Essex-Lopresti损伤的生物力学研究

目的 探讨Essex-Lopresti损伤的生物力学机制,为诊治Essex-Lopresti损伤提供生物力学依据.方法 取12具成人新鲜冰冻上肢标本予以处理,先将12具标本("完整状态组")分别在旋前位、旋后位及中立位三种状态下把标本夹持固定于MTS 858生物材料试验机上进行力学测试,恒定加载100 N的压力负荷,每种状态持续30 s后减载.随后将12具标本随机分为2组,6具切除桡骨头为"切头留膜组";另6具切断前臂骨间膜(interosseous membrane,IOM)中间腱性部分为"留头切膜组".每组按上述方法进行生物力学测试.最后将所有标本均切除桡骨头并切断IOM("切头切膜组")按上述方法进行生物力学测试.结果 前臂旋转状态或单纯切断IOM对桡骨纵向位移无影响.单纯切除桡骨头或联合切断IOM和切除桡骨头增加了桡骨的纵向位移.前臂中立位时的桡骨刚度比前臂旋前位大,但比前臂旋后位小.单纯切断IOM对桡骨刚度没有影响,单纯切除桡骨头或联合切断IOM和切除桡骨头则会使桡骨刚度下降.结论 桡骨头骨折合并IOM损伤可能是Essex-Lopresti损伤产生并发症的重要原因,其中桡骨头骨折是Essex-Lopresti损伤主要原因,而IOM损伤是次要原因.桡骨头切除后IOM是维持前臂纵向稳定的主要结构.     

前臂纵向分离的研究进展

前臂纵向分离(longitudinal radioulnar dissociation,LRUD)是指腕部受到轴向暴力,造成桡骨头/颈骨折或脱位合并骨间膜撕裂和下尺桡关节分离的复杂联合损伤,引起前臂纵向不稳定。生物力学研究表明在切除桡骨小头情况下,单纯重建骨间膜仅能减轻桡骨向近侧移位,而恢复LRUD前臂的纵向稳定性需要骨间膜重建与桡骨头金属假体置换联合。LRUD误诊和漏诊率高,MRI和B超是早期检查骨间膜损伤的有效方法。目前治疗强调修复LRUD的所有损伤结构而恢复前臂稳定性,即修复或重建桡骨头、矫正下尺桡关节,同时重建骨间膜。治疗成功与否取决于能否早期诊断。     

桡侧腕长伸肌肌腱重建骨间膜结合桡骨头置换恢复前臂纵向稳定性的生物力学研究

目的通过生物力学测试,评价桡侧腕长伸肌肌腱重建前臂骨间膜结合桡骨头置换恢复前臂纵向稳定性的效果。方法取10具新鲜冰冻成人前臂标本,男8具,女2具;年龄29~74岁,平均38.2岁。每个标本依次作以下处理:切除桡骨头(A组)、切除桡骨头+分离远侧尺桡关节(B组)、切除桡骨头+分离远侧尺桡关节+切除骨间膜中央束(C组)、桡侧腕长伸肌肌腱重建骨间膜(D组)、单纯桡骨头置换(E组)、桡侧腕长伸肌肌腱重建骨间膜+桡骨头置换(F组)。大体观察各组标本制备后在负荷及非负荷状态下,尺桡骨间距以及尺桡关节移位情况;行生物力学测试,记录桡骨向近端移位5 mm时施加在标本两端的负荷。结果恢复桡骨长度可以维持正常尺桡骨间距,骨间膜重建可以恢复尺桡骨间的负荷传导。生物力学测试显示,A~F组桡骨向近端移位5 mm所需负荷分别为(74.507±4.967)、(49.227±1.940)、(17.827±1.496)、(24.561±1.390)、(140.247±8.029)、(158.423±9.142)N,各组间比较差异均有统计学意义(P0.01)。结论单纯桡侧腕长伸肌肌腱重建骨间膜不能恢复前臂纵向稳定,而其联合桡骨头置换可有效重建前臂纵向稳定性。     

前臂完整性与尺桡肌的生物力学变化

目的：从生物力学角度探讨桡骨头切除后远期并发症的病因。方法：用新鲜解冻尸体上肢,在尺桡骨表面粘巾应变片,安装百分表。在生物力学试验机上连续加载和卸载,测试不同体位,不同解部状态各点应变值及纵轴位移。结果：应变值与载荷、体位及解剖状态有关。体位及单纯骨间膜切断对尺柳骨间纵轴稳定性影响甚微。切除桡骨小头,尺桡骨间稳定性降低,再切断骨间膜,将使以上改变加重。结论：桡骨小头切除后肱尺关节载荷紊乱及纵轴失稳     

前臂完整性与尺桡骨的生物力学变化

目的：从生物力学角度探讨桡骨头切除后远期并发症的病因。方法：用新鲜解冻尸体上肢,在尺桡骨表面粘贴应变片,安装百分表。在生物力学试验机上连续加载和卸载,测试不同体位,不同解剖状态各点应变值及纵轴位移。结果：应变值与载荷、体位及解剖状态有关。体位及单纯骨间膜切断对尺桡骨间纵轴稳定性影响甚微。切除桡骨小头,尺骨应力增加,尺桡骨间稳定性降低,再切断骨间膜,将使以上改变加重。结论：桡骨小头切除后肱尺关节载荷紊乱及纵轴失稳是多种术后并发症的原因。     

Essex-Lopresti损伤治疗

EssexLopresti损伤包括桡骨头骨折、尺桡远侧关节分离和骨间膜撕裂,导致前臂活动障碍和纵向不稳定。Essex-Lopresti损伤发病率极低,容易漏诊而未予处置,使患肢功能受损;治疗不充分也会使前臂急性不稳定变成更为复杂的陈旧性纵向不稳定。及时诊断有赖于对此类损伤的充分了解和详尽的物理、超声及放射线检查。急性期损伤治疗旨在防止桡骨向近侧移位,需要正确处理桡骨头骨折,避免桡骨头切除,修复三角纤维软骨复合体,损伤的骨间膜重建与否尚有争议;陈旧性损伤处理的中心环节是重建完整的稳定结构,恢复尺桡远侧关节高度,最终恢复前臂尺桡骨之间的正常关系,消除纵向不稳定,方法包括人工桡骨头置换、尺骨截骨短缩、骨间膜中央束重建和三角纤维软骨复合体修复。     

前臂骨间膜解剖和生物力学研究进展

前臂纵向稳定的维持依赖于前臂骨间膜等解剖结构的相互作用。前臂骨间膜是从桡骨斜向至尺骨的腱性纤维组织,由中间1/3的腱性部分和两端的膜性部分构成,其中腱性部分是骨间膜的主要力学功能区,承担着大部分由桡骨传递至尺骨的应力。组织学和生化学研究显示,骨间膜由大量胶原纤维和少量弹性蛋白组成,这些成分使其既具有韧性又具有弹性,可承受很大的载荷,在前臂旋转运动时维持尺桡骨的稳定,并将应力由桡骨传导至尺骨。桡骨头切除后前臂的纵向稳定主要由前臂骨间膜维持,如果同时并发骨间膜损伤,将导致进行性桡骨向近端移位和下尺桡关节分离,其治疗的关键在于恢复前臂的正常长度及重建骨间膜的功能。该文就前臂骨间膜解剖结构、组织学、生化学及力学功能的研究进展作一综述,并讨论其在临床方面的实际意义。     

Essex-Lopresti损伤的生物力学研究

目的 探讨Essex-Lopresti损伤的生物力学机制,为诊治Essex-Lopresti损伤提供生物力学依据.方法 取12具成人新鲜冰冻上肢标本予以处理,先将12具标本("完整状态组")分别在旋前位、旋后位及中立位三种状态下把标本夹持固定于MTS 858生物材料试验机上进行力学测试,恒定加载100 N的压力负荷,每种状态持续30 s后减载.随后将12具标本随机分为2组,6具切除桡骨头为"切头留膜组";另6具切断前臂骨间膜(interosseous membrane,IOM)中间腱性部分为"留头切膜组".每组按上述方法进行生物力学测试.最后将所有标本均切除桡骨头并切断IOM("切头切膜组")按上述方法进行生物力学测试.结果 前臂旋转状态或单纯切断IOM对桡骨纵向位移无影响.单纯切除桡骨头或联合切断IOM和切除桡骨头增加了桡骨的纵向位移.前臂中立位时的桡骨刚度比前臂旋前位大,但比前臂旋后位小.单纯切断IOM对桡骨刚度没有影响,单纯切除桡骨头或联合切断IOM和切除桡骨头则会使桡骨刚度下降.结论 桡骨头骨折合并IOM损伤可能是Essex-Lopresti损伤产生并发症的重要原因,其中桡骨头骨折是Essex-Lopresti损伤主要原因,而IOM损伤是次要原因.桡骨头切除后IOM是维持前臂纵向稳定的主要结构.

Abstract：

Objective To study the biomechanical mechanism of Essex-Lopresti injury, and provide biomechanical basis for diagnosis and treatment of Essex-Lopresti injury. Methods Twelve fresh frozen adult upper limbs were addressed. Firstly, 12 samples ("complete state group") were loaded 100 N of a compressive force lasting 30 seconds in pronation, supination and neutral position on the mechanical testing machine. Secondly, 12 specimens were randomly divided into 2 groups. In the group named resection of radial head, the radial head was removed and interosseous membrane (IOM)was intact. In the group named the section of interosseous membrane, IOM was cut off. Finally, the radial head were removed and IOM was cut off in all specimens. The group was named as resection of radial head and IOM. Each sample was tested according to the method as described. Results The forearm rotation or single excision of the IOM had no effect on radial longitudinal displacement. Simple radial head excision or resection of the IOM and the radial head increased the vertical displacement of the radius. The radial stiffness had a gradual decline in forearm supination, neutral position and pronation. Simple excision IOM has no effect on the radial stiffness. The radial stiffness had decreased under the condition of excision of radial head or resection of the IOM and the radial head. Conclusion These in vitro measurements validate that the radial head fracture with IOM injury may be important reason for complications of the Essex-Lopresti injury. Radial head fracture play a key role for Essex-Lopresti injury and the injury of IOM is secondary cause. IOM is responsible for maintaining the vertical stability of the forearm after radial head resection.     

前臂骨间膜的磁共振成像及其动态变化

前臂骨间膜（interosseous membrane,IOM）损伤常作为前臂骨折的伴随损伤而出现（如Essex—Lopresti骨折、盖氏骨折和桡骨远端骨折等）。由于常规平片检查无法显示骨间膜,因而漏诊和误诊的病例较多,患者多出现长期腕部疼痛、握持力量减弱、前臂旋转功能受限及肘关节活动障碍等严重并发症。IOM对于维护前臂的纵向稳定和旋转功能至关重要。Hotchkiss等研究指出,桡骨头切除后前臂纵向稳定强度的71％由IOM中央区维持。目前运用磁共振成像（MRI）对骨间膜进行研究已有报道,但在临床应用方面尚无太多经验。     

应用生物力学方法探讨桡骨小头切除术后晚期并发症的原因

自１９７８年，共施行健骨头切除术３７例。２７例获２年以上随访。肘外翻畸形，肘关节慢性不稳定，桡骨干上移和下尺桡关节脱位是主要并发症。作者用２０只新鲜上肢标本进行生物力学实验，发现肘关节内侧副韧带损伤，骨间膜撕裂伤和下尺桡关节脱位是引起或加重并发症的主要原因。其中内侧副韧带损伤是最重要的原因。同时，临床上也以桡骨头损伤合并内侧副韧带损伤多见。作者强调：桡骨头切除时，应考虑上述三种软组织损伤是否存在及其对预后的影响；桡骨头切除在青少年患者应视为禁忌；桡骨头切除应作为改善前臂功能的最后选择。     

Diagnosis and treatment of longitudinal instability of the forearm

Radio-ulnar dissociation can result from high-injury trauma that the compressive forces traverse the wrist forearm and elbow. This injury can be thought of as an "unhappy triad" of radial head fracture, triangular fibrocartilage complex failure, and a tear of the interosseous membrane. The radius is the primary stabilizer of the forearm with the forearm interosseous membrane enabling load sharing between the radius and the ulna. The central one-third of the interosseous membrane is 3 times stronger than the membranous portion and approaches the strength of the anterior cruciate ligament for determining interosseous membrane injury. Imaging studies with proven diagnostic efficacy include magnetic resonance imaging and ultrasound. Surgical treatment should be considered when circumstances imply longitudinal instability of the forearm. Surgical treatment includes open reduction/internal fixation or prosthetic replacement of the radial head as well as repair of the disrupted triangular fibrocartilage complex. Successful treatment of radioulnar dissociation is predicated on early diagnosis of the condition.     

Reconstruction of the interosseous ligament restores normal forearm compressive load transfer in cadavers

PURPOSE: Longitudinal radioulnar dissociation may result when compressive load to the hand causes excessive proximal migration of the radius with interosseous ligament (IOL) disruption and radial head fracture. Although radial head salvage or arthroplasty and temporary distal radioulnar joint pinning constitute the current treatment for this injury IOL reconstruction has been proposed to restore normal forearm mechanics. To help provide a biomechanical basis for IOL reconstruction we measured load transfer and proximal migration of the radius with the IOL intact, cut, and reconstructed while leaving the radial head intact. METHODS: We dissected the central third of 12 normal cadaveric forearms to bone-IOL-bone. We applied 136 N of compressive load to the hand and measured proximal radial migration and 3-dimensional force vectors acting in the distal radius, distal ulna, IOL, proximal radius, and proximal ulna. Experiments were performed in neutral forearm rotation and neutral elbow varus-valgus. The protocol was repeated with the IOL intact, cut, and reconstructed with single and double flexor carpi radialis allografts. RESULTS: With the IOL intact 94% +/- 3 % of hand load was in the distal radius with 75% +/- 2% was transmitted to the proximal radius. With the IOL cut 92% +/- 2% of hand load was in the distal radius and this was unchanged at the proximal radius. With single flexor carpi radialis reconstruction 94% +/- 3% of hand load was in the distal radius and 80% +/- 2% was in the proximal radius; with double flexor carpi radialis reconstruction these numbers changed to 95% +/- 3% and 74% +/- 2%, respectively. Forces in the forearm were mainly in the longitudinal and transverse directions with negligible components in the dorsal-volar direction. Transverse force in the IOL was about half that of the longitudinal force in the intact and reconstructed states. CONCLUSIONS: When the IOL is cut and load is applied to the hand the unloading of the proximal radius and the transversely directed force that compresses normally across the proximal and distalradioulnar joints is lost. Reconstruction of the IOL can restore the normal load transfer characteristics. These data help provide a biomechanical basis for IOL reconstruction. Further research on the biomechanics of IOL reconstruction in the setting of radial head replacement along with clinical evaluation is needed.     

Longitudinal radioulnar dissociation

Proximal translation of the radius is a complication of radial head fractures that occurs in association with disruption of the longitudinal soft-tissue stabilizers of the forearm. The sequelae of this process include debilitating wrist and elbow pain secondary to ulnocarpal and radiocapitellar abutment as well as loss of grip strength. When radioulnar dissociation is recognized early, treatment involves prevention of proximal radial migration by preservation of the radial head and stabilization of the distal radioulnar joint. When primary bony repair of the radial head is not feasible, prosthetic replacement of the radial head is necessary to prevent proximal radial migration. Management is complex in chronic cases in which longitudinal radioulnar dissociation is diagnosed after radial migration has occurred. Treatment goals include normalization of the radioulnar relationship and prevention of further migration. Although several reconstructive treatment options are available, no clear solutions exist, and long-term prognosis is guarded. Therefore, early recognition of longitudinal forearm instability is critically important.     

Reconstruction of the interosseous ligament of the forearm reduces load on the radial head in cadavers

Excision of the radial head after fracture may be complicated by longitudinal radio-ulnar instability (Essex-Lopresti lesion) if the forearm interosseous ligament has also been torn. In such cases proximal migration of the radius occurs, and ulnar impaction at the wrist and radiocapitellar contact at the elbow may impair function. Although metal radial head arthroplasties are now used for irreparable radial head fractures, the long-term clinical outcome may still be unsatisfactory because of excessive radiocapitellar load causing pain. Interosseous ligament reconstruction might improve outcome by restoring normal load transfer from the radius to ulna, but the biomechanical effect of reconstruction has not been reported. This study evaluated forearm load transfer following interosseous ligament reconstruction with an Achilles tendon allograft in a cadaveric model with the radial head intact. Interosseous ligament reconstruction reduced proximal radius loading by transferring force to the proximal ulna, but force transfer by the reconstruction was only half that by the intact ligament.     

History of radial head prosthesis in traumatology

A review of the literature was performed to survey the history of the radial head prosthesis in traumatology. Radial head resection was the treatment of choice before Speed first reconstructed the radial head with a metal prosthesis. Over the years, the indication for the use of a radial head prosthesis changed from the prevention of heterotopic ossification to the prevention of proximal migration of the radius and instability of the elbow. Currently, the optimal indication for the use of radial head prostheses is a non-reconstructible radial head fracture with associated injuries that would leave the elbow, or forearm unstable if the radial head were resected.     

Interosseous membrane reconstruction for forearm longitudinal instability

Forearm longitudinal instability results from an axial load to the forearm with fracture or dislocation of the radial head and disruption of the interosseous membrane and that of the distal radioulnar joint. Patients may present in the acute or chronic setting with radioulnar instability as manifested by persistent or new forearm discomfort and wrist and elbow pain. Reconstruction of the interosseous membrane has been described to restore longitudinal forearm stability. We describe reconstruction of the central band of the interosseous membrane with a bone-patellar tendon-bone graft. This procedure may be carried out in conjunction with radial head fixation or replacement and TFCC repair in the acute setting or ulnar shortening osteotomy in late presenting cases.