Comparative study of various internal fixation methods for treating patellar fractures by three-dimensional photoelasticity

Objective: To compare the biomechanical basis of 3 different internal fixation methods: nitinol patellar concentrator (NT-PC),tension band and wire circle in treating patellar fractures. Methods:The epoxy resin three dimensional photoelasticity patellar models were made by precise moulding, and were fixated by nitinol patellar concentrator (NT-PC) , tension band and wire circle respectively. The patellar models with frozen stress stripes were put into the polarized light field and the stress distributions were compared. As for the model fixated by NT-PC, by dividing layer, photographing and tracing, we used the iterative method to calculate the stress value of every internal node of the epoxy resin patellar model, and the character of stress was analyzed. Results:An overall stress field was yielded when the patellar model was fixated by NT-PC, and the stripes were more than that of tension band model and wire circle model, which have only few stress stripes in the fixated layers. Further analysis indicated that there were continuous fixated stresses in the facies articularis and distal pole of patella, and the character of stresses produced by NT-PC were mainly in longitudinal direction, then in transverse direction. The shearing stresses were small. Conclusion: The initiative and continuous memorial stress of NT-PC and its overall stress distribution character are the essence of NT-PC distinguished with tension band and wire circle in treating patellar fractures. The stress character produced by NT-PC is good for the stability of fracture site and prompts fracture healing.     

Effect of fixing distal radius fracture with volar locking palmar plates while preserving pronator quadratus

Background L-shaped incision of pronator quadratus （PQ） muscle along its radial and distal borders was always taken for distal radius fractures reduction and internal fixation.Repair of the PQ muscle was always recommended at the end of operation for some instructive reasons.But repair of PQ is not satisfied because of poor quality of muscle and fascial tissues which may cause pain or impede forearm pronation and supination for post-operative scarring around PQ.Inserting the locking palmar plate to pass under the pronator quadratus muscle and the locking screws are inserted through miniincisions in pronator quadratus in some patients with distal radius fractures is a reasonable technique which can preserve the pronator quadratus.The purpose of this study was to evaluate and compare the clinical effects after volar plating of the distal radius fractures while preserving the pronator quadratus and pronator quadratus repair.Methods Between September 2010 and April 2012,65 patients （42 males and 23 females; aged 20-68 years and a mean age of 42.5 years） with distal radius fracture underwent open reduction and internal fixation using the volar locking palmar plates （Depuy or Smith companies）.The patients were classified as 23A-2 through 23C-3 according to the Orthopaedic Trauma Association （OTA） classifications.All surgeries were completed by the same trained team.The volar locking palmar plates of distal radius performed with preserving pronator quadratus group involved 30 patients including 19 males and 11 females and performed with pronator quadratus repair group involved 35 patients including 23 males and 12 females.We compared the two groups for wrist pain,forearm range of motion,grip strength,pedoperative complications and wrist functional recovery score.Results The minimum follow-up for the whole cohort was one year.The differences between the two groups were significant with regard to wrist pain,forearm range of motion,grip strength and wrist function at 1,2,and 6 weeks postoperatively,but insi     

Clinical significance of three dimensional finite element analysis on humerus fracture

Objective: To treat humerus fracture with three dimensional pattern and finite element analysis, providing mechanical basis for treating humerus fracture. Methods: Humerus pattern was established based on the CT images, and calculation was done by ANSYS5. 6 software. Three dimensional ten-node tetrahedron unit was selected and were divided into 2 729 nodes, 49 041 units. Distribution and amount of axial compression of humerus were analyzed when clip angle was 30°, 45°, 90° between fracture face and axial line with fixed X, Y, Z directions. Results: The distribution of stress was greatly different between fracture face and non fracture face. Stress in fracture part was fairly concentrated with incomplete symmetric distribution around the center of fracture face; Greater stress distributed in the regions 10 mm from fracture face, which was 2-3 times that of other stress regions. Conclusion: Required load must be estimated under various conditions as to select the suitable internal fixation implants dur     

Treatment of type C3 distal radius fracture resulted from high-energy injuries by volar plate in combination with external fixator

Background With a type C3 distal radius fracture it is extremely difficult to maintain the reduction and to restore congruity of the articular surface because the support for the volar and dorsal bone cortex has been lost. An external fixator crossing wrist in combination with Kirschner wire （K-wire） fixation was popularly used by most studies in recent years. But loss of reduction often occurred especially in the volar sides. Methods A total of 30 cases of type C3 distal radius fracture were treated by a volar buttress plate combined with a transarticular external fixator and other techniques such as K-wire fixation and bone grafting if necessary. The postoperative volar tilt angles, ulnar inclinations, radial heights, range of motion, grip strength and complications were recorded to assess the therapeutic effects. Results Of the 30 patients, 27 patients were followed up for 12-29 （mean 18） months and all fractures healed in 8-13 weeks after surgery （mean 10 weeks）. The wrist function was excellent in 8 cases, good in 16 cases and fair in 3 cases according to the Sarmiento scoring system （modified by Stewart）. Conclusions For type C3 comminuted fracture with severe volar and dorsal instability, fixation by volar buttress plate combined with transarticular external fixator should be adopted. Dorsal instability could be further stabilized by other techniques such as Kirschner wire fixation, and bone grafting.     

Carpal instability associated with fracture of the distal radius. Incidence, influencing factors and pathomechanics.

134 fractures of the distal radius in 132 patients are reviewed to determine the incidence and influencing factors of coexisting carpal in stability. By measurement and analysis of the changes in carpal angles and joint spaces, carpal instability was discovered in 41 fractures, an incidence of 30.6%. Six patterns of instability were observed, including dorsal intercalated segmental instability (DISI), scapholunate dissociation, dorsal and palmar translocations, volar intercalated segmental instability (VISI) and ulnar carpal translocation. Accompanying carpal instability was more often seen in elderly patients. To a certain extent, the patterns of instability were related to the type of fracture and palmar tilt angle (PTA) values. DISI was often seen in fractures with PTA smaller than -15 degrees, while scapholunate dissociation was seen in fractures with PTA between -5 degrees and -20 degrees. The possible pathomechanics of the accompanying carpal instability were deduced based on the kinematics and influencing factors indicated in this study.

     

Comparison of adenosine stress and dobutamine stress by real-time myocardial contrast echocardiography in detecting myocardium ischemia in dogs

Background Real-time perfusion imaging （RTPI） using ultrasound contrast agents has shown good ＂accuracy＂ in detecting myocardial infarction, however its accuracy in the assessment of peri-infarct ischemia and stress echocardiography are not known. The aim of this study was to determine the accuracy of RTPI in assessment of peri-infarct ischemia during dobutamine and adenosine stress. Methods We employed the RTPI modality （Agilent and ATL Philips） in a canine model （18 dogs） of distal coronary occlusion and proximal coronary stenosis. Using coronary flow probe recordings, the physiologic significance of proximal coronary stenosis was established by confirming abolition of the coronary reserve. The contrast agent Optison was given as a slow bolus injection at baseline, during prolonged distal coronary occlusion, during adenosine bolus stress and during dobutamine stress. Triphenyltetrazolium chloride （TTC） staining was used to verity a distal infarction. RTPI recordings at baseline, the distal coronary occlusion and stress protocols were randomly mixed and reviewed blindly. Results In all but one dog, RTPI detected a distal infarct as small as 9% of the left ventricle. The sensitivity, specificity and overall diagnostic accuracy of RTPI in the detection of distal infarcts were： 94%, 89% and 92%, respectively. The sensitivity, specificity, and overall diagnostic accuracy of RTPI in the assessment of peri-infarction ischemia were 83%, 92% and 88% for adenosine stress and 95%, 86% and 91% for dobutamine stress, respectively. Conclusions Even small distal infarcts can be detected by RTPI; peri-infarct ischemia can be accurately recognized by RTPt during stress; adenosine and dobutamine stress appear equally reliable in the RTPI evaluation of peri-infarct ischemia.     

Stress analysis of three-dimensional finite element model of malunion calcanens during gait

Objective: To analyze the stress distribution of calcaneus with posterior articular facet compressed after fracture and talus during gait. Methods: A wedge under the posterior articular was transected from a normal finite element model of calcaneus and talus to simulate malformation of compression of the posterior facet after fracture of calcaneus. The model was used to simulate for three subphases of the stance during the gait( heel-strike, midstance, push-off) and calculate the finite element.The results were compared with normal situation. Results: The stress distribution within the bone in situation of malformation was obtained and regions of elevated stresses for three subphases were located. The results were significantly different from that of normal situation. Conclusion: The simulation of calcaneus and talus in malformation has important clinic implication and can provide an insight into the factors contributing to many clinic pathogenic changes after fracture of calcaneus.     

Modified distal osteotomy of shortening the first metatarsal and for treatment of hallux valgus.

We evaluated the results of distal osteotomy of shortening the first metatarsal head with internal fixation of shape memory metal compression staple for hallux valgus in 26 feet of 17 women with a mean age of 41.0 years (30-65 years). The time for return to light work averaged 18.2 days, and to full work and normal walking 40.3 days after the operation. 16 patients (25 feet) had complete pain relief. Only in one foot, the pain was transferred under the 2nd metatarsal head. The appearance of the feet was markedly improved and the width of the forefeet was decreased by a mean of 0.92 cm after the operation. All of the patients were satisfied with the appearance of their feet. Radiographic analysis of feet showed that all osteotomies united, and the average angle of hallux valgus was improved from 30.1 degrees to 16.0 degrees, with the mean intermetatarsal angle of 11.2 degrees-6.5 degrees. No external fixation of plaster splintage was used and the distal fragment during healing of the osteotomy was stable. The time of bone healing was shortened and patients were allowed to bear weight at early stage.

     

MODIFIED DISTAL OSTEOTOMY OF SHORTENING THE FIRST METATARSAL AND FOR TREAMTMENT OF HALLUX VALGUS

We evaluated the results of distal osteotomy of shortening the first metatarsal head with internal fixation of shape memory metal compression staple for hallux valgus in 26 feet of 17 women with a mean age of 41.0 years (30-65 years). The time for return to light work averaged 18.2 days, and to full work and normal walking 40.3 days after the operation. 16 patients (25 feet) had complete pain relief. Only in one foot, the pain was transferred under the 2nd metatarsal head. The appearance of the feet was markedly improved and the width of the forefeet was decreased by a mean of 0.92 cm after the operation. All of the patients were statisfied with the appearance of their feet. Radiographic analysis of feet showed that all osteotomies united, and the average angle of hallux valgus was improved from 30.1 ° to 16.0 ° , with the mean intermetatarsal angle of 11.2 ° -6.5 ° . No external fixation of plaster splintage was used and the distal fragment during healing of the osteotomy was stable. The time of bon     

Effects of chronic multiple stress on learning and memory and the expression of Fyn, BDNF, TrkB in the hippocampus of rats

Background The effect of chronic stress on cognitive functions has been one of the hot topics in neuroscience. But there has been much controversy over its mechanism. The aim of this study was to investigate the effects of chronic multiple stress on spatial learning and memory as well as the expression of Fyn, BDNF and TrkB in the hippocampus of rats. Methods Adult rats were randomly divided into control and chronic multiple stressed groups. Rats in the multiple stressed group were irregularly and alternatively exposed to situations of vertical revolution, sleep expropriation and restraint lasting for 6 weeks, 6 hours per day with night illumination for 6 weeks. Before and after the period of chronic multiple stresses, the performance of spatial learning and memory of all rats was measured using the Morris Water Maze （MWM）. The expression of Fyn, BDNF and TrkB proteins in the hippocampus was assayed by Western blotting and immunohistochemical methods. The levels of Fyn and TrkB mRNAs in the hippocampus of rats were detected by RT-PCR technique. Results The escape latency in the control group and the stressed group were 15.63 and 8.27 seconds respectively. The performance of spatial learning and memory of rats was increased in chronic multiple stressed group （P〈0.05）. The levels of Fyn, BDNF and TrkB proteins in the stressed group were higher than those of the control group （P〈0.05）. The results of immunoreactivity showed that Fyn was present in the CA3 region of the hippocampus and BDNF positive particles were distributed in the nuclei of CA1 and CA3 pyramidal cells as well as DG granular cells. Quantitative analysis indicated that level of Fyn mRNA was also upregulated in the hippocampus of the stressed group （P〈0.05）. Conclusions Chronic multiple stress can enhance spatial learning and memory function of rats. The expression of Fyn, BDNF and TrkB proteins and the level of Fyn mRNA are increased in the stessed rat hippocampus. These suggest that Fyn and BDNF/TrkB signal transduction pathways may participate in the process of the enhanced learning and memory durina chronic multiple stress.     

锁定加压钢板结合人工骨植入治疗桡骨远端骨折

目的：探讨锁定加压钢板（LCP）结合人工骨植入治疗桡骨远端骨折的效果。方法：选取2009年1月至2011年10月的桡骨远端骨折（AO分类C3型）患者24例,所有患者均掌侧入路LCP固定,均予骨缺损处人工骨植入。结果：术后随访12～26个月,平均20．9个月,所有骨折均骨性愈合,愈合时间10～13周,平均11．4周。按改良Gartland-Werley功能评估系统进行疗效评定,优良率为87％。随访结果显示,3例患者桡骨远端高度丢失,有严重的腕关节屈伸功能障碍。结论：LCP结合人工骨植入治疗桡骨远端骨折时,能够坚强固定,允许早期功能锻炼,尤其适用于骨折压缩粉碎性骨质疏松患者。     

桡骨远端T型锁定接骨板治疗桡骨远端不稳定性骨折的临床效果

目的探讨桡骨远端T型锁定接骨板治疗桡骨远端不稳定性骨折的临床效果。方法 60例桡骨远端不稳定性骨折患者分为观察组和对照组,每组30例。观察组患者给予桡骨远端T型锁定接骨板治疗,对照组患者给予外固定支架治疗,术后随访3个月,对患者行X线片检查,测量并记录2组患者的骨性愈合时间、掌倾角、尺偏角及腕关节活动度。结果 2组患者骨性愈合时间、掌倾角及尺偏角比较差异均无统计学意义(P>0.05)。观察组患者背伸、掌屈活动显著优于对照组,桡偏显著轻于对照组,差异均有统计学意义(P<0.05)。2组患者尺偏、旋前、旋后情况比较差异均无统计学意义(P>0.05)。观察组和对照组患者治疗效果优良率分别为90.0%和70.0%,观察组患者优良率高于对照组,差异有统计学意义(P<0.05)。观察组和对照组患者并发症发生率分别为6.7%和10.0%,2组患者并发症发生率比较差异无统计学意义(P>0.05)。结论应用桡骨远端T型锁定接骨板治疗桡骨远端不稳定性骨折对桡骨远端的骨性及腱鞘结构的影响较小,手术操作较为方便,可保持背侧软组织的完整性,复位效果好,固定可靠,疗效满意,且并发症少。     

桡骨远端不稳定骨折两种治疗方法效果比较

目的:比较锁定加压钢板内固定与手法复位闭合外固定治疗桡骨远端不稳定骨折效果。方法:采用随机对照设计将60名桡骨远端不稳定骨折患者随机分配到锁定加压钢板内固定组(30例)与手法复位闭合外固定组(30例)进行治疗,随访1年后比较两组患者Mcbride评分。结果:两组患者性别、年龄、骨折分型差异无统计学意义,具可比性。随访1年后,钢板内固定组优良率为83.3%,闭合外固定组优良率为60.0%,钢板内固定组Mcbride评分优于闭合外固定组(Z=3.307,P=0.001)。结论:锁定加压钢板内固定与传统手法复位闭合外固定相比,能够有效的稳定骨折复位,使患肢及早进行功能锻炼和恢复。     

掌侧可调式锁定加压钢板治疗桡骨远端骨折

目的:探讨桡骨远端掌侧可调式锁定加压钢板(ALCP)治疗桡骨远端骨折的临床治疗效果。方法:根据AO分型,对我科16例桡骨远端骨折行掌侧ALCP钢板内固定手术治疗,根据Dienst标准进行腕关节功能评估。结果:本组所有病例都得到4～9个月随访,平均5.9个月,所有骨折均骨性愈合,愈合时间为9～14周,平均11.8周。术后Dienst功能评估:优11例,良4例,可1例。结论:应用桡骨远端掌侧ALCP治疗桡骨远端骨折,可取得满意的治疗效果。     

掌侧锁定钢板治疗桡骨远端骨折

目的:探讨采用掌侧锁定钢板内固定治疗桡骨远端骨折的临床疗效.方法:对我院2006年5月至2010年6月,掌侧锁定钢板内固定治疗65例桡骨远端骨折的临床资料作分析.结果.65例均获随访,随访时间8～18个月,平均12个月.所有骨折均骨性愈合,无内固定物松动、断裂、感染、腕管综合征等并发症.按照Dienst腕关节功能评价标...     

外固定夹板治疗桡骨远端骨折

我国在运用夹板治疗桡骨远端骨折方面具有悠久的历史,随着科学技术的发展与进步,国内外医家在小夹板的基础上不断推陈出新,改进型小夹板不断出现,并且趋向专业化、系统化,如从宏观向微观、从粗材料向高科技含量材料等方向的发展,为小夹板的临床应用提供了理论根据。现代研究认为,夹板外固定符合动静结合的理念,其产生的微动是促进骨折愈合的重要机制。临床研究显示,大部分桡骨远端骨折运用夹板外固定治疗可取得较好的效果。     

锁定加压钢板治疗桡骨远端粉碎性骨折的临床研究

目的分析锁定加压钢板治疗桡骨远端粉碎性骨折的疗效,并与外固定支架作对照。方法对我院2008年9月。2011年9月80例桡骨远端粉碎性骨折患者进行观察,其中42例采用锁定加压钢板治疗的患者设立为A组,其余38例行外固定支架治疗的患者设立为B组,比较分析两种手术方式的治疗效果。结果两组患者切口均I期愈合,骨折愈合时间3-5个月。两组无内固定物弯曲、断裂及螺钉松动发生,也未见严重的骨和软组织感染、肌腱断裂和神经损伤等并发症,A组腕关节综合功能评定优良率明显大于B组,差异有显著性（P〈0,05）。结论桡骨远端锁定加压钢板具有固定可靠、退钉率低、并发症少的优点,值得广泛推广和应用。     

掌侧锁定加压钢板治疗桡骨远端C型骨折

目的 探讨锁定加压钢板(LCP)内固定治疗桡骨远端AO分型C型骨折的初期疗效.方法 总结从2007年1月～2009年1月应用锁定加压钢板(LCP)内固定治疗桡骨远端C型闭合性骨折26例.手术采用掌侧入路,复位后于掌侧置入LCP钢板,在C型臂X线机透视下检查桡骨长度、桡骨关节面、掌倾角及尺偏角复位情况,满意后置入锁定螺钉,对于严重骨缺损者应予植骨.术后第1天开始被动活动腕关节,1周后主动活动,功能锻炼.结果 全部获得随访,平均11个月(8～21个月).X线显示骨折全部Ⅰ期愈合,平均愈合时间为8周,所有病例均无感染、骨不连、钢板松动、腕管综合征、正中神经炎等并发症.按改良的Mcbride腕关节功能评价标准:优18例,良6例,可2例,优良率为92.31％.结论 坚强内固定下早期进行腕关节功能锻炼是治疗粉碎及不稳定桡骨远端骨折的有效措施,使用锁定加压钢板(LCP)内固定治疗桡骨远端C型骨折具有复位满意、固定坚强、可早期进行功能锻炼、关节功能恢复优良等优点.     

无头加压空心螺钉在桡骨远端骨折内固定术中的应用效果

目的:探究无头加压空心螺钉应用于桡骨远端骨折内固定术中的作用.方法:收集我院在2012年1月~2015年1月期间收治的桡骨远端骨折患者100例,按随机表法随机分成两组,行无头加压空心螺钉内固定术的50例为观察组,另外行锁定钢板内固定的50例设置为对照组,比较两组的应用情况.结果:在手术时间、术中出血量、术后住院时间的平均值的比较中,观察组都低于对照组的,且经统计学分析,两者之间的差异均在统计学意义上是显著的.观察组的Jakim标准功能评分优、良、可、差、总的优良率相比于对照组的,经统计学分析,差异无显著性.在手术后的随访下,观察组和对照组的腕关节功能优良率分别为86.00%和84.00%;两组的Cooney腕关节评分痛疼比较无明显差异,观察组的其它Cooney腕关节评分功能、活动范围、握力与对照组的进行对比,前者显著高于后者.结论:将无头加压空心钉的方式应用于桡骨远端骨折的治疗,能够极大地降低手术过程中的出血量和手术时长,在恢复腕关节功能的同时,还保证了与传统的锁定钢板的方式在疗效上相当.     

桡骨远端不稳定骨折的手术治疗与早期康复

目的探讨桡骨远端不稳定骨折手术治疗方法、效果及功能恢复情况。方法桡骨远端不稳定骨折患者23例,采用切开复位及外固定支架固定,术后早期开始术区功能锻炼,观察骨折愈合、并发症发生及腕关节功能恢复状况。结果经6～24个月随访,23例患者均获骨性愈合,无感染、神经损伤等并发症发生。2例发生轻度复位丢失,1例发生创伤性骨关节炎。总体优良率87.0%。结论桡骨远端不稳定骨折手术治疗可获得较理想的治疗效果,内固定与切开复位外固定均是可采取的手术方法,早期功能康复对腕关节功能恢复有重要作用。