下胫腓联合损伤对踝关节稳定性影响的生物力学研究

[目的]探讨下胫腓联合损伤对踝关节稳定性的生物力学影响。[方法]采用6例新鲜尸体标本,制作踝关节旋前外旋损伤模型,逐步离断下胫腓联合各韧带、骨间膜和三角韧带。对标本进行600 N轴向加载,同时对踝关节施加扭矩为5 Nm的外旋力。测量下胫腓联合不同程度损伤情况下,下胫腓联合的相对位移和踝关节外旋扭转角度。[结果]随着下胫腓联合韧带和三角韧带的序贯性离断,下胫腓联合的远端腓骨相对内外位移、前后位移、腓骨转角以及踝关节扭转角度呈逐渐增加趋势。[结论]下胫腓联合韧带维持踝关节稳定。在旋转稳定性方面,下胫腓后韧带的作用最为突出。下胫腓联合韧带离断后,再离断三角韧带,踝关节的稳定性进一步丢失。     

三角韧带与下胫腓联合韧带对踝关节稳定的生物力学影响

目的探讨三角韧带与下胫腓联合对踝关节稳定性的生物力学影响。方法采用6例新鲜踝关节标本,常规制成骨-韧带模型(标本可重复利用)。分为:A组:踝关节各韧带均完整;B组:三角韧带离断,下胫腓联合完整;C组:下胫腓联合离断,三角韧带完整;D组:下胫腓联合及三角韧带均离断;E组:锚钉修复三角韧带、螺钉固定下胫腓联合韧带组。对标本施加600 N轴向加载。分别测量三种体位(中立位、背伸10°位、跖屈20°位)在各种状态下胫距关节的接触面积、接触压力、压应力分布等变化。对比分析三角韧带及下胫腓联合韧带修复前后对踝关节稳定的作用。结果在三种体位下均可发现,随着下胫腓联合及三角韧带的离断,胫距关节接触面积逐渐减小,接触压力逐渐增大,与正常A组对比差异有统计学意义(P<0.05),压应力分布逐渐集中并有向外侧移位趋势;三角韧带与下胫腓联合修复前后的胫距关节的接触面积、接触压力等差异有统计学意义(P<0.05);修复后的胫距关节接触面积增大、接触压力减少,与正常组A组对比差异无统计学意义(P>0.05),压应力分布分散。结论三角韧带与下胫腓联合断裂后,距骨发生移位,胫距关节面接触面积、接触压力及压应力分布发生剧烈变化。目前骨锚钉修复三角韧带、螺钉固定下胫腓联合能获得即刻稳定,且其生物力学强度与正常组相似,推荐对三角韧带伴下胫腓联合损伤者行手术治疗以恢复其正常解剖关系。     

踝关节骨折伴下胫腓联合分离的手术治疗及临床意义

目的探讨治疗踝关节骨折伴下胫腓联合分离的手术方法及临床意义。方法自2002年1月～2005年12月对112例伴踝关节骨折下胫腓联合分离行腓骨内固定或不固定,内踝内固定,三角韧带探查修复术。未固定下胫腓联合。术后随访6～36个月,平均20.8个月。结果用Mazur评分系统评估手术疗效:优98例,良14例。未见骨折不愈合、关节不稳及创伤性关节炎等并发症。结论对伴下胫腓联合分离的踝关节骨折行手术治疗时,除了固定内、外踝,还要修复三角韧带损伤。恢复了内、外侧所有结构的完整性后才能真正恢复下胫腓联合及踝关节的正常生物力学环境和稳定性,这时即使不固定下胫腓联合,也可以获得下胫腓联合的稳定。固定内、外踝和下胫腓联合,而三角韧带的损伤不修复,虽然下胫腓韧带可以获得愈合,但三角韧带会愈合不佳、韧带松弛及功能不良,最终仍会导致创伤性关节炎。     

胫腓下联合分离的生物力学研究

目的分析踝关节内、外侧结构和胫腓下联合损伤对踝关节稳定性的影响,探讨胫腓下联合固定的指征。方法12具新鲜膝关节以下下肢标本,随机分为a、b两组,分别模拟内踝骨折和三角韧带撕裂的旋前-外旋型踝关节骨折,按该型骨折加重顺序依次切断周围韧带,用压敏片和位移传感器分别测定每次处理后的关节接触面积和胫腓下联合分离距离。分析各操作步骤对关节接触面积、胫腓下联合分离距离的影响。结果a组切断三角韧带、b组切断骨间韧带后,关节接触面积及胫腓下联合分离距离较基线状态均有明显改变,差异有极显著性意义(P<0.01)。关节接触面积和下联合分离距离呈线性回归关系。结论踝关节的稳定性主要由踝关节内、外侧结构和中间的胫腓下联合共同维持,只有当三者中两处以上发生不可逆性损伤时,踝关节的稳定性才会发生根本性改变。因此,胫腓下联合分离时,下联合固定应选择性地使用。     

胫腓下联合分离伴踝部骨折的治疗

目的探讨踝关节损伤时胫腓下联合分离的机制及胫腓下联合固定的利弊.方法伴胫腓下联合分离的踝关节损伤共31 例,其中19 例未行胫腓下联合分离固定,10 例用螺针固定胫腓下联合,2 例用下胫腓钩固定.内踝骨折以螺钉或张力带钢丝固定.外踝以螺钉或钢板固定,后踝用松质骨螺钉加压固定.结果胫腓下联合固定患者中2 例松动,2 例术后1～2 a取出固定螺钉,其余10 例均6～12周取出胫腓下联合固定螺钉.未发生胫腓下联合螺钉断裂.内外踝及后踝骨折内固定于6～29个月取出.未行胫腓下联合分离固定的病例均未出现胫腓下联合分离.结论胫腓下联合的稳定性不仅仅取决于胫腓下联合本身,胫腓下联合韧带损伤时,只有同时伴有踝关节内侧骨韧带复合体损伤,才会出现临床上的胫腓下联合分离,因此踝关节骨折脱位时,只要内外踝或后踝解剖复位,固定牢固,胫腓下联合分离即可自动复位,一般不必做胫腓下联合的固定.     

胫腓下联合分离伴踝部骨折的治疗

目的：探讨踝关节损伤时胫腓下联合分离的机制及胫腓下联合固定的利弊。方法：伴胫腓下联合分离的踝天节损伤共31例,其中19例未行胫腓下联合分离固定,10例用螺钉困定胫腓下联合,2例用下胫腓钩固定。内踝骨折以螺钉或张力带钢丝固定。外踝以螺钉或钢板固定,后踝用松质骨螺钉加压固定。结果：胫腓下联合固定患者中2例松动,2例术后1～2年取出固定螺钉,其余10例均6～12周取出胫腓下联合固定螺钉。未发生胫腓下联合螺钉断裂。内外踝及后踝骨折内固定于6～29个月取出。未行胫腓下联合分离固定的病例均未出现胫腓下联合分离。结论：胫腓下联合的稳定性不仅仅取决于胫腓下联合本身,胫腓下联合韧带损伤时,只有同时伴有踝关节内侧骨韧带复合体损伤,才会出现临床上的胫腓下联合分离,因此踝关节骨折脱位时,只要内外踝或后踝解剖复位,固定,牢固,胫腓下联合分离即可自动复位,一般不必做胫腓下联合的固定。     

下胫腓联合损伤的治疗进展

下胫腓联合又称下胫腓关节,是维持踝关节稳定性的重要结构,有下胫腓前韧带、下胫腓后韧带和骨间韧带组成.临床上下胫腓联合损伤多合并踝部的骨折,其占踝部损伤的1％ ～11％,有时也可单发生.在受伤早期,如不给予足够的重视,就会造成踝关节的不稳定、疼痛以及创伤性关节炎.对下胫腓联合损伤做出正确的诊断和治疗,可以显著减少并发症的发生[1].     

Weber-B型踝关节骨折修复下胫腓前韧带的生物力学研究

目的评价踝关节骨折修复下胫腓前韧带的生物力学稳定性。方法采集国人新鲜足标本一具,截取踝关节以上15cm下肢小腿横行截断,暴露下胫腓前韧带。载荷实现分级加载,选用小腿极限载荷（踝关节负重力为4.5BW）20%作为生理载荷,即以0、100、200、300、400、500N为分级载荷。万能材料试验机（WD-5）的加载速率为1.40 mm/min,以准静态方式加载,载荷施加于下肢胫腓骨上。并模拟足运动中立位、跖屈位（30°）、背屈位（20°）、旋后外旋位等四种生理运动状况,正常足及切除下胫腓前韧带测定踝关节的应力变化、距骨的移位变化及轴向刚度数据。结果标本在正常足及切断下胫腓前韧带的不同功能位上,踝关节的应力变化、距骨的移位变化及轴向刚度,统计学有显著性差异（P〈0.05）。结论在对内、外踝满意固定后,下胫腓前韧带的修复能更好恢复踝关节的生物弹性,最大限度恢复其原来的结构和功能,避免晚期创伤性关节炎的发生。     

下胫腓联合分离单螺钉固定的有限元分析

[目的]通过三维有限元法对下胫腓联合分离使用单螺钉固定的各方式进行对比评价,比较不同内固定生物力学特征,为临床提供理论依据.[方法]利用正常男性的足踝部螺旋CT扫描数据,建立下胫腓联合分离单螺钉内固定的三维有限元模型.模拟人体中立位单足站立踝关节受力方式,比较不同的内固定方式螺钉von Mises应力分布、胫腓骨的位移.[结果]建立12种包括骨、韧带在内的下胫腓联合分离单螺钉内固定的有限元模型.在人体中立位单足站立状态下,不同的内固定方式生物力学稳定性不同,直径4.5 mm螺钉距踝关节平面2 cm穿越4层骨皮质固定螺钉von Mises应力、胫腓骨的位移较小.[结论]下胫腓联合分离用4.5 mm螺钉距踝关节平面2 cm穿越4层骨皮质固定,可以取得较好的生物力学稳定性.     

下伸肌支持带重建下胫腓前韧带的解剖学基础

[目的]为下伸肌支持带重建下胫腓前韧带提供解剖学依据。[方法]8侧成人下肢标本,对下伸肌支持带上下内侧束及下胫腓前韧带的形态及解剖学数据进行观测,2侧新鲜标本进行模拟手术试验。[结果]下伸肌支持带跟骨附着点宽度(2.81±0.73)cm,自跟骨附着点至胫骨附着点的长度(8.53±0.42)cm,自趾长伸肌纤维管外侧壁至胫骨附着点的长度(5.87±0.62)cm;下胫腓前韧带的厚度(0.46±0.09)cm,在外踝附着点宽度(2.03±0.46)cm,在胫骨附着点宽度(1.35±0.27)cm,下伸肌支持带上内侧束胫骨附着点至下胫腓前韧带腓骨附着点的最短长度(5.45±1.06)cm。[结论]下伸肌支持带上内侧束潜行转位重建下胫腓前韧带具有可行性,自跟骨附着点切取下伸肌支持带全长可反折加强重建下胫腓前韧带。     

Tri-ligamentous Reconstruction of the Distal Tibiofibular Syndesmosis: A Minimally Invasive Approach

The distal tibiofibular syndesmosis provides stability to the ankle mortise, and it is composed of the anterior inferior tibiofibular, posterior inferior tibiofibular, interosseous, and inferior transverse tibiofibular ligaments and the interosseous membrane. Subacute or chronic syndesmosis injuries can present after missed diagnosis in the acute period or after failed or inadequate nonoperative management. It can result in chronic ankle pain and progressive degeneration of the ankle. Reconstructive options for chronic syndesmosis disruption include arthroscopic debridement and screw fixation, arthrodesis of the syndesmosis, advancement of the anterior tibiofibular ligament, reconstruction of the interosseous and anterior inferior tibiofibular ligament, or tri-ligamentous reconstruction of the syndesmosis. We describe a minimally invasive technique of nearly anatomical reconstruction of the 3 syndesmotic ligaments. The syndesmosis is debrided and reduced under arthroscopic guidance and anatomical reduction of the syndesmosis can be achieved. Although we describe this technique for surgeons to consider, we recognize that a thorough clinical review of the method, complete with objective and subjective clinical outcome measurements, is warranted before widespread use of the technique.     

下胫腓联合损伤的X线诊断研究

目的 通过对正常国人下胫腓联合及踝关节内侧间隙的数字化X线图像测量,探讨性别、年龄、身高、体质量对它们的影响,明确数字化X线检查在下胫腓联合损伤诊断中的意义. 方法选取492例正常踝关节,应用直接数字X线摄影术拍摄标准踝关节正、侧位片及踝穴位片,图像数据传送至影像工作站,在灰度显示器上对图像进行"软阅读",并利用PACS系统自带软件对下胫腓联合间隙、下胫腓联合重叠影、踝关节内侧间隙、腓骨宽度及腓前距进行模拟测量,对所得数据进行统计学处理,说明其与性别、年龄、身高及体质世的关系.结果正常成人下胫腓联合间隙参考值范围为(3.98±0.78)mm、 踝穴位为(3.67±0.68)mm, 下胫腓联合重叠影参考值范围为(7.06±1.98)mm、 踝穴位为(2.34±0.84)mm,踝关节内侧间隙参考值范围为(4.04±0.50)mm,腓骨宽度的参考值范围为(14.39±1.86)mm,腓前距参考值范围为(4.99±4.04)mm.下胫腓联合间隙、下胫腓联合重叠影、腓前距及内踝间隙与性别、年龄、身高、体质量间的决定系数及P值分别为R2a=0.229,P<0.01;R2a=0.066, P<0.01; R2a=0.032, P<0.01; R2a=0.059,P<0.01. 结论下胫腓联合间隙与身高、体质量、性别、年龄存在强相关性,不适合作为下胫腓联合损伤的评估指标;下胫腓重叠影、内踝间隙、腓前距与身高、体质量、性别、年龄存在弱相关性,可作为评估下胫腓联合早期损伤的重要指标.     

Verletzungen der unteren tibiofibularen Syndesmose

The incidence of isolated distal tibiofibular syndesmotic ruptures in acute ankle sprains lies between 1% and 11%. These injuries are frequently overseen or misdiagnosed as anterolateral rotational instability of the ankle and often become apparent through protracted courses. Although the pathomechanics and extent of syndesmotic injuries have been systematically described by Lauge-Hansen and Weber, no generally accepted guidelines exist as to when these complex injuries are to be treated surgically to ensure sufficient and stable healing of the syndesmosis besides correct alignment of the distal fibula. So far, systematic follow-up regarding syndesmotic injuries in ankle fractures is missing, although it has long been recognized that tibiofibular diastasis secondary to chronic syndesmotic instability leads to external rotation of the talus. In combination with a valgus position of the talus, this instability leads to a decrease in the contact area which results in posttraumatic arthritic changes. This paper reviews the standard diagnostic and therapeutic procedures for acute syndesmotic ruptures in fracture dislocations of the ankle. Among the few corrective procedures advocated for chronic syndesmotic insufficiency are tibiofibular arthrodesis, synthetic ligament substitutes, and tenodesis with the peroneus brevis tendon. A sufficient reconstruction must restore the stability of the ankle mortise and alignment of the fibula in the tibiofibular incisura to ensure limitation of talar rotation. Therefore, a tenodesis was developed which substitutes the three important ligaments of the syndesmotic complex. The Casting procedure for chronic syndesmotic insufficiency was modified with reconstruction of the interosseous tibiofibular ligament in addition to the anterior and posterior tibiofibular ligaments. The resulting three-point fixation of the distal fibula appears more anatomically, physiologically, and biomechanically advantageous. The operative procedure is given in detail. Distal tibiofibular syndesmosis. Persistent instability of the distal syndesmosis. Ankle fractures. Syndesmotic screw.     

Bandverletzungen am oberen Sprunggelenk

Ligamentous instability in the ankle frequently leads to chronic synovitis, cartilage lesions and osteophyte formation, which may degenerate into posttraumatic arthritis. Lesions of the distal tibiofibular syndesmosis are significant for the biomechanics of the ankle when the interosseous tibiofibular ligament is ruptured. Accurate reduction of the fibula to reposition it in the tibial incision and temporary fixation with a syndesmosis screw are essential if healing in the anatomical position is to be achieved. For treatment of a chronic instability of the distal tibiofibular syndesmosis anatomical ligamentoplasty is preferred. In the case of acute lateral ankle ligament ruptures conservative-functional treatment has become established over the last 20 years. Recent meta-analyses have failed to demonstrate any clear superiority of operative treatment, which has the potential for considerable complications. Chronic lateral ankle instability has a favorable prognosis with secondary interventions. Anatomical reconstruction should be given priority over extra-anatomical tenodesis procedures, since the latter are associated with considerable functional restrictions. Isolated ruptures of the deltoid ligaments are rare injuries that heal well with conservative-functional treatment after correct diagnosis.     

Syndesmosis transfixation screw

Instability of the distal tibia-fibular joint necessitates the implant of a fibular tibial transfixation screw. The screw should be placed 2 cm above the anterior syndesmosis. The angle of insertion is 30 degrees upwards from dorsal in relation to the frontal plane. If tibiofibular stability cannot be maintained following anatomical reconstruction of the fibula the transfixation screw must engage the medial tibial cortex. This is imperative, since the transfixation screw cannot withstand the biomechanical forces during motion and bearing of load if the screw penetrates only three corticals.     

Which Ankle Fractures Require Syndesmotic Stabilization?

Syndesmotic ruptures associated with ankle fractures are most commonly caused by external rotation of the foot, eversion of the talus within the ankle mortise, and excessive dorsiflexion. The distal tibiofibular syndesmosis consists of the anterior inferior tibiofibular ligament, posterior inferior tibiofibular ligament, and interosseous ligament, and it is essential for stability of the ankle mortise. Despite the numerous biomechanical and clinical studies pertaining to ankle fractures, there are no uniform recommendations regarding the use of the syndesmotic screw for specific injury patterns and fracture types. The objective of this review was to formulate recommendations for clinical practice related to the use of syndesmotic screw placement.     

Tibiofibular Space Widening Assessment With a Ball-Tipped Probe in a Syndesmosis Injury Model

Assessment of syndesmotic instability is not precise with existing evaluation methods. This study was conducted to investigate the use of a ball-tipped probe under arthroscopy for quantitative assessment of tibiofibular space widening in a syndesmosis injury model. The test specimens were 5 uninjured ankles from Thiel-fixed cadavers of 2 male subjects and 3 female subjects of mean age of 82.4 years at death. The ball-tipped probe consisted of a metal probe having a ball at each end with diameters ranging from of 1.5 mm to 5.0 mm, in increments of 0.5 mm. The tibiofibular joint was observed arthroscopically as the largest-diameter ball probe as possible was inserted into its anterior third, middle, or posterior third portion with the ankle in natural plantarflexion or under external rotational stress. These measurements were performed for the uninjured ankle and then performed following Bassett's ligament sectioning, anterior inferior tibiofibular ligament sectioning, interosseous membrane distal 15 cm sectioning, or deltoid ligament, and posterior inferior tibiofibular ligament sectioning, with the sections added in this sequence and each followed by a similar assessment. The results of quantitative assessment of tibiofibular space widening with the ball-tipped probe in the syndesmosis injury model under arthroscopy were that the maximum possible diameter of ball probe that could be inserted was 1.5 to 2.0 mm in the uninjured state, 3.0 to 3.5 mm in the sectioned anterior inferior tibiofibular ligament model, and 5.0 mm in the severe-state model. The ball probe can serve as an effective tool for quantitative assessment of the intraoperative instability in cases of syndesmosis injury.     

Finite element analysis of the influence of anterior talofibular ligament injury on Hook test results

AimTo determine whether the anterior talofibular ligament injury will influence the Hook test result.MethodA three-dimensional model of the ankle was established based on CT scan of a healthy volunteer and ligament attachment through references; Four groups (A–D) of operating conditions were set up. In group A, the anterior and posterior ligaments of the inferior tibiofibular joint were cut off and the anterior talofibular ligament was kept intact; in group B, all the anterior and posterior tibiofibular ligaments and the anterior talofibular ligament were cut off; in group C, the medial and lateral ligaments of the ankle joint and the inferior tibiofibular ligament were kept intact; in group D, only the talofibular ligament was cut off and other ligaments were kept intact. The proximal end of the model was restrained in all four groups, an outward pulling force of 100 N perpendicular to the fibula was applied, and displacement and rotation of the distal end of the fibula in the four groups was observed.ResultsWhen the inferior tibiofibular joint injury was associated with an anterior talofibular ligament injury, the Hook test indicated about 3.19 mm of displacement of the distal end of the fibula, and obvious external rotation occurred due to increased activity of the anterior border of the fibula. In the other groups, a single inferior tibiofibular joint injury or a single anterior talofibular ligament injury did not increase displacement or rotation of the distal end of the fibula.     

Chronic tibiofibular syndesmosis injury: the diagnostic efficiency of magnetic resonance imaging and comparative analysis of operative treatment

BACKGROUND: The purpose of this study was to determine the sensitivity and specificity of MRI in chronic syndesmosis injury by comparing the arthroscopic findings with MRI findings and to suggest therapeutic guidelines of syndesmotic fixation. METHODS: Between January, 2003, and January, 2004, 20 patients were diagnosed with chronic syndesmosis injury according to syndesmosis widening (>2 mm) on arthroscopic examination. The average age of the patients was 32 years. The minimum followup was 22 (22 to 30) months. MRI was obtained in all patients. For evaluating the therapeutic role of syndesmotic fixation, we separated the patients into two groups (with and without transfixation) and compared preoperative and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores and patient satisfaction. RESULTS: The sensitivity, specificity, and accuracy of MRI were 90.0%, 94.8%, and 93.4%, respectively. In group I with syndesmotic fixation, the AOFAS ankle-hindfoot scale improved from 52 to 87, and in group II without syndesmotic fixation the score improved from 63 to 90 at last followup, which showed no statistically significant difference (p = 0.6453). Also, patient satisfaction showed no difference between the two groups. CONCLUSIONS: MRI showed high sensitivity, specificity, and accuracy under the criteria we proposed, and we recommend it as the main diagnostic tool for diagnosing a chronic syndesmosis injury. These findings might suggest that pain is mainly caused by hypertrophy and impingement of the soft tissue in the distal tibiofibular joint. Arthroscopic debridement alone can be recommended if the distal tibiofibular chronic syndesmosis injury is not combined with medial ankle instability and lateral displacement of the talus.