MECHANICAL CONSIDERATIONS FOR THE SYNDESMOSIS SCREW - A CADAVER STUDY
MECHANICAL CONSIDERATIONS FOR THE SYNDESMOSIS SCREW - A CADAVER STUDY
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DOI：
10.2106/00004623-198971100-00014
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发表时间：
1989-12-01
影响因子：
5.3
通讯作者：
HURWITZ, SR
中科院分区：
文献类型：
--
作者：
BODEN, SD;LABROPOULOS, PA;HURWITZ, SR
本研究的目的是探讨在旋前-外旋型骨折的治疗中，使用关节突螺钉补充腓骨和内踝坚固内固定的力学必要性。30具防腐身体和5具新鲜身体的腿被解剖并通过胫骨安装到一个框架上，以便在标本和X光机之间保持恒定关系的情况下拍摄多张X光片。对足部施加标准化的旋前-外旋载荷，并在每个实验步骤后拍下插孔X线片，研究联结的增宽。在前人研究的基础上，我们发展了一种旋前-外旋性损伤模型，包括直至腓骨骨折水平的关节突和骨间膜的断裂。因此，通过骨间膜的渐进式近端分离，可以在同一标本中在多个水平上模拟多个修复的腓骨骨折。将标本分成两组。I组13个标本，对三角肌韧带、韧带和骨间膜按1.5厘米的增量进行连续切片。II组(10节)采用相同的手术方案，只是三角肌韧带保持完整，直到最后一步。5个新鲜标本的切片方法与I组相同。在I组，由于模拟旋前-外旋损伤包括三角骨撕裂，不可能进行刚性内侧固定，因此只能进行刚性腓骨固定。在这组患者中，当腓骨骨折平面从距踝关节近端1.5厘米上升到15厘米时，连带的平均宽度仅从0.5毫米逐渐增加到4.5毫米。五个新鲜标本的测量结果与防腐腿部的测量结果一致。在II组，旋前-外旋损伤模拟为内踝骨折，而不是三角骨撕裂。在内踝和腓骨模拟坚固固定后，只有最小的联合增宽(1.4±-)。0.3毫米)，即使当腓骨骨折在脚踝近端15厘米时也是如此。以三角肌韧带分离为最后一步的II组的最大联合平均宽度与I组相当，验证了两组的比较。临床相关性：考虑到临床可接受的关节突增宽范围，用钢板固定的腓骨骨折水平的关键过渡区是脚踝近端3到4.5厘米。当腓骨骨折位于该节段的近端，且不能进行坚固的内侧固定时，可能需要稳定关节突以补充钢板的固定。然而，坚固的内侧和外侧固定应该可以接受地稳定关节突，而不需要进一步补充。这项研究提供了机械证据，证明包括联合断裂在内的旋前外旋转损伤的内固定通常不需要辅以跨联合固定。
The purpose of this study was to examine the mechanical necessity of using a syndesmosis screw to supplement rigid internal fixation of the fibula and medial malleolus in the treatment of pronation-external rotation fractures. The legs of thirty embalmed and five fresh cadavera were dissected and mounted through the tibia to a frame so that multiple radiographs could be made with a constant relationship between the specimen and the x-ray apparatus. A standardized pronation-external rotation load was applied to the foot, and widening of the syndesmosis was studied on mortise radiographs that were made after each experimental step. On the basis of previous investigations, we developed a model for pronation-external rotation injuries that included disruption of the syndesmosis and interosseous membrane up to the level of the fibular fracture. Accordingly, multiple repaired fibular fractures could be simulated at several levels in the same specimen by incremental proximal division of the interosseous membrane. specimens were separated into two groups. Group I consisted of thirteen specimens in which the deltoid ligament, syndesmosis, and interosseous membrane were serially sectioned in 1.5-centimeter increments. Group II (ten sections) was subjected to the same protocol, except that the deltoid ligament was kept intact until the final step. The five fresh specimens were sectioned in the same way as those in Group I. In Group I, since the simulated pronation-external rotation injury included a deltoid tear, rigid medial fixation was not possible; accordingly, there was rigid fibular fixation only. In this group, the mean widening of the syndesmosis increased only gradually from 0.5 to 4.5 millimeters as the level of fibular fracture rose from 1.5 to fifteen centimeters proxial to the ankle. Measurements for the five fresh specimens were consistent with those for the embalmed legs. In Group II, the pronation-external rotation injury was simulated with a medial malleolar fracture rather than a deltoid tear. After simulated rigid fixation of both the medial malleolus and the fibula, only minimum widening of the syndesmosis (1.4 .+-. 0.3 millimeters) occurred, even when the fibular fracture was fifteen centimeters proximal to the ankle. The mean maximum widening of the syndesmosis in Group II, in which division of the deltoid ligament was the last step, was equivalent to that in Group I, validating comparison of the two groups. Clinical relevance: Considering the range of clinically acceptable widening of the syndesmosis, the critical transition zone for the level of a fibular fracture that is fixed with a plate is three to 4.5 centimeters proximal to the ankle. When the fibular fracture is proximal to this level and rigid medial fixation is not possible, the syndesmosis may have to be stabilized to supplement the fixation with the plate. However, rigid medial and lateral fixation should acceptably stabilize the syndesmosis without further additional supplementation. This study provides mechanical evidence that internal fixation of pronation-external rotation injuries that include disruption of the syndesmosis often does not need to be supplemented with trans-syndesmotic fixation.