The hook formation mechanism in continuously cast slabs of ultra-low carbon steel was analyzed in detail through numerical calculations and experimental observations using optical microscopy,and its distribution chara...The hook formation mechanism in continuously cast slabs of ultra-low carbon steel was analyzed in detail through numerical calculations and experimental observations using optical microscopy,and its distribution characteristics were determined.Numerical simulations confirmed that the freezing–overflow mechanism is the primary cause of hook formation.They also revealed that the freezing event occurs unpredictably,while the overflow event takes place during the positive strip time.The average pitch of oscillation marks(OMs)on the slab surface was 8.693 mm,while the theoretical pitch was 8.889 mm,with a difference of approximately 2%.This discrepancy primarily results from varying degrees of overflow,which affects the morphology of the OMs and the positions of their deepest points.Notably,this result further confirmed that the freezing and overflow in the meniscus were indeed caused by the periodic oscillation of the mold.Higher superheat hindered hook formation,leading to a negative correlation between the hook depth distribution around the slab and the temperature distribution within the mold.Therefore,the depth of the corner hook was greater than that of other positions,which was caused by the intensified cooling effect of the corner.Moreover,key factors influencing hook development were analyzed,providing insights into transient fluid flow and heat transfer characteristics within the mold.Transient fluid flow and heat transfer contributed to the randomness and tendency of hook formation.This randomness was reflected in the varying angles of the hooks,whereas the tendency was evident in the negative correlation between superheat and hook length.Based on the randomness and tendency of hook formation and its profile characteristics,a new method for controlling hook depth based on“sine law”is proposed.展开更多
BACKGROUND Hook of hamate fractures occur either due to repetitive stress from gripping sports(e.g.,golf,tennis,and baseball),leading to fatigue fracture,or as a result of trauma from falls or other injuries.The recom...BACKGROUND Hook of hamate fractures occur either due to repetitive stress from gripping sports(e.g.,golf,tennis,and baseball),leading to fatigue fracture,or as a result of trauma from falls or other injuries.The recommended treatment involves the excision of bone fragments to facilitate athletes’early return to sports;excision surgery is also performed in trauma cases.However,some patients prefer nonsurgical treatment options,and conservative treatment should be considered.AIM To present a case series of 16 patients conservatively treated for hook of hamate fractures.METHODS This study included 16(11 males and 5 females;right side,6 cases;left side,10)patients who desired conservative treatment and could be followed-up until bone union was achieved.The average age of the patients was 49.6(range:24-72)years.The average time from injury to consultation was 4.3(range:0.2-21.4)weeks.The treatment involved 4 weeks of casting from the forearm to the metacarpophalangeal joint,followed by 8 weeks of splint fixation of the wrist.Follow-up computed tomography scans were performed every 4 weeks.RESULTS Bone union was achieved in all patients.The average duration of casting was 3.7(range:0-5)weeks and that of splint fixation thereafter was 8.6(range:0-28)weeks.The patients did not exhibit joint contractures or range of motion restrictions due to prolonged immobilization.CONCLUSION Conservative treatment with external fixation may be an option for hook of hamate fractures.展开更多
This editorial critically evaluates the landmark study by Tanaka and Yoshii,which demonstrated a 100%union rate with conservative management of hamate hook fractures,challenging the historical preference for surgical ...This editorial critically evaluates the landmark study by Tanaka and Yoshii,which demonstrated a 100%union rate with conservative management of hamate hook fractures,challenging the historical preference for surgical intervention.In contrast to Scheufle et al’s report of 90%-100%failure rates with early surgical approaches,Tanaka and Yoshii’s protocol achieved universal healing despite delayed diagnoses in 25%of cases.Central to this success is the systematic inte-gration of high-resolution computed tomography for early diagnosis and dynamic monitoring of trabecular bone regeneration,significantly reducing missed dia-gnoses and guiding personalized immobilization timelines.The patient-centered strategy—allowing temporary splint removal during low-risk activities—balanced fracture stability with joint mobility preservation,avoiding post-treatment stiff-ness.However,limitations such as small sample size(n=16),selection bias,and insufficient long-term functional data(e.g.,grip strength,return-to-sport metrics)underscore the need for comparative trials.Emerging trends,including adjunct therapies like low-intensity pulsed ultrasound and biologics(e.g.,teriparatide),are proposed to accelerate healing while minimizing immobilization risks.This work redefines conservative fracture management paradigms,emphasizing in-novation without compromising efficacy.Overall,this assessment deepens our understanding of the conservative management of hook fractures and provides evidence-based insights for improved clinical decision-making.展开更多
During the continuous casting process of low carbon steel,the solidified hook formed in the mold has great effects on the surface quality of the cast slab.Some factory experiments have been conducted to investigate th...During the continuous casting process of low carbon steel,the solidified hook formed in the mold has great effects on the surface quality of the cast slab.Some factory experiments have been conducted to investigate the microscopic characteristics and reveal the influence of process parameters on solidified hooks.The depth of the hooks showed a positive correlation with the deflection angle,length,and oscillation mark(OM)depth,which indicates that the OM depth can serve as an approximate indicator for evaluating the depth of the solidified hooks.On the wide and narrow faces of the cast slab,the depth of the solidified hooks and the temperature distribution in the mold show opposite trends,with lower depths of solidified hooks at positions with higher temperatures.In addition,the influence of process parameters on solidified hooks was analyzed.With the increase in superheat,not only the depth of solidified hooks gradually decreases,but also the ratio of depression-typed marks increases.Increasing casting speed and decreasing immersion depth of the submerged entry nozzle will both lead to a decrease in the depth of the solidified hook.展开更多
Objective:To evaluate the therapeutic effect of dynamic fixation with a hook plate-double loop plate internal fixation system for high-energy acromioclavicular joint complex dislocation(denoted as HACD,i.e.,Rockwood t...Objective:To evaluate the therapeutic effect of dynamic fixation with a hook plate-double loop plate internal fixation system for high-energy acromioclavicular joint complex dislocation(denoted as HACD,i.e.,Rockwood type III-V dislocation).Methods:Fifty-eight patients with HACD were selected and evenly divided by drawing lots.The experimental group underwent ligament reconstruction treatment,while the reference group received hook plate fixation treatment.The efficacy and other indicators were compared between the groups.Results:The overall effective rates between the groups were similar(P>0.05).The experimental group had a longer surgical duration,lower pain scores at 6 months postoperatively,higher shoulder joint function scores,and a lower complication rate,with P<0.05 when compared between groups.Conclusion:The effectiveness of the double loop plate internal fixation system ligament reconstruction treatment for patients with HACD is comparable to that of hook plate fixation treatment.Although the surgical duration is slightly longer,postoperative pain is milder,facilitating the recovery of shoulder joint function in patients and offering higher safety.展开更多
基金financially supported by the National Natural Science Foundation of China(No.52174306)the Fundamental Research Funds for the Central Universities(Nos.N2225023 and N2425006)the Basic Research Projects of Liaoning Provincial Department of Education(No.LJ212410148027)。
文摘The hook formation mechanism in continuously cast slabs of ultra-low carbon steel was analyzed in detail through numerical calculations and experimental observations using optical microscopy,and its distribution characteristics were determined.Numerical simulations confirmed that the freezing–overflow mechanism is the primary cause of hook formation.They also revealed that the freezing event occurs unpredictably,while the overflow event takes place during the positive strip time.The average pitch of oscillation marks(OMs)on the slab surface was 8.693 mm,while the theoretical pitch was 8.889 mm,with a difference of approximately 2%.This discrepancy primarily results from varying degrees of overflow,which affects the morphology of the OMs and the positions of their deepest points.Notably,this result further confirmed that the freezing and overflow in the meniscus were indeed caused by the periodic oscillation of the mold.Higher superheat hindered hook formation,leading to a negative correlation between the hook depth distribution around the slab and the temperature distribution within the mold.Therefore,the depth of the corner hook was greater than that of other positions,which was caused by the intensified cooling effect of the corner.Moreover,key factors influencing hook development were analyzed,providing insights into transient fluid flow and heat transfer characteristics within the mold.Transient fluid flow and heat transfer contributed to the randomness and tendency of hook formation.This randomness was reflected in the varying angles of the hooks,whereas the tendency was evident in the negative correlation between superheat and hook length.Based on the randomness and tendency of hook formation and its profile characteristics,a new method for controlling hook depth based on“sine law”is proposed.
文摘BACKGROUND Hook of hamate fractures occur either due to repetitive stress from gripping sports(e.g.,golf,tennis,and baseball),leading to fatigue fracture,or as a result of trauma from falls or other injuries.The recommended treatment involves the excision of bone fragments to facilitate athletes’early return to sports;excision surgery is also performed in trauma cases.However,some patients prefer nonsurgical treatment options,and conservative treatment should be considered.AIM To present a case series of 16 patients conservatively treated for hook of hamate fractures.METHODS This study included 16(11 males and 5 females;right side,6 cases;left side,10)patients who desired conservative treatment and could be followed-up until bone union was achieved.The average age of the patients was 49.6(range:24-72)years.The average time from injury to consultation was 4.3(range:0.2-21.4)weeks.The treatment involved 4 weeks of casting from the forearm to the metacarpophalangeal joint,followed by 8 weeks of splint fixation of the wrist.Follow-up computed tomography scans were performed every 4 weeks.RESULTS Bone union was achieved in all patients.The average duration of casting was 3.7(range:0-5)weeks and that of splint fixation thereafter was 8.6(range:0-28)weeks.The patients did not exhibit joint contractures or range of motion restrictions due to prolonged immobilization.CONCLUSION Conservative treatment with external fixation may be an option for hook of hamate fractures.
文摘This editorial critically evaluates the landmark study by Tanaka and Yoshii,which demonstrated a 100%union rate with conservative management of hamate hook fractures,challenging the historical preference for surgical intervention.In contrast to Scheufle et al’s report of 90%-100%failure rates with early surgical approaches,Tanaka and Yoshii’s protocol achieved universal healing despite delayed diagnoses in 25%of cases.Central to this success is the systematic inte-gration of high-resolution computed tomography for early diagnosis and dynamic monitoring of trabecular bone regeneration,significantly reducing missed dia-gnoses and guiding personalized immobilization timelines.The patient-centered strategy—allowing temporary splint removal during low-risk activities—balanced fracture stability with joint mobility preservation,avoiding post-treatment stiff-ness.However,limitations such as small sample size(n=16),selection bias,and insufficient long-term functional data(e.g.,grip strength,return-to-sport metrics)underscore the need for comparative trials.Emerging trends,including adjunct therapies like low-intensity pulsed ultrasound and biologics(e.g.,teriparatide),are proposed to accelerate healing while minimizing immobilization risks.This work redefines conservative fracture management paradigms,emphasizing in-novation without compromising efficacy.Overall,this assessment deepens our understanding of the conservative management of hook fractures and provides evidence-based insights for improved clinical decision-making.
基金the financial support of National Key Research and Development Plan(No.2021YFB3702000)National Natural Science of China(Nos.52074076,52174306 and U20A20272)Fundamental Research Funds for the Central Universities(Nos.N2225023 and N2425006).Author information。
文摘During the continuous casting process of low carbon steel,the solidified hook formed in the mold has great effects on the surface quality of the cast slab.Some factory experiments have been conducted to investigate the microscopic characteristics and reveal the influence of process parameters on solidified hooks.The depth of the hooks showed a positive correlation with the deflection angle,length,and oscillation mark(OM)depth,which indicates that the OM depth can serve as an approximate indicator for evaluating the depth of the solidified hooks.On the wide and narrow faces of the cast slab,the depth of the solidified hooks and the temperature distribution in the mold show opposite trends,with lower depths of solidified hooks at positions with higher temperatures.In addition,the influence of process parameters on solidified hooks was analyzed.With the increase in superheat,not only the depth of solidified hooks gradually decreases,but also the ratio of depression-typed marks increases.Increasing casting speed and decreasing immersion depth of the submerged entry nozzle will both lead to a decrease in the depth of the solidified hook.
文摘Objective:To evaluate the therapeutic effect of dynamic fixation with a hook plate-double loop plate internal fixation system for high-energy acromioclavicular joint complex dislocation(denoted as HACD,i.e.,Rockwood type III-V dislocation).Methods:Fifty-eight patients with HACD were selected and evenly divided by drawing lots.The experimental group underwent ligament reconstruction treatment,while the reference group received hook plate fixation treatment.The efficacy and other indicators were compared between the groups.Results:The overall effective rates between the groups were similar(P>0.05).The experimental group had a longer surgical duration,lower pain scores at 6 months postoperatively,higher shoulder joint function scores,and a lower complication rate,with P<0.05 when compared between groups.Conclusion:The effectiveness of the double loop plate internal fixation system ligament reconstruction treatment for patients with HACD is comparable to that of hook plate fixation treatment.Although the surgical duration is slightly longer,postoperative pain is milder,facilitating the recovery of shoulder joint function in patients and offering higher safety.
