Study on CFRP-Strengthened Welded Steel Plates with Inclined Welds Considering Welding Residual Stress.

Welded steel plates are widely used in various structural applications, and the presence of inclined welds is often encountered in practical scenarios. Carbon fiber reinforced polymer (CFRP) has been proven to be effective for strengthening steel structures. However, the behavior of CFRP-strengthened welded steel plates with inclined welds, particularly considering the influence of welding residual stress, is limited. This paper aims to investigate the tensile behavior of CFRP-strengthened welded Q355 steel plates with inclined welds considering welding residual stress (WRS). First, WRS data were obtained by the X-ray diffraction (XRD) method at different locations. The maximum tensile and compressive residual stresses are 0.39 and 0.14 times the yield strength of the steel, respectively. Then, finite element models were established to investigate the effects of weld angles, weld width, and height on the WRS distribution of welded steel plates. Finally, the tensile performance of CFRP-strengthened welded plates with WRS was studied by numerical simulation. The results showed that the weld angles have little effect on the distribution pattern of residual stress but significantly affect the peak tensile WRS. When the weld angle changes from 0° to 60°, the peak tensile WRS decreases significantly from 0.32 to 0.06 times the yield strength of steel; furthermore, the influence of weld width and height on WRS is relatively limited. Under tension loading, the maximum stress occurs near the weld. The ends of the weld enter the yielding state later than the middle part of the weld due to the distribution of the WRS. As the weld angle increases and the length of the weld increases, the stress in the weld zone decreases, while the stress in the base material zone correspondingly increases. In addition, CFRP strengthening can reduce the magnitude of stress. This study provides preliminary references for understanding the tensile behavior of CFRP-strengthened welded steel plates with inclined welds.

[Clinical effect of allogeneic peroneal bone marrow support combined with plate fixation for the treatment of Neer type â £ proximal humeral fractures].

OBJECTIVE: To explore clinical effect of allogeneic peroneal bone marrow support combined with plate internal fixation in treating Neer type Ⅳproximal humeral fractures. METHODS: From December 2017 to December 2020,12 patients with Neer type Ⅳ proximal humeral fractures were treated with allogeneic peroneal bone marrow support combined with plate internal fixation,including 7 males and 5 females,aged from 56 to 78 years old;the time from injury to operation ranged from 1 to7 days. Operative time,fracture healing time and complications during follow-up were observed,and clinical efficacy was evaluated by Constant-Murley score at the latest follow-up. RESULTS: All patients were obtained follow up for 20 to 29 months. All patients got bone healing and incisicons were healed at stageⅠ,operative time ranged from 95 to 138 min,blood loss ranged from 210 to 275 ml,fracture healing time ranged from 14 to 18 weeks. Two patients occurred postoperative shoulder stiffness and recovered after 2 weeks of passive exercise. There were no complications such as infection,poor wound healing,and failure (fracture and loosening) of internal fixators occurred. Constant-Murley shoulder function score ranged from 69 to 89 at the latest follow up,2 patients got excellent results,9 good and 1 fair. CONCLUSION: The application of allogeneic fibular bone marrow placement could provide effective support for medial humerus,which is conducive to assisting reduction of fracture end,reducing occurrence of internal fixation failure caused by collapse of humerus head and screw perforation,and significantly improving function of shoulder joint.

Prediction of steel plate-based damper for improving the behavior of concentrically braced frames based on RSM and ML approaches for sustainable structures.

The stiffness (K) and slenderness factor (λ) of a steel plate-based damper has been studied on the basis of elastic-inelastic-plastic buckling (EIP) modes and flexural/shear/flexural-shear failure mechanisms (FSF-S), which has been designed for the improvement of the behavior of concentrically braced frames. Steel plate-based dampers offer significant benefits in terms of mode shapes and failure mechanisms, contributing to improved dynamic performance, enhanced structural resilience, and increased safety of civil engineering structures. Their effectiveness in mitigating dynamic loads makes them a valuable tool for engineers designing structures to withstand extreme environmental conditions and seismic events. This study was undertaken by using the learning abilities of the response surface methodology (RSM), artificial neural network (ANN) and the evolutionary polynomial regression (EPR). Steel plate dampers are special structural designs used to withstand the effect of special loading conditions especially seismic effects. Its design based on the prediction of its stiffness (K) and slenderness factor (λ) cannot be overlooked in the present-day artificial intelligence technology. In this research work, thirty-three entries based on the steel plate damper geometrical properties were recorded and deployed for the intelligent forecast of the fundamental properties (λ and K). Design ratios of the steel plate damper properties were considered and models behavior was recorded. From the outcome of the model, it can be observed that even though the EPR and ANN in that order outclassed the other techniques, the RSM produced model minimization and maximization features of the desirability levels, color factor scales and 3D surface observation, which shows the real model behaviors. Overall, the EPR with R2 of 0.999 and 1.000 for the λ and K, respectively showed to be the decisive model but the RSM has features that can be beneficial to the structural design of the studied steel plate damper for a more robust and sustainable construction. With these performances recorded in this exercise, the techniques have shown their potential to be applied in the prediction of steel damper stiffness with optimized characteristic features to withstand structural stresses.

Strengthening Cracked Steel Plates with Shape Memory Alloy Patches: Numerical and Experimental Investigations.

To investigate the retarding effect of bonding the shape memory alloy (SMA) patches on crack propagation in steel plates, both numerical and experimental analyses were conducted in the present study. A compact tension (CT) model was developed to clarify the feasibility of bonding the SMA patch to the reinforcement of the mode Ⅰ, mode Ⅱ, and mode Ⅲ cracks. On this basis, parametric analysis was conducted to investigate the strengthening parameters, i.e., the bonding area, the thickness, and the strengthening angle of the SMA patch. Subsequently, fatigue tests on the unreinforced steel plate and cracked steel plate strengthened by the SMA patches were conducted. The monitored stress variation, crack propagation behavior, and fatigue fracture surfaces were analyzed. Findings are meaningful to the application of the SMA reinforcement method in practical engineering.

Repairing Behaviors of Cracked Steel Plates Based on Bolted Fiber-Reinforced Polymer Plates.

The use of FRP materials to repair cracked/damaged steel structures has gradually been adopted by researchers. This paper investigates the repairing effect of bolted FRP plates for cracked steel plates based on experimental and numerical simulation methods. In the experimental investigation, the tensile strengths of six specimens, including three repaired specimens and three pure cracked steel specimens, were evaluated. The test outcomes indicated that the bolt repairing method significantly enhanced the tensile strengths of the cracked steel plates. As an example, the failure of a pure steel plate with a 1 mm width crack occurred at 813 N, whereas after being repaired, a tensile strength of 1298 N was observed. Based on finite element (FE) analysis, the influence of bolt preloads and interfacial friction coefficients were verified. The stress-relative ratio for specimens was contingent on the bolt preload magnitude and gradually decreased as the preload was augmented. By exploring the repairing effect for varied friction coefficients, it was concluded that using a higher bolt preload can aid in eliminating the performance discrepancy of the overall component caused by interface treatment errors.

[Effect of lag screw and support plate through axillary approach for the treatment of Ideberg typeâ ¡scapular pelvis fracture].

OBJECTIVE: To analyze the effect of lag screw and support plate through axillary approach for the treatment of Ideberg typeⅡscapular pelvis fracture. METHODS: From January 2016 to June 2021, 26 patients with Ideberg typeⅡglenoid fractures were treated with trans-axillary lag screw combined with supporting plate, including 15 males and 11 females. The age ranged from 21 to 75 years, with an average of (43.12±6.56) years old. The Constant-Murley Shoulder joint Scale and University of California at Los Angeles (UCLA) score were used to evaluate the function and clinical efficacy of shoulder joint. RESULTS: All patients were followed up, and the duration ranged from 19 to 42 months, with an average of (30.6±10.5) months. One year after surgery, the Constant-Murley score increased from preoperative 34.9±2.5(ranged, from 28 to 47) to 87.2±6.8(ranged, from 70 to 95). The UCLA score improved from preoperative 17.9±1.7(9 to 25) to 33.1±2.3(29 to 35). Seventeen patients got an excellent result, with 7 good, and 2 fair. None of the patients had infection, screw, and plate loosening, fracture, and other complications after surgery. Two patients had different degrees of Chronic pain in the shoulder during the follow-up period. CONCLUSION: The treatment of Ideberg typeⅡscapular glenoid fractures through axillary approach with lag screws and supporting steel plates has the advantages of convenient exposure, direct visual restoration of the normal anatomical shape of the scapular glenoid, selection of suitable positions for screw and steel plate placement, achieving better treatment results, and fewer complications. It is an effective and reliable surgical method.

Verification of Reinforced Surface Loose Layer of Zinc-Aluminum-Magnesium Steel Plate.

The corrosion resistance of zinc-aluminum-magnesium steel plates (Zn-Al-Mg steel plates) is significantly higher than that of galvanized steel plates. However, the unsatisfactory bonding performance of Zn-Al-Mg steel plates significantly limits their widespread application. In this study, X-ray photoelectron spectroscopy is employed to detect changes in the surface oxygen content of Zn-Al-Mg steel plates after different temperature treatments to confirm the existence of surface loose layers. In particular, changes in the surface oxygen content of the Zn-Al-Mg steel plates after the oxide layer is removed are investigated under saturated H2O vapor and O2 environmental conditions, and the cause of the formation of loose surface layers is determined. The uneven distribution of elements on the surface of the Zn-Al-Mg steel plates is investigated with scanning electron microscopy and energy dispersive spectroscopy. Nuclear magnetic resonance is employed to determine the size of the network spatial structure formed by silane coupling agents under different hydrolysis conditions and to further investigate the bonding performance of hydrolysate-modified Zn-Al-Mg steel plates. Several typical automotive adhesives are utilized to compare and examine the changes in the tensile strength of the Zn-Al-Mg steel plate bonding before and after modification with the silane coupling agent and analyze the structural damage of the adhesive at the bonding interface. The results confirm that the silane coupling agent strengthens the loose layer on the surface of the Zn-Al-Mg steel plate.

[Modified application of interface screw in femoral side during anterior cruciate ligament reconstruction].

OBJECTIVE: To compare clinical effects of the improved interface screw fixation of femoral end of anterior cruciate ligament with classic femoral lateral loop plate fixation. METHODS: A retrospective analysis of 65 patients who underwent arthroscopic anterior cruciate ligament reconstruction from January 2019 to September 2021 were performed. According to the different fixation methods of the femoral side, 35 patients were divided into loop plate fixation(loop plate group), including 27 males and 8 females, aged from 18 to 50 years old with an average of (35.00±7.60) years old;30 patients in interface screw fixation(interface screw group), including 20 males and 10 females, aged from 18 to 50 years old with an average of (32.00±8.50) years old. Hospital stay, hospital expenses, operation time, complications, C-reactive protein at 1, 3, 6 days after operation, and postoperative Lysholm score and International Knee Documentation Committee(IKDC) score at 18 months were compared between two groups. RESULTS: All patients were successfully operated, and obtained follow-up from 18 to 36 months with an average of (25.16±4.50) months. Anterior drawer test and Lachman test of all patients turned to negative. There were no statistical differences in hospital stay, hospital expenses and complications between two groups(P>0.05);operation time in loop plate group was (74.00±6.84) min, and (91.67±6.34) min in interface screw group, and had difference between two groups(P<0.05). C-reactive protein on the 1st and 3rd day after operation was (40.00±10.10), (20.00±8.23) mg·L-1 in loop plate group, and (60.00±8.93), (30.00±8.66) mg·L-1 in interface nail group, had statistical difference between two groups (P<0.05);while there was no difference in C-reactive protein on the 6th day after operation(P>0.05). At 18 months after operation, Lysholm and IKDC scores showed no significant difference between two groups (P>0.05). In loop plate group, medullary enlargement on coronal and sagittal views were (2.75±0.19) mm, (1.55±0.25) mm, and (2.81±0.22) mm, (1.61±0.20) mm in interface screw group, and had statistical difference between two groups(P<0.05). CONCLUSION: In the reconstruction of anterior cruciate ligament, the common interface screw on the femoral side is changed to the sheath interface screw, and intramedullary screw is changed to the compression and fixation of tendon from outside to inside of joint. Although the operation procedure is relatively complicated and operation time is slightly longer, it has advantages of no residual metal foreign body after operation, and clinical effect is no different from classical loop plate suspension fixation, which is still a good choice.

Effect of Local Laser Treatment on the Strengthening of Thin-Walled Structures Fabricated from Non-Alloy Steel.

This paper describes the development of new metal-processing technologies that enable the control and improvement of the microstructure and properties of metals. This study investigates the impact of one such technology, laser treatment, on the surface of a thin sheet of non-alloy structural steel. This research aims to address a crucial challenge in expanding the industrial applications of thin-sheet steel products by developing a laser processing technology to create structural strengthening ribs, which can significantly influence the overall strength and stiffness of metal components.

Effect analysis of medial bracing plate combined with cannulated screw in unstable femoral neck fracture assisted by surgical hip dislocation: a retrospective study.

BACKGROUND: Unstable femoral neck fractures have a high likelihood of causing severe disruption to the blood supply. This study aimed to assess the therapeutic effect of surgical hip dislocation using a medial support plate combined with cannulated screw fixation for the treatment of unstable femoral neck fractures in young and middle-aged adults. METHODS: We retrospectively analyzed the medical records of 68 young adults who underwent internal fixation of unstable femoral neck fractures. The observation group included 32 patients who had received medial support plate and cannulated screw fixation by the surgical hip dislocation method and 36 patients who had undergone anti-rotation screw composite compression system fixation comprised the comparison group. The amount of intraoperative bleeding, surgery duration, fracture recovery time and complications were recorded. The degree of femoral neck shortening and Garden index were assessed using the Zlowodzki method. Additionally, hip functionality was evaluated using the Harris score at 3 and 6 months and at the last follow-up. RESULTS: All 68 patients in both groups were followed up for 12-42 months (mean, 22.4 months). The postoperative incision was well-aligned and no inflation was observed. The intraoperative blood loss and surgery duration in the comparison group were longer than those in the observation. Additionally, the observation group had a significantly shorter fracture recovery time and a higher Garden index than the comparison at 6 months postoperatively; however, there was no significant statistical discrepancy between the two groups at the remaining time points. The observation group had higher Harris scores than the comparison at 3 and 6 months postoperatively. CONCLUSION: Surgical hip dislocation applied to the medial support plate combined with cannulated screw fixation has clinical application value in restoring the stability of femoral neck fractures while facilitating the maintenance of blood flow to the femoral head and neck.

Numerical Investigation of Longitudinal through Voids in Tunnel Secondary Lining Vaults and Steel Plate Strengthening.

This study investigates the influence of longitudinal through voids on vault lining. Firstly, a loading test was carried out on a local void model, and the CDP model was used for numerical verification. It was found that the damage to the lining caused by a longitudinal through void was primarily located at the void boundary. On the basis of these findings, an overall model of the vault's through void was established using the CDP model. The effects of the void on the circumferential stress, vertical deformation, axial force, and bending moment of the lining surface were analyzed, and the damage characteristics of the vault's through void lining were studied. The results indicated that the through void of the vault caused circumferential tensile stress on the lining surface of the void boundary, while the compressive stress of the vault increased significantly, resulting in a relatively uplifted vault. Furthermore, the axial force within the void range decreased, and the local positive bending moment at the void boundary increased significantly. The impact of the void increased gradually with the height of the void. If the height of the longitudinal through void is large, the inner surface of the lining at the void boundary will crack longitudinally, and the vault will be at risk of falling blocks or even being crushed.

[Efficacy of micro steel plate and Kirschner needle oblique and transverse internal fixation of adjacent metacarpal bone in the treatment of metacarpal diaphyseal oblique fracture].

OBJECTIVE: To compare the clinical efficacy of micro steel plate and Kirschner needle oblique and transverse internal fixation of adjacent metacarpal bone in the treatment of metacarpal diaphyseal oblique fracture. METHODS: Fifty-nine patients with metacarpal diaphyseal oblique fractures admitted between January 2018 and September 2021 were selected as the study subjects and divided into the observation group (29 cases) and the control group (30 cases) based on different internal fixation methods. The observation group was treated with Kirschner wire oblique and transverse internal fixation of adjacent metacarpal bones, while the control group was treated with micro steel plate internal fixation. Postoperative complications, operation time, incision length, fracture healing time, treatment cost, and metacarpophalangeal function were compared between the two groups. RESULTS: No incision or Kirschner wire infections occurred in the 59 patients, except for one in the observation group. No fixation loosening, rupture, or loss of fracture reduction occurred in any of the patients. The operation time and incision length in the observation group were (20.5±4.2) min and (1.6±0.2) cm, respectively, which were significantly shorter than those in the control group (30.8±5.6) min and (4.3±0.8) cm (P<0.05). The treatment cost and fracture healing time in the observation group were (3 804.5±300.8) yuan and (7.2±1.1) weeks, respectively, which were significantly lower than those in the control group (9 906.9±860.6) yuan and (9.3±1.7) weeks (P<0.05). The excellent and good rate of metacarpophalangeal joint function in the observation group was significantly higher than that in the control group at 1, 2, and 3 months after operation (P<0.05), but there was no significant difference between the two groups at 6 months after operation (P>0.05). CONCLUSION: Micro steel plate internal fixation and Kirschner wire oblique and transverse internal fixation of adjacent metacarpal bones are both viable surgical methods for treating metacarpal diaphyseal oblique fractures. However, the latter has the advantages of causing less surgical trauma, shorter operation time, better fracture healing, lower cost of fixation materials, and no need for secondary incision and removal of internal fixation.

Comparison of the clinical efficacy of three internal fixation methods in the treatment of Edinburgh type IB fractures of the proximal clavicle.

Clavicle fractures are one of the most common fractures and usually occur in the medial third of the clavicle. The study explored the efficacy of three internal fixation methods to treat Edinburgh IB fractures of the proximal clavicle. 68 patients with Edinburgh IB fractures of the proximal clavicle were divided into T-shaped plate group, double-miniature steel plate group and memory alloy embracing device group. Postoperative complications, return time to work, and fracture healing time were recorded. The clinical efficacy was evaluated by Constant-Murley score of shoulder joint, Visual Analogue Scale (VAS) score of pain, and arm-shoulder-hand dysfunction score. The operative time of the memory alloy embracing device group was significantly better than T-shaped plate group and double-miniature steel plate group. The length of surgical incision in the double-miniature steel plate group was significantly shorter than that in the T-shaped plate group and the memory alloy embracing device group. The hospitalization cost and recovery time of the double-plate and memory alloy hug groups were lower than those of the T-plate group. The double-miniature steel plate group and the memory alloy embracing device group were significantly better than the T-shaped plate group at two weeks after operation. Satisfactory clinical results can be obtained by using T-shaped plate, double-miniature steel plate and memory alloy embracing device in the treatment of Edinburgh IB fracture of proximal clavicle. However, the double-miniature steel plate group has the advantages of small incision, low cost, and quick postoperative recovery, and has more early advantages.

The Damage to Thick Steel Plates by Local Contact Explosions.

The paper presents the damage results of thick steel plates subjected to local blast loading using experimental and numerical approaches. Three steel plates with a thickness of 17 mm under the local contact explosion of trinitrotoluene (TNT) explosives were tested, and the damaged parts of the steel plates were scanned using a scanning electron microscope (SEM). ANSYS LS-DYNA software was used to simulate the damage results of the steel plate. By analyzing and comparing the experimental results with the numerical simulation results, the influence law of the TNT acting on the steel plate, the damage mode of the steel plate, the reliability verification of the numerical simulation, and the criterion for judging the damage mode of the steel plate were obtained. Results show that the damage mode of the steel plate changes with the changes in the explosive charge. The diameter of the crater on the surface of the steel plate is mainly related to the diameter of the contact surface between the explosive and the steel plate. The fracture mode of the steel plate in the process of generating cracks is a quasi-cleavage fracture, and the process of generating craters and perforations in the steel plate is a ductile fracture. The damage mode of the steel plates can be divided into three types. The numerical simulation results have minor errors and high reliability, and numerical simulation can be used as an auxiliary tool for experiments. A new criterion is proposed to predict the damage mode of the steel plates under contact explosion.

Effect of Microstructural Evolution on the Mechanical Properties of Ni-Cr-Mo Ultra-Heavy Steel Plate.

In this study, microstructural evolution and its effects on mechanical properties across the thickness of a 120 mm Ni-Cr-Mo industrial ultra-heavy steel plate were quantitatively investigated by means of optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) and electron back-scatter diffraction (EBSD). The results show that the martensite fraction is 65% at 10 mm and disappears at 40 mm, while granular bainite appears at 35 mm and climbs up to as high as 32% at 60 mm, with M-A constituents significantly coarsened. The strength drops with the gradual coarsening of the laths as well as decreased martensite fraction from the surface to the centre. The toughness is mainly affected by the block size and the morphology and quantity of M-A constituents. This study established a multivariate function between the microstructure and toughness (50% fibre area transition temperature, FATT50) with careful consideration of the influence of effective grain size (EGS) and M-A constituent size distribution.

Temperature Field and Stress Analysis of the Heavy-Concrete Transfer-Purge Chamber of the Nuclear Power Plant.

A transfer-purge chamber (TPC) is a double-steel-plate, heavy-concrete, curved-surface composite structure composed of steel plates, heavy concrete, and shear connectors. It is an important facility in the external refueling system of a nuclear power plant (NPP), providing a safe and reliable biological shielding space for reactor refueling operations. Temperature load is one of the most important factors that must be considered in the design of NPP structures. The temperature loads experienced by the TPC during its life cycle include those encountered in both normal and abnormal operation, which are distinct. In this study, we investigated the steady state and transient-state temperature fields and stresses of a TPC structure under normal operation and after 48 h of abnormal operation, respectively, which were calculated using Abaqus finite element software and the directly coupled method. During normal operation, the temperature field of the structure shows relatively uniform changes, and the temperature gradient of the internal concrete in the direction of its thickness has a constant value of 0.245 °C/cm. At the junction between the transfer and purge sub-chambers of the TPC, under the influence of wall curvature and deformation constraints, the maximum tensile strain of heavy concrete is 8.84 × 10-3, the maximum compressive strain is 2.04 × 10-3, the peak stress of the steel plate is 98.305 MPa, and the peak stress of the stud is 306.725 MPa. After 48 h of abnormal operation, the temperatures of the inner surface of the heavy concrete of the wall, the inner steel plate of the wall, the outer surface of the heavy concrete of the wall, and the inner steel plate of the wall increased by 8.12, 8.11, 0.31, and 0.30 °C, respectively. The tensile strain of the heavy concrete of the wall increased significantly by 52.64%, and the compressive strain of the concrete increased by 67.33%, whereas the stresses of the studs and steel plates increased by only 1.57% and 6.79%, respectively. These results show that the change in the temperature field greatly influences the stress and strain on the TPC structure. As measures for mitigating the development of this unfavorable situation of temperature stress concentration, the temperature operating range should be rationally controlled or the junction structure between the transfer and purge sub-chambers of the TPC optimized accordingly. The results of our study can provide basic data for a dynamic analysis of the TPC under conditions of combined earthquake and temperature loads.

Numerical Investigation on the Mechanical Properties of Vault Void Lining and Steel Plate Strengthening.

To study the mechanism of vault lining under different void heights and verify the strengthening effect of the attached steel plate, a CDP (concrete-damaged plasticity) model and the XFEM (extended finite element method) were used to construct the local numerical model of the vault void, and an experiment was carried out for verification. The strengthened structure of the steel plate was assembled with a combination of a two-component epoxy adhesive and chemical anchor bolts. Five lining models with various void thicknesses, together with their strengthened models, were evaluated. The results of the established numerical model were compared with the experimental results in terms of failure mode, vertical displacement, and load-deformation results. The results of the two numerical models were in good agreement with the experimental results, revealing the failure mechanism of the vault lining. The rigidity of the specimen after steel plate strengthening was significantly improved. When the void height was one-fourth of the secondary lining thickness, the lining cracks were reduced from 14 to 4, and the distribution width of the cracks was also reduced from 1.047 to 0.091 m after steel plate strengthening. The level of damage caused by cracking was significantly reduced, which proves the effectiveness of the surface-sticking method for steel plate strengthening.

Treatment with a proximal femoral locking plate versus a proximal femoral anti-rotation intramedullary nail for femoral intertrochanteric fractures in older adult patients / 中国基层医药

Objective:To investigate the efficacy of a proximal femoral locking plate (LPFP) versus a proximal femoral anti-rotation intramedullary nail (PFNA) in the treatment of femoral intertrochanteric fractures in older adult patients. Methods:A total of 130 older adult patients with femoral intertrochanteric fractures who received treatment in Linghu People's Hospital of Huzhou from May 2017 to June 2020 were included in this study. They were randomly assigned to undergo treatment with either a PFNA (observation group, n = 65) or an LPFP (control group, n = 65). Intraoperative blood loss, incision length, operative time, and time to fracture healing were determined in each group. At 1, 3, and 6 months after surgery, the Harris hip score was used to evaluate hip joint recovery. Coxa vara, incision infection, and internal fixation loosening were compared between the two groups. Results:Intraoperative blood loss in the observation group was less than that in the control group [(189.26 ± 48.15) mL vs. (96.47 ± 40.21) mL, t = -11.93, P < 0.001]. Incision length, operative time, and time to fracture healing in the observation group were significantly shorter than those in the control group [(4.03 ± 1.48) cm vs. (12.16 ± 1.55) cm, (72.13 ± 28.75) minutes vs. (120.34 ± 29.01) minutes, (9.89 ± 1.52) weeks vs. (13.63 ± 1.74) weeks, t = -30.59, -9.52, -13.05, all P < 0.001]. At 1 month after surgery, there was no significant difference in Harris hip score between the two groups ( t = 1.28, P > 0.05). At 3 and 6 months after surgery, the Harris hip score gradually increased in the control and observation groups ( F = 13.44, 8.26, both P < 0.001). At 3 and 6 months after surgery, Harris hip scores in the observation group were significantly higher than those in the control group [(85.17 ± 4.29) points vs. (79.50 ± 4.12) points, (95.30 ± 1.04) points vs. (87.69 ± 1.25) points, t = 7.69, 37.73, both P < 0.001]. The incidence of complications in the observation group was significantly lower than that in the control group [1.54% (1/65) vs. 10.77% (7/65), χ2 = 4.80, P = 0.029). Conclusion:Compared with LPFP, PFNA can effectively reduce intraoperative blood loss in older adult patients with femoral intertrochanteric fractures, accelerate the progress of fracture healing, promote the recovery of the hip joint, and has fewer complications. Therefore, PFNA is worthy of popularization.

Efficacy of micro steel plate and Kirschner needle oblique and transverse internal fixation of adjacent metacarpal bone in the treatment of metacarpal diaphyseal oblique fracture / 中国骨伤

OBJECTIVE@#To compare the clinical efficacy of micro steel plate and Kirschner needle oblique and transverse internal fixation of adjacent metacarpal bone in the treatment of metacarpal diaphyseal oblique fracture.@*METHODS@#Fifty-nine patients with metacarpal diaphyseal oblique fractures admitted between January 2018 and September 2021 were selected as the study subjects and divided into the observation group (29 cases) and the control group (30 cases) based on different internal fixation methods. The observation group was treated with Kirschner wire oblique and transverse internal fixation of adjacent metacarpal bones, while the control group was treated with micro steel plate internal fixation. Postoperative complications, operation time, incision length, fracture healing time, treatment cost, and metacarpophalangeal function were compared between the two groups.@*RESULTS@#No incision or Kirschner wire infections occurred in the 59 patients, except for one in the observation group. No fixation loosening, rupture, or loss of fracture reduction occurred in any of the patients. The operation time and incision length in the observation group were (20.5±4.2) min and (1.6±0.2) cm, respectively, which were significantly shorter than those in the control group (30.8±5.6) min and (4.3±0.8) cm (P<0.05). The treatment cost and fracture healing time in the observation group were (3 804.5±300.8) yuan and (7.2±1.1) weeks, respectively, which were significantly lower than those in the control group (9 906.9±860.6) yuan and (9.3±1.7) weeks (P<0.05). The excellent and good rate of metacarpophalangeal joint function in the observation group was significantly higher than that in the control group at 1, 2, and 3 months after operation (P<0.05), but there was no significant difference between the two groups at 6 months after operation (P>0.05).@*CONCLUSION@#Micro steel plate internal fixation and Kirschner wire oblique and transverse internal fixation of adjacent metacarpal bones are both viable surgical methods for treating metacarpal diaphyseal oblique fractures. However, the latter has the advantages of causing less surgical trauma, shorter operation time, better fracture healing, lower cost of fixation materials, and no need for secondary incision and removal of internal fixation.

Effect of lag screw and support plate through axillary approach for the treatment of Ideberg typeⅡscapular pelvis fracture / 中国骨伤

OBJECTIVE@#To analyze the effect of lag screw and support plate through axillary approach for the treatment of Ideberg typeⅡscapular pelvis fracture.@*METHODS@#From January 2016 to June 2021, 26 patients with Ideberg typeⅡglenoid fractures were treated with trans-axillary lag screw combined with supporting plate, including 15 males and 11 females. The age ranged from 21 to 75 years, with an average of (43.12±6.56) years old. The Constant-Murley Shoulder joint Scale and University of California at Los Angeles (UCLA) score were used to evaluate the function and clinical efficacy of shoulder joint.@*RESULTS@#All patients were followed up, and the duration ranged from 19 to 42 months, with an average of (30.6±10.5) months. One year after surgery, the Constant-Murley score increased from preoperative 34.9±2.5(ranged, from 28 to 47) to 87.2±6.8(ranged, from 70 to 95). The UCLA score improved from preoperative 17.9±1.7(9 to 25) to 33.1±2.3(29 to 35). Seventeen patients got an excellent result, with 7 good, and 2 fair. None of the patients had infection, screw, and plate loosening, fracture, and other complications after surgery. Two patients had different degrees of Chronic pain in the shoulder during the follow-up period.@*CONCLUSION@#The treatment of Ideberg typeⅡscapular glenoid fractures through axillary approach with lag screws and supporting steel plates has the advantages of convenient exposure, direct visual restoration of the normal anatomical shape of the scapular glenoid, selection of suitable positions for screw and steel plate placement, achieving better treatment results, and fewer complications. It is an effective and reliable surgical method.