BACKGROUND In recent years,the use of Magnesium alloy implants have gained renewed popularity,especially after the first commercially available ConformitéEuropéenne approved Magnesium implant became availabl...BACKGROUND In recent years,the use of Magnesium alloy implants have gained renewed popularity,especially after the first commercially available ConformitéEuropéenne approved Magnesium implant became available(MAGNEZIX®CS,Syntellix)in 2013.AIM To document our clinical and radiographical outcomes using magnesium implants in treating peri-articular elbow fractures.METHODS Our paper was based on a retrospective case series design.Intra-operatively,a standardized surgical technique was utilized for insertion of the magnesium implants.Post–operatively,clinic visits were standardized and physical exam findings,functional scores,and radiographs were obtained at each visit.All complications were recorded.RESULTS Five patients with 6 fractures were recruited(2 coronoid,3 radial head and 1 capitellum).The mean patient age and length of follow up was 54.6 years and 11 months respectively.All fractures healed,and none exhibited loss of reduction or complications requiring revision surgery.No patient developed synovitis of the elbow joint or suffered electrolytic reactions when titanium implants were used concurrently.CONCLUSION Although there is still a paucity of literature available on the subject and further studies are required,magnesium implants appear to be a feasible tool for fixation of peri-articular elbow fractures with promising results in our series.INTRODUCTION In recent years,the use of Magnesium alloy implants in orthopaedic surgeries have gained renewed popularity.Apart from being bioabsorbable,negating the need for implant removal,magnesium also has good osteoconductive properties[1-4].Biomechanically,it exhibits greater biomechanical strength than any pre-existing polymers,and reduces the stress-shielding effect associated with titanium and steel implants as it has a Young’s modulus closer to bone[4].Currently,the main utility of magnesium implants in the orthopaedic community is within the foot and ankle community where satisfactory results have been reported with its utility in forefoot osteotomies[5-7].However,its utility in the setting of orthopaedic trauma has been steadily increasing[8].Our study aims to document our clinical and radiographical outcomes using magnesium implants to treat peri-articular elbow fractures.To our knowledge,our study is the first study analyzing outcomes in radial head and coronoid fractures in the English literature.展开更多
Background: Elbow dislocations in pediatric patients are rare injuries. This is a therapeutic emergency because a delay in treatment can have disastrous consequences on the functional level of the upper limb. Objectiv...Background: Elbow dislocations in pediatric patients are rare injuries. This is a therapeutic emergency because a delay in treatment can have disastrous consequences on the functional level of the upper limb. Objective: To present the management of elbow dislocation in children in cases of limited resources. Presentation of the Cases: These were 2 older male children aged 7 and 9 years old, admitted to the emergency room for painful functional impotence of the right elbow after a fall and landing on the right hand. Clinical and radiological examinations were in favor of posterior elbow dislocations. The reductions were carried out under sedation and immobilization in Jersey. According to Robert’s criteria, the functional result was excellent in both patients. Conclusion: Emergency reduction and immobilization whatever the means ensure an excellent functional prognosis even in cases of limited resources.展开更多
Portability is an important performance to the design of exoskeleton for rehabilitation and assistance.However,the structure of traditional exoskeletons will decrease the portability because of their heavy weight and ...Portability is an important performance to the design of exoskeleton for rehabilitation and assistance.However,the structure of traditional exoskeletons will decrease the portability because of their heavy weight and large volume.This paper proposes a novel bionic portable elbow exoskeleton based on a human-exoskeleton gravity-balancing coupled model.The variable stiffness characteristics of the coupled model is analyzed based on the static analysis.In addition,the optimization of human-exoskeleton joint points is analysis to improve the bionic motor characteristics of the exoskeleton.Theoretical prototype is designed and its driving power and dynamic performance are analyzed.Then,a prototype is designed and manufactured with a total weight of 375 g.The merits of driving power reducing is verified by simulation and the isokinetic experiments.The simulation and isokinetic results show that the driving torque and the driving power of the subject were significantly decreased with wearing the proposed exoskeleton.The driving torques are reduced 79.28%and 57.38%from the simulation results and isokinetic experiment results,respectively.The driving work of experiment was reduced by 56.5%.The development of the novel elbow exoskeleton with gravity-balancing mechanism can expand the application of exoskeleton in home-based rehabilitation.展开更多
k-means is a popular clustering algorithm because of its simplicity and scalability to handle large datasets.However,one of its setbacks is the challenge of identifying the correct k-hyperparameter value.Tuning this v...k-means is a popular clustering algorithm because of its simplicity and scalability to handle large datasets.However,one of its setbacks is the challenge of identifying the correct k-hyperparameter value.Tuning this value correctly is critical for building effective k-means models.The use of the traditional elbow method to help identify this value has a long-standing literature.However,when using this method with certain datasets,smooth curves may appear,making it challenging to identify the k-value due to its unclear nature.On the other hand,various internal validation indexes,which are proposed as a solution to this issue,may be inconsistent.Although various techniques for solving smooth elbow challenges exist,k-hyperparameter tuning in high-dimensional spaces still remains intractable and an open research issue.In this paper,we have first reviewed the existing techniques for solving smooth elbow challenges.The identified research gaps are then utilized in the development of the new technique.The new technique,referred to as the ensemble-based technique of a self-adapting autoencoder and internal validation indexes,is then validated in high-dimensional space clustering.The optimal k-value,tuned by this technique using a voting scheme,is a trade-off between the number of clusters visualized in the autoencoder’s latent space,k-value from the ensemble internal validation index score and one that generates a value of 0 or close to 0 on the derivative f″′(k)(1+f′(k)^(2))−3 f″(k)^(2)f″((k)2f′(k),at the elbow.Experimental results based on the Cochran’s Q test,ANOVA,and McNemar’s score indicate a relatively good performance of the newly developed technique in k-hyperparameter tuning.展开更多
BACKGROUND Simple lateral elbow dislocation(SLED)is a rare type of elbow dislocation;however,its treatment may be complicated by accompanying soft tissue or neurovascular damage.Herein,we report a rare case of SLED ma...BACKGROUND Simple lateral elbow dislocation(SLED)is a rare type of elbow dislocation;however,its treatment may be complicated by accompanying soft tissue or neurovascular damage.Herein,we report a rare case of SLED managed secondarily with open reduction and soft tissue repair following failure of closed reduction.CASE SUMMARY A 67-year-old woman suffered SLED after falling on her outstretched left hand with her elbow extended.She developed pain,swelling,and movement restriction in the elbow;there were no neurovascular symptoms,except for numbness in the 4th and 5th digits.Radiologic investigation confirmed the SLED,and a closed reduction under anesthesia was performed.The follow-up radiographs at 1-wk revealed failure of reduction;accordingly,open reduction with lateral collateral ligament and common extensor origin repair were carried out.The patient regained full elbow range of motion by six weeks.CONCLUSION Adequate concentric reduction for SLED,conservatively or surgically,reduces complications and provides a more functional joint.展开更多
AIM:To evaluate the effect of different elbow and forearm positions on radiocapitellar alignment.METHODS:Fifty-one healthy volunteers were recruited and bilateral elbow radiographs were taken to form a radiologic data...AIM:To evaluate the effect of different elbow and forearm positions on radiocapitellar alignment.METHODS:Fifty-one healthy volunteers were recruited and bilateral elbow radiographs were taken to form a radiologic database.Lateral elbow radiographs were taken with the elbow in five different positions:Maximal extension and forearm in neutral,maximal flexion and forearm in neutral,elbow at 90° and forearm in neutral,elbow at 90° and forearm in supination and elbow at 90° and forearm in pronation.A goniometer was used to verify the accuracy of the elbow's position for the radiographs at a 90° angle.The radiocapitellar ratio(RCR)measurements were then taken on the collected radiographs using the Slice Omatic software.An orthopedic resident performed the radiographic measurements on the 102 elbows,for a total of 510 lateral elbow radiographic measures.ANOVA paired t-tests and Pearson coefficients were used to assess the differences and correlations between the RCR in each position.RESULTS:Mean RCR values were-2% ± 7%(maximal extension),-5% ± 9%(maximal flexion),and for elbow at 90° and forearm in neutral-2% ± 5%,supination 1% ± 6% and pronation 1% ± 5%.ANOVA analyses demonstrated significant differences between the RCRin different elbow and forearm positions.Paired t-tests confirmed significant differences between the RCR at maximal flexion and flexion at 90°,and maximal extension and flexion.The Pearson coefficient showed significant correlations between the RCR with the elbow at 90°-maximal flexion;the forearm in neutralsupination;the forearm in neutral-pronation.CONCLUSION:Overall,95% of the RCR values are included in the normal range(obtained at 90° of flexion)and a value outside this range,in any position,should raise suspicion for instability.展开更多
AIM:To evaluate short-to medium term outcome of total elbow arthroplasty(TEA)in complex fractures of the distal humerus.METHODS:A consecutive series of 24 complex distal humerus fractures operated with TEA in the peri...AIM:To evaluate short-to medium term outcome of total elbow arthroplasty(TEA)in complex fractures of the distal humerus.METHODS:A consecutive series of 24 complex distal humerus fractures operated with TEA in the period2006-2012 was evaluated with the Mayo Elbow Performance score(MEPS),plain radiographs,complications and overall satisfaction.The indications for surgery were 1:AO type B3 or C3 or Sheffield type 3 fracture and age above 65 or 2:fracture and severe rheumatoid arthritis.Mean follow-up time was 21 mo.RESULTS:Twenty patients were followed up.Four patients,of which 3 had died,were lost to follow up.According to the AO classification there were 17 C3,1B2 and 2 A2 fractures.Mean follow-up was 21 months(range 4-54).Mean MEPS was 94(range 65-100).Mean flexion was 114 degrees(range 80-140).According to MEPS there were 15 excellent,4 good and 1 fair result.Patient satisfaction:8 excellent,10 good,2 fair and 1poor.There were two revisions due to infection treated successfully with revision and three months of antibiotics.In two patients the locking split had loosened.One was referred to re-insertion and one chose yearly con-trols.Two patients had persistent dysaesthesia of their5th finger,but were able to discriminate between sharp and blunt.CONCLUSION:Our study suggests that TEA in complex fractures of the distal humerus in elderly patients can result in acceptable short-to medium term outcome.展开更多
With the increase in mining depth, mine heat harm has appeared to be more prominent. The mine heat harm could be resolvedor reduced by ice refrigeration. Thus, ice transportation through pipeline becomes a critical pr...With the increase in mining depth, mine heat harm has appeared to be more prominent. The mine heat harm could be resolvedor reduced by ice refrigeration. Thus, ice transportation through pipeline becomes a critical problem; typically flowresistance occurs in the elbow. In the present study, according to the analysis of the surface morphology of fish scale, abiomimetic functional surface structure for the interior wall of elbow is designed. Based on the theory of liquid-solid two phaseflow, a CFD numerical simulation of ice-water mixture flowing through the elbow is carried out using finite element method.Conventional experiments of pressure drop and flow resistance for both bionic and common elbows are conducted to test theeffect of the bionic elbow on flow resistance reduction. It is found that with the increase in the ice mass fraction in the ice-watermixture, the effect of bionic elbow on resistance reduction becomes more obvious.展开更多
The medial ulnar collateral ligament complex of the elbow, which is comprised of the anterior bundle [AB, more formally referred to as the medial ulnar collateral ligament(MUCL)], posterior(PB), and transverse ligamen...The medial ulnar collateral ligament complex of the elbow, which is comprised of the anterior bundle [AB, more formally referred to as the medial ulnar collateral ligament(MUCL)], posterior(PB), and transverse ligament, is commonly injured in overhead throwing athletes. Attenuation or rupture of the ligament results in valgus instability with variable clinical presentations. The AB or MUCL is the strongest component of the ligamentous complex and the primary restraint to valgus stress. It is also composed of two separate bands(anterior and posterior) that provide reciprocal function with the anterior band tight in extension, and the posterior band tight in flexion. In individuals who fail co-mprehensive non-operative treatment, surgical repair or reconstruction of the MUCL is commonly required to restore elbow function and stability. A comprehensive understanding of the anatomy and biomechanical properties of the MUCL is imperative to optimize reconstructive efforts, and to enhance clinical and radiographic outcomes. Our understanding of the native anatomy and biomechanics of the MUCL has evolved over time. The precise locations of the origin and insertion footprint centers guide surgeons in proper graft placement with relation to bony anatomic landmarks. In recent studies, the ulnar insertion of the MUCL is described as larger than previously thought, with the center of the footprint at varying distances relative to the ulnar ridge, joint line, or sublime tubercle. The purpose of this review is to consolidate and summarize the existing literature regarding the native anatomy, biomechanical, and clinical significance of the entire medial ulnar collateral ligament complex, including the MUCL(AB), PB, and transverse ligament.展开更多
Lateral epicondylitis is a relatively common clinical prob lem, easily recognized on palpation of the lateral protu berance on the elbow. Despite the "itis" suffix, it is no an inflammatory process. Therapeu...Lateral epicondylitis is a relatively common clinical prob lem, easily recognized on palpation of the lateral protu berance on the elbow. Despite the "itis" suffix, it is no an inflammatory process. Therapeutic approaches with topical non-steroidal anti-inflammatory drugs, cortico steroids and anesthetics have limited benefit, as would be expected if inflammation is not involved. Other ap proaches have included provision of healing cytokine from blood products or stem cells, based on the recog nition that this repetitive effort-derived disorder repre sents injury. Noting calcification/ossification of tendon attachments to the lateral epicondyle(enthesitis), dry needling, radiofrequency, shock wave treatments and surgical approaches have also been pursued. Physi ologic approaches, including manipulation, therapeuti ultrasound, phonophoresis, iontophoresis, acupuncture and exposure of the area to low level laser light, ha also had limited success. This contrasts with the benefi of a simple mechanical intervention, reducing the stres on the attachment area. This is based on displacemen of the stress by use of a thin(3/4-1 inch) band applied just distal to the epicondyle. Thin bands are required as thick bands(e.g., 2-3 inch wide) simply reduce mus cle strength, without significantly reducing stress. Thi approach appears to be associated with a failure rateless than 1%, assuming the afflicted individual modifies the activity that repeatedly stresses the epicondylar attachments.展开更多
Direct coaptation of contralateral C7 to the upper trunk could avoid the interposition of nerve grafts. We have successfully shortened the gap and graft lengths, and even achieved direct coaptation. However, direct re...Direct coaptation of contralateral C7 to the upper trunk could avoid the interposition of nerve grafts. We have successfully shortened the gap and graft lengths, and even achieved direct coaptation. However, direct repair can only be performed in some selected cases, and partial procedures still require autografts, which are the gold standard for repairing neurologic defects. As symptoms often occur after autografting, human acellular nerve allografts have been used to avoid concomitant symptoms. This study investigated the quality of shoulder abduction and elbow flexion following direct repair and acellular allografting to evaluate issues requiring attention for brachial plexus injury repair. Fifty-one brachial plexus injury patients in the surgical database were eligible for this retrospective study. Patients were divided into two groups according to different surgical methods. Direct repair was performed in 27 patients, while acellular nerve allografts were used to bridge the gap between the contralateral C7 nerve root and upper trunk in 24 patients. The length of the harvested contralateral C7 nerve root was measured intraoperatively. Deltoid and biceps muscle strength, and degrees of shoulder abduction and elbow flexion were examined according to the British Medical Research Council scoring system;meaningful recovery was defined as M3–M5. Lengths of anterior and posterior divisions of the contralateral C7 in the direct repair group were 7.64 ± 0.69 mm and 7.55 ± 0.69 mm, respectively, and in the acellular nerve allografts group were 6.46 ± 0.58 mm and 6.43 ± 0.59 mm, respectively. After a minimum of 4-year follow-up, meaningful recoveries of deltoid and biceps muscles in the direct repair group were 88.89% and 85.19%, respectively, while they were 70.83% and 66.67% in the acellular nerve allografts group. Time to C5/C6 reinnervation was shorter in the direct repair group compared with the acellular nerve allografts group. Direct repair facilitated the restoration of shoulder abduction and elbow flexion. Thus, if direct coaptation is not possible, use of acellular nerve allografts is a suitable option. This study was approved by the Medical Ethical Committee of the First Affiliated Hospital of Sun Yat-sen University, China (Application ID:[2017] 290) on November 14, 2017.展开更多
The elbow joint is a complex joint, which, when impaired in function, leads to severe disability. In some cases however, an arthroplasty might be an appropriate treatment. In the past four decades, large steps havebee...The elbow joint is a complex joint, which, when impaired in function, leads to severe disability. In some cases however, an arthroplasty might be an appropriate treatment. In the past four decades, large steps havebeen taken to optimize this treatment in order to achieve better post-operative outcomes. To understand these progresses and to discover aspects for upcoming improvements, we present a review on the past developments, the present state of affairs and future developments which may improve patient care further.展开更多
In this article, we present a case of humeral biepicondylar fracture dislocation concomitant with ulnar nerve injury in a seventeen year-old male patient. Physical examination of our patient in the emergency room reve...In this article, we present a case of humeral biepicondylar fracture dislocation concomitant with ulnar nerve injury in a seventeen year-old male patient. Physical examination of our patient in the emergency room revealed a painful, edematous and deformed-looking left elbow joint. Hypoesthesia of the little finger was also diagnosed on the left hand. Radiological assessment ended up with a posterior fracture dislocation of the elbow joint accompanied by intra-articular loose bodies. Open reduction-Internal fixation of the fracture dislocation and ulnar nerve exploration were performed under general anesthesia at the same session as surgical treatment of our patient. Physical therapy and rehabilitation protocol was implemented at the end of two weeks post-operatively. Union of the fracture lines, as well as the olecranon osteotomy site, was achieved at the end of four months post-operatively. Ulnar nerve function was fully restored without any sensory or motor loss. Range of motion at the elbow joint was 20-120 degrees at the latest follow-up.展开更多
In this work,computational fuid dynamics(CFD)is used to study elbow erosion due to a gas-solid two-phase fow.In particular,the direct simulation Monte Carlo(DSMC)method is used to study the impact of inter-particle co...In this work,computational fuid dynamics(CFD)is used to study elbow erosion due to a gas-solid two-phase fow.In particular,the direct simulation Monte Carlo(DSMC)method is used to study the impact of inter-particle collision on the erosion behavior.The two-way coupled Euler-Lagrange method is used to solve the gas-solid fow,and the DSMC method is used to consider the collision behavior between particles.The efects of key factors,such as the particle concentration distribution and inter-particle collision,on the erosion ratio are evaluated and discussed.The efectiveness of the method is verifed from experimental data.The results show that the inter-particle collision signifcantly infuences the particle movement path and erosion ratio.When the inter-particle collision is considered,the maximum erosion position is ofset.The erosion model proposed by Oka et al.,who used the DSMC method,agrees best with the experimental data,and the average percentage error decreases from 39.2 to 27.4%.展开更多
Consistent with an aging population, the overall number of distal humeral fractures in the elderly is increasing. Indications for application of acute total elbow arthroplasty (TEA) in the setting of distal humeral fr...Consistent with an aging population, the overall number of distal humeral fractures in the elderly is increasing. Indications for application of acute total elbow arthroplasty (TEA) in the setting of distal humeral fractures are still being defined. A variety of factors including chronologic age, physiologic age, bone quality, presence of pre-existing arthritis and pre-existing medical conditions need to be considered. Optimally the decision to proceed with TEA verses open reduction internal fixation (ORIF) is made preoperatively. The need to abandon ORIF may be not be apparent until after fracture exposure, and the presence of an olecranon osteotomy makes performing TEA challenging. A case is presented of acute conversion from ORIF to TEA following olecranon osteotomy, utilizing internal fixation bridging the ulnar component and its cement mantle.展开更多
This study presents the numerical evaluation about the impact of flow disturbance near the intrados and extrados regions of the 90 degree bended elbow using CFX for several practical cases where the 90 degree bended u...This study presents the numerical evaluation about the impact of flow disturbance near the intrados and extrados regions of the 90 degree bended elbow using CFX for several practical cases where the 90 degree bended upward elbow is located in a proximity to the butterfly valve and the butterfly valve open angle is changed. For the change of a butterfly valve open angle from 60% to 100% and the increase of the distance between a valve and a 90 degree bended elbow, the effect of FAC (Flow-Accelerated Corrosion) in the 90 degree bended elbow may be neglected because the value and distribution of the velocity and shear stress is rapidly decreased comparing with the present status installed in an industry, and the data of 100% valve open (Case 3) and L/D ≈ 5 (Case 4) are very good agreement comparing with the reference data, L/D ≈ 8 (Case 2). The reasons are that flow already maintains a fully developed condition and a steady state in spite of less distance than the reference case, L/D = 8. Therefore, smooth flow fields have approached at a 90 degree bended elbow. Then, the effect of shear stress and vortex is hardly investigated around the intrados area of 90 degree bended elbow.展开更多
BACKGROUND Joint stiffness after elbow surgery is not a rare complication,and is always accompanied by deformity.The causes of joint stiffness are multiple in different patients,and divided into intrinsic and extrinsi...BACKGROUND Joint stiffness after elbow surgery is not a rare complication,and is always accompanied by deformity.The causes of joint stiffness are multiple in different patients,and divided into intrinsic and extrinsic causes.Herein,we report an unusual case of posttraumatic elbow stiffness due to multiple and rare causes.CASE SUMMARY A 19-year-old male was hospitalized with the loss of motion of the left elbow for over ten years.Left limb computed tomography revealed left elbow stiffness with bony block and connection.The patient underwent surgery,and the etiology of joint stiffness was found to be a rare combination of common and uncommon causes.During an 18-mo follow-up period,the patient’s left elbow had normal motion and he was symptom-free.CONCLUSION However,this case combined with multiple and rare causes highlights that the patient with scar physique is likely to be accompanied with more severe soft tissue,nerve contracture,and heterotypic ossification,even during recurrence.展开更多
The secondary flow downstream of a triple elbow layout was studied experimentally and numerically to visualize the flow behavior under swirling inlet flow conditions. The inlet swirling condition was generated by a sw...The secondary flow downstream of a triple elbow layout was studied experimentally and numerically to visualize the flow behavior under swirling inlet flow conditions. The inlet swirling condition was generated by a swirl generator, consisting of a rotary pipe and honeycomb assembly. The experiments were carried out in turbulent water flow condition at Reynolds number Re = 1 × 104 and inlet swirl intensity S = 1. Ultrasonic measurements were taken at four locations downstream of the third elbow. The two-dimensional velocity field of the flow field was measured using the phased array ultrasonic velocity profiler technique to evaluate the flow field with separation. Furthermore, a numerical simulation was performed and its results were compared with the experimental data. The numerical result was obtained by solving three-dimensional, Reynolds-averaged Navier-Stokes equations with the renormalization group k-ε turbulence model. The experimental results confirmed that the swirling flow condition modified the size of the separation region downstream of the third elbow. A qualitative comparison between the experimental and CFD simulation results of the averaged velocity field downstream of the third elbow showed similar tendency on reverse flow.展开更多
Anterior transolecranon dislocation of the elbow is rarely observed in children, reported in only a small series. The present case involves an anterior transolecranon dislocation of the left elbow joint in a 7-year-ol...Anterior transolecranon dislocation of the elbow is rarely observed in children, reported in only a small series. The present case involves an anterior transolecranon dislocation of the left elbow joint in a 7-year-old child, which was surgically treated. Two attempts of closed reduction failed because the radial head had buttonholed via the joint capsule. After its release, open reduction was easily performed; osteosynthesis of the olecranon was not performed. Remarkably, good result was obtained, despite a mild flexion deformity at the last follow-up. This case report aims to highlight this treatment method, which may be considered for such an uncommon injury.展开更多
文摘BACKGROUND In recent years,the use of Magnesium alloy implants have gained renewed popularity,especially after the first commercially available ConformitéEuropéenne approved Magnesium implant became available(MAGNEZIX®CS,Syntellix)in 2013.AIM To document our clinical and radiographical outcomes using magnesium implants in treating peri-articular elbow fractures.METHODS Our paper was based on a retrospective case series design.Intra-operatively,a standardized surgical technique was utilized for insertion of the magnesium implants.Post–operatively,clinic visits were standardized and physical exam findings,functional scores,and radiographs were obtained at each visit.All complications were recorded.RESULTS Five patients with 6 fractures were recruited(2 coronoid,3 radial head and 1 capitellum).The mean patient age and length of follow up was 54.6 years and 11 months respectively.All fractures healed,and none exhibited loss of reduction or complications requiring revision surgery.No patient developed synovitis of the elbow joint or suffered electrolytic reactions when titanium implants were used concurrently.CONCLUSION Although there is still a paucity of literature available on the subject and further studies are required,magnesium implants appear to be a feasible tool for fixation of peri-articular elbow fractures with promising results in our series.INTRODUCTION In recent years,the use of Magnesium alloy implants in orthopaedic surgeries have gained renewed popularity.Apart from being bioabsorbable,negating the need for implant removal,magnesium also has good osteoconductive properties[1-4].Biomechanically,it exhibits greater biomechanical strength than any pre-existing polymers,and reduces the stress-shielding effect associated with titanium and steel implants as it has a Young’s modulus closer to bone[4].Currently,the main utility of magnesium implants in the orthopaedic community is within the foot and ankle community where satisfactory results have been reported with its utility in forefoot osteotomies[5-7].However,its utility in the setting of orthopaedic trauma has been steadily increasing[8].Our study aims to document our clinical and radiographical outcomes using magnesium implants to treat peri-articular elbow fractures.To our knowledge,our study is the first study analyzing outcomes in radial head and coronoid fractures in the English literature.
文摘Background: Elbow dislocations in pediatric patients are rare injuries. This is a therapeutic emergency because a delay in treatment can have disastrous consequences on the functional level of the upper limb. Objective: To present the management of elbow dislocation in children in cases of limited resources. Presentation of the Cases: These were 2 older male children aged 7 and 9 years old, admitted to the emergency room for painful functional impotence of the right elbow after a fall and landing on the right hand. Clinical and radiological examinations were in favor of posterior elbow dislocations. The reductions were carried out under sedation and immobilization in Jersey. According to Robert’s criteria, the functional result was excellent in both patients. Conclusion: Emergency reduction and immobilization whatever the means ensure an excellent functional prognosis even in cases of limited resources.
基金the financial support by National Natural Science Foundation of China(61803265,61903255)Shanghai Science and Technology Development Foundation,China(Grant no.20S31905400).
文摘Portability is an important performance to the design of exoskeleton for rehabilitation and assistance.However,the structure of traditional exoskeletons will decrease the portability because of their heavy weight and large volume.This paper proposes a novel bionic portable elbow exoskeleton based on a human-exoskeleton gravity-balancing coupled model.The variable stiffness characteristics of the coupled model is analyzed based on the static analysis.In addition,the optimization of human-exoskeleton joint points is analysis to improve the bionic motor characteristics of the exoskeleton.Theoretical prototype is designed and its driving power and dynamic performance are analyzed.Then,a prototype is designed and manufactured with a total weight of 375 g.The merits of driving power reducing is verified by simulation and the isokinetic experiments.The simulation and isokinetic results show that the driving torque and the driving power of the subject were significantly decreased with wearing the proposed exoskeleton.The driving torques are reduced 79.28%and 57.38%from the simulation results and isokinetic experiment results,respectively.The driving work of experiment was reduced by 56.5%.The development of the novel elbow exoskeleton with gravity-balancing mechanism can expand the application of exoskeleton in home-based rehabilitation.
文摘k-means is a popular clustering algorithm because of its simplicity and scalability to handle large datasets.However,one of its setbacks is the challenge of identifying the correct k-hyperparameter value.Tuning this value correctly is critical for building effective k-means models.The use of the traditional elbow method to help identify this value has a long-standing literature.However,when using this method with certain datasets,smooth curves may appear,making it challenging to identify the k-value due to its unclear nature.On the other hand,various internal validation indexes,which are proposed as a solution to this issue,may be inconsistent.Although various techniques for solving smooth elbow challenges exist,k-hyperparameter tuning in high-dimensional spaces still remains intractable and an open research issue.In this paper,we have first reviewed the existing techniques for solving smooth elbow challenges.The identified research gaps are then utilized in the development of the new technique.The new technique,referred to as the ensemble-based technique of a self-adapting autoencoder and internal validation indexes,is then validated in high-dimensional space clustering.The optimal k-value,tuned by this technique using a voting scheme,is a trade-off between the number of clusters visualized in the autoencoder’s latent space,k-value from the ensemble internal validation index score and one that generates a value of 0 or close to 0 on the derivative f″′(k)(1+f′(k)^(2))−3 f″(k)^(2)f″((k)2f′(k),at the elbow.Experimental results based on the Cochran’s Q test,ANOVA,and McNemar’s score indicate a relatively good performance of the newly developed technique in k-hyperparameter tuning.
文摘BACKGROUND Simple lateral elbow dislocation(SLED)is a rare type of elbow dislocation;however,its treatment may be complicated by accompanying soft tissue or neurovascular damage.Herein,we report a rare case of SLED managed secondarily with open reduction and soft tissue repair following failure of closed reduction.CASE SUMMARY A 67-year-old woman suffered SLED after falling on her outstretched left hand with her elbow extended.She developed pain,swelling,and movement restriction in the elbow;there were no neurovascular symptoms,except for numbness in the 4th and 5th digits.Radiologic investigation confirmed the SLED,and a closed reduction under anesthesia was performed.The follow-up radiographs at 1-wk revealed failure of reduction;accordingly,open reduction with lateral collateral ligament and common extensor origin repair were carried out.The patient regained full elbow range of motion by six weeks.CONCLUSION Adequate concentric reduction for SLED,conservatively or surgically,reduces complications and provides a more functional joint.
基金Supported by Fondation de Recherche et d’éducation en Orthopédie de Montréal
文摘AIM:To evaluate the effect of different elbow and forearm positions on radiocapitellar alignment.METHODS:Fifty-one healthy volunteers were recruited and bilateral elbow radiographs were taken to form a radiologic database.Lateral elbow radiographs were taken with the elbow in five different positions:Maximal extension and forearm in neutral,maximal flexion and forearm in neutral,elbow at 90° and forearm in neutral,elbow at 90° and forearm in supination and elbow at 90° and forearm in pronation.A goniometer was used to verify the accuracy of the elbow's position for the radiographs at a 90° angle.The radiocapitellar ratio(RCR)measurements were then taken on the collected radiographs using the Slice Omatic software.An orthopedic resident performed the radiographic measurements on the 102 elbows,for a total of 510 lateral elbow radiographic measures.ANOVA paired t-tests and Pearson coefficients were used to assess the differences and correlations between the RCR in each position.RESULTS:Mean RCR values were-2% ± 7%(maximal extension),-5% ± 9%(maximal flexion),and for elbow at 90° and forearm in neutral-2% ± 5%,supination 1% ± 6% and pronation 1% ± 5%.ANOVA analyses demonstrated significant differences between the RCRin different elbow and forearm positions.Paired t-tests confirmed significant differences between the RCR at maximal flexion and flexion at 90°,and maximal extension and flexion.The Pearson coefficient showed significant correlations between the RCR with the elbow at 90°-maximal flexion;the forearm in neutralsupination;the forearm in neutral-pronation.CONCLUSION:Overall,95% of the RCR values are included in the normal range(obtained at 90° of flexion)and a value outside this range,in any position,should raise suspicion for instability.
文摘AIM:To evaluate short-to medium term outcome of total elbow arthroplasty(TEA)in complex fractures of the distal humerus.METHODS:A consecutive series of 24 complex distal humerus fractures operated with TEA in the period2006-2012 was evaluated with the Mayo Elbow Performance score(MEPS),plain radiographs,complications and overall satisfaction.The indications for surgery were 1:AO type B3 or C3 or Sheffield type 3 fracture and age above 65 or 2:fracture and severe rheumatoid arthritis.Mean follow-up time was 21 mo.RESULTS:Twenty patients were followed up.Four patients,of which 3 had died,were lost to follow up.According to the AO classification there were 17 C3,1B2 and 2 A2 fractures.Mean follow-up was 21 months(range 4-54).Mean MEPS was 94(range 65-100).Mean flexion was 114 degrees(range 80-140).According to MEPS there were 15 excellent,4 good and 1 fair result.Patient satisfaction:8 excellent,10 good,2 fair and 1poor.There were two revisions due to infection treated successfully with revision and three months of antibiotics.In two patients the locking split had loosened.One was referred to re-insertion and one chose yearly con-trols.Two patients had persistent dysaesthesia of their5th finger,but were able to discriminate between sharp and blunt.CONCLUSION:Our study suggests that TEA in complex fractures of the distal humerus in elderly patients can result in acceptable short-to medium term outcome.
基金supported bv the National Natural Science Foundation of China(Grant No.50975164)the Science and Technology Planning Project of Shandong Proyince(Grant No.J09LD05)the Foundation of Key LaboratOry of Mine Hazard Prevention and Control (Grant No.MDPC0810)
文摘With the increase in mining depth, mine heat harm has appeared to be more prominent. The mine heat harm could be resolvedor reduced by ice refrigeration. Thus, ice transportation through pipeline becomes a critical problem; typically flowresistance occurs in the elbow. In the present study, according to the analysis of the surface morphology of fish scale, abiomimetic functional surface structure for the interior wall of elbow is designed. Based on the theory of liquid-solid two phaseflow, a CFD numerical simulation of ice-water mixture flowing through the elbow is carried out using finite element method.Conventional experiments of pressure drop and flow resistance for both bionic and common elbows are conducted to test theeffect of the bionic elbow on flow resistance reduction. It is found that with the increase in the ice mass fraction in the ice-watermixture, the effect of bionic elbow on resistance reduction becomes more obvious.
文摘The medial ulnar collateral ligament complex of the elbow, which is comprised of the anterior bundle [AB, more formally referred to as the medial ulnar collateral ligament(MUCL)], posterior(PB), and transverse ligament, is commonly injured in overhead throwing athletes. Attenuation or rupture of the ligament results in valgus instability with variable clinical presentations. The AB or MUCL is the strongest component of the ligamentous complex and the primary restraint to valgus stress. It is also composed of two separate bands(anterior and posterior) that provide reciprocal function with the anterior band tight in extension, and the posterior band tight in flexion. In individuals who fail co-mprehensive non-operative treatment, surgical repair or reconstruction of the MUCL is commonly required to restore elbow function and stability. A comprehensive understanding of the anatomy and biomechanical properties of the MUCL is imperative to optimize reconstructive efforts, and to enhance clinical and radiographic outcomes. Our understanding of the native anatomy and biomechanics of the MUCL has evolved over time. The precise locations of the origin and insertion footprint centers guide surgeons in proper graft placement with relation to bony anatomic landmarks. In recent studies, the ulnar insertion of the MUCL is described as larger than previously thought, with the center of the footprint at varying distances relative to the ulnar ridge, joint line, or sublime tubercle. The purpose of this review is to consolidate and summarize the existing literature regarding the native anatomy, biomechanical, and clinical significance of the entire medial ulnar collateral ligament complex, including the MUCL(AB), PB, and transverse ligament.
文摘Lateral epicondylitis is a relatively common clinical prob lem, easily recognized on palpation of the lateral protu berance on the elbow. Despite the "itis" suffix, it is no an inflammatory process. Therapeutic approaches with topical non-steroidal anti-inflammatory drugs, cortico steroids and anesthetics have limited benefit, as would be expected if inflammation is not involved. Other ap proaches have included provision of healing cytokine from blood products or stem cells, based on the recog nition that this repetitive effort-derived disorder repre sents injury. Noting calcification/ossification of tendon attachments to the lateral epicondyle(enthesitis), dry needling, radiofrequency, shock wave treatments and surgical approaches have also been pursued. Physi ologic approaches, including manipulation, therapeuti ultrasound, phonophoresis, iontophoresis, acupuncture and exposure of the area to low level laser light, ha also had limited success. This contrasts with the benefi of a simple mechanical intervention, reducing the stres on the attachment area. This is based on displacemen of the stress by use of a thin(3/4-1 inch) band applied just distal to the epicondyle. Thin bands are required as thick bands(e.g., 2-3 inch wide) simply reduce mus cle strength, without significantly reducing stress. Thi approach appears to be associated with a failure rateless than 1%, assuming the afflicted individual modifies the activity that repeatedly stresses the epicondylar attachments.
基金supported by the National Natural Science Foundation of China,No.81572130(to LQG)and 81601057(to JTY)the National Key Research and Development Plan of China,No.2016YFC1101603(to XLL)the Natural Science Foundation of Guangdong Province of China,No.2015A030310350(to JTY)
文摘Direct coaptation of contralateral C7 to the upper trunk could avoid the interposition of nerve grafts. We have successfully shortened the gap and graft lengths, and even achieved direct coaptation. However, direct repair can only be performed in some selected cases, and partial procedures still require autografts, which are the gold standard for repairing neurologic defects. As symptoms often occur after autografting, human acellular nerve allografts have been used to avoid concomitant symptoms. This study investigated the quality of shoulder abduction and elbow flexion following direct repair and acellular allografting to evaluate issues requiring attention for brachial plexus injury repair. Fifty-one brachial plexus injury patients in the surgical database were eligible for this retrospective study. Patients were divided into two groups according to different surgical methods. Direct repair was performed in 27 patients, while acellular nerve allografts were used to bridge the gap between the contralateral C7 nerve root and upper trunk in 24 patients. The length of the harvested contralateral C7 nerve root was measured intraoperatively. Deltoid and biceps muscle strength, and degrees of shoulder abduction and elbow flexion were examined according to the British Medical Research Council scoring system;meaningful recovery was defined as M3–M5. Lengths of anterior and posterior divisions of the contralateral C7 in the direct repair group were 7.64 ± 0.69 mm and 7.55 ± 0.69 mm, respectively, and in the acellular nerve allografts group were 6.46 ± 0.58 mm and 6.43 ± 0.59 mm, respectively. After a minimum of 4-year follow-up, meaningful recoveries of deltoid and biceps muscles in the direct repair group were 88.89% and 85.19%, respectively, while they were 70.83% and 66.67% in the acellular nerve allografts group. Time to C5/C6 reinnervation was shorter in the direct repair group compared with the acellular nerve allografts group. Direct repair facilitated the restoration of shoulder abduction and elbow flexion. Thus, if direct coaptation is not possible, use of acellular nerve allografts is a suitable option. This study was approved by the Medical Ethical Committee of the First Affiliated Hospital of Sun Yat-sen University, China (Application ID:[2017] 290) on November 14, 2017.
文摘The elbow joint is a complex joint, which, when impaired in function, leads to severe disability. In some cases however, an arthroplasty might be an appropriate treatment. In the past four decades, large steps havebeen taken to optimize this treatment in order to achieve better post-operative outcomes. To understand these progresses and to discover aspects for upcoming improvements, we present a review on the past developments, the present state of affairs and future developments which may improve patient care further.
文摘In this article, we present a case of humeral biepicondylar fracture dislocation concomitant with ulnar nerve injury in a seventeen year-old male patient. Physical examination of our patient in the emergency room revealed a painful, edematous and deformed-looking left elbow joint. Hypoesthesia of the little finger was also diagnosed on the left hand. Radiological assessment ended up with a posterior fracture dislocation of the elbow joint accompanied by intra-articular loose bodies. Open reduction-Internal fixation of the fracture dislocation and ulnar nerve exploration were performed under general anesthesia at the same session as surgical treatment of our patient. Physical therapy and rehabilitation protocol was implemented at the end of two weeks post-operatively. Union of the fracture lines, as well as the olecranon osteotomy site, was achieved at the end of four months post-operatively. Ulnar nerve function was fully restored without any sensory or motor loss. Range of motion at the elbow joint was 20-120 degrees at the latest follow-up.
基金The authors acknowledge the fnancial support by the National Natural Science Foundation of China(No.51874340)by the Shandong Provincial Natural Science Foundation,China(No.ZR2018MEE004).
文摘In this work,computational fuid dynamics(CFD)is used to study elbow erosion due to a gas-solid two-phase fow.In particular,the direct simulation Monte Carlo(DSMC)method is used to study the impact of inter-particle collision on the erosion behavior.The two-way coupled Euler-Lagrange method is used to solve the gas-solid fow,and the DSMC method is used to consider the collision behavior between particles.The efects of key factors,such as the particle concentration distribution and inter-particle collision,on the erosion ratio are evaluated and discussed.The efectiveness of the method is verifed from experimental data.The results show that the inter-particle collision signifcantly infuences the particle movement path and erosion ratio.When the inter-particle collision is considered,the maximum erosion position is ofset.The erosion model proposed by Oka et al.,who used the DSMC method,agrees best with the experimental data,and the average percentage error decreases from 39.2 to 27.4%.
文摘Consistent with an aging population, the overall number of distal humeral fractures in the elderly is increasing. Indications for application of acute total elbow arthroplasty (TEA) in the setting of distal humeral fractures are still being defined. A variety of factors including chronologic age, physiologic age, bone quality, presence of pre-existing arthritis and pre-existing medical conditions need to be considered. Optimally the decision to proceed with TEA verses open reduction internal fixation (ORIF) is made preoperatively. The need to abandon ORIF may be not be apparent until after fracture exposure, and the presence of an olecranon osteotomy makes performing TEA challenging. A case is presented of acute conversion from ORIF to TEA following olecranon osteotomy, utilizing internal fixation bridging the ulnar component and its cement mantle.
文摘This study presents the numerical evaluation about the impact of flow disturbance near the intrados and extrados regions of the 90 degree bended elbow using CFX for several practical cases where the 90 degree bended upward elbow is located in a proximity to the butterfly valve and the butterfly valve open angle is changed. For the change of a butterfly valve open angle from 60% to 100% and the increase of the distance between a valve and a 90 degree bended elbow, the effect of FAC (Flow-Accelerated Corrosion) in the 90 degree bended elbow may be neglected because the value and distribution of the velocity and shear stress is rapidly decreased comparing with the present status installed in an industry, and the data of 100% valve open (Case 3) and L/D ≈ 5 (Case 4) are very good agreement comparing with the reference data, L/D ≈ 8 (Case 2). The reasons are that flow already maintains a fully developed condition and a steady state in spite of less distance than the reference case, L/D = 8. Therefore, smooth flow fields have approached at a 90 degree bended elbow. Then, the effect of shear stress and vortex is hardly investigated around the intrados area of 90 degree bended elbow.
文摘BACKGROUND Joint stiffness after elbow surgery is not a rare complication,and is always accompanied by deformity.The causes of joint stiffness are multiple in different patients,and divided into intrinsic and extrinsic causes.Herein,we report an unusual case of posttraumatic elbow stiffness due to multiple and rare causes.CASE SUMMARY A 19-year-old male was hospitalized with the loss of motion of the left elbow for over ten years.Left limb computed tomography revealed left elbow stiffness with bony block and connection.The patient underwent surgery,and the etiology of joint stiffness was found to be a rare combination of common and uncommon causes.During an 18-mo follow-up period,the patient’s left elbow had normal motion and he was symptom-free.CONCLUSION However,this case combined with multiple and rare causes highlights that the patient with scar physique is likely to be accompanied with more severe soft tissue,nerve contracture,and heterotypic ossification,even during recurrence.
文摘The secondary flow downstream of a triple elbow layout was studied experimentally and numerically to visualize the flow behavior under swirling inlet flow conditions. The inlet swirling condition was generated by a swirl generator, consisting of a rotary pipe and honeycomb assembly. The experiments were carried out in turbulent water flow condition at Reynolds number Re = 1 × 104 and inlet swirl intensity S = 1. Ultrasonic measurements were taken at four locations downstream of the third elbow. The two-dimensional velocity field of the flow field was measured using the phased array ultrasonic velocity profiler technique to evaluate the flow field with separation. Furthermore, a numerical simulation was performed and its results were compared with the experimental data. The numerical result was obtained by solving three-dimensional, Reynolds-averaged Navier-Stokes equations with the renormalization group k-ε turbulence model. The experimental results confirmed that the swirling flow condition modified the size of the separation region downstream of the third elbow. A qualitative comparison between the experimental and CFD simulation results of the averaged velocity field downstream of the third elbow showed similar tendency on reverse flow.
文摘Anterior transolecranon dislocation of the elbow is rarely observed in children, reported in only a small series. The present case involves an anterior transolecranon dislocation of the left elbow joint in a 7-year-old child, which was surgically treated. Two attempts of closed reduction failed because the radial head had buttonholed via the joint capsule. After its release, open reduction was easily performed; osteosynthesis of the olecranon was not performed. Remarkably, good result was obtained, despite a mild flexion deformity at the last follow-up. This case report aims to highlight this treatment method, which may be considered for such an uncommon injury.
