Objective:To explore the mechanical behavior of acetabulum loaded by static stress and provide the mechanical basis for clinical analysis and judgement on acetabular mechanical distribution and effect of static stress...Objective:To explore the mechanical behavior of acetabulum loaded by static stress and provide the mechanical basis for clinical analysis and judgement on acetabular mechanical distribution and effect of static stress.Methods:By means of computer simulation, acetabular three dimensional model was input into three dimensional finite element analysis software ANSYS7.0. The acetabular mechanical behavior was calculated and the main stress value, stress distribution and acetabular unit displacement in the direction of main stress were analyzed when anterior wall of acetabulum and acetabular crest were loaded by 1 000 N static stress. Results:When acetabular anterior wall loaded by X direction and Z direction composition force, the stress passed along 4 directions: (1)from acetabular anterior wall to pubic symphysis along superior branch of pubis firstly, (2)from acetabular anterior wall to cacroiliac joint along pelvic ring,(3)in the acetabulum,(4)from the suffered point to ischium. When acetabular crest loaded by X direction and Y direction composition force, the stress transmitted to 4 directions: (1)from acetabular crest to ilium firstly, (2)from suffered point to cacroiliac joint along pelvic ring,(3) in the acetabulum ,(4)along the pubic branch,but no stress transmitted to the ischium branch.Conclusion:Analyzing the stress distribution of acetabulum and units displacement when static stress loaded can provide internal fixation point for acetabular fracture treatment and help understand the stress distribution of acetabulum.展开更多
Background: The management of traumatic acetabular injuries (TAI), which are often complex and diverse, is difficult and costly in the context of low-income African countries. Objective: To evaluate the treatment of t...Background: The management of traumatic acetabular injuries (TAI), which are often complex and diverse, is difficult and costly in the context of low-income African countries. Objective: To evaluate the treatment of traumatic acetabular lesions in the Orthopedics and Traumatology Department of the Yalgado Ouedraogo University Hospital, for their better management. Patients and Methods: This was a retrospective study, conducted in our department from January 2012 to December 2016. Sixty-three patients with TAI and complete records were selected. The mean age of patients with coxofemoral dislocations was 34.2 years and 36.4 years for acetabulum fractures with male predominance in both injury types. The injuries were mainly caused by a violent road traffic accident (RTA) (90.5%). Forty hip dislocations and 41 acetabular fractures were reported, with a prevalence of iliac dislocations (52.5%) and posterior wall fractures of the acetabulum (24.4%). Results: The average time to manage TAI was 15.9 hours (range 2 - 100). Medical treatment was performed in all patients. Thirty-eight coxofemoral dislocations and 34 acetabular fractures were treated by orthopedic methods. Seven complex acetabular fractures and two coxo-femoral dislocations were performed by surgical method. Two patients died (3.2%), one in a hemorrhagic shock table and the other in a septic shock table. Immediate and late complications were identified. Conclusion: Early and adequate management of our TAI, requires a modern technical platform and a sufficient number of qualified medical personnel to improve their functional outcomes.展开更多
BACKGROUND Total hip arthroplasty(THA)is a common procedure for end stage osteoarthritis.The learning curve for THA is complex and challenging.One of the most difficult skills to master is acetabular reaming.We wish t...BACKGROUND Total hip arthroplasty(THA)is a common procedure for end stage osteoarthritis.The learning curve for THA is complex and challenging.One of the most difficult skills to master is acetabular reaming.We wish to identify if experience in arthroplasty leads to preservation of more bone stock.AIM To investigate if increasing surgeon experience will predict an ever decreasing acetabular cup size.METHODS A retrospective case series of four attending orthopaedic surgeons was completed.All uncemented elective total hip arthroplasties since appointment were selected for inclusion.The size of acetabular cup used was noted and logistic regression was used to identify if a trend to smaller cups existed.RESULTS A total of 1614 subjects were included with a mean age of 64 years.Overall cups were on average 0.18mm smaller per year(95%confidence interval-0.25 to-0.11,P<0.001).Individual surgeon trends showed cup sizes to decrease 0.27 mm/year for surgeon A,0.02 mm/year for surgeon B,0.15 mm/year for surgeon C and 0.29 mm/year for surgeon D.Three of the four surgeons had a more pronounced trend to smaller cups for male subjects than their female counterparts.CONCLUSION We found increasing surgeon experience to be associated with an ever-decreasing acetabular cup size.Smaller acetabular cup size may act as a surrogate marker of surgical proficiency by virtue of decreased acetabular reaming.展开更多
BACKGROUND Selecting the optimal size of components is crucial when performing a primary total hip arthroplasty.Implanting the accurate size of the acetabular component can occasionally be exacting,chiefly for surgeon...BACKGROUND Selecting the optimal size of components is crucial when performing a primary total hip arthroplasty.Implanting the accurate size of the acetabular component can occasionally be exacting,chiefly for surgeons with little experience,whilst the complications of imprecise acetabular sizing or over-reaming can be potentially devastating.AIM To assist clinicians intraoperatively with a simple and repeatable tip in elucidating the ambivalence when determining the proper acetabular component size is not straightforwardly achieved,specifically when surgeons are inexperienced or preoperative templating is unavailable.METHODS This method was employed in 263 operations in our department from June 2021 to December 2022.All operations were performed by the same team of joint reconstruction surgeons,employing a typical posterior hip approach technique.The types of acetabular shells implanted were:The Dynasty®acetabular cup system(MicroPort Orthopedics,Shanghai,China)and the R3®acetabular system(Smith&Nephew,Watford,United Kingdom),which both feature cementless press-fit design.RESULTS The mean value of all cases was calculated and collated with each other.We distinguished as oversized an implanted acetabular shell when its size was>2 mm larger than the size of the acetabular size indicator reamer(ASIR)or when the implanted shell was larger than 4 mm compared to the preoperative planned cup.The median size of the implanted acetabular shell was 52(48–54)mm,while the median size of the preoperatively planned cup was 50(48–56)mm,and the median size of the ASIR was 52(50–54)mm.The correlation coefficient between ASIR size and implanted acetabular component size exhibited a high positive correlation with r=0.719(P<0.001).Contrariwise,intraoperative ASIR measurements precisely predicted the implanted cups’size or differed by only one size(2 mm)in 245 cases.CONCLUSION In our study,we demonstrated that the size of the first acetabular reamer not entering freely in the acetabular rim corroborates the final acetabular component size to implant.This was also corresponding in the majority of the cases with conventional preoperative templating.It can be featured as a valid tool for avoiding the potentially pernicious complications of acetabular cup over-reaming and over-sizing in primary total hip arthroplasty.It is a simple and reproducible technical note useful for confirming the predicted acetabular cup size preoperatively;thus,its application could be considered routinely,even in cases where preoperative templating is unavailable.展开更多
Background With advance of age, alterations in bone quality, quantity and microarchitecture render osteoporotic trabecular bone become more sensitive to local failure. The aims of the present study were to clarify the...Background With advance of age, alterations in bone quality, quantity and microarchitecture render osteoporotic trabecular bone become more sensitive to local failure. The aims of the present study were to clarify the extent to which the distribution of tissue-level stresses and strains was affected by structural changes and the extent to which osteoporotic acetabular trabecular bone was damaged at small strains. Methods Using a DAWING 4000A supercomputer, nonlinear micro-finite element （μFE） analyses were performed to calculate the tissue-level strains and stresses for each element in the trabecular bone of one osteoporotic acetabulum at small strains to quantify the tissue-level damage accumulation and mechanical properties. Results In contour plots of the tissue, maximum principal logarithmic strains, high tissue-level strains, both compressive and tensile, were observed in the osteoporotic trabecular bone at small apparent strains from 0.2% to 0.5% strain. The compressive apparent stress-strain curve showed typical nonlinear behavior and tangent modulus reduction with increasing strains. The microdamage curve suggested that microdamage began at 0.2% apparent strain in the osteoporotic trabecular bone and increased sharply, although very few microfractures occurred. The quartiles of the maximum principal logarithmic strains, minimum principal logarithmic strains and Von Mises stresses increased nonlinearly. For the inter-quartile range of the Von Mises stresses, a leap occurred at small strains ranging from 0.2% to 0.3% while microdamage commenced. Conclusions Extensive microdamage was primarily responsible for the large loss in apparent mechanical properties that occurred in the trabecular bone of the osteoporotic acetabulum at small strains. With increasing apparent strains, continuous nonlinear increments of tissue-level strains and stresses resulted in microdamage that propagated throughout the specimen with very few microfractures. Chin Med J 2009; 122（17）：2041-204 7展开更多
目的探讨3D打印半骨盆假体置换治疗EnnekingⅡ+Ⅲ区骨盆恶性肿瘤的疗效及保留髂前下棘的安全性及有效性。方法收集2018年1月至2020年1月进行3D打印半骨盆假体置换的25例骨盆Ⅱ+Ⅲ区恶性肿瘤患者资料。男11例,女14例;年龄17~77岁,平均(49...目的探讨3D打印半骨盆假体置换治疗EnnekingⅡ+Ⅲ区骨盆恶性肿瘤的疗效及保留髂前下棘的安全性及有效性。方法收集2018年1月至2020年1月进行3D打印半骨盆假体置换的25例骨盆Ⅱ+Ⅲ区恶性肿瘤患者资料。男11例,女14例;年龄17~77岁,平均(49.96±9.73)岁。其中普通型骨肉瘤11例,软骨肉瘤6例,毛细血管扩张型骨肉瘤3例,尤文氏肉瘤3例,转移性副神经节瘤(原发部位为腰椎)1例,转移性肾透明细胞癌1例。其中根据手术方式不同分为研究组(保留髂前下棘,10例)和对照组(未保留髂前下棘,15例)。记录两组患者手术时间及术中出血量。通过影像学评估假体的髋臼旋转中心偏移情况。以肌肉骨骼肿瘤协会评分(musculoskeletal tumor society,MSTS)、Harris髋关节功能评分及美国特种外科医院(hospital for special surgery,HSS)膝关节功能评分进行评估,并记录肿瘤学预后及并发症。结果随访时间16~27个月,平均为(21.92±3.40)个月。研究组与对照组手术时间及术中出血量对比差异均无统计学意义(P>0.05)。术后及末次随访时,研究组MSTS功能评分、Harris髋关节功能评分、HSS膝关节功能评分均高于对照组,差异均有统计学意义(P<0.05)。末次随访时,研究组与对照组的假体髋臼旋转中心偏移对比差异无统计学意义(P>0.05)。术后3例患者出现术区感染,2例出现切口周围脂肪液化坏死,经治疗后痊愈。末次随访时1例骨盆转移瘤患者在术后1年发现肝转移,靶向药物控制,带瘤存活;其余患者均未发现肿瘤复发及转移。结论3D打印半骨盆假体置换治疗骨盆EnnekingⅡ+Ⅲ区恶性肿瘤是一种安全、有效的手术方法。此外,保留髂前下棘及肌肉附着点对髋关节及膝关节功能恢复具有重要的意义。展开更多
Fractures of the acetabulum in elderly patients were often caused by low energy trauma.Fractures involving anterior column are more common and often associated with impaction and comminution.Osteoporosis further compl...Fractures of the acetabulum in elderly patients were often caused by low energy trauma.Fractures involving anterior column are more common and often associated with impaction and comminution.Osteoporosis further complicates the management.Percutaneous fracture fixation has low morbidity but it is a technically demanding procedure.Open reduction and fracture fixation is done with or without simultaneous total hip replacement.Delayed total hip replacement is considered in posttraumatic arthritis patients.Patients with minimal displaced fractures,associated both-column fractures with secondary congruence of joint and patients who are medically unfit for surgery can be managed non-operatively.Whatever be the method of management,these elderly patients should be mobilised as early as possible.展开更多
Objective： To explore the treatment methods and outcome of posterior wall fractures of the acetabulum. Methods： The data of 31 patients （25 males and 6 females, aged 19-59 years, mean： 40.5 years） with posterior ...Objective： To explore the treatment methods and outcome of posterior wall fractures of the acetabulum. Methods： The data of 31 patients （25 males and 6 females, aged 19-59 years, mean： 40.5 years） with posterior wall fractures of the acetabulum hospitalized in our department from 2002 to 2006 were analyzed retrospectively in this study. The types of fractures, number of fragments, combined dislocations, and sciatic nerve function were documented before admission. All the fractures were treated with open reduction and internal fixation. Based on the fracture type and site, either screws alone or reconstructive plates were used. The patients were immobilized for an average of 12 weeks before partial weight bearing was permitted. After follow-up for 12-70 months （43.6 months on average）, modified Merle d＇Aubigne score was adopted to evaluate the outcomes of the operations. Results： The percentages of the excellent, good, fair and poor results were 48.4%, 41.9%, 6.5%, and 3.3%, respectively, with a good to excellent rate of 90.2%. Idiopathic sciatic nerve injury occurred in only one case. Conclusions： The sciatic nerve should be routinely exposed and protected during the surgery. The type of fixation should be based on the fracture type and site. Prolonged immobilization may be helpful in improving the final outcomes.展开更多
The mechanical properties of the pelvic trabecular bone have been studied at the continuum level. However, nothing is known about the tissue-level damage in the trabecular bone of the healthy human acetabulum at appar...The mechanical properties of the pelvic trabecular bone have been studied at the continuum level. However, nothing is known about the tissue-level damage in the trabecular bone of the healthy human acetabulum at apparent small strains characteristic of habitual. By a DAWING 4000 A supercomputer, nonlinear micro-finite element (μFE) analysis was performed to quantify tissue-level damage accumulation in trabecular bone at small strains. The data indicate that damage in trabecular bone commence at 0.2% apparent strain. The findings imply that tissue yielding can initiate at very low strains in the trabecular bone of the healthy acetabulum and that this local failure has negative consequences on the apparent mechanical properties of trabecular bone.展开更多
文摘Objective:To explore the mechanical behavior of acetabulum loaded by static stress and provide the mechanical basis for clinical analysis and judgement on acetabular mechanical distribution and effect of static stress.Methods:By means of computer simulation, acetabular three dimensional model was input into three dimensional finite element analysis software ANSYS7.0. The acetabular mechanical behavior was calculated and the main stress value, stress distribution and acetabular unit displacement in the direction of main stress were analyzed when anterior wall of acetabulum and acetabular crest were loaded by 1 000 N static stress. Results:When acetabular anterior wall loaded by X direction and Z direction composition force, the stress passed along 4 directions: (1)from acetabular anterior wall to pubic symphysis along superior branch of pubis firstly, (2)from acetabular anterior wall to cacroiliac joint along pelvic ring,(3)in the acetabulum,(4)from the suffered point to ischium. When acetabular crest loaded by X direction and Y direction composition force, the stress transmitted to 4 directions: (1)from acetabular crest to ilium firstly, (2)from suffered point to cacroiliac joint along pelvic ring,(3) in the acetabulum ,(4)along the pubic branch,but no stress transmitted to the ischium branch.Conclusion:Analyzing the stress distribution of acetabulum and units displacement when static stress loaded can provide internal fixation point for acetabular fracture treatment and help understand the stress distribution of acetabulum.
文摘Background: The management of traumatic acetabular injuries (TAI), which are often complex and diverse, is difficult and costly in the context of low-income African countries. Objective: To evaluate the treatment of traumatic acetabular lesions in the Orthopedics and Traumatology Department of the Yalgado Ouedraogo University Hospital, for their better management. Patients and Methods: This was a retrospective study, conducted in our department from January 2012 to December 2016. Sixty-three patients with TAI and complete records were selected. The mean age of patients with coxofemoral dislocations was 34.2 years and 36.4 years for acetabulum fractures with male predominance in both injury types. The injuries were mainly caused by a violent road traffic accident (RTA) (90.5%). Forty hip dislocations and 41 acetabular fractures were reported, with a prevalence of iliac dislocations (52.5%) and posterior wall fractures of the acetabulum (24.4%). Results: The average time to manage TAI was 15.9 hours (range 2 - 100). Medical treatment was performed in all patients. Thirty-eight coxofemoral dislocations and 34 acetabular fractures were treated by orthopedic methods. Seven complex acetabular fractures and two coxo-femoral dislocations were performed by surgical method. Two patients died (3.2%), one in a hemorrhagic shock table and the other in a septic shock table. Immediate and late complications were identified. Conclusion: Early and adequate management of our TAI, requires a modern technical platform and a sufficient number of qualified medical personnel to improve their functional outcomes.
文摘BACKGROUND Total hip arthroplasty(THA)is a common procedure for end stage osteoarthritis.The learning curve for THA is complex and challenging.One of the most difficult skills to master is acetabular reaming.We wish to identify if experience in arthroplasty leads to preservation of more bone stock.AIM To investigate if increasing surgeon experience will predict an ever decreasing acetabular cup size.METHODS A retrospective case series of four attending orthopaedic surgeons was completed.All uncemented elective total hip arthroplasties since appointment were selected for inclusion.The size of acetabular cup used was noted and logistic regression was used to identify if a trend to smaller cups existed.RESULTS A total of 1614 subjects were included with a mean age of 64 years.Overall cups were on average 0.18mm smaller per year(95%confidence interval-0.25 to-0.11,P<0.001).Individual surgeon trends showed cup sizes to decrease 0.27 mm/year for surgeon A,0.02 mm/year for surgeon B,0.15 mm/year for surgeon C and 0.29 mm/year for surgeon D.Three of the four surgeons had a more pronounced trend to smaller cups for male subjects than their female counterparts.CONCLUSION We found increasing surgeon experience to be associated with an ever-decreasing acetabular cup size.Smaller acetabular cup size may act as a surrogate marker of surgical proficiency by virtue of decreased acetabular reaming.
文摘BACKGROUND Selecting the optimal size of components is crucial when performing a primary total hip arthroplasty.Implanting the accurate size of the acetabular component can occasionally be exacting,chiefly for surgeons with little experience,whilst the complications of imprecise acetabular sizing or over-reaming can be potentially devastating.AIM To assist clinicians intraoperatively with a simple and repeatable tip in elucidating the ambivalence when determining the proper acetabular component size is not straightforwardly achieved,specifically when surgeons are inexperienced or preoperative templating is unavailable.METHODS This method was employed in 263 operations in our department from June 2021 to December 2022.All operations were performed by the same team of joint reconstruction surgeons,employing a typical posterior hip approach technique.The types of acetabular shells implanted were:The Dynasty®acetabular cup system(MicroPort Orthopedics,Shanghai,China)and the R3®acetabular system(Smith&Nephew,Watford,United Kingdom),which both feature cementless press-fit design.RESULTS The mean value of all cases was calculated and collated with each other.We distinguished as oversized an implanted acetabular shell when its size was>2 mm larger than the size of the acetabular size indicator reamer(ASIR)or when the implanted shell was larger than 4 mm compared to the preoperative planned cup.The median size of the implanted acetabular shell was 52(48–54)mm,while the median size of the preoperatively planned cup was 50(48–56)mm,and the median size of the ASIR was 52(50–54)mm.The correlation coefficient between ASIR size and implanted acetabular component size exhibited a high positive correlation with r=0.719(P<0.001).Contrariwise,intraoperative ASIR measurements precisely predicted the implanted cups’size or differed by only one size(2 mm)in 245 cases.CONCLUSION In our study,we demonstrated that the size of the first acetabular reamer not entering freely in the acetabular rim corroborates the final acetabular component size to implant.This was also corresponding in the majority of the cases with conventional preoperative templating.It can be featured as a valid tool for avoiding the potentially pernicious complications of acetabular cup over-reaming and over-sizing in primary total hip arthroplasty.It is a simple and reproducible technical note useful for confirming the predicted acetabular cup size preoperatively;thus,its application could be considered routinely,even in cases where preoperative templating is unavailable.
文摘Background With advance of age, alterations in bone quality, quantity and microarchitecture render osteoporotic trabecular bone become more sensitive to local failure. The aims of the present study were to clarify the extent to which the distribution of tissue-level stresses and strains was affected by structural changes and the extent to which osteoporotic acetabular trabecular bone was damaged at small strains. Methods Using a DAWING 4000A supercomputer, nonlinear micro-finite element （μFE） analyses were performed to calculate the tissue-level strains and stresses for each element in the trabecular bone of one osteoporotic acetabulum at small strains to quantify the tissue-level damage accumulation and mechanical properties. Results In contour plots of the tissue, maximum principal logarithmic strains, high tissue-level strains, both compressive and tensile, were observed in the osteoporotic trabecular bone at small apparent strains from 0.2% to 0.5% strain. The compressive apparent stress-strain curve showed typical nonlinear behavior and tangent modulus reduction with increasing strains. The microdamage curve suggested that microdamage began at 0.2% apparent strain in the osteoporotic trabecular bone and increased sharply, although very few microfractures occurred. The quartiles of the maximum principal logarithmic strains, minimum principal logarithmic strains and Von Mises stresses increased nonlinearly. For the inter-quartile range of the Von Mises stresses, a leap occurred at small strains ranging from 0.2% to 0.3% while microdamage commenced. Conclusions Extensive microdamage was primarily responsible for the large loss in apparent mechanical properties that occurred in the trabecular bone of the osteoporotic acetabulum at small strains. With increasing apparent strains, continuous nonlinear increments of tissue-level strains and stresses resulted in microdamage that propagated throughout the specimen with very few microfractures. Chin Med J 2009; 122（17）：2041-204 7
文摘目的探讨3D打印半骨盆假体置换治疗EnnekingⅡ+Ⅲ区骨盆恶性肿瘤的疗效及保留髂前下棘的安全性及有效性。方法收集2018年1月至2020年1月进行3D打印半骨盆假体置换的25例骨盆Ⅱ+Ⅲ区恶性肿瘤患者资料。男11例,女14例;年龄17~77岁,平均(49.96±9.73)岁。其中普通型骨肉瘤11例,软骨肉瘤6例,毛细血管扩张型骨肉瘤3例,尤文氏肉瘤3例,转移性副神经节瘤(原发部位为腰椎)1例,转移性肾透明细胞癌1例。其中根据手术方式不同分为研究组(保留髂前下棘,10例)和对照组(未保留髂前下棘,15例)。记录两组患者手术时间及术中出血量。通过影像学评估假体的髋臼旋转中心偏移情况。以肌肉骨骼肿瘤协会评分(musculoskeletal tumor society,MSTS)、Harris髋关节功能评分及美国特种外科医院(hospital for special surgery,HSS)膝关节功能评分进行评估,并记录肿瘤学预后及并发症。结果随访时间16~27个月,平均为(21.92±3.40)个月。研究组与对照组手术时间及术中出血量对比差异均无统计学意义(P>0.05)。术后及末次随访时,研究组MSTS功能评分、Harris髋关节功能评分、HSS膝关节功能评分均高于对照组,差异均有统计学意义(P<0.05)。末次随访时,研究组与对照组的假体髋臼旋转中心偏移对比差异无统计学意义(P>0.05)。术后3例患者出现术区感染,2例出现切口周围脂肪液化坏死,经治疗后痊愈。末次随访时1例骨盆转移瘤患者在术后1年发现肝转移,靶向药物控制,带瘤存活;其余患者均未发现肿瘤复发及转移。结论3D打印半骨盆假体置换治疗骨盆EnnekingⅡ+Ⅲ区恶性肿瘤是一种安全、有效的手术方法。此外,保留髂前下棘及肌肉附着点对髋关节及膝关节功能恢复具有重要的意义。
文摘Fractures of the acetabulum in elderly patients were often caused by low energy trauma.Fractures involving anterior column are more common and often associated with impaction and comminution.Osteoporosis further complicates the management.Percutaneous fracture fixation has low morbidity but it is a technically demanding procedure.Open reduction and fracture fixation is done with or without simultaneous total hip replacement.Delayed total hip replacement is considered in posttraumatic arthritis patients.Patients with minimal displaced fractures,associated both-column fractures with secondary congruence of joint and patients who are medically unfit for surgery can be managed non-operatively.Whatever be the method of management,these elderly patients should be mobilised as early as possible.
文摘Objective： To explore the treatment methods and outcome of posterior wall fractures of the acetabulum. Methods： The data of 31 patients （25 males and 6 females, aged 19-59 years, mean： 40.5 years） with posterior wall fractures of the acetabulum hospitalized in our department from 2002 to 2006 were analyzed retrospectively in this study. The types of fractures, number of fragments, combined dislocations, and sciatic nerve function were documented before admission. All the fractures were treated with open reduction and internal fixation. Based on the fracture type and site, either screws alone or reconstructive plates were used. The patients were immobilized for an average of 12 weeks before partial weight bearing was permitted. After follow-up for 12-70 months （43.6 months on average）, modified Merle d＇Aubigne score was adopted to evaluate the outcomes of the operations. Results： The percentages of the excellent, good, fair and poor results were 48.4%, 41.9%, 6.5%, and 3.3%, respectively, with a good to excellent rate of 90.2%. Idiopathic sciatic nerve injury occurred in only one case. Conclusions： The sciatic nerve should be routinely exposed and protected during the surgery. The type of fixation should be based on the fracture type and site. Prolonged immobilization may be helpful in improving the final outcomes.
基金the National High Technology Research and Development Program (863) of China(No. 2006AA02A137the Postgraduate Creativity Foundation of Shanghai Jiaotong University (No. BXJ0730)
文摘The mechanical properties of the pelvic trabecular bone have been studied at the continuum level. However, nothing is known about the tissue-level damage in the trabecular bone of the healthy human acetabulum at apparent small strains characteristic of habitual. By a DAWING 4000 A supercomputer, nonlinear micro-finite element (μFE) analysis was performed to quantify tissue-level damage accumulation in trabecular bone at small strains. The data indicate that damage in trabecular bone commence at 0.2% apparent strain. The findings imply that tissue yielding can initiate at very low strains in the trabecular bone of the healthy acetabulum and that this local failure has negative consequences on the apparent mechanical properties of trabecular bone.
