters between the two groups. On subgroup analysis between 10 PSO patients and the mismatched group, the mismatched group showed a higher incidence of radiographic ASD (16 [55%] vs. 1 patient [10%], P = 0.041) and worse ODI scores (49.7 ±â€Š20.5 vs. 39.0 ±â€Š20.7, P = 0.040). Preoperative Pfirrmann grade at L1-2 (odds ratio [OR] = 4.191, 95% confidence interval [CI]: 1.754-10.013, P = 0.001) and postoperative PI-LL mismatch (OR = 4.890, 95% CI: 1.550-15.427, P = 0.007) showed significant relationships with the development of radiographic ASD at postoperative 2 years. CONCLUSION: The restoration of optimal sagittal alignment, even with PSO, may provide a protective effect on the development of radiographic ASD, although the preoperative disc degeneration grade was a risk factor for radiographic ASD. LEVEL OF EVIDENCE: 3.

Lumbar Disc Herniation Within Solid Fused Segments After Removal of Pedicle Screws: A Case Report.

CASE: A 73-year-old man with instrumented fusion of L3-4-5 underwent the removal of previous pedicle screws and posterior instrumented fusion of L1-2-3. The solid dorsal fusion mass of L3-5 was identified intraoperatively and preoperatively. At 3 years after the second surgery, he presented with abrupt radiating pain in the left leg. Plain radiographs showed a collapse of the intervertebral disc space, and magnetic resonance imaging showed disc herniation of L3-4. CONCLUSIONS: Disc herniation even in solid fused segments may occur. Removal of pedicle screws and cranial extension of interbody fusion may increase the intradiscal stress associated with physiologic cantilever motion of the disc.

Minimally Invasive Lateral Lumbar Interbody Fusion for Clinical Adjacent Segment Pathology: A Comparative Study With Conventional Posterior Lumbar Interbody Fusion.

STUDY DESIGN: This was a retrospective comparative study. OBJECTIVE: The main objective of this article was to evaluate the clinical and radiologic efficacies of minimally invasive lateral lumbar interbody fusion (LLIF) for clinical adjacent segment pathology (ASP). SUMMARY OF BACKGROUND DATA: Minimally invasive techniques have been increasingly applied for spinal surgery. No report has compared LLIF with conventional posterior lumbar interbody fusion for clinical ASP. METHODS: Forty patients undergoing LLIF with posterior fusion (hybrid surgery) were compared with 40 patients undergoing conventional posterior lumbar interbody fusion (posterior surgery). The radiologic outcomes including indirect decompression in hybrid surgery group, and clinical outcomes such as the Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) were assessed. Postoperative major complications and reoperations were also compared between the 2 groups. RESULTS: Correction of coronal Cobb's angle and segmental lordosis in the hybrid surgery were significantly greater postoperatively (2.8 vs. 0.9 degrees, P=0.012; 7.4 vs. 2.5 degrees, P=0.009) and at the last follow-up (2.4 vs. 0.5 degrees, P=0.026; 4.8 vs. 0.8 degrees, P=0.016) compared with posterior surgery. As regards indirect decompression of the LLIF, significant increases in thecal sac (83.4 vs. 113.8 mm) and foraminal height (17.8 vs. 20.9 mm) were noted on postoperative magnetic resonance imaging. Although postoperative back VAS (4.1 vs. 5.6, P=0.011) and ODI (48.9% vs. 59.6%, P=0.007) were significantly better in hybrid surgery, clinical outcomes at the last follow-up were similar. Moreover, intraoperative endplate fractures developed in 17.7% and lower leg symptoms occurred in 30.0% of patients undergoing hybrid surgery. CONCLUSIONS: Hybrid surgery for clinical ASP has advantages of segmental coronal and sagittal correction, and indirect decompression compared with conventional posterior surgery. However, LLIF-related complications such as endplate fracture and lower leg symptoms also developed. LLIF should be performed considering advantages and approach-related complications for the clinical ASP.

Clinical and Radiographic Features of Subtypes of Acute Proximal Junctional Failures Following Correction Surgery for Degenerative Sagittal Imbalance.

OBJECTIVE: To identify clinical and radiographic features of subtypes of acute proximal junctional failures (PJFs) following correction surgery for degenerative sagittal imbalance. METHODS: The study included 157 patients with mean age 68.0 ± 6.3 years who underwent correction surgery for degenerative sagittal imbalance. Acute PJFs were categorized into 4 subtypes: fracture at uppermost instrumented vertebra (UIV), fracture at vertebra just proximal to UIV (UIV+1), fixation failure at UIV, and junctional subluxation. Demographic, clinical, and radiographic data were analyzed retrospectively. RESULTS: There were 18 patients with acute PJFs. PJF group had significantly lower T-score (-3.3 ± 1.1 vs. -1.9 ± 1.5) on bone densitometry and lower body mass index (BMI) (23.0 ± 3.9 kg/m2 vs. 25.6 ± 3.7 kg/m2) than non-PJF group. Radiographic parameters exhibited no significant differences. UIV fracture, UIV+1 fracture, UIV fixation failure, and junctional subluxation were observed in 5, 6, 4, and 3 patients. Fixation failure developed the earliest (median 1.3 months), followed by UIV fracture (1.5 months). UIV fracture occurred earlier than UIV+1 fracture (36 months). Patients with UIV or UIV+1 fracture had significantly lower T-scores than others. Although BMI and T-score were significant risk factors for all PJFs (P = 0.043 and P = 0.021, respectively), different risk factors for each subtype of PJFs were identified on separate risk factor analysis. CONCLUSIONS: Patients with acute PJFs had lower T-score and BMI. Each subtype of PJFs had different clinical and radiographic features. Although BMI and T-score were associated with all PJFs, each subtype may have different risk factors. Identifying risk factors for each subtype of acute PJFs may help avoid it.

Clinical Significance of Preoperative Embolization for Non-Hypervascular Metastatic Spine Tumors.

OBJECTIVE: The efficacy of preoperative embolization for hypervascular metastatic spine disease (MSD) such as renal cell and thyroid cancers has been reported. However, the debate on the efficacy of preoperative embolization for non-hypervascular MSD still remains unsettled. The purpose of this study is to determine whether preoperative embolization for non-hypervascular MSD decreases perioperative blood loss. METHODS: A total of 79 patients (36 cases of preoperative embolization and 43 cases of non-embolization) who underwent surgery for metastatic spine lesions were included. Representative hypervascular tumors such as renal cell and thyroid cancers were excluded. Intraoperative and perioperative estimated blood losses (EBL), total number of transfusion and calibrated EBL were recorded in the embolization and non-embolization groups. The differences in EBL were also compared along with the type of surgery. In addition, the incidence of Adamkiewicz artery and complications of embolization were assessed. RESULTS: The average age of 50 males and 29 females was 57.6±13.5 years. Lung (30), hepatocellular (14), gastrointestinal (nine) and others (26) were the primary cancers. The demographic data was not significantly different between the embolization and the non-embolization groups. There were no significant differences in intraoperative EBL, perioperative EBL, total transfusion and calibrated EBL between two groups. However, intraoperative EBL and total transfusion in patients with preoperative embolization were significantly lower than in non-embolization in the corpectomy group (1645.5 vs. 892.6 mL, p=0.017 for intraoperative EBL and 6.1 vs. 3.9, p=0.018 for number of transfusion). In addition, the presence of Adamkiewicz artery at the index level was noted in two patients. Disruption of this major feeder artery resulted in significant changes in intraoperative neuromonitoring. CONCLUSION: Preoperative embolization for non-hypervascular MSD did not reduce perioperative blood loss. However, the embolization significantly reduced intraoperative bleeding and total transfusion in corpectomy group. Moreover, the procedure provided insights into the anatomy of tumor and spinal cord vasculature.

Clinical and Radiologic Features of Osteoporotic Spine Fracture with Delayed Neurologic Compromises.

OBJECTIVES: Osteoporotic spine fractures (OSFs) with delayed neurologic compromises (NCs) have been increasingly reported. Although several studies have addressed that the pathologic mechanism of NC involves nonunion and segmental instability, the risk factors remain unclear. Therefore, the purpose of this study was to assess the radiologic and clinical features of OSFs with delayed NC. METHODS: Thirty patients with delayed NC (group 1) were matched in a 1-to-1 format with 30 patients without delayed NC (group 2) by age, bone mineral density, body mass index, and medical treatment for osteoporosis. Clinical and radiologic parameters were assessed to determine the risk factors related to delayed NC. Clinical outcomes were also compared between the 2 groups. RESULTS: Neurologic compromises were presented as myelopathy in 20 patients and radiculopathy in 10 patients. Initial kyphotic angle (KA) and height loss (HL) were significantly greater in group 1 (21.6 ± 12.9 degrees vs. 10.5 ± 8.6 degrees, P = 0.0001 for KA; 55.8% ± 15.2% vs. 19.9% ± 10.9%, P = 0.0001 for HL). Fracture instability with intravertebral cleft, posterior wall involvement, midportion type of magnetic resonance classification, thoracolumbar level, and aortic calcification were significantly correlated with delayed NC. In multivariate analysis, initial HL (hazard ratio = 1.24; P = 0.012) and midportion-type fracture (hazard ratio = 14.9: P = 0.03) were the independent risk factors related to delayed NC. In addition, clinical outcomes at the last follow-up were significantly better in group 2. CONCLUSIONS: Initial HL and midportion-type fracture were correlated with delayed NC following OSFs. Moreover, pre-existing stenotic lesions might be associated with delayed NC.

Delayed bilateral facet dislocation at L4-5: A case report.

RATIONALE: Traumatic bilateral facet dislocation in the lumbar (L) spine has rarely been reported. All reported cases were presented with acute facet dislocation. However, we present the first case of delayed bilateral facet dislocation at L4-5. PATIENT CONCERNS: A 34-year-old woman presented with back pain after a head-on collision. The patient was treated conservatively for 3 months with rigid orthosis and activity restriction. Even after this conservative treatment, she continued to suffer from persistent back pain that radiated down her left leg and a progressively kyphotic posture. DIAGNOSES: Initial imaging studies revealed a fracture of the left L5 superior articular process with a posterior ligament complex (PLC) injury. Subsequent radiographs showed the locked facet dislocation with kyphotic changes. INTERVENTIONS: The patient underwent surgical reduction and fusion, and the operative findings revealed the L4-5 bilateral facet dislocation and rupture of the PLC at the index level. OUTCOMES: After surgical reduction and fusion at L4-5 by posterior interbody fusion, we achieved a satisfactory clinical outcome. LESSONS: Injury of the PLC in the lower lumbar region deserves careful attention for the development of sequelae. The anatomic transition from lordosis to kyphosis, in the lumbosacral region may be related to this type of injury.

Arthroscopic-assisted plate fixation for displaced large-sized comminuted greater tuberosity fractures of proximal humerus: a novel surgical technique.

PURPOSE: The purpose of the present study was to describe the use of a novel hybrid surgical technique-arthroscopic-assisted plate fixation-and evaluate its clinical and anatomical outcomes in the management of large, displaced greater tuberosity (GT) fractures with comminution. METHODS: From 2009 to 2011, this novel technique was performed in 11 patients [2 men and 9 women; median age, 64 years (range 41-83 years)] with large, comminuted GT fractures, with fragment displacements of >5 mm. The preoperative mean posterior and superior migration of the fractured fragment, as measured on computed tomography (CT), was 19.5 and 5.5 mm, respectively. Two patients had shoulder fracture-dislocation, and three had associated undisplaced surgical neck fracture. The mean duration between injury and surgery was 4 days. The mean follow-up duration was 26 months. RESULTS: At the final follow-up, the mean postoperative ASES, UCLA and SST scores were 84, 29, and 8, respectively. The mean range of motion was as follows: forward flexion, 138°; abduction, 135°; external rotation at the side, 19°; and internal rotation, up to the L2 level. The mean posterior and superior displacements of fracture fragments on postoperative CT scan [0.7 ± 0.8 mm (range 0-2.1 mm) and 2.8 ± 0.5 mm (range 3.4-5.3 mm), respectively] were significantly improved (p < 0.05). On arthroscopy, a partial articular-side supraspinatus tendon avulsion lesion was identified in 10 of 11 patients (91 %), and 1 of these patients had a partial tear of the biceps and 1 had a partial subscapularis tear, respectively (9 %). Intraoperatively, 1 anchor pullout and 1 anchor protrusion through the humeral head were noted and corrected. Postoperatively, the loss of reduction in the fracture fragment was noted in 1 patient at 4 weeks, after corrective reduction and fixation surgery. CONCLUSIONS: The novel arthroscopic-assisted anatomical plate fixation technique was found to be effective in reducing large-sized, displaced, comminuted GT fractures and in allowing concurrent management of intra-articular pathologies and early functional rehabilitation. Compared with the conventional plate fixation or arthroscopic suture anchor fixation technique, arthroscopic-assisted plate fixation enabled accurate restoration of the medial footprint of the GT fracture and provided an effective buttress to the large-sized GT fracture fragments. LEVEL OF EVIDENCE: Retrospective clinical study, Level IV.

Clinical and radiological outcomes of unstable proximal humeral fractures treated with a locking plate and fibular strut allograft.

PURPOSE: To evaluate the clinical and radiological outcomes of unstable proximal humeral fractures (PHFs) treated with a locking plate and fibular strut allograft. METHODS: This study included 36 patients [7 men, 29 women; mean age, 68 years (range, 22-94 years)] with unstable PHFs with medial column disruption. All patients were treated with open reduction and internal fixation using a locking plate and fibular strut allograft. Post-operative assessment included clinical outcomes, shoulder range of motion, radiographic examination, and any complications. Post-operative radiological assessment including the humerus neck-shaft angle (NSA) and the humeral head height was performed. RESULTS: At the mean two year follow-up visit, the mean American Shoulder and Elbow Society (ASES) and University of California, Los Angeles (UCLA) scores were 77 and 28, respectively. According to the UCLA rating scale, the result was excellent in six, good in 20, fair in six, and poor in four cases. According to the Paavolainen method, 31 patients had good results with an NSA of 130 ± 10°; three patients showed fair results with an NSA of 100-120°, and two patients experienced a poor result with an NSA of <100°. When calculating the humeral head height, the mean loss of reduction was measured as 1.6 mm (from 10.8 or 9.2 mm). Varus collapse and avascular necrosis of the humeral head was noted in two patients for each condition. CONCLUSIONS: For unstable proximal humerus fractures, particularly in elderly patients with severe osteoporosis or in younger patients with a four-part fracture, locking plate fixation with a fibular strut allograft provided rigid medial support and showed satisfactory clinical and radiological outcomes.

Anterior cerebral artery aneurysm associated with multiple intracranial aneurysms and abdominal aorta aneurysm.

We found multiple aneurysms in the intracranial arteries and abdominal aorta of an 87-year-old Korean female cadaver, whose cause of death was reported as "cholangiocarcinoma." An abdominal aortic aneurysm was observed in the infrarenal aorta, where the inferior mesenteric artery arose. The intracranial aneurysms were found in the A3 segment of the anterior cerebral artery and at the bifurcation of the middle cerebral artery. This case provides an example of the very rare association of peripheral intracranial aneurysms with an abdominal aortic aneurysm. Clinicians as well as anatomists should recognize the potential association between these two aneurysm types.

Nitrided ITQ-2 as an efficient Knoevenagel condensation catalyst.

The nitrogen-substituted delaminated ITQ-2 zeolite was found to be a highly active and recyclable catalyst for the Knoevenagel condensation of bulky aromatic aldehydes with ethyl cyanoacetate which cannot take place over the base sites placed within the micropores of conventional zeolites due to spatial limitations.

Direct observation of hexamethylbenzenium radical cations generated during zeolite methanol-to-olefin catalysis: an ESR study.

The generation of hexamethylbenzenium radical cations as the key reaction intermediate in chabazite-type molecular sieve acids (i.e., H-SAPO-34 and H-SSZ-13) during the methanol-to-olefin process has been directly evidenced by ESR spectroscopy.

The effect of Er:YAG laser irradiation on the scanning electron microscopic structure and surface roughness of various implant surfaces: an in vitro study.

The purpose of this study was to evaluate the surface roughness (R(a)) and microscopic change to irradiated dental implant surfaces in vitro and ultimately to determine the proper pulse energy power and application time for the clinical use of Er:YAG lasers. Anodic oxidized surface implants and sand-blasted, large-grit, and acid-etched (SLA) surface implants were used. Each experimental group of implant surfaces included ten implants. Nine implants were used for the laser irradiation test groups and one for the control group. Each test group was equally divided into three subgroups by irradiated pulse energy power. Using an Er:YAG laser, each subgroup of anodic oxidized surface implants was split into 60-, 100-, and 140-mJ/pulse groups, with each subgroup of SLA surface implants irradiated with a 100-, 140-, or 180-mJ/pulse. Three implants in every test subgroup were respectively irradiated for 1, 1.5, and 2 min. The R(a) values for each specimen were recorded and every specimen was observed by SEM. Irradiation by Er:YAG laser led to a decrease in implant surface roughness that was not statistically significant. In anodic oxidized surfaces, the oxidized layer peeled off of the surface, and cracks appeared on implant surfaces in the 100- and 140-mJ/pulse subgroups. However, with SLA surfaces, no significant change in surface texture could be found on any implant surface in the 100- and 140-mJ/pulse subgroups. The melting and fusion phenomena of implant surfaces were observed with all application times with 180 mJ/pulse irradiation. The SLA implant surfaces are stable with laser intensities of less than 140 mJ/pulse and an irradiation time of less than 2 min. The anodic oxidized surfaces were not stable with laser intensities of 100 mJ/pulse when an Er:YAG laser was used to detoxify implant surfaces.