Microstructure and mechanical properties of stationary shoulder friction stir welding joint of 2A14-T62 aluminum alloy

2A14-T62 butt joint was successfully welded by stationary shoulder friction stir welding(SSFSW)method.The results showed that using a pin with small shoulder could broaden the process window,and under a rotation speed of 2000 r/min and welding speed of 30 mm/min,joint with smooth surface,small reduction in thickness and little inner defects was obtained.The weld nugget zone was approx-imately circular,which was a unique morphology for SSFSW.The heat-affected zone(HAZ)and thermo-mechanically affected zone(TMAZ)were both quite narrow due to the lower heat input and slight mechanical action of the stationary shoulder.The fraction of high angle grain boundaries(HAGBs)exhibited a“W”shape along horizontal direction(from advancing side to retreating side),and the minim-um value located at HAZ.The average ultimate tensile strength and elongation of the joint were 325 MPa and 4.5%,respectively,with the joint efficiency of 68.3%.The joint was ductile fractured and the fracture surface contained two types of dimples morphology in different re-gions of the joint.Microhardness distribution in the joint exhibited a“W”shape,and the difference along the thickness direction was negli-gible.The joint had strong stress corrosion cracking susceptibility,and the slow stain rate tensile strength was 139 MPa.Microcrack and Al2O3 particulates were observed at the fracture surface.

Pulmonary embolism after shoulder surgery:Is it a real threat?

Pulmonary embolism(PE)is a rare but devastating complication of shoulder surgery.Apart from increased morbidity and mortality rates,it may significantly impair postoperative recovery and functional outcome.Its frequency accounts for up to 5.7%of all shoulder surgery procedures with a higher occurrence in women and patients older than 70 years.It is most commonly associated with thrombophilia,diabetes mellitus,obesity,smoking,hypertension,and a history of malignancy.PE usually occurs secondary to upper or lower-extremity deep vein thrombosis(DVT).However,in rare cases,the source of the thrombi cannot be determined.Prophylaxis for PE following shoulder surgery remains a topic of debate,and the standard of care does not routinely require prophylactic medication for DVT prophylaxis.Early ambulation and elastic stockings are important preventative measures for DVT of the lower extremity and medical agents such as aspirin,low-molecular-weight heparin,and vitamin K antagonists are indicated for high-risk patients,long-lasting operations,or concomitant severe acute respiratory syndrome coronavirus 2 infection.The most common symptoms of PE include chest pain and shortness of breath,but PE can also be asymptomatic in patients with intrinsic tolerance of hypoxia.Patients with DVT may also present with swelling and pain of the respective extremity.The treatment of PE includes inpatient or outpatient anticoagulant therapy if the patient is hemodynamically unstable or stable,respectively.Hemodynamic instability may require transfer to the intensive care unit,and cardiovascular arrest can be implicated in fatal events.An important issue for patients with PE in the postoperative period after shoulder surgery is residual stiffness due to a delay in rehabilitation and a prolonged hospital stay.Early physiotherapy and range-of-motion exercises do not adversely affect the prognosis of PE and are highly recommended to preserve shoulder mobility and function.

CLINICAL REPORT ON IMPROVEMENT OF MOBILITY OF AFFECTED SHOULDER JOINT CAUSED BY ACUTE CEREBRAL INFARCTION TREAT-ED WITH ACUPUNCTURE AND MASSAGE

Objective To observe the effects of acupuncture and massage to improve the mobility of affected shoulder joint caused by acute cerebral infarction. Methods 120 cases of acute cerebral infarction were randomized into two groups, named treatment group with acupuncture and massage and control group with western medicine. Acupoint selection of treatment group with acupuncture and massage： Yōngquán （涌泉 KI1）, Láogōng （劳宫 PC8）, Hòuxī （后溪SI3）, Gōngsūn （公孙 SP4）, Fēngchī （风池 GB20）, Jiānyú （肩髃 LI15）, Qūchí （曲池 LI11）, Hégǔ （合谷 LI4）, Huántiào （环跳 GB30）, Zúsānlǐ （足三里 ST36）, Tàichōng （太冲 LR3）, Anterior Oblique Line of Vertex-Temporal and Posterior Oblique Line of Vertex-Temporal. Massage techniques： roll for relax, hold and press, flick and fiddle, and shake. Control group with western medicine was treated with mannitol ＋ low molecular weight dextran ＋ CDP-choline. Results Compared with control group, treatment group could apparently improve the mobility of shoulder joint and lower the injury percentage （P〈0. 01） ; and the therapeutic effect of treatment group is better than that of control group （P〈0. 05） for treating acute cerebral infarction. Conclusion The therapy of acupuncture combined with massage could improve the function of the affected shoulder joint caused by acute cerebral infarction, and enhance therapeutic effect.

Therapeutic efficacy of acupuncture combined with neuromuscular joint facilitation in treatment of hemiplegic shoulder pain

BACKGROUND Stroke is a type of cerebrovascular disease with high prevalence,mortality,and onset of disability.As a neurodevelopmental therapy,neuromuscular joint facilitation(NJF)is widely used in the treatment of orthopedic and neurological disorders in the clinical practice.It is mainly used for central nervous system diseases or orthopedic diseases,movement disorders,and pain rehabilitation.According to related studies,NJF can also be used as a rehabilitation treatment in patients with hemiplegic shoulder pain(HSP).AIM To investigate the clinical efficacy of acupuncture combined with NJF in patients with HSP.METHODS Forty patients with HSP were randomly divided into a treatment group and a control group.The treatment group was treated with acupuncture combined with NJF and the control group was treated with acupuncture alone.All patients were assessed by using the visual analogue scale(VAS),Fugl-Meyer assessment(FMA),Barthel index(BI),and passive range of motion(PROM)before and after the training.All the clinical data were analyzed using SPSS 20.0 statistical software.RESULTS There was no statistical difference in the general characteristics between the two groups.In the terms of duration of treatment,age,and pre-treatment indicators,the two groups were comparable(P>0.05).After the treatment,VAS,PROM,BI,and FMA scores were significantly improved in the two groups of patients(P<0.05).The VAS,PROM and FMA scores were significantly higher in the treatment group than in the control group(P<0.05).However,there was no significant difference in BI scores between the two groups(P>0.05).CONCLUSION Both acupuncture alone and acupuncture combined with NJF in the treatment of HSP are effective,and can improve the clinical symptoms of patients.Acupuncture combined with NJF can improve the upper limb motor function,relieve pain,and increase joint mobility in patients with HSP.The combination therapy is better than acupuncture alone.However,there is no significant difference in improving the score of patients’self-care ability.

Accuracy of shoulder joint injections with ultrasound guidance:Confirmed by magnetic resonance arthrography

BACKGROUND Intra-articular glenohumeral joint injections are essential procedures for treating various shoulder disorders. Fluoroscopy-guided injections have been extensively used;however, they pose a risk of radiation exposure and are expensive and timeconsuming. Recently, it has been suggested that ultrasound-guided injections are accurate and cost effective procedures.AIM To evaluate the accuracy of ultrasound-guided glenohumeral injections using a posterior approach that is confirmed using magnetic resonance arthrography(MRA).METHODS The study included 179 shoulders of patients with recurrent anterior instability(150 patients;103 and 76 right and left shoulders, respectively;160 males and 19 females;average age = 20.5 years;age range: 14-63 years) who underwent MRA for preoperative diagnosis. They were injected with 12 m L lidocaine(1%) using the ultrasound-guided posterior approach and then underwent magnetic resonance imaging. Two shoulder surgeons, except for the injector, evaluated the transverse relaxation(T2)-weighted images of axial planes and classified the intraarticular condition of injected contrast into three groups based on one of the three following scenarios: no leakage, injection into the glenohumeral joint without leakage;minor leakage, practical intra-articular injection with some leakage outside the posterior rotator cuffs;and major leakage, inaccurate injection with mass leakage without any contrast into the joint. The inter-rater reliability between two assessors was also evaluated by calculating Cohen’s kappa coefficient. The learning curve was assessed regarding the inaccurate injection rate by analyzing Spearman’s rank correlation coefficient.RESULTS Of the 179 injections, 163 shoulders(91.0%) had no leakage, 10 shoulders(5.6%) had minor leakage, and six shoulders(3.4%) had major leakage. In total, 173 shoulders(96.6%) were intraarticularly injected;thus, we could detect anterior labrum and capsular pathologies. Regarding the inter-rater reliability, the kappa coefficient was 0.925, indicating consistency in the evaluations by both examiners. Regression analysis of the inaccurate injection rate for assessingtechnical learning showed a logarithmic curve with a downward trend(R;= 0.887, P < 0.001). Three(50%) of the six inaccurate injections classified into “major leakage” were observed in the first 30 injections, indicating that the accurate injection showed a leaning effect.CONCLUSION Ultrasound-guided intra-articular glenohumeral injections using a posterior approach had high accuracy;however, injection accuracy depends on clinical experience.

Restoration of the joint geometry and outcome after stemless TESS shoulder arthroplasty

AIM To evaluate the joint geometry and the clinical outcome of stemless, anatomical shoulder arthroplasty with the TESS system.METHODS Twenty-one shoulders with a mean follow-up 18 of months were included. On scaled digital radiographs the premorbid center of rotation(CoR) was assessed and compared to the CoR of the prosthesis by using the MediC AD~? software. Additionally, the pre-and post-operative geometry of the CoR was assessed in relation to the glenoid, the acromion as well as to the proximal humerus. Radiological changes, such as radiolucencies, were also assessed. Clinical outcome was assessed with the Constant and DASH score. RESULTS Both, the Constant and DASH scores improved signifi-cantly from 11% to 75% and from 70 to 30 points, P < 0.01 respectively. There were no significant differences regarding age, etiology, cemented or metal-backed glenoids, etc.(P > 0.05). The pre-and postoperative humeral offset, the lateral glenohumeral offset, the height of the CoR, the acromiohumeral distance as well as neckshaft angle showed no significant changes(P > 0.05). The mean deviation of the CoR of the prosthesis from the anatomic center was 1.0 ± 2.8 mm. Three cases showed a medial deviation of more than 3 mm. These deviations of 5.1, 5.7 and 7.6 mm and were caused by an inaccurate humeral neck cut. These 3 patients showed a relatively poor outcome scoring.CONCLUSION TESS arthroplasty allows an anatomical joint reconstruction with a very good outcome. Outliers described in this study sensitize the surgeon for an accurate humeral neck cut.

Analysis of CT and MRI in the Diagnosis of Shoulder Joint Injury

Objective: To observe the effect of multi-slice spiral CT and magnetic resonance imaging (MRI) in the diagnosis of shoulder injury. Methods: 120 patients with shoulder injury who were treated in our hospital (January 2020 to December 2021) and underwent surgical treatment were diagnosed as shoulder injury. They were divided into CT group, MRI group and joint diagnosis group. The detection rates of the two methods were compared. Results: In the diagnosis of shoulder injury, MRI group was higher than CT group, and the joint diagnosis group was higher than the other two groups. Conclusion: In the diagnosis of shoulder injury, the joint examination of multi-slice spiral CT and magnetic resonance imaging (MRI) can obtain a higher diagnostic rate and ideal effect.

A Case of Septic Arthritis of the Shoulder Joint That Developed after Suprascapular Nerve Block

Septic arthritis of the shoulder is uncommon in the immunocompetent patient with no previous risk factors for joint infection. We treated an immunocompetent patient who developed septic arthritis of the shoulder after suprascapular nerve block for pain due to rotator cuff tear. An 80-year-old man with no underlying disease visited a nearby orthopedics clinic with complaint of left shoulder joint pain. Left suprascapular nerve block was performed, but the pain gradually aggravated. On the day after the block, he had a fever of 39&deg;C and came to our department. On examination, enlargement and tenderness were present at the injection site. Cellulitis at the site was suspected. He was admitted and administration of a cephem anti-biotic was started. Pain subsequently decreased. Magnetic resonance imaging (MRI) performed 4 days after hospitalization showed massive effusion close to the injection site. The effusion spread into the joint cavity through the tear site of the supraspinatus. Septic arthritis of the shoulder was strongly suspected, open irrigation and debridement were performed 11 days after hospitalization. After surgery, pain immediately improved. In our case the extra-articular infection caused by suprascapular nerve block considered to spread into the shoulder joint cavity through the site of rotator cuff tear, although there have been no reports of such cases. This case suggests the possibility that patients with rotator cuff tear may easily develop septic arthritis because extra-articular infection may spread into the joint cavity through the site of tear.

High Frequency Ultrasound in Determining the Causes of Acute Shoulder Joint Pain

Shoulder ultrasonography is approved as the examination of choice for rotator cuff abnormality in many centers around the world since it is an inexpensive and safe tool for investigation of rotator cuff abnormalities. The goal of this study was to determine the ultrasound findings in patients with acute shoulder joint pain, and also to identify possible predictors of shoulder pain, as well as to compare the ultrasound diagnostic performance to that of MRI in such condition. A total of 65 (mean age 28 ± 1.2 years) consequential patients were recruited for a period of six months between July 2015 and June 2016 in this study. Collected data were confined on age, medical history, and clinical symptoms. Shoulder ultrasound was performed with a linear array transducer (10 - 15 MHz) connected to HI vision Avius ultrasound unit;Hitachi. MRI for the shoulder joint was performed in all cases to confirm the ultrasound results, using 1.5-T MRI system (Magnetom Espree);Siemens. Statistical analysis was completed using the standard Statistical Package for the Social Sciences (SPSS Inc., Chicago, IL, USA) version 20 for windows. Ultrasound manages to determine the causes of acute shoulder joint pain in 98% of the patients. Fitted achievement values for shoulder ultrasound in the diagnosis the causes of shoulder joint pain were 100% sensitivity and a range of 96% to 100% of accuracy. Ultrasound presents a high sensitivity and accuracy in diagnosis a wide spectrum of shoulder joint lesions, with a diagnostic performance near to that of MRI.

Shoulder joint flexibility in top athletes

Joint range of motion (ROM) is very important in daily activities, sport and in clinical diagnosis. Many factors have been reported to influence joint ROM. Musculoskeletal adaptation and some special side effects due to his or her physical demands and movement patterns in professional athletes are very important subjects in sport sciences. The present study is a comparison of shoulder joint ROM in elite athlete and non-athlete groups and its relationship to their age, post and years of their tournament play. The subjects in this study included 106 men with mean age (23.65 &#177;3.45) and mean years of tournament play (5.60 &#177;2.23). The groups of subjects included 26 handball players, 25 volleyball players, 25 soccer players and 30 non-athletes. Data were collected through questionnaires and inspection, and subjects’ ROM was measured by “Leighton flex- ometer” (r = 0.90 – 0.99) in external rotation and abduction of shoulder joint in dominant and non-domi- nant hands. Data were analyzed by correlation coefficient, t – test, ANOVA and post hock Schaffe test. The results showed that an increase in age and years of tournament play reduced the shoulder ROM of subjects (p ≤ 0.05). There were significant differences in shoulder ROM among athletic groups. Additionally, there are significant differences between dominant and non-dominant hands (p ≤ 0.05). It can be concluded that more specific stretching exercises and warm-up for shoulder in all athletes and especially in older and experienced players should be performed by coaches. The results also emphasized routine screening, corrective exercise programs and a design of preventing strategies by athletic trainers and coaches.

Effects of bridge combined internal fixation system internal fixation on fracture healing and shoulder joint function in elderly patients with displaced midshaft clavicle fractures

Objective:To compare the clinical therapeutic effect of bridge combined internal fixation system and locking compression plate internal fixation in the treatment of displaced midshaft clavicle fractures by emphatically observing fracture healing and shoulder joint function.Methods:Totally 44 elderly patients with Robinson type 2B displaced midshaft clavicle fractures were included from the Department of Orthopaedics,Shenyang Fourth People's Hospital during February 2016 and December 2018,including 23 males and 21 females,mean age(69.8±10.2)years old.The patients were divided into a bridge combined internal fixation system group(bridge group,n=22)and a locking compression plate internal fixation group(plate group,n=22)according to the internal fixation methods.The operation time,intraoperative blood loss,fracture healing time,and postoperative complications were recorded.At 12 months after surgery,the shoulder joint Constant-Murley score and DASH score were used to assess the recovery of joint function.The serum levels of bone turnover biochemical markers procollagen I N-terminal peptide(P1NP),cross-linked Carboxy-terminal telopeptide of typeⅠcollagen(CTX-I),and osteoblast specific factor(OSF)were measured before and 3 months after surgery.Results:The operation time,intraoperative blood loss and fracture healing time of the bridge group were significantly shorter than those of the plate group(P<0.05).Constant scores and DASH scores in the bridge group were significantly better than those of the plate group at 12 months after surgery(P<0.05).Serum levels of CTX-I was significantly decreased,while the P1NP and OSF were significantly increased compared with before surgery in the both groups(P<0.05),and the changes were more obvious in the bridge group(P<0.05).The incidence of complications was similar between the two groups(P<0.05).Conclusion:Compared with the locking plate system,the bridge combined internal fixation system can effectively improve the operation efficiency,have more benefits on fracture healing,better promote the recovery of patients'function,and reduce the failure rate of internal fixation,thus providing a better choice to treat displaced midshaft clavicle fractures by intraoperative internal fixation.

Follow-up effect and safety value of nano-carbon on shoulder joint after lymphatic chemotherapy for breast cancer

Objective:To investigate the effect and safety of nano-carbon on shoulder joint after lymphatic chemotherapy for breast cancer. Methods:164 patients Breast cancer patients, Sc group (docetaxel + CNP), Dd group (docetaxel), Sc group and Dd group were selected to observe shoulder joint function, docetaxel concentration in Sc group and Dd group after 12 h, 24 h, 36 h and 48 h injection of chemotherapy, apoptotic index of metastatic lymph nodes, apoptosis rate of lymph node cells, Sc group and Dd group were observed. The occurrence of adverse reactions. Results:The concentration of paclitaxel in the lymph nodes of the Sc group was significantly higher than that of the Dd group at 12h, 24h, 36, 48h. The concentration of paclitaxel was the highest in the group of 24h in the Sc group, and the lowest in the 48h group. 0.05);The AI index of the chemotherapy group was significantly higher than that of the Dd group at 12h, 24h, 36, 48h in the Sc group (P<0.05). The AI index of the AI index of the 36h injection chemotherapy group and the 48h injection chemotherapy group in the Sc group and the Dd group were compared. The difference was not significant (P>0.05). The apoptosis rate of lymphocytes in the group of 12h, 24h, 36th and 48h in the Sc group was significantly higher than that in the Dd group (P<0.05). The patients in the Sc group and the Dd group were injected with chemotherapy for 48 hours. There was no significant difference in lymph node cell apoptosis rate between the injection chemotherapy patients (P>0.05);the incidence of adverse reactions in the Dd group (15%) was higher than that in the Sc group (7.1%), but there was no difference (P>0.05);There was no significant difference in the function of shoulder joint function between the Dd group and the Dd group (P>0.05). The score of the shoulder joint function score in the Sc group was increased compared with the Dd group (P<0.05). Conclusions:Carbon nanoparticles are of high value and safety in the application of lymphatic chemotherapy to shoulder joint after breast cancer surgery, which is worthy of wide application in clinical treatment of breast cancer.

Effect of electroacupuncture combined with rehabilitation techniques on shoulder function in patients with rotator cuff injuries

BACKGROUND The rotator cuff is located below the acromion and deltoid muscles and comprises multiple tendons that wrap around the humeral head,maintaining shoulder joint stability.AIM To explore the effect of electroacupuncture combined with rehabilitation techniques on shoulder function in patients with rotator cuff injuries.METHODS We selected 97 patients with rotator cuff injuries treated in the People's Hospital of Yuhuan from February 2020 to May 2023.Patients were grouped using the envelope method.RESULTS After treatment,the study group’s treatment effective rate was 94.90%(46/49 patients),significantly higher than that in the control group(79.17%,38/48 cases;P<0.05).Before treatment,there was no difference in Constant Murley Score(CMS)scores,shoulder mobility,or 36-Item Short Form Health Survey(SF-36)scale scores(P>0.05).Compared with those before treatment,the CMS scores(including pain,daily living ability,shoulder mobility,and muscle strength),all aspects of shoulder mobility(forward flexion,posterior extension,external rotation,internal rotation),and SF-36 scale scores(including physiological,psychological,emotional,physical,vitality,and health status)were higher in both groups after treatment and significantly higher in the study group(P<0.05).There was no difference in the occurrence of complications between the two treatment groups(P>0.05).CONCLUSION Electroacupuncture combined with rehabilitation techniques has a good treatment effect on patients with rotator cuff injuries,helps accelerate the recovery of shoulder function,improves the quality of life,and is highly safe.

Blood metal concentrations and cardiac structure and function in total joint arthroplasty patients

BACKGROUND There is concern regarding potential long-term cardiotoxicity with systemic distribution of metals in total joint arthroplasty(TJA)patients.AIM To determine the association of commonly used implant metals with echocardiographic measures in TJA patients.METHODS The study comprised 110 TJA patients who had a recent history of high chromium,cobalt or titanium concentrations.Patients underwent two-dimensional,three-dimensional,Doppler and speckle-strain transthoracic echocardiography and a blood draw to measure metal concentrations.Age and sex-adjusted linear and logistic regression models were used to examine the association of metal concentrations(exposure)with echocardiographic measures(outcome).RESULTS Higher cobalt concentrations were associated with increased left ventricular end-diastolic volume(estimate 5.09;95%CI:0.02-10.17)as well as left atrial and right ventricular dilation,particularly in men but no changes in cardiac function.Higher titanium concentrations were associated with a reduction in left ventricle global longitudinal strain(estimate 0.38;95%CI:0.70 to 0.06)and cardiac index(estimate 0.08;95%CI,-0.15 to-0.01).CONCLUSION Elevated cobalt and titanium concentrations may be associated with structural and functional cardiac changes in some patients.Longitudinal studies are warranted to better understand the systemic effects of metals in TJA patients.

Cyclic shear behavior of en-echelon joints under constant normal stiffness conditions

To reveal the mechanism of shear failure of en-echelon joints under cyclic loading,such as during earthquakes,we conducted a series of cyclic shear tests of en-echelon joints under constant normal stiffness(CNS)conditions.We analyzed the evolution of shear stress,normal stress,stress path,dilatancy characteristics,and friction coefficient and revealed the failure mechanisms of en-echelon joints at different angles.The results show that the cyclic shear behavior of the en-echelon joints is closely related to the joint angle,with the shear strength at a positive angle exceeding that at a negative angle during shear cycles.As the number of cycles increases,the shear strength decreases rapidly,and the difference between the varying angles gradually decreases.Dilation occurs in the early shear cycles(1 and 2),while contraction is the main feature in later cycles(310).The friction coefficient decreases with the number of cycles and exhibits a more significant sensitivity to joint angles than shear cycles.The joint angle determines the asperities on the rupture surfaces and the block size,and thus determines the subsequent shear failure mode(block crushing and asperity degradation).At positive angles,block size is more greater and asperities on the rupture surface are smaller than at nonpositive angles.Therefore,the cyclic shear behavior is controlled by block crushing at positive angles and asperity degradation at negative angles.

Experimental and simulation research on hollow AZ31 magnesium alloy three-channel joint by hot extrusion forming with sand mandrel

Magnesium alloy is one of the lightest metal structural materials.The weight is further reduced through the hollow structure.However,the hollow structure is easily damaged during processing.In order to maintain the hollow structure and to transfer the stresses during the high temperature deformation,the sand mandrel is proposed.In this paper,the hollow AZ31 magnesium alloy three-channel joint is studied by hot extrusion forming.Sand as one of solid granule medium is used to fill the hollow magnesium alloy.The extrusion temperatures are 230℃ and 300℃,respectively.The process parameters(die angle,temperature,bottom thickness,sidewall thickness,edge-to-middle ratio in bottom,bottom shape)of the hollow magnesium alloy are analyzed based on the results of experiments and the finite element method.The results are shown that the formability of the hollow magnesium alloy will be much better when the ratio of sidewall thickness to the bottom thickness is 1:1.5.Also when edge-to-middle ratio in bottom is about 1:1.5,a better forming product can be received.The best bottom shape in these experiments will be convex based on the forming results.The grain will be refined obviously after the extrusion.Also the microstructures will be shown as streamlines.And these lines will be well agreement with the mold in the corner.

Ipsilateral Rockwood type V acromioclavicular joint dislocation and midshaft clavicle fracture:A case report

BACKGROUND Clavicle fractures are among the most common fractures seen in the emergency department.While acromioclavicular(AC)joint injuries are much less common.However,ipsilateral combinations of these injuries are quite rare with only a few cases reported in the literature.CASE SUMMARY A 29-year-old man who sustained a combination of ipsilateral AC joint dislocation and midshaft clavicle fracture.He underwent open reduction and plate fixation of the clavicle fracture,as well as semi-rigid surgical implants used to restore both the AC ligaments and the coracoclavicular joint.one year follow-up revealed that the patient had a complete range of motion and excellent shoulder scores.This case presents a rare presentation of such combination of injuries,contributing valuable insights to the literature on such rare injuries.CONCLUSION Combined midshaft clavicle fractures and AC joint dislocations are considered quite rare.Timely diagnosis of such injuries leads to great functional outcomes.AC joint dislocation should be suspected with midshaft clavicle fractures and should be investigated radiologically and clinically in an appropriate manner.Still,there is no consensus on the optimal management of such injuries.

Analysis of the joint detection capability of the SMILE satellite and EISCAT-3D radar

The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)satellite is a small magnetosphere–ionosphere link explorer developed cooperatively between China and Europe.It pioneers the use of X-ray imaging technology to perform large-scale imaging of the Earth’s magnetosheath and polar cusp regions.It uses a high-precision ultraviolet imager to image the overall configuration of the aurora and monitor changes in the source of solar wind in real time,using in situ detection instruments to improve human understanding of the relationship between solar activity and changes in the Earth’s magnetic field.The SMILE satellite is scheduled to launch in 2025.The European Incoherent Scatter Sciences Association(EISCAT)-3D radar is a new generation of European incoherent scatter radar constructed by EISCAT and is the most advanced ground-based ionospheric experimental device in the high-latitude polar region.It has multibeam and multidirectional quasi-real-time three-dimensional(3D)imaging capabilities,continuous monitoring and operation capabilities,and multiple-baseline interferometry capabilities.Joint detection by the SMILE satellite and the EISCAT-3D radar is of great significance for revealing the coupling process of the solar wind–magnetosphere–ionosphere.Therefore,we performed an analysis of the joint detection capability of the SMILE satellite and EISCAT-3D,analyzed the period during which the two can perform joint detection,and defined the key scientific problems that can be solved by joint detection.In addition,we developed Web-based software to search for and visualize the joint detection period of the SMILE satellite and EISCAT-3D radar,which lays the foundation for subsequent joint detection experiments and scientific research.

A photogrammetric approach for quantifying the evolution of rock joint void geometry under varying contact states

Accurate measurement of the evolution of rock joint void geometry is essential for comprehending the distribution characteristics of asperities responsible for shear and seepage behaviors.However,existing techniques often require specialized equipment and skilled operators,posing practical challenges.In this study,a cost-effective photogrammetric approach is proposed.Particularly,local coordinate systems are established to facilitate the alignment and precise quantification of the relative position between two halves of a rock joint.Push/pull tests are conducted on rock joints with varying roughness levels to induce different contact states.A high-precision laser scanner serves as a benchmark for evaluating the photogrammetry method.Despite certain deviations exist,the measured evolution of void geometry is generally consistent with the qualitative findings of previous studies.The photogrammetric measurements yield comparable accuracy to laser scanning,with maximum errors of 13.2%for aperture and 14.4%for void volume.Most joint matching coefficient(JMC)measurement errors are below 20%.Larger measurement errors occur primarily in highly mismatched rock joints with JMC values below 0.2,but even in cases where measurement errors exceed 80%,the maximum JMC error is only 0.0434.Thus,the proposed photogrammetric approach holds promise for widespread application in void geometry measurements in rock joints.

Shear behavior and off-fault damage of saw-cut smooth and tension-induced rough joints in granite

The damage of rock joints or fractures upon shear includes the surface damage occurring at the contact asperities and the damage beneath the shear surface within the host rock.The latter is commonly known as off-fault damage and has been much less investigated than the surface damage.The main contribution of this study is to compare the results of direct shear tests conducted on saw-cut planar joints and tension-induced rough granite joints under normal stresses ranging from 1 MPa to 50 MPa.The shear-induced off-fault damages are quantified and compared with the optical microscope observation.Our results clearly show that the planar joints slip stably under all the normal stresses except under 50 MPa,where some local fractures and regular stick-slip occur towards the end of the test.Both post-peak stress drop and stick-slip occur for all the rough joints.The residual shear strength envelopes for the rough joints and the peak shear strength envelope for the planar joints almost overlap.The root mean square(RMS)of asperity height for the rough joints decreases while it increases for the planar joint after shear,and a larger normal stress usually leads to a more significant decrease or increase in RMS.Besides,the extent of off-fault damage(or damage zone)increases with normal stress for both planar and rough joints,and it is restricted to a very thin layer with limited micro-cracks beneath the planar joint surface.In comparison,the thickness of the damage zone for the rough joints is about an order of magnitude larger than that of the planar joints,and the coalesced micro-cracks are generally inclined to the shear direction with acute angles.The findings obtained in this study contribute to a better understanding on the frictional behavior and damage characteristics of rock joints or fractures with different roughness.