LaMothe Jeremy M, Baxter Josh R, Murphy Conor, Gilbert Susannah, DeSandis Bridget, Drakos Mark C
University of Calgary, Section of Orthopaedic Surgery, Health Sciences Centre, Calgary, AB, Canada
Human Motion Lab, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USA.
Foot Ankle Int. 2016 Dec;37(12):1350-1356. doi: 10.1177/1071100716666865. Epub 2016 Sep 20.
Suture-button constructs are an alternative to screw fixation for syndesmotic injuries, and proponents advocate that suture-button constructs may allow physiological motion of the syndesmosis. Recent biomechanical data suggest that fibular instability with syndesmotic injuries is greatest in the sagittal plane, but the design of a suture-button construct, being a rope and 2 retention washers, is most effective along the axis of the rope (in the coronal plane). Some studies report that suture-button constructs are able to constrain fibular motion in the coronal plane, but the ability of a tightrope to constrain sagittal fibular motion is unknown. The purpose of this study was to assess fibular motion in response to an external rotation stress test in a syndesmotic injury model after fixation with a screw or suture-button constructs.
Eleven fresh-frozen cadaver whole legs with intact tibia-fibula articulations were secured to a custom fixture. Fibular motion (coronal, sagittal, and rotational planes) in response to a 6.5-Nm external rotation moment applied to the foot was recorded with fluoroscopy and a high-resolution motion capture system. Measures were taken for the following syndesmotic conditions: intact, complete lateral injury, complete lateral and deltoid injury, repair with a tetracortical 4.0-mm screw, and repair with a suture button construct (Tightrope; Arthrex, Naples, FL) aimed from the lateral fibula to the anterior medial malleolus.
The suture-button construct allowed significantly more sagittal plane motion than the syndesmotic screw. Measurements acquired with mortise imaging did not detect differences between the intact, lateral injury, and 2 repair conditions. External rotation of the fibula was significantly increased in both injury conditions and was not restored to intact levels with the screw or the suture-button construct.
A single suture-button placed from the lateral fibula to the anterior medial malleolus was unable to replicate the motion observed in the intact specimen when subjected to an external rotation stress test and allowed significantly more posterior motion of the fibula than when fixed with a screw in simulated highly unstable injuries.
Fixation of a syndesmotic injury with a single suture-button construct did not restore physiological fibular motion, which may have implications for postoperative care and clinical outcomes.
缝线纽扣装置是下胫腓联合损伤螺钉固定的一种替代方法，其支持者主张缝线纽扣装置可允许下胫腓联合进行生理性活动。最近的生物力学数据表明，下胫腓联合损伤时腓骨不稳定在矢状面最为明显，但缝线纽扣装置的设计是一根绳索和两个固定垫圈，在绳索轴向上（冠状面）最为有效。一些研究报告称，缝线纽扣装置能够限制腓骨在冠状面的活动，但缝线装置限制腓骨矢状面活动的能力尚不清楚。本研究的目的是评估在使用螺钉或缝线纽扣装置固定后，下胫腓联合损伤模型中腓骨在外部旋转应力测试中的活动情况。
将11条胫骨 - 腓骨关节完整的新鲜冷冻尸体全腿固定在定制的固定装置上。通过荧光透视和高分辨率运动捕捉系统记录在对足部施加6.5 N·m外部旋转力矩时腓骨的活动情况（冠状面、矢状面和旋转面）。针对以下下胫腓联合情况进行测量：完整、完全外侧损伤、完全外侧和三角韧带损伤、用四皮质4.0 mm螺钉修复以及用缝线纽扣装置（Tightrope；Arthrex，那不勒斯，佛罗里达州）从腓骨外侧至内踝前方进行修复。
缝线纽扣装置允许的矢状面活动明显多于下胫腓联合螺钉。通过踝关节正位成像获得的测量结果未发现完整、外侧损伤和两种修复情况之间存在差异。在两种损伤情况下，腓骨的外部旋转均显著增加，并且使用螺钉或缝线纽扣装置均未恢复到完整水平。
在进行外部旋转应力测试时，从腓骨外侧至内踝前方放置单个缝线纽扣装置无法复制完整标本中观察到的活动情况，并且在模拟高度不稳定损伤时，与使用螺钉固定相比，该装置允许腓骨有明显更多的向后活动。
使用单个缝线纽扣装置固定下胫腓联合损伤不能恢复腓骨的生理性活动，这可能对术后护理和临床结果产生影响。
