The effect of fibular malreduction on contact pressures in an ankle fracture malunion model
The effect of fibular malreduction on contact pressures in an ankle fracture malunion model
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DOI：
10.2106/00004623-199712000-00006
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发表时间：
1997-12-01
影响因子：
5.3
通讯作者：
Bakshian, S
中科院分区：
文献类型：
--
作者：
Thordarson, DB;Motamed, S;Bakshian, S
通过膝关节分离9个新鲜冷冻尸体标本，除骨间韧带和骨间膜外，仅将软组织移除至踝关节水平。距下关节用螺钉固定在中立位（约5度外翻）。接触压力在胫距关节测量使用低级别的压敏薄膜，这是通过前囊切开术放置。对于每次测量，将700牛顿的载荷施加到试样上一分钟。扫描胶片印记，并在距骨圆顶上的9个相等象限中定量接触压力。在腓骨远端固定一个复位装置;该装置允许单独或联合移位，包括腓骨缩短、侧向移位和外旋。踝关节保持中立屈曲。通过将三角韧带、前下胫腓韧带和骨间膜的深层纤维分离到距踝关节近端平均53 mm的点，模拟踝关节旋前-外旋骨折相关的韧带损伤。仅测定关节内的基线接触面积和接触压力，然后在腓骨缩短2、4和6 mm后;在腓骨侧向移位2、4和6 mm后;以及在腓骨外旋5、10和15度后进行测量。这三种类型的位移分别进行了测试，以及在combined.The模拟的畸形被发现会导致转移的接触压力的中外侧和后外侧象限的距骨圆顶，压力高达4.1兆帕。在距骨圆顶的内侧象限中观察到接触压力的相应降低。记录腓骨最大短缩、最大短缩和外侧移位的组合、最大短缩和外旋的组合以及最大短缩、外侧移位和外旋的组合的最高压力。在一般情况下，每个位移变量的增加对应于增加接触pressure.CLINICAL RELEVANCE：以前的生物力学研究已经证明了混合的结果，在踝关节接触压力的影响，距骨的侧向位移。我们相信，我们是第一个评估通过胫骨平台施加载荷时腓骨短缩、侧向移位和旋转不良的个体和综合效应的研究-也就是说，而胫骨和腓骨以比以前更生理的方式加载。本研究的结果证实，（2毫米或更多的缩短或侧向移位或5度或更多的外旋）增加了踝关节中的接触压力。因此，在这些损伤中腓骨移位是不被接受的。
Nine fresh-frozen cadaveric specimens were disarticulated through the knee, and the soft tissues, except for the interosseous ligaments and interosseous membrane, mere removed to the level of the ankle. The subtalar joint was secured with screws in neutral position (approximately 5 degrees of valgus). Contact pressures in the tibiotalar joint were measured with use of low-grade pressure-sensitive film, which was placed through an anterior capsulotomy. For each measurement, 700 newtons of load was applied to the specimen for one minute. The film imprints were scanned, and the contact pressures were quantitated in nine equal quadrants over the talar dome. A fracture-displacement device was secured to the distal end of the fibula; the device allowed for individual or combined displacements consisting of shortening, lateral shift, and external rotation of the fibula. The ankle was maintained in neutral flexion. The ligamentous injury associated with a pronation-lateral rotation fracture of the ankle was simulated by dividing the deep fibers of the deltoid ligament, the anterior-inferior tibiofibular ligament, and the interosseous membrane to a point that was an average of fifty-three millimeters proximal to the ankle joint. Baseline contact area and contact pressure in the joint mere determined, followed by measurements after two, four, and six millimeters of shortening of the fibula; after two, four, and six millimeters of lateral shift of the fibula; and after 5, 10, and 15 degrees of external rotation of the fibula. The three types of displacement were tested individually as well as in combination.The simulated deformities were found to cause a shift of the contact pressure to the mid-lateral and posterolateral quadrants of the talar dome, with pressures as high as 4.1 megapascals. A corresponding decrease in the contact pressures was noted in the medial quadrants of the talar dome. The highest pressures were recorded for maximum shortening of the fibula, the combination of maximum shortening and lateral shift, the combination of maximum shortening and external rotation, and the combination of maximum shortening, lateral shift, and external rotation. In general, increases in each displacement variable corresponded to increasing contact pressures.CLINICAL RELEVANCE: Previous biomechanical studies have demonstrated mixed results regarding the effect of lateral displacement of the talus on contact pressures in the ankle joint. We believe that we are the first to evaluate the individual and combined effects of shortening, lateral displacement, and malrotation of the fibula while load was applied through the tibial plateau - that is, while the tibia and fibula were loaded in a more physiological manner than accomplished previously The findings of the present study confirm that substantial displacement of the fibula (two millimeters or more of shortening or lateral shift or 5 degrees or more of external rotation) increases the contact pressures in the ankle joint. Therefore, displacement of the fibula in these injuries should not be accepted.