PURPOSE:To investigate the prognostic value of neutrophil-to-lymphocyte ratio (NLR) in predicting post-traumatic osteoarthritis (PTOA) following surgical fixation of intra-articular ankle fractures. METHODS:This retrospective cohort study included patients who underwent surgery for closed, intra-articular ankle fractures in a tertiary care center between January 2019 and December 2021, with a minimum follow-up of 3 years. NLR was calculated from routine blood tests within 24 hours post-injury. PTOA was diagnosed radiographically based on the Kellgren-Lawrence grading system. Multivariable logistic regression was employed to assess the independent predictive role of NLR after adjusting for covariates. RESULTS:A total of 764 patients were included, including 455 (59.6%) males and 309 (40.4%) females, with a mean age of 43.9 ± 14.6 years. The restricted cubic spline (RCS) model demonstrated a nonlinear relationship between NLR and PTOA, with risk sharply rising above the 6.5 threshold. High-NLR patients (n = 159) also exhibited higher surgical complexity, increased bleeding, and more frequent emergency interventions, as compared with low-NLR group (n = 605). The risk of PTOA was 37.7% (60/159) and 19.5% (118/605) in both groups, respectively (P < 0.001). An NLR ≥ 6.5 was associated with a significantly increased risk of PTOA (adjusted OR = 2.299, 95% CI: 1.517-3.483, P < 0.001). CONCLUSIONS:These findings suggest that elevated early post-injury NLR may be associated with the development of PTOA following ankle fracture surgery; however, given the single time-point assessment, further prospective studies with serial measurements are needed to clarify its role.

Background and aimChronic pancreatitis (CP) in children has exhibited an annual increase in incidence in recent years. Pediatric CP presents unique clinical features compared to adult cases. Endoscopic retrograde pancreatography (ERP) serves as a valuable and safe tool for diagnosing and treating CP in adults. However, data on endoscopic treatment of CP in children are still limited.MethodsDemographics, etiology, surgical indications, diagnosis, treatment details, associated complications, and follow-up information were retrospectively studied in consecutive patients (<18 years old) who underwent ERP for CP between January 2020 and October 2024.ResultsA total of 17 children (7 male, 10 female) with a mean age of 10.0 ± 2.7 years were included in the study. A total of 34 endoscopic treatments were conducted. Recurrent abdominal pain was the primary clinical symptom. Imaging predominantly revealed pancreatic duct abnormalities such as tortuous dilatation and the presence of pancreatic duct stones. Notably, 41.2% (7 cases) involved genetic and congenital anatomical variations. Pancreatic duct stent placement was successfully performed in all 17 children (100.0% success rate). Stent replacements occurred on average 2.2 times (range 1–5) at intervals of 3–6 months. Postoperative pancreatitis developed in 2 cases (5.9%, 2/34), and hyperamylasemia occurred in 5 cases (14.7%, 5/34). The postprocedure visual analogue scale (VAS) score for abdominal pain significantly decreased from 6 to 1 (P < 0.001). The annual frequency of pancreatitis episodes showed a significant reduction, decreasing from 2.4 times pre-treatment to 0.6 times post-treatment (P < 0.05). Body mass index (BMI) also showed a significant improvement post-treatment compared to pre-treatment (P < 0.05).ConclusionsERP performed by trained endoscopists utilizing standard adult endoscopes and accessories proved a safe and effective treatment option for pediatric CP, with complication rates comparable to those reported in adult cases.

Pancreaticobiliary maljunction is a congenital malformation in which the pancreatic and bile ducts join anatomically outside the duodenal wall, usually forming a markedly long common channel, which can cause reciprocal reflux between pancreatic juice and bile. Cholangiography, endoscopic ultrasonography, surgery, and autopsy can be used to diagnose pancreaticobiliary maljunction. Elevated amylase levels in bile and extrahepatic bile duct dilatation strongly suggest the existence of pancreaticobiliary maljunction. The regurgitation may lead to the development of various hepatobiliary and pancreatic disorders such as pancreatitis and biliary carcinoma. The pathogenesis of pancreaticobiliary maljunction is the result of a series of pathophysiological changes caused by reflux. Surgery is recommended for patients diagnosed with pancreaticobiliary maljunction irrespective of the presence or absence of symptoms because of its high biliary carcinogenicity, but the treatment strategy is quite different between adult patients with and without biliary dilatation.

AimThe study aimed to explore the impact of transversus abdominis plane block (TAPB) combined with intravenous lidocaine on rapid recovery after bariatric surgery.MethodsA total of 80 patients who underwent elective bariatric surgery from October 2022 to October 2023 were selected as study participants and divided into a control group (CG) and a study group (SG). The CG received ultrasound-guided TAPB with ropivacaine, while the SG received ultrasound-guided TAPB with ropivacaine plus intravenous lidocaine. The two groups were compared in terms of total doses of propofol, remifentanil, and sufentanil used; pain intensity; intraoperative conditions; levels of inflammatory factors; additional use of postoperative analgesics; incidence of adverse reactions; and postoperative recovery time.ResultsCompared to the CG, the SG showed significant reductions in the total intraoperative doses of propofol, remifentanil, and sufentanil (p < 0.05). In addition, the SG had lower visual analog scale (VAS) scores at rest and during coughing at 12, 24, and 48 h postoperatively (p < 0.05), as well as lower heart rate (HR) and mean arterial pressure (MAP) values at time points T1–T3 (p < 0.05). On the first day after surgery, the levels of tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) in the SG were significantly lower than those in the CG (p < 0.05), and the SG also required less additional use of postoperative analgesics (p < 0.05). Furthermore, the SG exhibited a shorter time to first flatus, first defecation, and first ambulation, as well as a shorter length of hospital stay compared to the CG (all p < 0.05).ConclusionTAPB combined with intravenous lidocaine may provide effective postoperative analgesia for patients after bariatric surgery and may accelerate their rapid recovery.

Objective:To review and summarize the projections of radiographic images during cephalomedullary nailing fixation for intertrochanteric femoral fractures, and to propose a set of three projections as standard requirement in immediate postoperative fluoroscopy. Methods:Papers on intertrochanteric femoral fractures treated with cephalomedullary nailing fixation that published in a three-year period of 2021-2023 in four leading English orthopedic trauma journals were searched in PubMed. The presented radiographic pictures were identified and scrutinized as whether they were in standard anteroposterior and/or lateral projections of the implanted nails. The nonstandard presence percentage was calculated. Combined with clinical experience, the standard anteroposterior and lateral perspective images of femoral neck, the current situation of radiographic imaging in the operation of cephalomedullary nails, the literature analysis of nonstandard images, the impact of limb rotation on image interpretation, and the characteristics of anteromedial 30° oblique perspective were summarized and analyzed. Results:The presence of nonstandard radiographic pictures is 32.1% in anteroposterior view and 69.2% in lateral view in leading orthopedic trauma journals. In cephalomedullary nailing fixation operation of intertrochanteric femoral fractures, it is reasonable to use the radiographic images of the implanted nails to represent the fractured head-neck, as the head-neck implant (lag screw or helical blade) is aimed to put into centrally in femoral head in lateral projection. Limb rotation or nonstandard projections produced distortion of images, which interfers the surgeons' judgement of fracture reduction quality and the measurement of implant position parameters in femoral head (such as neck-shaft angle and tip-apex distance), and finally lead to a meaningless comparison with the accurate normal value. The 30° anteromedial oblique view from the true lateral (set as 0°) is a tangential projection of the cortices at the anteromedial inferior corner, which gives a clear profile for the determination of cortical apposition status and mechanical support. It is essential to get firstly the true standard lateral fluoroscopy of the nail (shown as a line), then rotate the C-arm to 90° and 30° to get anteroposterior and anteromedial oblique views, and use these three immediate postoperative radiographies as the baseline for evaluation of operative quality and follow-up comparisons. Conclusion:As for real-time monitoring of surgical steps, intraoperative fluoroscopy follows the "Enough is Good" principle, but as for immediate postoperative data storage and basis for operative quality evaluation and baseline for follow-up comparison, it is recommended to obtain a set of three standard radiographic pictures in anteroposterior, true lateral, and 30° anteromedial oblique fluoroscopic projections.

BACKGROUND:Intrahepatic cholangiocarcinoma (ICCA) is a heterogeneous group of malignant tumors characterized by high recurrence rate and poor prognosis. Heterochromatin Protein 1α (HP1α) is one of the most important nonhistone chromosomal proteins involved in transcriptional silencing via heterochromatin formation and structural maintenance. The effect of HP1α on the progression of ICCA remained unclear. METHODS:The effect on the proliferation of ICCA was detected by experiments in two cell lines and two ICCA mouse models. The interaction between HP1α and Histone Deacetylase 1 (HDAC1) was determined using Electrospray Ionization Mass Spectrometry (ESI-MS) and the binding mechanism was studied using immunoprecipitation assays (co-IP). The target gene was screened out by RNA sequencing (RNA-seq). The occupation of DNA binding proteins and histone modifications were predicted by bioinformatic methods and evaluated by Cleavage Under Targets and Tagmentation (CUT & Tag) and Chromatin immunoprecipitation (ChIP). RESULTS:HP1α was upregulated in intrahepatic cholangiocarcinoma (ICCA) tissues and regulated the proliferation of ICCA cells by inhibiting the interferon pathway in a Signal Transducer and Activator of Transcription 1 (STAT1)-dependent manner. Mechanistically, STAT1 is transcriptionally regulated by the HP1α-HDAC1 complex directly and epigenetically via promoter binding and changes in different histone modifications, as validated by high-throughput sequencing. Broad-spectrum HDAC inhibitor (HDACi) activates the interferon pathway and inhibits the proliferation of ICCA cells by downregulating HP1α and targeting the heterodimer. Broad-spectrum HDACi plus interferon preparation regimen was found to improve the antiproliferative effects and delay ICCA development in vivo and in vitro, which took advantage of basal activation as well as direct activation of the interferon pathway. HP1α participates in mediating the cellular resistance to both agents. CONCLUSIONS:HP1α-HDAC1 complex influences interferon pathway activation by directly and epigenetically regulating STAT1 in transcriptional level. The broad-spectrum HDACi plus interferon preparation regimen inhibits ICCA development, providing feasible strategies for ICCA treatment. Targeting the HP1α-HDAC1-STAT1 axis is a possible strategy for treating ICCA, especially HP1α-positive cases.

The inferior breakdown strength of epoxy resin (EP) is one of the greatest barriers which restricts the evolution of advanced electrical equipment and electronic devices. It had been reported that constructing fluorine hybrid polymers was successful in improving the breakdown strength of organic dielectrics. Therefore, in this study, we constructed fluorine hybrid EP with a satisfactory breakdown strength by surface fluorination. It was found experimentally that the fluorination introduced CFn groups into EP molecules and contributed to a greater trap level and breakdown strength. After fluorination at 80 degrees C for 1 h, the CF3 fraction in fluorinated EP was 14.31%, and the breakdown strength was increased by 27.64%, from 427.87 to 546.13 kV/mm. The density functional theory simulations showed that the CF3 groups increased the maximum of positive Mulliken charge (MPMC) of EP molecules. Compared to pristine EP, after introducing CF3 groups, the MPMC was increased from 0.655 to 0.973 eV, which was instrumental in constructing electron traps with a greater level. Thus, the charge transport process in fluorinated EP was repressed and contributed to the superior breakdown strength. This study proposed a strategy to exploit EP polymers with greater breakdown strength and could promote the development of advanced insulation dielectrics for power devices.

Due to many desired properties, liquid silicone rubber (LSR) is the first choice for external insulation of all kinds of bushing in substations or converter stations. This report compares basic electrical properties and hydrophobicity of three commercial LSRs before and after direct fluorination. They are fluorinated in a laboratory reactor with the same fluorination temperature, pressure and time, using the same F2/N2 mixture. This report shows the effect of SR formulation on the basic electrical properties, and further reveals the effect of the formulation on the changes in basic electrical properties caused by the fluorination. Measurements of water contact angles show that the fluorination always results in final high hydrophobicity for three LSRs, regardless of the initial contact angle after the fluorination. Based on ATR-IR and XPS analyses and SEM observation, this report characterizes the physicochemical characteristics of the SR fluorinated layers.

Various composite films with high energy storage performance and/or dielectric strength have been fabricated. However, due to some reasons, few of them have been used in practice, and biaxially oriented polypropylene (BOPP) film is still regarded as the state-of-the-art capacitor dielectric film. Previous work has indicated that direct fluorination can improve the dielectric strength of BOPP films. Herein, as a continuation of previous work, the energy storage performance and basic dielectric properties of the surface fluorinated BOPP film are investigated. The charge–discharge experimental results show that the surface fluorinated BOPP sample has the maximum energy storage or release density of 5.27 or 4.43 J/cm3, which is 59.8% or 44.6% higher than that of the virgin BOPP sample. The dielectric measurement results indicate that the surface fluorinated BOPP sample has slightly higher dielectric constant and dielectric loss than the virgin BOPP sample. The analyses of physicochemical characteristics reveal that the 0.75- $\mu \text{m}$ -thick fluorinated surface layer has a high degree of fluorination. The results of the calculation based on the three-layer dielectric model and the dielectric measurements further show that the fluorinated surface layer has high dielectric constant and loss factor, similar to nonperfluoropolymers. The enhancement of energy storage performance and dielectric strength is mainly attributed to the blocking of the fluorinated layer to electron injection from the cathode due to a 60% reduction of the interfacial electric field and a decrease in free volume of the surface layer by the fluorination.

Dielectric response of polymer dielectrics determines their applications in electronic devices. Although fluoropolymers were widely accepted in communication technology, electronic packing and electrical insulating for their extraordinary dielectric properties, the underlying effect of fluorine hybridization on the dielectric response of polymers is still unclear. Here, surface fluorination was conducted to construct fluorine hybrid epoxy resin (EP), and the dielectric response of EP before and after fluorination was studied. It was found that at low temperature, the electronic polarization was dominated on the dielectric response. The fluorine hybridization reduced the electronic polarization, which led to a lower permittivity of the fluorinated EP. However, at a higher temperature, the fluorine hybridization increased the thermal expansion coefficient and enlarged the free volume fraction, which allowed flexible reorientations of dipoles and led to an enhanced dipolar polarization, and thus, it proved an enhanced permittivity for fluorinated EP. Therefore, the effect of fluorine hybridization on dielectric response of EP polymers was temperature-dependent, with the low-temperature-dominated electronic polarization and high-temperature-dominated dipolar polarization, respectively. This work revealed the influence of fluorine hybridization on dielectric response of epoxy polymers and could promote the application of organic dielectrics in communication and electronic devices.

Objective:To introduce a novel comprehensive classification for femoral intertrochanteric fractures, and to accommodate the clinical requirement for the world-wide outbreak of geriatric hip fractures and surgical operations.Methods:On the basis of reviewing the history of classification of femoral intertrochanteric fractures and analyzing the advantages and disadvantages of AO/Orthopaedic Trauma Association (AO/OTA) classification in different periods, combined with the current situation of extensive preoperative CT scan and three-dimensional reconstruction and widespread use of intramedullary nail fixation in China, the "Elderly Hip Fracture" Research Group of the Reparative and Reconstructive Surgery Committee of the Chinese Rehabilitation Medical Association proposed a novel comprehensive classification for femoral intertrochanteric fractures, focusing on the structure of fracture stability reconstruction during internal fixation.Results:The novel comprehensive classification of femoral intertrochanteric fractures incorporates multiple indicators of fracture classification, including the orientation of the fracture line, the degree of fracture fragmentation, the lesser trochanteric bone fragment and its distal extension length (>2 cm), the posterior coronal bone fragment and its anterior extension width (involving the lateral cortex of the head and neck implant entry point), transverse fracture of the lateral and anterior wall and its relationship with the implant entry point in the head and neck, and whether the cortex of the anteromedial inferior corner can be directly reduced to contact, etc. The femoral intertrochanteric fractures are divided into 4 types (type A1 is simple two-part fractures, type A2 is characterized by lesser trochanter fragment and posterior coronal fractures, type A3 is reverse obliquity and transverse fractures, type A4 is medial comminution which lacks anteromedial cortex transmission of compression force), each of which is subdivided into 4 subtypes and further subdivide into finer subgroups. In a review of 550 trochanteric hip fracture cases by three-dimensional CT, type A1 accounted for 20.0%, type A2 for 62.5%, type A3 for 15.5%, and type A4 for 2.0%, respectively. For subtypes, A2.2 is with a "banana-like" posterior coronal fragment, A2.4 is with distal cortex extension >2 cm of the lesser trochanter and anterior cortical expansion of the posterior coronal fragment to the entry portal of head-neck implants, A3.4 is a primary pantrochanteric fracture, and A4.4 is a concomitant ipsilateral segmental fracture of the neck and trochanter region.Conclusion:The novel comprehensive classification of femoral intertrochanteric fractures can describe the morphological characteristics of fractures in more detail, include more rare and complex types, provide more personalized subtype selection, and adapt to the clinical needs of both fractures and surgeries.

ObjectiveFracture classification evolves dynamically with new and enhanced imaging modalities. This paper aims to introduce a novel hypothesis of a sophisticated fracture classification system for the proximal femur trochanteric region (AO/OTA-31A) based on 3D-CT images and accommodate the clinical requirement of the worldwide outbreak of geriatric hip fractures with large amounts of surgical operations.MethodsIn the current practice of widely preoperative 3D-CT application and cephalomedullary nailing, we attempt to propose a new comprehensive classification system to describe the fracture characteristics in a more detailed and sophisticated architecture, and pay the most important concern to the parameters that contribute to fracture stability reconstruction in osteosynthesis.ResultsThe new four-by-four comprehensive classification system, followed the structure of the AO/OTA system, incorporates many fracture characteristics as dividing indexes into multiple grade levels, such as fracture line direction, the number of fragments, the lesser trochanter fragment and its distal extension (>2 cm), the posterior coronal fragment and its anterior expansion (to the entry portal of head–neck implant at the lateral cortex), the lateral wall and anterior cortex fracture, and the anteromedial inferior corner comminution. From a panoramic perspective, there are four types and each type has four subtypes. A1 is simple two-part fractures (20%), A2 is characterized by lesser trochanter fragment and posterior coronal fractures (62.5%), A3 is reverse obliquity and transverse fractures with complete lateral wall broken (15.5%), and A4 is medial wall comminution which further lacks anteromedial cortex transmission of compression force (2%). For subtypes, A2.2 is with a banana-like posterior coronal fragment, A2.4 is with distal cortex extension >2 cm of the lesser trochanter and anterior expansion of the posterior coronal fragment(s) to the entry portal of head–neck implants, A3.4 is a primary pantrochanteric fracture, and A4.4 is a concomitant ipsilateral segmental fracture of the neck and trochanter region.ConclusionClassification represents diversity under consistency. The four-by-four sophisticated classification system delineates fracture characteristics in more detail. It is applicable in the time of rapid outbreak of trochanteric fractures in the older population, the large amounts of surgical operations, and incorporates various rare and/or more complicated subtypes which is unclassifiable before.

Cartilage extracellular matrix (ECM) metabolism disorder caused by mechanical instability is a leading cause of osteoarthritis (OA), but the exact mechanisms have not been fully elucidated. Recent studies have suggested an important role of circular RNAs (circRNAs/circs) in OA. The present study aimed to investigate whether circRNAs might have a role in mechanical instability-regulated chondrocyte matrix metabolism in OA. The expression levels of circPhc3 in human and mouse OA cartilage samples were measured using reverse transcription-quantitative PCR and fluorescence in situ hybridization. The effects of circPhc3 on chondrocyte ECM metabolism were further investigated by overexpressing and knocking down circPhc3 in OA chondrocytes. The downstream target of circPhc3 was examined by performing a luciferase reporter assay. The results showed that the expression of circPhc3 was reduced in human and mouse OA cartilage. Moreover, circPhc3 was involved in mechanical loading-regulated production of ECM and cartilage-degrading enzymes. Further studies showed that circPhc3 regulated chondrocyte matrix metabolism primarily by binding to microRNA (miR)-93-3p, and mechanistic studies found that miR-93-3p targeting of FoxO1 was involved in chondrocyte matrix metabolism. Taken together, these results indicated that circPhc3 may serve an important role in the progression of OA and may be a good target for the treatment of OA.

BACKGROUND:Delayed gastric emptying (DGE) is a common complication following laparoscopic pancreaticoduodenectomy (LPD), although it remains incompletely understood, and only few studies have investigated the clinical benefits of hepatic branch of the vagus nerve (HBVN) preservation on DGE after LPD until now. We intended to evaluate the effect of preservation of the HBVN during LPD on the incidence of DGE.METHODS:A total of 274 consecutive LPDs performed at a single center between July 2014 and December 2019 with available videos were retrospectively reviewed. DGE was defined according to the International Study Group of Pancreatic Surgery (ISGPS) criteria, and HBVN condition during the LPD procedure was evaluated through a video review. Risk factors associated with DGE were assessed by performing univariate and multivariate logistic regression analyses. Postoperative outcomes between the HBVN-preserved and HBVN-injury groups were compared before and after propensity score matching (PSM).RESULTS:One hundred fifty-six (56.93%) patients underwent LPD with HBVN-preserved and 118 (43.07%) with HBVN injury. DGE occurred in 33.2% of patients (n = 91) with grades B and C occurring at 13.9% (n = 38) and 7.7% (n = 21), respectively. Longer operative time, more EIBL, HBVN injury, POPF (grades B and C), postoperative hemorrhage, intra-abdominal infection, and Clavien-Dindo ≥III were identified as risk factors for DGE in the univariate analysis. Then, in the multivariate analysis, HBVN injury and intra-abdominal infection were found to be independent risk factors affecting the incidence of DGE (any grade) or clinically relevant DGE (grades B and C). Furthermore, the prevalence of DGE was significantly higher in the HBVN-injury group than in the HBVN-preserved group before and after PSM analysis (46.61% vs. 23.08%, P<0.001; 42.59% vs. 23.15%, P=0.013).CONCLUSIONS:HBVN preservation during LPD might be associated with a reduced incidence of DGE as a framework for prospective quality improvement.

In this study, direct fluorination is used to modify the surface of silicone rubber. Moisture barrier properties of the SIR surface layers fluorinated at different temperatures are evaluated by moisture absorption experiments at a temperature of 30 or 60°C and at a relative humidity of 75 or 97%. Physicochemical characteristics of the fluorinated SIR surface layers are investigated on the basis of ATR-IR, XPS and SEM techniques. The moisture absorption measurements show that the fluorinated surface layer has a distinct moisture barrier to the entry of water into the interior of SIR at each humidity and temperature condition, and a close association of the barrier properties with fluorination temperature or physicochemical characteristics of the fluorinated layer. The barrier is particularly significant for such a surface layer fluorinated at a lower temperature, which has higher fluorine content and compactness although a small thickness, compared to the surface layer fluorinated at higher temperatures. In addition, fitting analysis of the experimental data further shows a lower apparent diffusivity of the surface fluorinated samples than the unfluorinated sample.

Effective suppression of charge accumulation on epoxy spacers in high voltage gas insulated systems is one of the most concerned problems for the researchers and engineers in the field of electrical insulation, being of great significance for the development of HVDC/HVAC GIL or GIS. In order to suppress charge accumulation on the epoxy insulator and to improve its dc flashover performance, the first attempt to direct fluorination of epoxy insulators has been carried out as early as the second half of 2010 in Tongji University. In the next decade, a series of studies have been carried out, ranging from samples and model insulators to actual insulators, especially in terms of improving dc flashover performance and arc resistance. The research results achieved so far will provide strong support for the improvement by direct fluorination in practical performance of epoxy spacers in the future. This report reviews the results of a series of studies and the mechanisms behind the property/ performance improvements in terms of the changes in material composition and structure.

Liquid silicone rubber (LSR) sheet samples of a commercial formulation and surface fluorinated using a F2/N2 mixture at various temperatures are studied in this work. The intrinsic DC flashover of the surface fluorinated samples is evaluated using a sheet sample/finger electrode configuration and under a stepwise increasing voltage. The tests show an increase up to 64% in the intrinsic DC flashover voltage of the LSR by the fluorination and an influence on the flashover on the fluorination temperature. ATR-IR and XPS analyses indicate that there are Si-F bonds as well as C-F bonds in the fluorinated layers. SEM shows the thickness of the fluorinated surface layers with nanostructured surfaces. Surface conductivity and potential decay measurements reveal that the fluorination caused a large increase in surface conduction, in association with fluorination temperature. The improvement in the intrinsic DC flashover is mainly attributed to the suppression of surface charge accumulation on the LSR by the increased surface conduction.

OBJECTIVE:To study the anteromedial cortical morphology of intertrochanteric fracture with CT three-dimensional reconstruction technique, and to provide a reference for further study of cortical buttress reduction theory. METHODS:CT data of 75 patients with unstable intertrochanteric fracture with complete imaging data treated between January 2016 and January 2019 were retrospectively analyzed, including 32 males and 43 females, aged 65-98 years (mean, 79.8 years). According to AO/Orthopaedic Trauma Association typing of 2018 edition, there were 46 cases of 31-A2.2 type and 29 cases of 31-A2.3 type. The image processing techniques such as segmentation modeling and virtual reset were performed. The thickness of the cortex at the anteromedial corner, the angle between the anterior wall fracture line and the coronal horizontal line, the angle between the medial wall fracture line and the sagittal horizontal line, the width of the cortex supported by the medial wall were measured, and the morphology of the cortical bone at the anteromedial corner were observed. RESULTS:The angle between the anterior wall fracture line and the coronal horizontal line was 51.8-72.6°, with an average of 62.4°; the angle between the medial wall fracture line and the sagittal horizontal line ranged from 17.6° to -47.3°, with an average of -15.8°; the thickness of the cortex at the anteromedial angle was 3.6-6.1 mm, with an average of 4.4 mm; and the width of the cortex supported by the medial wall was 14.3-21.2 mm, with an average of 16.8 mm. The morphology of the cortical bone at the anteromedial corner had 3 forms: angle with femoral neck axis >90°, 57 cases (76.0%); perpendicular to femoral neck axis, 7 cases (9.3%); angle with femoral neck axis <90° (including reverse angle), 11 cases (14.7%). CONCLUSION:CT three-dimensional reconstruction can clearly show the cortical morphology and the direction of the fracture line of intertrochanteric fracture, which can indicate the stability of the intertrochanteric fracture after reduction, and has a good guiding on the form of cortical buttress reduction.

Objective To evaluate the clinical efficacy and safety of planed conversion from temporary external fixation to internal fixation for open fractures of tibial shaft.Methods We retrospectively reviewed 31 patients with high-energy open fracture of tibial shaft who had been treated from October 2008 to October 2016 at Department of Orthopaedics,in our hospital.They were 20 males and 11 females,with an average age of 38.7 years (from 15 to 79 years).By the Gustilo classification,2 cases were type Ⅰ,9 type Ⅱ,17 type ⅢA and 3 type ⅢB;by the AO/OTA classification,3 cases were type 42A,10 type 42B,and 18 type 42C.External fixation was temporally applied for the fracture ends after thorough debridement to recover the tibial length and alignment.The wounds were closed directly in 23 cases and covered with vacuum sealing drainage in 8.The external fixators were removed after their systemic condition and/or local condition of soft tissue recovered.After plaster casts were maintained for 4 to 7 days to allow for healing of the pin tracts,conversion into secondary definite internal fixation started.Plating was applied in 24 patients and intramedullary nailing in 7 patients.Results The 31 patients gained fellow-up from 13 to 61 months (mean,22.3 months).All fractures gained bony union after an average of 18.7 weeks (from 14 to 31 weeks).No wound complication or infection was observed.According to the Johner-Wruh's criteria,24 cases were rated as excellent,4 as good and 3 as fair,giving an excellent to good rate of 90.3％.Conclusion The staged conversion from temporary external fixation to internal fixation is effective and safe for open fractures of tibial shaft,leading to limited complications of soft-tissue and a high rate of fracture union.