骨锚置入先天性马蹄内翻足矫形固定胫前肌腱过程中的生物力学变化

背景：先天性马蹄内翻足矫形术中胫前肌腱通常用钢丝固定,需二次手术抽出和可能发生感染,尝试应用骨锚来固定胫前肌腱。目的：分析骨锚在先天性马蹄内翻足矫形术中固定胫前肌腱的生物力学特性。方法：采用儿童截肢后的小腿,解剖出胫前肌腱和楔骨,用Mitek GII锚钉和No.2Ethibond缝线分别固定,所有的样本进行生物力学垂直拔出试验,直到失败。结果与结论：骨锚固定楔骨的失败模式如下：10枚骨锚全部拔出,无缝线断裂,骨锚无损坏,平均最大拔出载荷137N。缝线固定楔骨的失败模式如下：10根No.2Ethibond缝线全部断裂,平均最大拔出载荷为92N。提示骨锚固定的生物力学性能优于经骨的缝线固定,达到先天性马蹄内翻足矫形术中固定胫前肌腱的强度。     

胫前肌延长外移治疗先天性马蹄内翻足31例分析

目的：对胫前肌延长外移治疗先天性马蹄内翻足的疗效进行评价。方法：采用胫前肌延长外移治疗先天性马蹄内翻足31例,术后对患者采用G arceau标准进行评价。结果：胫前肌延长外移治疗先天性马蹄内翻足优良率95.56%。结论：胫前肌延长外移结合软组织松解、石膏固定是治疗先天性马蹄内翻足可靠方法之一。     

普迪斯丝线代替钢丝在马蹄内翻足矫治手术中的应用

目的:应用普迪斯丝线代替钢丝在马蹄内翻足畸形外科矫治手术中将转移的肌腱固定于足跗骨,观察其治疗效果。方法:于2004-09/2005-01选择解放军第四军医大学西京医院骨科收治的马蹄内翻足畸形矫治手术患者133例165足,主要手术方式是软组织松解矫正畸形、转移胫前肌或胫后肌肌腱至第三楔状骨、建立肌动力平衡,所用将肌腱固定于骨的材料是普迪斯丝线。用普迪斯丝线编织拟转移的肌腱,经第三楔状骨钻骨洞,将肌腱引入骨洞中,调整张力合适(使足背伸在5°～10°位)后,丝线用钮扣固定于足底,保持一定的张力,术后长腿管型石膏固定,术后2周时更换石膏,继续固定4周。结果:术后随访时间为2个月～3年,其中术后2个月随访133例,术后6个月随访133例,术后1年随访102例,术后3年随访86例。①治疗效果:133例患者165足中,155足术后2周更换石膏时,检查转移的肌腱能维持良好的张力,能使足背伸在5°～10°位,术后6周拆除石膏,开始功能锻炼,转移肌肉能维持良好足背伸功能;8足胫前肌肌力<Ⅲ级,转移后不能发挥足背伸的功能,畸形复发,再次手术转移胫后肌腱,畸形纠正,足背伸的功能良好。1足复发病例且年龄超过10岁,畸形较重且僵硬,肌腱转移后踝关节活动度不佳,畸形复发,后改行截骨及外固定架矫形;1足系小儿麻痹后遗症病例且年龄超过10岁,转移后不能发挥足背伸的功能,畸形复发,后行关节融合手术。②材料的不良事件和副反应:全部病例没有出现排异反应及手术切口并发症,石膏外固定周期内未出现普迪斯丝线断裂情况和石膏松脱情况。结论:普迪斯丝线可作为一种选择,代替钢丝在马蹄内翻足畸形外科矫治手术操作中将转移的肌腱固定于足跗骨,治疗效果好。     

Ponseti方法治疗早期先天性马蹄内翻足31例分析

目的：观察Ponseti方法治疗早期先天性马蹄内翻足的疗效。方法：对31例47足6月龄内先天性马蹄内翻足患儿应用Ponseti方法治疗。结果：所有患儿均获随访,随访时间16～29个月,平均21个月。43足外观畸形纠正,踝关节背屈〉0°,无内收,无内翻,高弓消失,踝关节功能正常。4足有轻度足内翻,通过胫前肌腱外移术矫正。结论：Ponseti方法是治疗早期先天性马蹄内翻足的有效方法。     

手术及术后系统康复治疗大龄儿童先天性马蹄内翻足60例

目的探讨大年龄儿童先天性马蹄内翻足治疗方法及疗效。方法对 60例行跟腱延长,改良胫前肌外移术,并用后内侧软组织松解 18足,距舟、跟骰关节楔形截骨 21足,三关节固定 15足。术后配合康复治疗。结果术后随访 54例 60足 1年 10个月～ 8年,优 27足,良 24足,可 3足,差 6足,优良率 85％。结论改良胫前肌外移术后配合系统的康复治疗,对大年龄儿童先天性马蹄内翻足效果满意。     

手术及术后系统康复治疗大龄儿童先天性马蹄内翻足 60例

目的探讨大年龄儿童先天性马蹄内翻足治疗方法及疗效。方法对60例行跟腱延长,改良胫前肌外移术,并用后内侧软组织松解18足,距舟、跟骰关节楔形截骨21足,三关节固定15足。术后配合康复治疗。结果术后随访54例60足1年10个月～8年,优27足,良24足,可3足,差6足,优良率85%。结论改良胫前肌外移术后配合系统的康复治疗,对大年龄儿童先天笥马蹄内翻足效果满意。     

儿童先天性马蹄内翻足肌力平衡术后继发外翻原因分析

目的分析先天性马蹄内翻足肌力平衡术后继发外翻的原因并提出预防措施.方法对23例24足先天性马蹄内翻足肌力平衡术后继发外翻的原因进行分析.结果手术后继发外翻的主要原因包括肌力平衡术中解剖定位错误、转移肌腱附丽点选择不当,张力过大等.结论在彻底软组织松解、纠正畸形的同时,选择发育良好的肌肉、正确的肌腱附丽点位置(第3楔状骨为宜)及合适的张力以建立有效的肌力平衡是预防肌力平衡术后继发外翻的关键.     

先天性马蹄内翻足的术后护理

先天性马蹄内翻足是常见的一种先天畸形．其发病翠约占0.1％。畸形包括前足内收，踝关节马蹄．跟骨内翻，随着年龄增加病情日趋加重。从治疗效果分析分为松软型与僵硬型。我院自1996年1月-2001年6月．共施行56例3个月～3岁婴幼儿先天性马蹄内翻足的矫形术。通过加强对围手术期的治疗和细致观察、护理．疗效满意。现将护理经验总结如下。     

伊利扎诺夫技术治疗儿童顽固性马蹄内翻足:11例随访

背景儿童顽固性马蹄内翻足包括先天性多发性关节挛缩症、未经治疗的大年龄儿童先天性马蹄内翻足及反复手术治疗失败的病例,对该类患儿的治疗目前仍非常棘手.探索新的治疗方法具有重要意义.目的采用伊利扎诺夫技术治疗儿童顽固性马蹄内翻足以提高畸形效果.设计前后对照研究.单位南京医科大学附属南京儿童医院骨科.对象1990/2000南京医科大学附属南京儿童医院骨科共收治儿童先天性多发性关节挛缩症3例、未经任何治疗10岁以上的大年龄儿童先天性马蹄内翻足2例、先天性马蹄内翻足术后复发6例,全部病例均表现为足畸形僵硬和短足畸形.方法采用伊利扎诺夫技术治疗儿童顽固性马蹄内翻足畸形11例12足.先行跟腱延长和足后路松解,再在胫骨中下1/3处、跟骨及1～5跖骨骨干多平面贯穿张力细克氏针或橄榄针,分别固定于环形、半环形及马蹄形骨外固定器上,并通过多根螺纹杆相互连接成三维立体的骨外固定装置.通过对骨外固定装置各部件间距进行延长、压缩和旋转等调节,以及舟、骰骨的截骨延长,从而矫正畸形足的跖屈、内翻、内收及短足畸形.主要观察指标全部11例病例均获得随访,随访时间2～10年,平均4.5年.随访主要观察足的形态、距小腿(踝)关节活动度、畸形矫正度等指标.结果按Garceau临床疗效分级标准评定优5例6足,良4例4足,可2例2足,优良率达83.3%.有2例2足遗留轻度前足内收畸形,4例4足有较明显的跗骨间关节僵硬,但其步态和负重力线均与正常儿童无明显差别.结论采用伊利扎诺夫技术治疗儿童顽固性马蹄内翻足畸形,疗效好,副作用小,但应严格掌握手术适应证.     

儿童先天性马蹄内翻足肌力平衡术后发外翻原因分析

目的：分析先天性马蹄内翻足肌力平衡术后继发外翻的原因并提出预防措施。方法：对２３例２４足先天性马蹄内翻足肌力平衡术后继发外翻的原因进行分析。结果：手术后继发外翻的主要原因包括肌力平衡术中解剖定位错误、转移肌腱附丽点选择不当，张力过大等。结论：在彻底软组织松解、纠正畸形的同时，选择发育良好的肌肉，正确的肌腱附丽点位置（第３楔状骨为宜）及合适的张力以建立有效的肌力平衡是预防肌力平衡术后继发外翻的关键。．     

Pullout strength of standard vs. cement-augmented rotator cuff repair anchors in cadaveric bone

BackgroundWe evaluate a novel method of rotator cuff repair that uses arthroscopic equipment to inject bone cement into placed suture anchors. A cadaver model was used to assess the pullout strength of this technique versus anchors without augmentation.MethodsSix fresh-frozen matched pairs of upper extremities were screened to exclude those with prior operative procedures, fractures, or neoplasms. One side from each pair was randomized to undergo standard anchor fixation with the contralateral side to undergo anchor fixation augmented with bone cement. After anchor fixation, specimens were mounted on a servohydraulic testing system and suture anchors were pulled at 90° to the insertion to simulate the anatomic pull of the rotator cuff. Sutures were pulled at 1 mm/s until failure.FindingsThe mean pullout strength was 540 N (95% confidence interval, 389 to 690 N) for augmented anchors and 202 N (95% confidence interval, 100 to 305 N) for standard anchors. The difference in pullout strength was statistically significant (P < 0.05).InterpretationThis study shows superior pullout strength of a novel augmented rotator cuff anchor technique. The described technique, which is achieved by extruding polymethylmethacrylate cement through a cannulated in situ suture anchor with fenestrations, significantly increased the ultimate failure load in cadaveric human humeri. This novel augmented fixation technique was simple and can be implemented with existing instrumentation. In osteoporotic bone, it may substantially reduce the rate of anchor failure.     

Effect of suture material on gap formation and failure in type 1 FDP avulsion repairs in a cadaver model

BACKGROUND: An in vitro cyclical testing simulating a passive mobilisation protocol was used to compare repair of flexor digitorum profundus tendon with modified-Bunnell two-strand pullout technique using a monofilament (Prolene), braided polyester (Ethibond) and a synthetic polyfilament ensheathed by caprolactan (Supramid) sutures. METHODS: Eighteen fresh-frozen cadaveric fingers were randomly divided into three repair groups (n = 6); modified-Bunnell technique with 3/0 Prolene, Ethibond or Supramid. After repair, specimens were cyclically loaded from 2 to 15N at 5N/s, for a total of 500 cycles. Gap formation at the tendon-bone interface was assessed every 100 cycles. Samples were tested to failure at the completion of 500 cycles. FINDINGS: All sutures held in all specimens during cyclic testing. The gap formation after 500 cycles was greatest with Prolene suture (6.8 mm, SD 1.2) followed by Supramid suture (4.0 mm, SD 1.1) and Ethibond suture (1.7 mm, SD 1.7) (P < 0.05). Repairs with Supramid displayed higher failure load (52.7 N, SD 5.5) as compared to Prolene (37.6N, SD 4.7) (P = 0.001) but not compared to Ethibond (44.9 N, SD 7.1). The failure loads between Prolene and Ethibond did not differ (P = 0.130). INTERPRETATION: Gap formation with Ethibond was significantly lower compared to Supramid and Prolene. The four strand nature of the Supramid repair was superior to Prolene but did not differ compared to Ethibond with respect to failure load. Prolene is the least favourable suture when considering gap formation and failure load, while Ethibond is the most favourable.     

带线锚钉材料在跟腱断裂修复中的应用

背景：带线锚钉材料修复跟腱断裂较传统可吸收线编织法具有操作简单、固定可靠、生物力学强度大的优势。目的：观察应用带线锚钉材料修复跟腱断裂的临床效果。方法：选择急性跟腱断裂患者30例,根据患者自愿原则采取两种方法修复跟腱,实验组采用带线锚钉材料以编织法行断端缝合,对照组采用可吸收缝线以编织法行断端缝合。随访1年观察患者足踝功能修复效果。结果与结论：实验组足踝功能、跖屈肌力、患者满意度明显优于对照组（P〈0.05）。表明带线锚钉材料可更好修复跟腱断裂,保护踝关节功能。     

Tendon fixation in arthroscopic latissimus dorsi transfer for irreparable posterosuperior cuff tears: an in vitro biomechanical comparison of interference screw and suture anchors

Background

The fixation of the tendon to the bone remains a challenging problem in the latissimus dorsi tendon transfer for irreparable cuff tears and can lead to unsatisfactory results. A new arthroscopic method of tendon to bone fixation using an interference screw has been developed and the purpose of this study was to compare its biomechanical properties to the ones of a standard fixation technique with anchors.

Methods

Six paired fresh frozen cadaveric human humeri were used. The freed latissimus dorsi tendon was randomly fixed to the humeral head with anchors or with interference screw after a tubularization procedure. Testing consisted to apply 200 cycles of tensile load on the latissimus dorsi tendon with maximal loads of 30 N and 60 N, followed by a load to failure test. The stiffness, displacements after cyclic loadings, ultimate load to failure, and site of failure were analysed.

Findings

The stiffness was statistically higher for the tendons fixed with interference screws than for the ones fixed with anchors for both 30 N and 60 N loadings. Likewise, the relative bone/tendon displacements after cyclic loadings were lower with interference screws compared to anchors. Load to failure revealed no statistical difference between the two techniques.

Interpretation

Compared to the standard anchor fixation, the interference screw fixation technique presents higher or similar biomechanical performance. These results should be completed by further biomechanical and clinical trials to confirm the interest of this new technique as an alternative in clinical use.     

The history of suture anchors in orthopaedic surgery

The suture anchor allows secure fixation of soft tissue to bone and has become an invaluable tool for the orthopaedic surgeon. The original suture anchor was developed over 3 decades ago when a suture was bonded to a headless screw. Since then anchors have undergone a wide variety of design modifications to increase strength and allow for new applications based on biomechanical and clinical evidence. The suture anchor chain consists of the anchor to bone fixation, anchor suture interface, suture itself and suture to soft tissue interface. The early suture anchors failed most commonly from anchor pull out or breakage, with the strongest early design being a bone-screw-suture complex. Early concerns of metalwork complications saw the introduction of biodegradable suture anchors, originally lactic acid polymers and then osteoconductive bio-composites. Improvements in anchor design saw the suture become the main link of failure until the advent of novel suture materials made of ultrahigh molecular weight polyethylene. A form failure of suture at the anchor eyelet via cut-out led to redesign of the anchor suture interface with novel eyelet designs. Further innovations in the anchor suture interface have seen the advent of knotless anchors, especially useful in arthroscopic surgery. The newest products are all-suture anchors which show impressive strength whilst reducing the iatrogenic damage caused by insertion. The further biomechanical development of suture anchors is likely to produce new designs that continue to increase strength whilst managing size requirements for tailored clinical applications.     

Adjustable-length loop cortical button versus interference screw fixation in quadriceps tendon anterior cruciate ligament reconstruction – A biomechanical in vitro study

BackgroundThis biomechanical cadaveric in vitro study aimed to evaluate and compare the dynamic elongation behavior and ultimate failure strength of tibial adjustable-length loop cortical button versus interference screw fixation in quadriceps tendon-based anterior cruciate ligament reconstruction.MethodsSixteen human quadriceps tendons were harvested and fixed into porcine tibiae using either biodegradable interference screw (n = 8) or adjustable loop device (n = 8) fixation. An acrylic block was utilized for femoral adjustable loop device fixation for both groups. All constructs were precycled for 10 times at 0.5 Hz and manually retensioned before tested in position and force control mode each for 1000 cycles at 0.75 Hz according to in vitro loading conditions replicating the in vivo ACL environment. Subsequently, an ultimate failure test at 50 mm/min was performed with mode of failure noted.FindingsTibial IS fixation showed no statistically significant differences in the initial (−0.46 vs. −0.47 mm; P = 0.9780), dynamic (2.18 mm vs. 2.89 mm; P = 0,0661), and total elongation (1.72 mm vs. 2.42 mm; P = 0,0997) compared to adjustable loop device fixation. The tibial button fixation revealed an increased ultimate failure load (743.3 N vs. 606.3 N; P = 0.0027), while stiffness was decreased in comparison to screw fixation (133.2 N/mm vs. 153.5 N/mm; P = 0,0045).InterpretationAnterior cruciate ligament reconstruction for quadriceps tendon graft using a tibial adjustable-length loop cortical button provides for comparable dynamic stabilization of the knee with increased ultimate failure load at decreased stiffness compared to screw fixation.     

关节镜下微创治疗对胫骨髁间棘骨折的疗效

目的 探讨关节镜下复位不同内固定方法治疗胫骨髁间棘撕脱性骨折的疗效.方法 采用关节镜下治疗胫骨髁间棘撕脱性骨折83例,其中Ⅱ型27例,Ⅲ型38例,Ⅳ型18例.在关节镜监视下行骨折复位、利用前交叉韧带胫骨导向器准确确定骨床上的钻孔位置;于胫骨结节内下部经皮向关节腔钻入一个骨隧道;采用双股5号尼龙编织缝线套扎前交叉韧带基底并经骨隧道引出关节外固定于胫骨结节内侧门型钉上.结果 术后83例获得随访6～36个月,平均15个月.术后Lachman和抽屉试验均为阴性.X线片显示除2例骨块前缘有2 mm上撬外均为解剖复位,骨折全部愈合.膝关节活动均正常.结论 关节镜下复位及双股尼龙编织缝线套扎固定治疗胫骨髁间棘撕脱骨折,复位满意、固定可靠;该手术方法简便易行,创伤小,有利于膝关节功能恢复.     

线缆与丝线捆扎固定前交叉韧带胫骨止点撕脱性骨折

背景：关节镜下治疗前交叉韧带胫骨止点撕脱骨折已被广泛应用并取得了良好效果,但在内固定方法的许多方面仍未达成共识,甚至颇具争议。目的：分析关节镜下手术进行前交叉韧带胫骨止点撕脱骨折复位AO线缆固定与丝线固定对膝关节运动功能和稳定性的影响。方法：选择关节镜下手术治疗前交叉韧带胫骨止点撕脱骨折患者25例,其中应用AO线缆行骨折块内固定治疗者13例,应用丝线行骨折块固定治疗者12例。比较两组治疗后的膝关节活动度及稳定性。结果与结论：治疗后随访6个月-5年,两组伸膝及屈膝运动功能差异无显著性意义,AO线缆组膝关节稳定性明显好于丝线组（P〈0.05）。表明在关节镜下复位固定前交叉韧带胫骨止点撕脱骨折使用AO线缆固定较使用丝线固定效果满意。     

Biomechanical investigation of different internal fixations in medial opening-wedge high tibial osteotomy

BACKGROUND: The medial opening-wedge osteotomy for treatment of varus gonarthritis has become very popular in recent years. Different implants for internal fixation after the osteotomy have been created. It is still unclear, which principle of internal fixation (angle stable or non-angle-stable plate with or without spacer) has the best biomechanical properties. The aim of this study was to determine the biomechanical properties of different fixation techniques in medial opening-wedge high tibial osteotomy in a porcine bone model. METHODS: A 10-mm high tibial opening-wedge osteotomy was performed and stabilized with plates of similar dimensions but different functional principle (conventional plate, angle stable plate with or without spacer). Biomechanical properties (stiffness, displacement within the osteotomy space and load at failure) were evaluated under axial load. RESULTS: Plates which contain a spacer had a significantly higher stiffness at a load at 1000 N (p < 0.05). This correlates with a significantly reduced deformation within the osteotomy space. The strength at failure was not different between the groups. The use of a spacer in a conventional plate produces fractures of the lateral tibial cortex. In angle stable plates and plates containing spacers, the failure was caused by fractures of the lateral tibia surface, the fibula or by displacement within the tibio-fibular joint. The failure was caused primarily by implant insufficiency in plates without spacers. CONCLUSIONS: In a model with comparable conditions, implants which contain a spacer have superior biomechanical properties. Angle stable plates may prevent fractures of the lateral cortex after opening-wedge osteotomy.