Experimental Demonstration of a Tunable Energy-Selective Gamma-Ray Imaging System Based on Recoil Electrons.

The domain of gamma-ray imaging necessitates technological advancements to surmount the challenge of energy-selective imaging. Conventional systems are constrained in their dynamic focus on specific energy ranges, a capability imperative for differentiating gamma-ray emissions from diverse sources. This investigation introduces an innovative imaging system predicated on the detection of recoil electrons, addressing the demand for adjustable energy selectivity. Our methodology encompasses the design of a gamma-ray imaging system that leverages recoil electron detection to execute energy-selective imaging. The system's efficacy was investigated experimentally, with emphasis on the adaptability of the energy selection window. The experimental outcomes underscore the system's adeptness at modulating the energy selection window, adeptly discriminating gamma rays across a stipulated energy spectrum. The results corroborate the system's adaptability, with an adjustable energy resolution that coincides with theoretical projections and satisfies the established criteria. This study affirms the viability and merits of utilizing recoil electrons for tunable energy-selective gamma-ray imaging. The system's conceptualization and empirical validation represent a notable progress in gamma-ray imaging technology, with prospective applications extending from medical imaging to astrophysics. This research sets a solid foundation for subsequent inquiries and advancements in this domain.

Adrenarche-accompanied rise of adrenal sex steroid precursors prevents NAFLD in Young Female rats by converting into active androgens and inactivating hepatic Srebf1 signaling.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) has rapidly become the most common cause of chronic liver disease in children and adolescents, but its etiology remains largely unknown. Adrenarche is a critical phase for hormonal changes, and any disturbance during this period has been linked to metabolic disorders, including obesity and dyslipidemia. However, whether there is a causal linkage between adrenarche disturbance and the increasing prevalence of NAFLD in children remains unclear. RESULTS: Using the young female rat as a model, we found that the liver undergoes a transient slowdown period of growth along with the rise of adrenal-derived sex steroid precursors during adrenarche. Specifically blocking androgen actions across adrenarche phase using androgen receptor antagonist flutamide largely increased liver weight by 47.97% and caused marked fat deposition in liver, thus leading to severe NAFLD in young female rats. Conversely, further administrating nonaromatic dihydrotestosterone (DHT) into young female rats across adrenarche phase could effectively reduce liver fat deposition. But, administration of the aromatase inhibitor, formestane across adrenarche had minimal effects on hepatic de novo fatty acid synthesis and liver fat deposition, suggesting adrenal-derived sex steroid precursors exert their anti-NAFLD effects in young females by converting into active androgens rather than into active estrogens. Mechanistically, transcriptomic profiling and integrated data analysis revealed that active androgens converted from the adrenal sex steroid precursors prevent NAFLD in young females primarily by inactivating hepatic sterol regulatory element-binding transcription factor 1 (Srebf1) signaling. CONCLUSIONS: We firstly evidenced that adrenarche-accompanied rise of sex steroid precursors plays a predominant role in preventing the incidence of NAFLD in young females by converting into active androgens and inactivating hepatic Srebf1 signaling. Our novel finding provides new insights into the etiology of NAFLD and is crucial in developing effective prevention and management strategies for NAFLD in children.

Deep Learning of GNSS Acquisition.

Signal acquisition is a crucial step in Global Navigation Satellite System (GNSS) receivers, which is typically solved by maximizing the so-called Cross-Ambiguity Function (CAF) as a hypothesis testing problem. This article proposes to use deep learning models to perform such acquisition, whereby the CAF is fed to a data-driven classifier that outputs binary class posteriors. The class posteriors are used to compute a Bayesian hypothesis test to statistically decide the presence or absence of a GNSS signal. The versatility and computational affordability of the proposed method are addressed by splitting the CAF into smaller overlapping sections, which are fed to a bank of parallel classifiers whose probabilistic results are optimally fused to provide a so-called probability ratio map from which acquisition is decided. Additionally, the article shows how noncoherent integration schemes are enabled through optimal data fusion, with the goal of increasing the resulting classifier accuracy. The article provides simulation results showing that the proposed data-driven method outperforms current CAF maximization strategies, enabling enhanced acquisition at medium-to-high carrier-to-noise density ratios.

Peripheral iridectomy for glaucoma is more effective than compound trabeculectomy and significantly reduces Hcy and hs-CRP levels.

OBJECTIVE: To investigate the efficacy of peripheral iridectomy and compound trabeculectomy for glaucoma and the changes in homocysteine (Hcy) and hypersensitivity C-reactive protein (hs-CRP) levels before and after treatment. METHODS: Altogether 104 patients with primary angle-closure glaucoma who were admitted from February 2020 to January 2022 were enrolled in this study for a retrospective analysis. Among them, 49 cases treated by peripheral iridectomy were considered as the research group, and 55 treated by compound trabeculectomy were seen as the control group. The intraocular pressure (IOP), vision, anterior chamber depth (ACD), surgical efficiency and complications before and after surgery was compared between the two groups of patients. Patients' venous blood was collected before and after treatment to test the Hcy and hs-CRP levels, and the relationship between the levels and treatments was analyzed. The ROC curves of Hcy and hs-CRP diagnostic efficacy after treatment were also plotted, and the relationship between Hcy and hs-CRP and patient outcomes was tested by Pearson correlation coefficient. RESULTS: There were no marked differences in IOP, vision and ACD between the two groups before surgery (P>0.05). After surgery, the IOP was dramatically lower, and ACD and vision were dramatically higher in the research group than those in the control group (P<0.01). Compared to the control group, the treatment success rate in the research group was markedly higher, and the incidence of adverse reactions was lower. There was no difference in Hcy and hs-CRP levels before surgery between the two groups (P>0.05). After surgery both Hcy and hs-CRP levels decreased (P<0.05), and levels in the research group were lower than in the control group (P<0.05). Patients with better outcomes had lower postoperative Hcy and hs-CRP levels (P<0.05). ROC curves of the diagnostic efficacy of Hcy and hs-CRP after treatment manifested that the areas under the curve were >0.7. Both Hcy and hs-CRP levels were found to be negatively correlated with patient outcomes by Pearson correlation coefficient (P<0.001). CONCLUSION: The efficacy of peripheral iridotomy for glaucoma is better than that of compound trabeculectomy. Monitoring Hcy and hs-CRP levels in patients before and after surgery can effectively assess clinical outcomes as well as the safety of the procedure.

Influences of Rapamycin on Retinal Ganglion Cells in Rats with Acute High Intraocular Pressure Through Regulating COX-2.

The study aimed to explore the influences of rapamycin on the retinal ganglion cells in rats with acute high intraocular pressure through regulating cyclooxygenase-2 (COX-2). 36 Sprague-Dawley rats were randomly assigned to the normal group (n=12), model group (n=12) and rapamycin group (n=12). The rats in the normal group were normally fed, those in the model group were prepared the model of acute high intraocular pressure and injected with normal saline, and those in the rapamycin group were given rapamycin. At 7 d after the operation, sampling was performed. The expressions of COX-2 and Caspase-3 were detected via immunohistochemistry, and their protein expressions were determined using Western blotting (WB). Quantitative polymerase chain reaction (qPCR) was conducted to measure the messenger ribonucleic acid (mRNA) expression levels, and cell apoptosis was evaluated using terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) assay. The content of interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α) was determined via enzyme-linked immunosorbent assay (ELISA). Compared with those in the normal group, the positive expression levels rose substantially in the other two groups, and those in the rapamycin group were notably lower (p<0.05). The relative protein expression levels in the model group and rapamycin group were higher, and the rapamycin group exhibited remarkable decreases (p<0.05). In comparison with the normal group, the other two groups had considerably raised relative mRNA expression levels and those in the rapamycin group were lower (p<0.05). The cells in the model and rapamycin groups had a higher apoptosis rate, and the apoptosis rate of cells in the rapamycin group was lower (p<0.05). Compared with that in the normal group, the content of IL-6 and TNF-α was elevated in the other two groups and their content in the rapamycin group was lower. Rapamycin inhibits COX-2 to repress inflammation and apoptosis, thereby exerting a protective effect on the retinal ganglion cells in rats with acute high intraocular pressure.

Embryonic stem cells-derived exosomes enhance retrodifferentiation of retinal Müller cells by delivering BDNF protein to activate Wnt pathway.

OBJECTIVE: The present study was intended to investigate the role of embryonic stem cell-derived exosomes (ESC-Exos) in Müller cell retrodifferentiation and their specific mechanism. METHODS: Following co-incubation of the extracted ESC-Exos and Müller cells, their effects on the retrodifferentiation and proliferation of Müller cells were measured by EdU staining, immunofluorescence, and western blot. ESCs transfected with small interfering RNA of BDNF were co-incubated with Müller cells to determine Müller cell proliferation and retrodifferentiation. ß-catenin expression in the nucleus and GSK-3ß phosphorylation were measured to determine the role of the Wnt pathway in Müller cells. The function of the retina in RCS rats was observed using flash electroretinogram. RESULTS: Co-incubation of ESCs with Müller cells or overexpression of BDNF contributed to Müller cell retrodifferentiation and proliferation, as evidenced by increased cell proliferation, fluorescence intensities of proliferation markers and retinal stem cell markers, and expression of BDNF and ß-catenin, and suppressed GSK-3ß phosphorylation. However, co-incubation with ESCs silencing BDNF or treatment with GW4869 inhibited the proliferation and retrodifferentiation of retinal Müller cells. In addition, exosome injection increased BDNF, BrdU, PH3, SOX2, and Pax6 expression, enhanced ß-catenin expression in the nucleus, diminished GSK-3ß, and improved retinal degeneration in RCS rats. CONCLUSION: ESC-Exos accelerated Müller cell retrodifferentiation and proliferation through Wnt pathway activation by delivering BDNF protein to Müller cells.

Robust Filtering Techniques for RTK Positioning in Harsh Propagation Environments.

Global navigation satellite systems (GNSSs) play a key role in intelligent transportation systems such as autonomous driving or unmanned systems navigation. In such applications, it is fundamental to ensure a reliable precise positioning solution able to operate in harsh propagation conditions such as urban environments and under multipath and other disturbances. Exploiting carrier phase observations allows for precise positioning solutions at the complexity cost of resolving integer phase ambiguities, a procedure that is particularly affected by non-nominal conditions. This limits the applicability of conventional filtering techniques in challenging scenarios, and new robust solutions must be accounted for. This contribution deals with real-time kinematic (RTK) positioning and the design of robust filtering solutions for the associated mixed integer- and real-valued estimation problem. Families of Kalman filter (KF) approaches based on robust statistics and variational inference are explored, such as the generalized M-based KF or the variational-based KF, aiming to mitigate the impact of outliers or non-nominal measurement behaviors. The performance assessment under harsh propagation conditions is realized using a simulated scenario and real data from a measurement campaign. The proposed robust filtering solutions are shown to offer excellent resilience against outlying observations, with the variational-based KF showcasing the overall best performance in terms of Gaussian efficiency and robustness.

Robust Statistics for GNSS Positioning under Harsh Conditions: A Useful Tool?

Navigation problems are generally solved applying least-squares (LS) adjustments. Techniques based on LS can be shown to perform optimally when the system noise is Gaussian distributed and the parametric model is accurately known. Unfortunately, real world problems usually contain unexpectedly large errors, so-called outliers, that violate the noise model assumption, leading to a spoiled solution estimation. In this work, the framework of robust statistics is explored to provide robust solutions to the global navigation satellite systems (GNSS) single point positioning (SPP) problem. Considering that GNSS observables may be contaminated by erroneous measurements, we survey the most popular approaches for robust regression (M-, S-, and MM-estimators) and how they can be adapted into a general methodology for robust GNSS positioning. We provide both theoretical insights and validation over experimental datasets, which serves in discussing the robust methods in detail.

Huber's Non-Linearity for GNSS Interference Mitigation †.

Satellite-based navigation is prevalent in both commercial applications and critical infrastructures, providing precise position and time referencing. As a consequence, interference to such systems can have repercussions on a plethora of fields. Additionally, Privacy Preserving Devices (PPD)—jamming devices—are relatively inexpensive and easy to obtain, potentially denying the service in a wide geographical area. Current jamming mitigation technology is based on interference cancellation approaches, requiring the detection and estimation of the interference waveform. Recently, the Robust Interference Mitigation (RIM) framework was proposed, which leverages results in robust statistics by treating the jamming signal as an outlier. It has the advantage of rejecting jamming signals without detecting or estimating its waveform. In this paper, we extend the framework to situations where the jammer is sparse in some transformed domain other than the time domain. Additionally, we analyse the use of Huber’s non-linearity within RIM and derive its loss of efficiency. We compare its performance to state-of-the-art techniques and to other RIM solutions, with both synthetic and real signals, showing remarkable results.

Evolution of Grain Interfaces in Annealed Duplex Stainless Steel after Parallel Cross Rolling and Direct Rolling.

Changes in various grain interfaces, including the grain boundary and phase boundary, are a strong indication of microstructural changes, particularly ultra-fined grains achieved by large strain deformation and subsequent annealing. After direct rolling and cross rolling with the same strain of ε = 2, the distributions of the interfaces in annealed UNS S32304 duplex stainless steel were investigated using electron backscatter diffraction (EBSD) in this study. The ferrite experienced continued recovery, and a high density of low-angle grain boundaries (LAGBs) was produced. The percentage and number of twin boundaries (TBs) and LAGBs varied within the austenite. TBs were frequently found within austenite, showing a deviation from the Kurdjumov-Sachs (K-S) orientation relationship (OR) with ferrite matrix. However, LAGBs usually occur in austenite, with the K-S OR in the ferrite matrix. LAGBs were prevalent in the precipitated austenite grains, and therefore a strong texture was introduced in the cross-rolled and annealed samples, in which the precipitated austenite readily maintained the K-S OR in the ferrite matrix. By contrast, more TBs and a less robust texture were found in the precipitated austenite in direct-rolled and annealed samples, deviating from the K-S OR.

Retraction Note: Long noncoding RNA ANRIL is activated by hypoxia-inducible factor-1α and promotes osteosarcoma cell invasion and suppresses cell apoptosis upon hypoxia.

[This retracts the article DOI: 10.1186/s12935-016-0349-7.].

Arsenic sulfide induces apoptosis and autophagy through the activation of ROS/JNK and suppression of Akt/mTOR signaling pathways in osteosarcoma.

Osteosarcoma is a common primary malignant bone tumor, the cure rate of which has stagnated over the past 25-30 years. Arsenic sulfide (As2S2), the main active ingredient of the traditional Chinese medicine realgar, has been proved to have antitumor efficacy in several tumor types including acute promyelocytic leukemia, gastric cancer and colon cancer. Here, we investigated the efficacy and mechanism of As2S2 in osteosarcoma both in vitro and in vivo. In this study, we demonstrated that As2S2 potently suppressed cell proliferation by inducing G2/M phase arrest in various osteosarcoma cell lines. Also, treatment with As2S2 induced apoptosis and autophagy in osteosarcoma cells. The apoptosis induction was related to PARP cleavage and activation of caspase-3, -8, -9. As2S2 was demonstrated to induce autophagy as evidenced by formation of autophagosome and accumulation of LC3II. Further studies showed that As2S2-induced apoptosis and autophagy could be significantly attenuated by ROS scavenger and JNK inhibitor. Moreover, we found that As2S2 inhibited Akt/mTOR signaling pathway, and suppressing Akt and mTOR kinases activity can increase As2S2-induced apoptosis and autophagy. Finally, As2S2in vivo suppressed tumor growth with few side effects. In summary, our results revealed that As2S2 induced G2/M phase arrest, apoptosis, and autophagy via activing ROS/JNK and blocking Akt/mTOR signaling pathway in human osteosarcoma cells. Arsenic sulfide may be a potential clinical antitumor drugs targeting osteosarcoma.

Long noncoding RNA ANRIL is activated by hypoxia-inducible factor-1α and promotes osteosarcoma cell invasion and suppresses cell apoptosis upon hypoxia.

BACKGROUND: Osteosarcoma is the most common malignancy of bone. Intratumoral hypoxia occurs in many solid tumors, where it is associated with the development of aggressive phenotype. ANRIL has been shown to be a long noncoding RNA that facilitates the progression of a number of malignancies. Yet, few studies have explored the expression pattern of ANRIL in osteosarcoma and the effect of hypoxia on ANRIL. METHODS: We evaluated the expression levels of ANRIL in osteosarcoma tissues, adjacent normal tissues and cells with quantitative real-time polymerase chain reaction. Multiple approaches including luciferase reporter assay with nucleotide substitutions, chromatin immunoprecipitation assay and electrophoretic mobility shift assay were used to confirm the direct binding of HIF-1α to the ANRIL promoter region. SiRNA-based knockdown and other molecular biology techniques were employed to measure the effect of HIF-1α on the expression of ANRIL. RESULTS: We found that the expression of ANRIL was upregulated in 15 pairs of osteosarcoma compared with adjacent normal tissues. We found that hypoxia is sufficient to upregulate ANRIL expression in osteosarcoma cells (MNNG and U2OS). HIF-1α directly binds to the putative hypoxia response element in the upstream region of ANRIL. What's more, siRNA and small molecular inhibitors-mediated HIF-1α suppression attenuated ANRIL upregulation under hypoxic conditions. Upon hypoxia, ANRIL promoted cancer cell invasion and suppressed cell apoptosis. CONCLUSION: Taken together, these data suggest that HIF-1α may contribute to the upregulation of ANRIL in osteosarcoma under hypoxic conditions. ANRIL is involved in hypoxia-induced aggressive phenotype in osteosarcoma.

Impact of ischemic preconditioning on ischemia-reperfusion injury of the rat sciatic nerve.

The aim of this study was to assess the preventive effects of ischemic preconditioning (IPC) on ischemia-reperfusion (IR) injury in the sciatic nerve of the rat hind limb. This study included two experiments. For Experiment 1, 40 Sprague-Dawley (SD) rats were randomly divided into 4 equal groups that received different IPC treatments prior to IR. Serum concentrations of aspartate aminotransferase (AST), lactate dehydrogenase (LDH), malondialdehyde (MDA), and superoxide dismutase (SOD) were assessed following reperfusion. Furthermore, we tested the electrophysiological response and ultrastructural changes in the ipsilateral sciatic nerve after IR. After determining the best IPC protocol for protection, we performed a second experiment with 30 SD rats randomly divided into 3 equal groups. Each group underwent 1, 2, or 3 IPC cycles before prolonged ischemia and reperfusion. The same analyses as in Experiment 1 were performed. In Experiment 1, the AST, LDH, and MDA concentrations were decreased in all IPC groups compared with the control group. Concentration of these enzymes showed decreases with increasing IPC cycle number in Experiment 2; however, the difference between 2 and 3 cycles of IPC did not reach significance. Conversely, SOD activity increased in the rapid and delayed groups, and with increasing cycles of IPC. The electrophysiological test showed a decrease in amplitude and increase in conduction velocity with increasing IPC cycles. Moreover, ultrastructural damage decreased with increasing IPC cycles. IPC protected against IR injury in the peripheral nerves. This effect was positively correlated with the number of IPC cycles.

Regression analysis of controllable factors of surgical incision complications in closed calcaneal fractures.

BACKGROUND: In surgeries of closed calcaneal fractures, the lateral L-shaped incision is usually adopted. Undesirable post-operative healing of the incision is a common complication. In this retrospective study, controllable risk factors of incision complications after closed calcaneal fracture surgery through a lateral L-shaped incision are discussed and the effectiveness of clinical intervention is assessed. MATERIALS AND METHODS: A review of medical records was conducted of 209 patients (239 calcaneal fractures) surgically treated from June 2005 to October 2012. Univariate analyses were performed of seven controllable factors that might influence complications associated with the surgical incision. Binomial multiple logistic regression analysis was performed to determine factors of statistical significance. RESULTS: Twenty-one fractures (8.79%) involved surgical incision complications, including 8 (3.35%) cases of wound dehiscence, 7 (2.93%) of flap margin necrosis, 5 (2.09%) of hematoma, and 1 (0.42%) of osteomyelitis. Five factors were statistically significant : The time from injury to surgery, operative duration, post-operative drainage, retraction of skin flap, bone grafting, and patients' smoking habits. The results of multivariate analyses showed that surgeries performed within 7 days after fracture, operative time > 1.5 h, no drainage after surgery, static skin distraction, and patient smoking were risk factors for calcaneal incision complications. The post-operative duration of antibiotics and bone grafting made no significant difference. CONCLUSION: Complications after calcaneal surgeries may be reduced by postponing the surgery at least 7 days after fracture, shortening the time in surgery, implementing post-operative drainage, retracting skin flaps gently and for as short a time as possible, and prohibiting smoking.

Restoration of horizontal stability in complete acromioclavicular joint separations: surgical technique and preliminary results.

BACKGROUND: Our purpose was to investigate the clinical efficacy of arthroscope-assisted acromioclavicular ligament reconstruction in combination with double endobutton coracoclavicular ligament reconstruction for the treatment of complete acromioclavicular joint dislocation. METHODS: During the period from February 2010 to October 2012, ten patients with Rockwood types IV and V acromioclavicular joint dislocation were hospitalized and nine were treated with acromioclavicular ligament reconstruction combined with double endobutton of coracoclavicular ligament reconstruction. The improvement in shoulder functions was assessed using a Constant score and visual analog scale (VAS) system. RESULTS: The mean follow-up period was 33.6 ± 5.4 months. The mean Constant scores improved from 25.2 ± 6.6 preoperatively to 92.4 ± 6.5 postoperatively, while the mean VAS score decreased from 5.9 ± 1.4 to 1.2 ± 0.9; significant differences were observed. The final follow-up revealed that excellent outcomes were achieved in eight patients and good outcome in two patients. CONCLUSION: Arthroscope-assisted acromioclavicular ligament reconstruction in combination with double endobutton of coracoclavicular ligament reconstruction is an effective approach for treatment of acute complete acromioclavicular joint dislocation.

[Assisting plate with reamed intramedullary nailing for segmental fractures of proximal-middle tibia].

OBJECTIVE: To evaluate the efficacy and safety of combining reduction plating with reamed intramedullary nailing for segmental fractures of proximal-middle tibia. METHODS: From June 2007 to October 2011, 31 patients with segmental fractures of proximal-middle tibia were admitted. There were 18 males and 13 females, with an average age of 45.2 years (range: 23-77 years), of whom, 9 were Gustilo I type open fractures and 22 were close fractures. All the patients were treated with assisting plate combined with reamed intramedullary nailing. The operation was performed averagely 35 h (range: 16-72 h) after injury. During the post-operation follow-up radiographic evaluation, the range of knee joint, and Johner-Wruhs scores were measured. RESULTS: All the patients were followed-up for 18.5 months (range: 17-24 months). No wound infection or osteofascial compartment syndrome happened. All the fractures healed after 5.1 months (range: 4-6 months). The proximal and distal fracture sites healed simultaneously. No malunion was found. In the last follow-up, the mean range of knee joint was 9°-0°-127°, and according to Johner-Wruhs scores, 19 were excellent, 10 good, and 2 fair. CONCLUSION: Assisting plate with reamed intramedullary nailing is a safe and effective alternative choice for segmental fractures of proximal-middle tibia, which can ease the difficulty of the procedure, improve the quantity of reduction and enhance the stability of the hardware.

Retrograde nailing versus locked plating of extra-articular distal femoral fractures: comparison of 36 cases.

OBJECTIVE: The purpose of this study was to retrospectively evaluate the use of locked plating (LP) and retrograde nailing (RN) for treating extra-articular distal femoral fractures. MATERIALS AND METHODS: From January 2004 to March 2009, 36 patients with extra-articular distal femoral fractures were surgically treated at our Trauma Center. The patients were divided into two groups according to the treatment method, with 19 patients being treated by LP (LP group) and 17 patients via RN (RN group). RESULTS: The demographics of age (p = 0.460) and gender (p = 0.481) in both LP and RN groups were similar. No differences were found with respect to postoperative malreduction, deep infection, hardware failure, operating time, knee pain, HSS score and range of knee movement. The mean intraoperative blood loss was significantly higher in the RN group (298 ± 65.2 ml, range 200-410) than in the LP group (200 ± 48.9 ml, range 130-300) (p < 0.01). However, a higher rate of union disturbance was observed in the LP group (36.8%) compared to the RN group (5.9%) (p = 0.044). CONCLUSIONS: The overall union disturbance rate in the LP group was higher than in the RN group. However, further analysis revealed that clinical outcome may largely depend on surgical technique rather than on the choice of implant. Therefore, correct rules (the same for every procedure) should be strictly adhered to, especially in the application of LP.

Management of femoral diaphyseal nonunion after nailing with augmentative locked plating and bone graft.

OBJECTIVES: Exchange nailing (EN) for aseptic femoral shaft nonunion is currently a standard orthopaedic treatment modality. However, according to recent studies there is occasionally a high failure rate when EN is used. In the present study, augmentative locked plating and bone graft was used as an alternative method for treating such cases. The purpose of this study was to report the treatment outcomes of selected femoral diaphyseal nonunions that had initially been treated by nailing. METHODS: Thirteen patients with femoral diaphyseal nonunions underwent revision surgery with locked plate and bone graft. The inclusion criteria were: (a) nonisthmic nonunion; (b) atrophic/oligotrophic nonunion. All patients were managed by augmentative locked plating and bone graft. RESULTS: All patients were followed up for a mean of 1.2 years (range, 1-2 years). After revision surgery all nonunions achieved bony union, the average union time being 7.5 months (range, 6-12 months). No major complications were observed in this case series. CONCLUSION: Augmentative locked plating is an effective and simple technique for treatment of femoral diaphyseal nonunion after nailing in selected cases.

Treatment of ipsilateral concomitant fractures of proximal extra capsular and distal femur.

OBJECTIVES: Ipsilateral concomitant fractures of proximal extracapsular and distal femur are rare injuries and pose a great challenge for orthopaedics. In this study, we reviewed and examined the approaches and outcomes of this complex injury. METHODS: From August 2002 to January 2010, seven patients (six males and one female) with a mean age of 39 years (range, 20-48 years) were involved in the study. They had suffered from ipsilateral concomitant fractures of proximal extracapsular and distal femur, with two cases of unstable intertrochanteric fractures, three cases of subtrochanteric fractures and two cases of extracapsular femoral neck fractures. The distal femoral fractures were categorised based on the Arbeitsgemeinschaft für Osteosynthes (AO) classification: 2, A3; 2, C1; 2, C2 and 1, C3, and the proximal femoral fractures were stabilised via nailing, whilst the distal ones via less-invasive stabilisation system-distal femur (LISS-DF) plating in all six patients. In the one with the 'floating knee' injury, the subtrochanteric fracture was stabilised by reversed LISS-DF, and the distal one, by retrograde nailing. The healing of each femoral fracture was evaluated radiologically and clinically with follow-up. The functional outcomes were assessed through the Friedman and Wyman system. RESULTS: The mean follow-up interval was 2 years (range, 1.5-3 years). Six femoral fractures healed uneventfully, whilst the one with the 'floating knee' injury developed a delayed union postoperatively due to metal failure in 6 months, and, eventually, a malunion with coxa vara deformity 1.5 years later. The clinical functions at the final follow-up were found to be good in five cases, and fair and poor in one case each. CONCLUSION: The nailing of a proximal femoral fracture and an LISS-DF fixation of a distal one could be a reliable and effective approach to handle ipsilateral concomitant fractures of a proximal extracapsular and distal femur.