不同聚丙烯网用于乳房下垂矫正的生物力学研究

目的 探讨4种不同的聚丙烯网片的生物力学性能,为真皮帽法乳房缩小术中内置式乳罩的选择提供依据.方法 以实验用小型猪作动物模型,将4种不同的聚丙烯网埋置于腹部皮下,90 d后采集标本,比较其生物力学性能.结果 4种聚丙烯网在拉伸强度、应力-应变关系、应力松弛和蠕变4个方面显示出不同的生物力学特性,这显然与它们所采用的材料和编织结构不同有关.结论 应力松弛和蠕变作为网片特殊的生物力学特性在维持术后乳房正常形态上有重要意义,在内置式乳罩的选择标准中占有重要的地位.Premilene Mesh LP~(R)作为新型的轻重量、小孔径网片,在生物力学性能上优于其他网片.     

Mechanical properties of polypropylene mesh used in pelvic floor repair

The aim of this study was the comparison of the stiffness of different meshes under two types of mechanical tests. Five different mesh types were mechanically tested. The methods used consisted on uniaxial tension test (tensile stiffness) and tape ring tests, experimental continuous compression of the mesh loops (flexural stiffness). The most significant difference of tensile stiffness behaviour appears between Aris™ and TVTO™. From the analysis of the experimental data, we divided the flexural stiffness, in two main groups. The first group includes Auto Suture™ and Aris™ meshes. The two meshes seem to have a similar flexural behaviour. The second group includes TVTO™, Uretex™ and Avaulta™. The difference between these two groups is clearly evident comparing TVTO™ and Aris™. This study shows that there are significant differences on the mechanical properties between urogynecology meshes. An erratum to this article can be found at     

Tensile properties of commonly used prolapse meshes

Introduction and hypothesis  To improve our understanding of the differences in commonly used synthetic prolapse meshes, we compared four newer generation meshes to Gynecare PS™ using a tensile testing protocol. We hypothesize that the newer meshes have inferior biomechanical properties. Methods  Meshes were loaded to failure (n = 5 per group) generating load–elongation curves from which the stiffness, the load at failure, and the relative elongation were determined. Additional mesh samples (n = 3) underwent a cyclic loading protocol to measure permanent elongation in response to subfailure loading. Results  With the exception of Popmesh, which displayed uniform stiffness, other meshes were characterized by a bilinear behavior. Newer meshes were 70–90% less stiff than Gynecare™ (p < 0.05) and more readily deformed in response to uniaxial and cyclical loading (p < 0.001). Conclusion  Relative to Gynecare™, the newer generation of prolapse meshes were significantly less stiff, with irreversible deformation at significantly lower loads.     

组配式人工半骨盆假体重建的生物力学分析

目的 探讨组配式人工半骨盆假体重建后骨盆生物力学改变及假体力学结构特点.方法 (1)建立正常骨盆的三维有限元模型和离体试验骨盆模型.于骨盆表面选取8个特征测点,在相同的载荷及边界条件下,利用有限元模型计算测点表面应力(σFEM),通过离体试验测量测点应变值,并计算标本表面应力(σEXP).对σFEM和σEXP进行线性回归分析验证.(2)利用验证的正常骨盆有限元模型进行左侧骨盆缺损(Ⅱ+Ⅲ区)及人工假体重建模型的建模.计算重建骨盆健侧特征测点的表面应力(σRS)及患侧髂骨截骨处内、外侧皮质表面应力(σRR),分别与正常骨盆相同位置测点应力值(σNS,σNR)进行比较.(3)分析假体应力传导结构表面应力分布特点及应力集中部位.结果 (1)骨盆有限元计算结果 与离体试验结果 有良好的一致性(R~2=0.87),模型仿真度较高.(2)重建后健侧特征测点σRS与正常骨盆σNS近似(t=1.81,P=0.08).患侧髂骨截骨处内侧皮质σRR与σNR差异无统计学意义(t=0.47,P=0.65),外侧皮质σRR明显高于σNR(t=2.78,P=0.02).(3)假体应力传导结构主要由后侧传导.应力集中部位位于下排钉孔周围、髂骨固定座与侧面固定翼片连接处、人工髋臼与髂骨固定连接处,系统应力峰值(183 MPa)位于人工髋臼与髂骨固定座连接部位.结论 组配式人工半骨盆假体重建符合骨盆生物力学特点,较好地恢复了应力传导.     

Biomechanical aspects of pelvic ring reconstruction techniques: Evidence today

Despite the remarkable advances achieved within the boundaries of the new discipline of Pelvic surgery, pelvic ring disruptions remain challenging and complex problems in orthopaedics. The long-term complications related to reconstruction techniques of these injuries have motivated researchers and surgeons to explore various alternative treatment modalities. Several biomechanical studies have addressed these issues. We performed a medline search including studies published during the last 30 years. Our search yielded 114 studies, 39 of which met the pre-specified inclusion criteria and were further critically analysed and discussed regarding the biomechanical aspects of pelvic ring reconstruction techniques. Based on observational approach and evaluation of the studies specific keypoints are highlighted comprising the clinical translation of the biomechanical supported findings.     

四种聚丙烯网用于矫正乳房下垂的生物相容性研究

目的探讨外科网片的皱缩和粘连影响其作为内置式乳罩纠正轻、中度乳房下垂的术后效果，通过比较4种不同的聚丙烯网在生物相容性上的差异，找出异物反应与术后效果的关系，以便为内置式乳罩选用聚丙烯网片提供依据。方法以实验用小型诸作为动物模型，将4种不同的聚丙烯网置入腹部皮下，90d后采集标本，比较并发症、肄物反应、胶原纤维与弹力纤维的形成，并在透射电子最微镜下观察超微结构。结果4种聚丙烯网在生物相容性上存存差异。异物反应的程度决定生物相容性的差异，同时对术后乳房形态有显著的影响。结论Premilene Mesh LP作为新型的轻质量网片，生物相容性优于其他网片。     

Adhesion formation and reherniation differ between meshes used for abdominal wall reconstruction

Incisional hernia is a common surgical problem, frequently requiring prosthetic mesh repair. The demands of the ideal mesh seem conflicting; ingrowth at the mesh–fascia interface, without development of adhesions at the visceral mesh surface. Various antiadhesives combined with macroporous mesh and composite meshes were studied for prevention of adhesions to mesh and ingrowth into the fascia. In 60 rats an abdominal wall defect was created and repaired with underlay mesh. Rats were divided into six groups and treated with polypropylene mesh (PPM, control), PPM with auto-cross-linked polymers (ACP) gel, PPM with fibrinogen glue (FG), polypropylene/expanded polytetrafluoroethylene (ePTFE) mesh, polypropylene/sodium hyaluronate/carboxymethylcellulose (HA/CMC) mesh, and polypropylene-collagen/polyethylene-glycol/glycerol (CPGG) mesh. Mesh infection was assessed in the postoperative period, adhesions and reherniations were scored at sacrifice 2 months after operation, and tensile strength of the mesh–tissue interface was measured. Six rats developed mesh infection, half of them were treated with PPM/ePTFE. The PPM/HA/CMC group showed a significant reduction in the amount and severity of adhesions. In animals treated with PPM/ACP and PPM/FG, severity of adhesions was reduced as well. Reherniation rate in the PPM/ACP group was 50% and significantly higher than that in other groups. Rats in the PPM/HA/CMC had the highest tensile strength. PPM/HA/CMC approaches the demands of the ideal mesh best, having superior antiadhesive properties, no reherniation and no infection in this rat model of incisional hernia.     

经阴道网片盆底重建术治疗盆底脏器脱垂患者临床疗效

目的探讨经阴道网片盆底重建术治疗盆底脏器脱垂（pelvic organ prolapse,POP）患者的临床效果观察及安全性疗效。 方法选取2016年1月至2017年12月,河北省邯郸市中心医院118例POP患者的临床资料,按照术式不同分为2组,每组患者59例。对照组采用传统的手术方式进行治疗,试验组采用经阴道网片盆底重建术进行治疗。 结果试验组手术时间、术后首次下床活动及住院时间均短于对照组,差异有统计学意义（P<0.05）。试验组术中出血量与对照组比较比较,差异无统计学意义（P>0.05）。试验组术后有效率明显高于对照组,差异有统计学意义（P<0.05）。 结论经阴道网片盆底重建术是治疗POP患者有效、安全的术式,可显著改善患者的临床症状,但需严格按照手术适应症进行。     

肋软骨生物力学性能及在耳廓再造手术时机选择中的意义

目的 探讨不同年龄组肋软骨的生物力学特性的变化,以期为肋软骨作为耳廓再造的支架材料应用于整形外科的最佳手术时机提供理论参考.方法 将5～25岁行耳廓再造的患者按年龄分为3组.对不同年龄组肋软骨的应力-应变、应力松弛、蠕变和极限抗拉强度等各项生物力学性能指标进行测试,对测试结果进行统计学分析处理.结果 儿童组肋软骨的极限抗拉强度、应力-应变、应力松弛及蠕变等生物力学指标明显优于青少年组和成人组,3组当中以青少年组的力学性能最差,经统计学分析,差异具有统计学意义(P＜0.05).结论 鉴于肋软骨的生物力学性能随年龄发生变化,综合各方面因素,在利用肋软骨进行耳廓再造手术时,应优先考虑在肋软骨生物力学性能最佳的儿童期进行.     

重建指屈肌腱鞘滑车方法的力学实验研究

目的通过对移植肌腱重建A2滑车的不同缝合方法和宽度进行力学对比分析，为临床重建滑车提供理论依据。方法（1）选用60条新鲜人体指浅屈肌腱，随机分为10组，每组6条指浅屈肌腱。分别用缠绕肌腱一圈（宽0．5cm）和缠绕两圈（宽1．0锄）的方法重建直径为1．5cm的A2滑车。两种宽度均选用Kessler、Tsugel、Bunnell、Kleinert、Koch-mason5种方法缝合肌腱。肌腱缝合后在Css-44020型电子万能实验机上匀速直线拉伸，记录最大抗拉强度，并对该数据进行方差分析。（2）比较两种重建A2滑车的方法对屈肌腱滑动摩擦力的影响。结果所有重建滑车的断裂方式为缝线豁出，无缝线断裂。（1）5种缝合方法中，用指浅屈肌腱缠绕一圈重建A2滑车中，Tsugel法的平均最大抗拉强度为41．65N，大于其他4种方法，两者差异有统计学意义（P〈0．05）。（2）用指浅屈肌腱缠绕两圈重建A2滑车法中，Tsugel法的平均最大抗拉强度为221．47N，大于其他4种方法，两者差异有统计意义（P〈0．05）。（3）用指浅屈肌腱缠绕两圈重建A2滑车法比缠绕一圈的方法对指屈肌腱的摩擦力小，两者差异有统计学意义（P〈0．05）。结论（1）5种缝合方法中，Tsugel法重建A2滑车的最大抗拉强度最大。（2）用指浅屈肌腱重建A2滑车缠绕两圈法的最大抗拉强度较缠绕一圈的最大抗拉强度大。（3）用指浅屈肌腱缠绕两圈重建A2滑车法对指屈肌腱的滑动摩擦力小于缠绕一圈重建滑车法，并在一定程度上克服了对指屈肌腱的绞勒作用。     

Differences in polypropylene shrinkage depending on mesh position in an experimental study

BACKGROUND: Polypropylene (PP) mesh is one of the most frequent materials used in hernia repair. We have experimentally evaluated the shrinkage of PP mesh depending on the place of implantation. METHODS: In 15 New Zealand rabbits a muscular defect measuring 3 x 3 cm was created in both pararectal sides of the abdominal wall. The defect was repaired using a PP mesh measuring 5 x 3.5 cm that was placed in the right side in the sublay location and in the left side in the onlay location. Five animals were killed on the 30th, 60th, and 90th postoperative days. Macroscopic measurement and microscopic study of the prosthesis-host tissue interfaces were performed. RESULTS: One rabbit was killed because of severe infection in the onlay mesh. Another 2 infections were tolerated in the onlay mesh side. All the prostheses were integrated in the host tissue at death. In the macroscopic evaluation the mesh areas were reduced by 25.92% on the 30th day, by 28.67% on the 60th day, and by 29.02% on the 90th day. The mesh shrinkage was greater in the onlay group than in the sublay group at the 3 time intervals. More inflammatory leukocyte and mononuclear responses also were seen in the onlay group. CONCLUSIONS: These observations support the theory of PP mesh shrinkage as a consequence of the incorporation of the biomaterial to the scarring tissue. This shrinkage is significantly more intense if the meshes are placed in the onlay position.     

Biomechanical evaluation of six femurgraft-tibia complexes in ACL reconstruction

Soft tissue graft-tibial tunnel fixation is considered the weak point in reconstruction of the anterior cruciate ligament (ACL). We hypothesized that the biomechanical properties of fixation devices used in ACL reconstruction can be better evaluated by testing complete constructs (femoral tunnel fixation-graft-tibial tunnel fixation). Porcine knees were reconstructed with bovine digital extensor tendons using 6 different commercially available fixation device combinations, and biomechanically tested with cyclic loads (1000 cycles, 0–150 N, 0.5 Hz) and until failure (crosshead speed, 250 mm/min). The device combinations tested (in groups of 6) were EndoButton CL-BioRCI, Swing Bridge-Evolgate, Rifidfix-Intrafix, Bone Mulch- Washerlock, Transfix-Retroscrew, and Transfix-Deltascrew. Ultimate failure load, stiffness, slippage at cycles 1, 100, 500 and 1000 and mode of failure were evaluated. The statistical differences between pairs of groups were assessed with Student’s unpaired t test. The ultimate failure load of complexes made with the Swing Bridge- Evolgate was significantly higher than any other device (968 N; p<0.05), while that of devices made with Transfix-Retrofix was significantly lower than the others (483 N, p<0.05). The stiffness of Swing Bridge-Evolgate complexes was significantly higher than the others (270 N/mm, p<0.05). Regarding mode of failure, Rigidfix-Intrafix complexes showed a failure of the femoral fixation in all specimens. All failures of the other specimens occurred at the tibial side, except one specimen in the EndoButton CL-BioRCI group. Many commercially available tibial fixation devices showed biomechanically appreciable properties, sometimes better than femoral devices.     

Biomechanical properties of lightweight versus heavyweight meshes for laparoscopic inguinal hernia repair and their impact on recurrence rates

Background  Laparoscopic inguinal hernia repair can be performed using light- or heavyweight meshes. Apart from the size of the mesh, its friction coefficient (μ₀) and flexural stiffness are of crucial importance to avoidance of hernia recurrence. Methods  In the current biomechanical study, tensile tests were performed to determine the ultimate tensile strength and modulus of elasticity of six lightweight meshes and six heavyweight meshes for laparoscopic inguinal hernia repair. To determine their friction coefficient (μ₀), the meshes were placed between a resected peritoneum and groin muscles during an autopsy. Meshes measuring 15 × 10 cm in size then were used in a hernia model with an opening size of 1.5, 3, or 5 cm. Results  The ultimate tensile strength and modulus of elasticity were significantly lower in the lightweight mesh group than in the heavyweight mesh group. The mean friction coefficient (μ₀) of the meshes was 0.4. Given an opening of 1.5 cm, all meshes remained adequately stable. At opening sizes of 3 and 5 cm, the lightweight meshes flexed on the average by 3.16 ± 0.4 mm and 10.40 ± 2.5 mm, respectively. Heavyweight meshes, on the other hand, were significantly less flexible. Their mean flexure was, respectively, 0.34 ± 0.2 mm and 3.97 ± 0.7 mm (p < 0.001). Conclusion  Stable meshes are characterized by a small degree of flexure and do not slide into the gap even when subjected to repetitive loads. Therefore, in terms of hernia recurrence, meshes with greater flexural stiffness or well-fixed lightweight meshes that adequately overlap the hernia defect can be used for laparoscopic treatment of large inguinal hernias.     

垂直不稳定骨盆骨折内固定垂直稳定性的生物力学研究

目的探讨垂直不稳定骨盆骨折空心螺钉和钢板内固定前后环或后环的垂直方向稳定性差异。方法：将6具尸体骨盆随机取3具做压力测试为正常组，然后制成垂直不稳定骨盆骨折模型，分别行后环空心螺钉结合前环空心钉、后环空心螺钉、后环结合前环钢板、后环钢板内固定。结果在垂直方向，后环空心螺钉内固定强于钢板螺丝钉内固定，增加前环内固定可以显著增加前环的稳定性。结论垂直不稳定骨盆骨折空心螺钉内固定具有较好的生物力学稳定性，前后环内固定要优于单纯后环内固定。     

Complications of transvaginal monofilament polypropylene mesh in pelvic organ prolapse repair

Introduction and hypothesis  This study aimed to document intraoperative and postoperative complications associated with the use of transvaginal polypropylene mesh in the repair of pelvic organ prolapse (POP). Methods  This is a retrospective review of 127 cases of transvaginal repair of POP using synthetic mesh. Results  Mean postoperative value (±SD) for pelvic organ prolapse quantification (POPQ) measurements Aa, Ap, and C were: −2.4 ± 1.1 (cm), −2.4 ± 0.9 (cm), and −7.7 ± 1.2 (cm), respectively. The difference between preoperative and postoperative values of these points was significant (p < 0.0001). Mesh erosion rate was 13/127 (10.2%) with significant correlation between mesh erosion and concurrent vaginal hysterectomy (p = 0.008). Combined anterior and posterior vaginal mesh surgery increased the risk of intraoperative bleeding and blood transfusion (p < 0.05). Conclusions  Concurrent vaginal hysterectomy is associated with increased risk of vaginal mesh erosion. Combined anterior and posterior vaginal mesh repair is an increased risk factor for intraoperative bleeding and blood transfusion.     

钉-棒系统与外固定支架固定骨盆不稳定损伤模型的生物力学比较

目的 通过对钉-棒系统和骨盆髂骨翼外固定支架固定骨盆水平旋转不稳定损伤模型的生物力学进行测试,对比两者固定骨盆的力学稳定性,为临床治疗提供理论依据. 方法 取经福尔马林处理的正常成人骨盆标本7具,保留从L5至股骨近端中上20 cm的骨盆标本,保留完整的耻骨联合、双侧髋关节、双侧骶髂关节、双侧骶结节韧带、双侧骶棘韧带、双侧骶髂前韧带、双侧骶髂后韧带.将骨盆置于AGX生物力学试验机上,模拟人体正常双足站立中立位,由L5垂直向下加压至500 N,依次测量下述4种情况下的耻骨联合位移:①完整骨盆;②骨盆水平旋转不稳定Tile B1型损伤模型;③钉-棒系统固定骨盆Tile B1型损伤模型;④骨盆髂骨翼外固定支架固定骨盆Tile B1型损伤模型.结果 在500 N的压力下,4组耻骨联合位移由小到大依次为完整骨盆[(0.121 ±0.025) mm]、钉-棒系统固定模型[(0.656±0.103) mm]、髂骨翼外固定支架固定模型[(1.512±0.101) mm]、Tile B1型损伤模型[(4.512±0.391) mm],4组间两两比较差异均有统计学意义(P＜0.05).结论钉-棒系统固定骨盆水平旋转不稳定损伤模型的生物力学稳定性明显优于骨盆髂骨翼外固定支架,能有效恢复骨盆环的力学稳定性.     

兔保留与切除残迹前交叉韧带重建生物力学的比较

目的比较兔保留与切除残迹前交叉韧带（ACL）重建的生物力学差异,探讨保留残迹的意义。方法新西兰兔10只,体重（2．66±0．32）kg。切断双侧ACL,右侧股骨与胫骨端各保留残迹2mm,左侧完全切除两端残迹。切取跟腱制备移植物,对应ACL印迹解剖位分别建立胫骨与股骨隧道,重建双侧ACL。于术后8周,行单轴拉力测试。SPSS19．0软件进行数据统计。结果术后8周,保留残迹组的最大载荷（t=2．931,P〈0．05）、屈服载荷（t=2．680,P〈0．05）、刚度（t=5．411,P〈0．05）明显高于切除残迹组,两组之间差异均有统计学意义;保留残迹组拉伸长度显著低于切除残迹组,两组差异有统计学意义（t=-3．872,P〈0．05）。两组损毁模式不同,保留残迹组多表现为移植物关节内断裂,而切除残迹组多表现为移植物自骨隧道拔出。Fisher精确检验表明两组的样本损毁模式有统计学差异（P〈0．05）。结论保留残迹ACL重建的生物力学特征优于切除残迹ACL重建,提示临床采用保留残迹技术重建ACL有可能促进移植物腱-骨愈合和“韧带化”,从而改进治疗效果。     

颈椎单开门两种固定方法的固定效果之生物力学研究

目的 :分析颈椎单开门不同固定方法的固定效果。方法 :新鲜成人颈椎标本 6具 ,模拟单开门椎管扩大术式 ,依次分 2组 ,A组 :单开门后 ,椎板用 10号丝线固定在对侧椎旁肌肌膜和关节囊 ;B组 :单开门后 ,椎板用 10号丝线斜拉分别固定在C2 和C7棘突。应用生物力学方法 ,测试颈椎单开门后再关门负荷及功耗。结果 :再关门过程中A组和B组的最大负荷分别为 ( 8.5 7± 1.80 )N、( 12 .93± 2 .2 3)N ;完全关门时负荷分别为 ( 8.12± 2 .17)N、( 12 .93± 2 .2 3)N ;功耗分别为 ( 0 .0 6 2± 0 .0 2 1)J、( 0 .0 83± 0 .0 2 3)J。相互间差异显著 (P <0 .0 5或P <0 .0 1)。结论 :斜拉棘突固定法固定效果较好