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Abstract This study retrospectively assessed radiographic outcomes and risk factors associated with non-union in femoral shaft fragmentary segmental fractures (AO/OTA 32C3) treated with reamed antegrade intra-medullary nailing. Radiological outcomes, including union and alignment, were evaluated. The risk factors for non-union were investigated, including demographics and treatment-related characteristics, such as the number of interlocking screws, segmentation length, main third fragment length, distance of the main third fragment, width ratio and exposed nail length in one cortex from immediate post-operative radiographs. Multivariate logistic regression was used for statistical analysis. Among 2295 femoral shaft fracture patients from three level-1 trauma centers, 51 met the inclusion criteria. The radiological union was achieved in 37 patients (73%) with a mean union time of 10.7 ± 4.8 months. The acceptable axial alignment was observed in 30 patients (59%). Multiple logistic regression analysis identified only exposed nail length as a significant risk factor for non-union (odds ratio: 1.599, p = 0.003) and the cut-off value was 19.1 mm (sensitivity, 0.786; specificity, 0.811). The study revealed high rates of non-union (27%) and malalignment (41%). Therefore, patients who underwent intramedullary nailing with an exposed nail length greater than 19.1 mm or about twice the nail diameter should be cautioned of the potential non-union.

Abstracts: Objective: Most prognostic indexes for ischemic stroke mortality lack radiologic information. We aimed to create and validate a deep learning-based mortality prediction model using brain diffusion weighted imaging (DWI), apparent diffusion coefficient (ADC), and clinical factors. Methods: Data from patients with ischemic stroke who admitted to tertiary hospital during acute periods from 2013 to 2019 were collected and split into training (n = 1109), validation (n = 437), and internal test (n = 654). Data from patients from secondary cardiovascular center was used for external test set (n = 507). The algorithm for predicting mortality, based on DWI and ADC (DLP_DWI), was initially trained. Subsequently, important clinical factors were integrated into this model to create the integrated model (DLP_INTG). The performance of DLP_DWI and DLP_INTG was evaluated by using time-dependent area under the receiver operating characteristic curves (TD AUCs) and Harrell concordance index (C-index) at one-year mortality. Results: The TD AUC of DLP_DWI was 0.643 in internal test set, and 0.785 in the external dataset. DLP_INTG had a higher performance at predicting one-year mortality than premise score in internal dataset (TD- AUC: 0.859 vs. 0.746; p = 0.046), and in external dataset (TD- AUC: 0.876 vs. 0.808; p = 0.007). DLP_DWI and DLP_INTG exhibited strong discrimination for the high-risk group for one-year mortality. Interpretation: A deep learning model using brain DWI, ADC and the clinical factors was capable of predicting mortality in patients with ischemic stroke.

Abstract Background The accuracy of distal femoral resection in intramedullary (IM) guided total knee arthroplasty (TKA) depends on femoral morphology and varies according to individual anatomy. This study aimed to characterise coronal plane femoral bowing in Far East Asians according to age, sex, and severity of varus deformity to identify optimal strategies for distal femoral resection in TKA. Method Femoral anatomical parameters in 656 patients (M/F = 232:424) were assessed using standing long-leg anteroposterior radiography which was fulfilling strict standard. The femur was divided into three longitudinal segments to measure the segmental anatomical axial deviation from the mechanical axis and intersegmental bowing. Coronal plane femoral bowing pattern was categorised based on combined gross bowing and distal bowing. Results Mean hip–knee–ankle angle; neck–shaft angle; proximal, middle, and distal segmental axial differences; mechanical lateral distal femoral angle; and femur length were 6.7 ± 6.8°, 125.0 ± 5.5°, 5.9 ± 1.7°, 6.1 ± 1.1°, 5.3 ± 1.6°, 88.4 ± 2.6°, and 432.3 ± 23.9 mm in male and 8.4 ± 5.5°, 126.4 ± 5.6°, 5.4 ± 1.5°, 6.6 ± 0.9°, 5.6 ± 1.6°, 89.3 ± 2.6°, and 410.6 ± 23.3 mm in female, respectively. Mean proximal, distal, and gross femoral bowing was 0.3 ± 1.8°, − 0.8 ± 1.8°, and − 0.5 ± 2.9° in male and 1.2 ± 1.6°, − 1.0 ± 1.6°, and 0.2 ± 2.7° in female, respectively. Conclusions Grossly straight femur with a straight distal part was the most common femoral bowing pattern in Far East Asians. Distal bowing was proved to be a key factor to choose method for distal femoral resection in TKA. Using IM-guide to achieve accurate distal femoral resection in the femora with distal segmental axial deviation between 4–8° and distal bowing less than ± 1° is considered feasible.

Summary: Objective: The purpose of this study was to determine whether TAE negatively impacted perioperative outcomes in patients who underwent open surgery for pelvic trauma. Methods: We retrospectively reviewed the medical records and radiographs of patients who had open surgery for an acute pelvic trauma between February 2014 and May 2017. The patients were classified into two groups: those who underwent TAE and those who did not. We evaluated preoperative demographics and perioperative outcomes between the two groups. Injury type-specific comparisons were also performed. Results: A total of 136 patients (50 TAE and 86 non-TAE) were included in this study. There were significant differences in preoperative demographics including the type of injury, injury severity score, revised trauma score, surgical approach, initial blood pressure, and the amount of transfusion within 24 h between the two groups. However, no differences in perioperative outcomes were identified except for the amount of total transfusion. There were significant differences between the two groups in the injury type-specific comparisons, specifically in the amount of transfusion within 24 h in patients with pelvic ring injury and in the injury severity score in patients with acetabular fracture. However, there was no difference in perioperative outcomes between the groups for either injury type. Conclusion: In the present study, we were unable to identify negative effects of TAE on perioperative outcomes. Therefore, when considering open surgery subsequent to TAE, there is no evidence of increased risk for negative perioperative outcomes, especially with respect to bone healing and deep infection.

Abstract We investigated the effect of κ-carbide precipitates on the strain hardening behavior of aged Fe–Mn-Al-C alloys by microstructure analysis. The κ-carbides-strengthened Fe–Mn-Al-C alloys exhibited a superior strength-ductility balance enabled by the recovery of the strain hardening rate. To understand the relation between the κ-carbides and strain hardening recovery, dislocation gliding in the aged alloys during plastic deformation was analyzed through in situ tensile transmission electron microscopy (TEM). The in situ TEM results confirmed the particle shearing mechanism leads to planar dislocation gliding. During deformation of the 100 h-aged alloy, some gliding dislocations were strongly pinned by the large κ-carbide blocks and were prone to cross-slip, leading to the activation of multiple slip systems. The abrupt decline in the dislocation mean free path was attributed to the activation of multiple slip systems, resulting in the rapid saturation of the strain hardening recovery. It is concluded that the planar dislocation glide and sequential activation of slip systems are key to induce strain hardening recovery in polycrystalline metals. Thus, if a microstructure is designed such that dislocations glide in a planar manner, the strain hardening recovery could be utilized to obtain enhanced mechanical properties of the material.

Purpose Management options for extraperitoneal bladder injury (EBI) associated with pelvic fracture are variable. Predictive factors of operative management (OM) in patients with EBI associated pelvic fracture have not been previously addressed. This study assessed the current epidemiology of blunt traumatic urinary bladder injury and evaluated relevant clinical findings of patients with EBI associated with pelvic fracture who received OM. Methods Patients with urinary bladder injury with or without pelvic fracture from blunt trauma from January 1, 2014 to December 31, 2019 were identified from the institute trauma registry (n = 12,891). Demographics, mechanism of injury, type of urinary bladder injury, pelvic fracture configuration, and management options were analysed in the study population (n = 9,894). Results Of the 1,400 patients who had pelvic and/or acetabular fracture, 32 (2.3%) had urinary bladder injury. Of the 8,494 patients without pelvic and/or acetabular fracture, 12 (0.1%) had non-pelvic fracture urinary bladder injury. The total incidence of urinary bladder injuries in the study population was 0.4% (44/9,894). Patients with EBI associated with pelvic fracture who underwent OM, had a higher frequency of high-grade pelvic injury (100% vs 0%, p = 0.015), concomitant pelvic surgery (75.0% vs 0%, p = 0.001), and non-lateral compression type pelvic fracture (62.5% vs 10.0%, p = 0.043) compared with patients who underwent non-operative management of EBI. Conclusions These data suggest that OM may be considered especially in patients with EBI associated with pelvic fracture with high grade pelvic injury, concomitant pelvic surgery, and non-lateral compression type pelvic fracture.

Abstract Background This study aimed to compare the radiological results between closed nailing without bone graft (BG) and open nailing with BG for aseptic subtrochanteric nonunion and to determine when an open procedure with BG should be considered. Methods In this retrospective study, we investigated patients who underwent surgical intervention for subtrochanteric nonunion between January 2008 and March 2018 in two institutions. Patients with infection, large bone defect, pathologic fracture, open fracture, previous surgery using plate, and follow-up of less than 1 year were excluded. We compared the demographic details and radiological results between patients who underwent the open procedure with BG (BG group) and the closed procedure without BG (non-BG group) as a historical control, and risk factors for the failure of revision surgery were evaluated. Results Thirty-seven patients met the criteria and were divided into the following two groups: the BG group (n=19) who underwent open nailing with BG and the non-BG group (n=18) who underwent closed reamed nailing without BG. The mean degrees of correction of varus and flexion deformity were significantly different (p=0.001, respectively), 6.2° and 2.9° in the BG group and 4.1° and 0.6° in the non-BG group, respectively. Bony union was observed in 17 cases (89.5%) in an average of 7.4 months in the BG group and in 16 cases (88.9%) in 7.6 months in the non-BG group, with no significant differences. The factors that were significantly associated with failure of revision were atypical fracture, two or more previous surgeries, and varus and sagittal anterior angulation. Conclusions The radiological results of closed reamed nailing without BG for subtrochanteric nonunion were satisfactory. In the effort of percutaneous realignment, gap reduction, and intramedullary reaming, the radiological results of closed nailing without BG were not different from those of open nailing with BG; therefore, closed procedure without BG may be an acceptable option in appropriately selected patients.

Abstract Background Transverse acetabular fractures, although classified as elementary, have worse outcomes than other types of acetabular fractures. Prognostic factors for this fracture type are not clearly established. This study aimed to assess the surgical outcomes of transverse acetabular fractures and subtypes thereof and to investigate the prognostic factors. Methods Between 2014 and 2019, 39 patients (39 hips) had transverse fractures or subtypes thereof. We reviewed the surgical outcomes and evaluated patient factors, injury factors, and surgical factors in relation to osteoarthritis (OA) and conversion to total hip arthroplasty (THA). Additionally, we analyzed the cutoff values for postoperative residual gaps and steps. Results Twenty-three male patients and sixteen female with a mean age of 41.7 years (range, 18–78 years) were included. There were 29 satisfactory reductions (74.4%). Eleven hips (28.2%) developed OA, and five (12.8%) of them underwent THA. Dome impaction (odds ratio [OR], 41.173; 95% confidence interval [CI], 1.804–939.814; p = 0.020) and residual gaps (OR, 4.251; 95% CI, 1.248–14.479; p = 0.021) were correlated with poor outcomes. Residual gaps (≥3 mm) and residual steps (≥1 mm) were significantly associated with OA. Conclusions Relatively poor reduction was found for transverse acetabular fractures and subtypes thereof. However, the rates of OA and conversion to THA were not high. Dome impaction and wide residual gaps were identified as risk factors for poor outcomes. The development of OA significantly increased if residual gap and step were more than 3 mm and 1 mm, respectively.

A 37-year-old man was transferred to our level I trauma center after a road traffic accident, presenting with right acetabular fracture, multiple rib fractures, epidural hemorrhage, and liver contusion. Severe traumatic tricuspid regurgitation was also discovered during the work-up for surgery. Our initial attempt at acetabular surgery failed when the patient experienced near cardiac arrest during anesthetic induction. It was hence decided that tricuspid valve repair should precede orthopedic surgery. Minimally invasive tricuspid valve repair using the double orifice technique was successfully performed. Subsequently, acetabular surgery was performed and he was discharged 35 days post-trauma without any complications.

Fire resistance of structural steels used in buildings is typically evaluated based on the ratio of the yield strength at 600 °C to that at room temperature. Fire-resistant steel shows a yield strength ratio of more than 2:3 between 600 °C and room temperature and achieves an excellent high-temperature strength. Alloying elements such as Mo and Nb are used to improve the strength at elevated temperatures. In this study, the effects of the addition of Mo and Nb on the fire resistance of steel were carefully investigated using SEM, TEM, in-situ TEM, EPMA, 3D-APT, positron annihilation lifetime spectroscopy, and first principles calculations. The fire resistance in Mo and Nb added steel (Mo + Nb) was shown to be drastically improved compared to plain carbon steel (CMn). The improvement in the high-temperature strength in Mo + Nb was attributed to the precipitation of fine Nb-rich MX particles and a solid solution of Mo and Nb hindering the dislocation movement, and thereby minimizing the dislocation annihilation at elevated temperature. The solid solution of Mo and Nb lowers the vacancy formation energy and allows a vacancy to form more easily, leading to a large lattice distortion which results in a slower dislocation mobility in Mo + Nb.

In this study, the resistance to pitting corrosion of Fe-18Cr-9Mn-5.5Ni-0.3(C + N) austenitic stainless steel γ-SSs (in wt%) with different C/(C + N) ratios (0.02, 0.29, and 0.60) was evaluated. It was found to be difficult to form a γ-matrix without precipitation, because the Cr23C6 precipitation rate in the γ-SSs with the C/(C + N) value of 0.60 was too fast. Thus, it was recommended to maintain the C/(C + N) ratio below 0.6 in Fe-18Cr-9Mn-5.5Ni-0.3(C + N) γ-SSs. As a result of the potentiodynamic polarization tests, the γ-SS with a C/(C + N) ratio of 0.29 showed the highest resistance to pitting corrosion, and the resistance level of this alloy was superior to that of the AISI 304 γ-SS. Analysis of the passive film and matrix dissolution rates revealed that a higher C/(C + N) ratio of γ-SS increased the protective ability of the passive film and decreased the growth rate of the pits. Therefore, it could be concluded that partial substitution of C for N was advantageous for improving the pitting corrosion resistance of Fe-18Cr-9Mn-5.5Ni-0.3(C + N) γ-SSs, as long as C and N existed in a solid solution state.

PURPOSE We conclude that exercise training-induced effects in metabolic hormones continue for a prolonged period of detraining, but they are not associated with exercise intensity or detraining-induced increases in body weight.The purpose of this study was to examine the effect of diverse exercise training intensities, training periods and detraining periods on metabolic hormones. METHODS Eighty-four male Sprague-Dawley rats (aged 6 weeks, 173-200 g) were divided into 12 different groups by training, detraining, and control conditions. Exercise training consisted of low-intensity training and high-intensity training programs performed in the laboratory on a motor-driven rodent treadmill once per day, 5 days per week for 12 weeks. RESULTS Body weight significantly increased in all the conditions after the 12-week training period, with significant interaction among the conditions (p

On newly developed Febalance-18Cr-7Mn-3Mo-3W-0.4N-(0.03, 0.57)Ni (in wt%) lean duplex stainless steels, the microstructure, element partitioning behavior, and resistance to pitting corrosion were investigated. After solution treatments, the two alloys were found to have similar microstructures in terms of phase fraction and grain size, and have a precipitation-free matrix. The polarization tests revealed that the addition of Ni was beneficial to improve the resistance to pitting corrosion, which was confirmed by the rise in pitting and repassivation potentials. The uniform corrosion behavior and galvanic corrosion rate of the matrix were investigated to explain the improved pitting corrosion resistance of the Ni-added lean duplex stainless steel. As a result, it was found that the addition of Ni enhanced the resistance to uniform corrosion by reducing the galvanic corrosion rate between the ferrite and austenite phases in the lean duplex stainless steel; thus, the pit growth rate was decreased, leading to improvement of the resistance to pitting corrosion.

The effects of C-substitution for part of the N content, on the pitting corrosion resistance and repassivation tendencies of duplex stainless steels (DSSs) were investigated. For this investigation, normal UNS S32205 containing N only (DSS-N) and the C-substituted DSS (DSS-NC) were fabricated. Microstructural analyses confirmed that the two DSSs had dual-phase microstructures without precipitates, and they possessed similar initial microstructure, including their grain sizes and phase fractions. Polarization and immersion tests performed in concentrated chloride solutions revealed that the DSS-NC was more resistant against stable pitting corrosion and possessed a higher repassivation tendency than the DSS-N. Furthermore, the corrosion pits initiated and propagated to a less corrosion resistant α phase. Polarization tests and corrosion depth measurements conducted in an HCl solution indicated that the DSS-NC exhibited lower galvanic corrosion rate between the α and γ phases than the DSS-N. Therefore, the growth rate of pit embryo was lowered in the DSS-NC, which shifted the potentials for the stable pit initiation and the pit extinction to the higher values.