Biomechanical comparison of fixation stability using a Lisfranc plate versus transarticular screws

Background

To obtain adequate fixation in treating Lisfranc soft tissue injuries, the joint is commonly stabilized using multiple transarticular screws; however iatrogenic injury is a concern. Alternatively, two parallel, longitudinally placed plates, can be used to stabilize the 1st and 2nd tarsometatarsal joints; however this may not provide adequate stability along the Lisfranc ligament. Several biomechanical studies have compared earlier methods of fixation using plates to the standard transarticular screw fixation method, highlighting the potential issue of transverse stability using plates. A novel dorsal plate is introduced, intended to provide transverse and longitudinal stability, without injury to the articular cartilage.

Stabilization of Lisfranc joint injuries: a biomechanical study

BACKGROUND: Lisfranc joint injuries are often misdiagnosed, leading to significant morbidity. Methods for anatomic reduction of the tarsometatarsal joint include closed reduction with casting or surgical stabilization with either Kirschner wires and/or cortical screw fixation. Controversy exists as to which fixation technique offers optimal stability. In the present study, the biomechanical stability of three fixation methods was tested: (1) four Kirschner wires, (2) three cortical screws plus two Kirschner wires, and (3) five cortical screws. METHODS: Ten matched pairs of fresh-frozen cadaveric feet were dissected to their ligamentous and capsular elements. The tarsometatarsal ligaments were completely transected to replicate a Lisfranc dislocation; the "injury" was reduced and stabilized using one of the three methods. Biomechanical studies were performed by applying a 100-N cyclic load physiologically distributed to the plantar aspect of the metatarsal heads. Displacement and force measurements were taken from the first and fifth metatarsal heads. Average stiffness of each construct was calculated from the force displacement curves. RESULTS AND CONCLUSIONS: Method 2 provided significantly more stability than Kirschner wire fixation. Method 3 created more stiffness than method 2 at the medial portion of the foot; no statistical difference between the two methods was evident at the lateral foot. CLINICAL RELEVANCE: Cortical screw fixation provides a more rigid and stable method of fixation for Lisfranc injuries as compared to Kirschner wire fixation. This fixation method allows maintenance of anatomic reduction and possibly earlier mobilization with a decreased risk of posttraumatic arthrosis.     

PLA screw fixation of Lisfranc injuries

Fourteen patients with Lisfranc injuries were treated with open reduction and internal fixation with PLA absorbable screw fixation by a single surgeon. From one to four PLA screws were used in each case (average two). In four patients, K-wires were inserted and removed at six weeks following surgery for instability of the fourth and/or fifth tarsometatarsal joints. Average follow-up was 20 months (range, three to 45 months). No patient was noted to have a soft tissue reaction to the screws. No evidence of osteolysis was noted on any of the follow-up X-rays at the screw sites. No loss of reduction was noted in any follow-up X-rays compared to immediate postoperative radiographs. The use of absorbable screws in this small series was found to be safe, without reaction and obviated the need for screw removal at short-term follow-up.     

下颈椎经关节螺钉固定的生物力学研究

目的比较下颈椎经关节螺钉3层皮质和4层皮质固定的生物力学拔出力的区别。方法10具新鲜尸体颈椎标本（C3-T1），游离成3个颈椎运动节段（C3～C4、C5～C6、C7～T1），在椎体两侧随机进行经关节螺钉3层皮质和4层皮质固定，置入直径为3．5mm的皮质骨螺钉。置入经关节螺钉行拔出力试验，比较经关节螺钉2种固定方式的最大轴向拔出力。结果下颈椎经关节螺钉4层皮质固定的平均拔出力为430N，而3层皮质固定的平均拔出力为412N，但两者间差异无统计学意义（P〉0．05）。经关节螺钉两种固定方式在颈椎各节段间差异无统计学意义（P〉0．05）。结论下颈椎后路经关节螺钉3层皮质固定的力学性能与4层皮质固定差异并不明显。经关节螺钉3层皮质固定可能在减少和避免置钉相关的神经血管损伤并发症方面有着重要的临床意义。     

Dynamic compression plate fixation: a biomechanical comparison of unicortical vs bicortical distal screw fixation

The use of unicortical screws instead of bicortical screws in the extreme outer holes of dynamic compression plates (DCPs) has been recommended to minimize the stress riser effect at the end of the plates. The authors examined in vitro two groups of paired canine femurs after compression plates had been applied to the anterolateral diaphyseal surface bilaterally. Group I: intact paired femurs with bicortical peripheral screws in one DCP and unicortical peripheral screws in the other; Group II: osteotomized paired femurs again comparing unicortical and bicortical peripheral DCP screws. All specimens were torsion tested to failure and the torque, stiffness, energy, rotation, and failure fracture length were calculated. Unicortical screws did not enhance the torsional strength in either group, and significantly compromised stiffness, energy, and rotation in the osteotomized group. The only apparent benefit of unicortical peripheral screws in a DCP was a shorter, less comminuted fracture upon failure.     

人工寰齿关节置换与Magerl经关节螺钉固定的生物力学比较

[目的]测试人工寰椎齿状突关节置换后寰枢椎的稳定性和功能,并与Magerl经关节螺钉固定进行比较.[方法]将12例新鲜的成人头颈部标本随机分为两组,第1组在齿状突切除术后使用人工寰齿关节置换;第2组在齿状突切除术后使用Magerl经关节螺钉固定.对两组的每一标本分别测定完整状态、人工关节置换术后或经关节螺钉固定后的运动范围和中性区.[结果]人工关节置换术后与完整状态相比前屈、后伸、左右侧屈的运动范围和中性区明显减小(P＜0.05),左右旋转的运动范围无显著差异(P＞0.05),中性区增大(P＜0.05).Maged经关节螺钉固定后与完整状态相比前屈、后伸、左右侧屈及左右旋转的运动范围和中性区均明显减小(P＜0.05).人工关节置换术后及Magerl经关节螺钉固定后两组在前屈、后伸及左右侧屈的ROM稳定指数和NZ稳定指数相比均无显著差异(P＞0.05).[结论]实验证实在齿状突切除后,进行自行设计的人工寰椎齿状突关节置换可取得与Magerl经关节螺钉固定相似的前屈、后伸及左右侧屈稳定性,重要的是与完整状态相比左右旋转的运动范围无显著差异,最大限度的保留了寰枢复合体重要的旋转功能,对以往齿状突切除、脊髓减压后需要使用寰枢椎融合的患者,提供了另一种术式的选择.     

A biomechanical study of unilateral posterior atlantoaxial transarticular screw fixation

The purpose of this study was to investigate the fixation of C1-C2 instability with the use of a unilateral screw. Transarticular screw placement across C1-C2 may be contra-indicated in up to 20% of specimens on at least one side because of anatomic variations or other pathological processes. Hence the current study looks into unilateral screw fixation of C1- C2 instability. Eight cervical spine specimens, C1 through C5, were harvested from fresh human cadavers (4 male and 4 female) of average age 67 years (54-80). C1 and C2-C5 vertebrae were potted to allow motion only at the C1-C2 articulation. Cutting the transverse ligament on both sides of the odontoid and the tectorial membrane destabilized the specimens. Transarticular screw fixation of C1-C2 was performed in a manner similar to the technique described by Magerl. The stability was tested after fixation with one transarticular screw together with a posterior graft and wire. Placement of the screw was randomized, resulting in half the specimens receiving screws on the right side and the remaining half on the left side. The stiffness of the C1-C2 articulation was tested in rotation, lateral bending, flexion, and anterior translation in random order. The rotational stiffness was 1.44 +/- 0.44 N-m/deg, while lateral bending stiffness values were 2.33 +/- 1.14 N-m/mm (right bending) and 2.81 +/- 1.36 N-m/mm (left bending). The stiffness value in flexion was 0.813 +/- 0.189 N-m/mm and in translation 67.1 +/- 25.1 N/m. It was found that stability after unilateral transarticular screw fixation was less than that previously reported after bilateral transarticular screw fixation, but similar to that found with modified Brooks posterior wiring, which has been shown to provide better stability than other posterior wiring methods, and fusion rates of 96% have been reported. We concluded that C1-C2 unilateral posterior transarticular screw fixation with supplemental posterior graft and wiring would confer adequate stability in cases where bilateral screw placement is contraindicated.     

微型钢板内固定治疗跖跗关节损伤21例

目的探讨切开复位微型钢板内固定治疗跖跗关节损伤的临床疗效。方法应用国产钛合金微型钢板内固定治疗跖跗关节损伤21例。结果切口均一期愈合,有2例切口边缘部分坏死,经换药后痊愈。患者均获随访,时间9～16（12.2±3.6）个月。术后9～16个月拆除内固定。根据美国足踝外科协会AOFAS评分为73～95（86.5±9.8）分,优10例,良9例,中2例。结论切开复位微型钢板内固定治疗跖跗关节损伤,可达到坚强稳定跖跗关节的效果,可以早期活动踝部诸关节,达到较理想的临床疗效。     

Anatomic and biomechanical assessment of transarticular screw fixation for atlantoaxial instability.

The purpose of this study is to elucidate anatomically the atlantoaxial transarticular screw fixation described by Magerl in 1979 and compare it biomechanically with Gallie wiring. Five human C1-C2 specimens were tested in flexion/extension and rotation intact, then after wiring and screw fixation. Mean screw length was 39 mm, 25 mm in the C2 lamina and 14 mm in the lateral mass. Angular displacement of screwed specimens was significantly less than control or wired groups. Stiffness at 0-0.5 Nm loads was significantly greater for screwed specimens than for wired or controls (101 +/- 49 Nm, 10.3 +/- 9.2 Nm, and 1.96 +/- 0.18 Nm, respectively). All specimens withstood 5 Nm in flexion and extension without failure. Screw fixation provides stability comparable to Gallie wiring and is stiffer at low-range forces and rotational angles.     

寰枢关节后路内固定稳定性的生物力学比较研究

目的比较寰枢椎后路手术中常用的Gallie、Brooks、Magerl双螺钉、Maged单螺钉等内固定方法单独应用或联合应用时的力学稳定性,为临床选择治疗术式提供实验依据.方法取5具新鲜冷冻人体颈椎(C1～C5)标本,固定C1和C2~C5,仅保留C1～C2之间活动.切断寰椎横韧带和齿状突,造成寰枢关节不稳定.每个标本依次行Maged单螺钉、Maged双螺钉、Gallie、Maged单螺钉 Gallie、Maged双螺钉 Gallie、Brooks固定.在生物力学试验机上应用位移控制法测定各组的稳定性,前屈和侧屈的位移定为lmm,旋转角度为30°测定正常组、损伤组及内固定各组在前屈、双侧侧屈和旋转状态下的刚度,比较内固定各组的稳定性.结果在各组内固定中,Maged双侧侧块螺钉 GaUie刚度最大,最稳定.Magerl单螺钉 Gallie和Maged双螺钉相比.在各种状态下.二者刚度均无显著性差异(P＞0.05),在旋转状态下,其刚度值分别为1.55 0.07Nm/3°和1.44 0.13Nm/3°(P＞0.05);而Maged单螺钉的刚度在各种状态下均明显低于Magerl双螺钉(P＜0.05),其中在旋转状态下分别为0.96±0.17Nm/3°和1.44±0.13Nrn/3°(P＜0.05).结论Maged单螺钉 Gallie钢丝固定稳定性好,可替代Magerl双螺钉,而Maged单螺钉固定效果不佳,应尽量避免单独使用.     

寰枢关节前后路侧块螺钉内固定的生物力学比较

目的：比较寰枢关节前、后路侧块螺钉固定的效果，并测定其双侧、单侧侧块螺钉固定的稳定性，为临床应用提供理论依据。方法：取5具新鲜冷冻人体颈椎标本C1～C5，用牙托粉和螺钉固定C1和C2-C5，保留C1-C2之间的活动．切断寰椎横韧带和齿状突，造成寰枢关节不稳定，每个标本依次行前路单侧、前路双侧、Margel单侧、Margel双侧侧块螺钉固定：在生物力学试验机上应用位移控制法测定6种状态下的稳定性，前屈和侧屈的位移定值为1mm．旋转角度为3°。测定完好标本、损伤后及各种内固定下在前屈、双侧侧屈和旋转状态下的刚度．比较其稳定性。结果：所有内固定组的刚度均明显高于损伤组及完好组的刚度，前路双侧侧块螺钉和后路双侧侧块螺钉固定的稳定性无明显差异。前路双侧侧块螺钉固定在前屈、左侧屈、右侧屈、旋转时的稳定性高于前、后路单侧侧块螺钉：前路单侧侧块螺钉与后路单侧侧块螺钉固定的稳定性无明显差异。结论：前、后路双侧侧块螺钉固定效果好，可单独应用于临床；而单侧侧块螺钉稳定性不足，术后需加用外固定。     

Outcome after open reduction and internal fixation of Lisfranc joint injuries

BACKGROUND: Open reduction and internal fixation has been recommended as the treatment for most unstable injuries of the Lisfranc (tarsometatarsal) joint. It has been thought that purely ligamentous injuries have a poor outcome despite such surgical management. METHODS: We performed a retrospective study of patients who underwent open reduction and screw fixation of a Lisfranc injury in a seven-year period. Among ninety-two adults treated for that injury, forty-eight patients with forty-eight injuries were followed for an average of fifty-two months (range, thirteen to 114 months). Fifteen injuries were purely ligamentous, and thirty-three were combined ligamentous and osseous. Patient outcome was assessed with use of the American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score and the long-form Musculoskeletal Function Assessment (MFA) score. RESULTS: The average AOFAS midfoot score was 77 points (on a scale of 0 to 100 points, with 100 points indicating an excellent outcome), with patients losing points for mild pain, decreased recreational function, and orthotic requirements. The average MFA score was 19 points (on a scale of 0 to 100 points, with 0 points indicating an excellent outcome), with patients losing points because of problems with "leisure activities" and difficulties with "life changes and feelings due to the injury." Twelve patients (25 percent) had posttraumatic osteoarthritis of the tarsometatarsal joints, and six of them required arthrodesis. The major determinant of a good result was anatomical reduction (p = 0.05). The subgroup of patients with purely ligamentous injury showed a trend toward poorer outcomes despite anatomical reduction and screw fixation. CONCLUSIONS: Our results support the concept that stable anatomical reduction of fracture-dislocations of the Lisfranc joint leads to the best long-term outcomes as patients so treated have less arthritis as well as better AOFAS midfoot scores.     

切开复位内固定治疗Lisfranc关节损伤

目的探讨切开复位内固定治疗Lisfranc关节损伤的临床疗效。方法应用切开复位技术,根据骨折类型不同,分别选用螺钉、克氏针及微型钢板作内固定材料,对27例Lisfranc关节损伤患者进行治疗。结果术后患者均未发生感染及骨筋膜室综合征。27例均获随访,时间9～12个月。根据美国足踝外科协会AO-FAS评分标准评估疗效:优13例,良11例,可3例,优良率为88.9%。结论切开复位内固定治疗Lisfranc关节损伤,可以获得良好的临床效果。     

不同类型前路钢板固定应用于颈椎屈曲牵张型损伤的生物力学研究

目的探讨采用前路钢板固定颈椎屈曲牵张型损伤治疗的可靠性,并比较静力化固定和动力化固定等不同设计类型钢板在恢复损伤节段稳定性方面的差异。方法采用12具小牛颈椎标本,在C_(4,5)节段制作屈曲牵张损伤模型,切除椎间盘、植骨后随机分为3组,分别采用Orion、Codman、Window钢板、螺钉固定,测试手术固定各组在颈椎前屈、后伸、侧屈及旋转运动时的稳定性并与正常标本比较。结果颈椎屈曲损伤后,无论采用哪种钢板固定,其术后运动范围(ROM值)均比正常颈椎要大。Orion固定最接近正常标本,但在旋转运动时有明显差异。Codman固定仅在侧曲时的稳定性接近正常和Orion固定组。Window固定最弱,在各运动状态下的刚度均明显低于正常组。结论在颈椎屈曲牵张型损伤时,前路静力化固定相对稳定,动力化固定可能牺牲一定的固定强度,尤其是选择平移类设计的钢板固定更要谨慎。     

Percutaneous fixation of Lisfranc injuries

Lisfranc injuries may occur in the form of fracture-dislocations or pure ligamentous dislocations or subluxations. These innocuous appearing injuries have the potential for significant morbidity and long-term sequelae resulting in permanent deformities. Ligamentous subluxations account for 20% of these injuries and cases with partial incongruity are amenable to percutaneous fixation. In this article, we present step-by-step percutaneous fixation of these injuries as well as the post-operative management.     

Lisfranc joint injuries: diagnosis and treatment

Injuries to the tarsometatarsal or Lisfranc joint, though rare, are often undiagnosed or inadequately treated, resulting in poor long-term outcomes. Clinical and radiographic data are needed to recognize and treat these injuries for optimal outcomes. In this article, we review the anatomy, biomechanics, injury mechanisms, clinical presentation, radiographic evaluation, injury classification, treatment, outcome, and complications of Lisfranc joint injuries.     

寰枕关节后路经关节螺钉固定的解剖学研究

目的 :对 枕寰 枢 复合 体进 行 解剖 学研 究 ,为临 床 上枕 寰枢 后 路经 关节 螺 钉固 定提 供 解剖 学 依据 。 方 法 :对 100 例 中 国成 年人 枕 骨髁 和寰 椎 干燥 标本 进 行解 剖学 测 量;对 12 例 新鲜 尸体 枕 颈部 标本 进 行枕 寰 枢 后 部结构解 剖学 观 察。结 果:枕骨 髁与 寰 椎侧 块上 关 节面 咬合 成 寰枕 关节 ,枕 髁关 节 面呈 内倾 。其 中枕 髁关 节 面舌 下神经管 间距 为 9.66±1.13m m ,枕 髁 关节 面的 前 后 径 和横 径 、寰椎 侧 块 上 关节 面 前 后 径、侧 块上 关 节 面 横径 、侧 块与后弓 移行 处 侧块 厚度 均 在 5m m 以 上。新 鲜尸 体标 本 观察 发现 ,椎 动脉 第 三段 恒定 行 走于 椎动 脉 沟。第 颈 神经 1背侧 支和 第 2 颈 神经 背 侧支 与寰 椎 侧块 下关 节 突后 方几 乎 无交 叉,并有 一定 的 活动 度。 结 论:寰枕 关 节 的解 剖学形 态与 其 生物 力学 性 质密 切相 符 ;寰枕 关 节后 路经 关 节螺 钉内 固 定在 解剖 学 上是 可行 的 。     

Percutaneous fixation of Lisfranc joint injuries: A systematic review of the literature

ObjectiveThe aim of this systematic review was to present the outcome of Lisfranc joint injuries treated with closed reduction and screw percutaneous fixation.MethodsWe searched in Pubmed and Google Scholar Databases for articles regarding screw percutaneous fixation of Lisfranc injuries. Seven studies in total were found to be compatible to our search, according to PRISMA guidelines. Four of those met the criteria of the review and they were included in the meta-analysis. A total number of 106 patients were separated into five groups according to the type of injury and the mean AOFAS score of each group was calculated. Cases in which percutaneous fixation was converted to open treatment due to poor reduction were not included in the study. In addition we compared the outcome score between types of injury according to Myerson classification as well as between purely ligamentous and osseoligamentous injuries. The characteristics of all seven selected studies, such as kind of screw used for fixation, post operative protocol, complications and outcome are mentioned as well.ResultsAverage AOFAS score was 86,2 for type A, 87,54 for type B, and 85 for type C injuries respectively. In pure dislocation group the average AOFAS score was 86,43 and in fracture dislocation group was 87,36. Good to excellent outcome can be expected in patients with different types of injury according to Myerson classification following percutaneous fixation of lisfranc joint injury. Patients with type B injury or a fracture dislocation injury might have better outcome, although this difference was not found to be statistically significant.ConclusionPercutaneous fixation of tarsometatarsal joint injuries is a relatively simple and safe method of treatment, leading to a good functional outcome, especially for Myerson type B as well as for fracture dislocation type of injuries, provided that an anatomical reduction has been achieved.Level of EvidenceLevel III, Therapeutic Study.