Meissner A, Fell M, Wilk R, Boenick U, Rahmanzadeh R
Abteilung für Unfall- und Wiederherstellungschirurgie, Klinikum Benjamin Franklin, Freie Universität Berlin.
Unfallchirurg. 1996 Jun;99(6):415-21.
For estimation of the loads of fixation devices, physiological movements and acting forces at the symphysis pubis are examined. Experimentally, Walheim determined the movements of the pubic symphysis under physiological conditions (one-leg stance, walking): there is no effective mobility in the horizontal direction. During the one-leg stance he observed symphyseal mobility of up to 2.6 mm (Phi 1.2 mm) in the vertical direction and 1.3 mm (Phi 0.6 mm) in the sagittal direction. During walking he found symphyseal mobility of up to 2.2 mm (Phi 0.9 mm) in the vertical direction and 1.3 mm (Phi 0.6 mm) in the sagittal direction. Until now the forces leading to symphyseal mobility have not been estimated either experimentally or mathematically. In our experimental study we examined ten fresh cadaver anterior pelvic rings by means of a multidirectional force-mobility measurement. Maximal physiological movements, as determined by Walheim, were increasingly induced in ten equal steps, and the forces required were measured for every single step. Out of the resulting force-mobility curves for the ten cadaver specimens the mean force required (with standard deviation) was calculated for each of the ten measure points, separately for the vertical (y-) direction and sagittal (z-) direction. The values were graphically transferred, and a regression curve was created. This curve allows the acting force to be estimated for every movement of the pubic symphysis: During the one-leg stance the mean force to induce mean mobility is 169 N in vertical direction and 148 N in sagittal direction; for maximal mobility a force of 398 N in the vertical direction and 148 N in the sagittal direction is necessary. During walking, the force required to induce mean movement of the symphysis pubis is 120 N in the vertical direction and 68 N in the sagittal direction; for maximal mobility 333 N is required in the vertical direction and 136 N in the sagittal direction. For mobilization of patients with a symphyseal rupture (type Tile B 1) with partial weight-bearing, neutralization of the mean acting forces during the one-leg stance (169 N in the vertical direction, 68 N in the sagittal direction) must be achieved by an adequate fixation device. In cases where full weight bearing is desirable, such as in patients with limited compliance, stability can only be reached by neutralization of the maximal acting forces during walking (333 N in the vertical direction, 136 N in the sagittal direction).
为了估算固定装置的负荷，对耻骨联合处的生理运动和作用力进行了研究。通过实验，瓦尔海姆确定了耻骨联合在生理条件下（单腿站立、行走）的运动情况：在水平方向上没有有效的活动度。在单腿站立时，他观察到耻骨联合在垂直方向上的活动度可达2.6毫米（标准差1.2毫米），在矢状方向上为1.3毫米（标准差0.6毫米）。在行走时，他发现耻骨联合在垂直方向上的活动度可达2.2毫米（标准差0.9毫米），在矢状方向上为1.3毫米（标准差0.6毫米）。到目前为止，无论是通过实验还是数学方法，都尚未对导致耻骨联合活动的力进行估算。在我们的实验研究中，我们通过多方向力-活动度测量对10个新鲜尸体的骨盆前环进行了检查。按照瓦尔海姆确定的最大生理运动，以十个相等的步骤逐渐诱导运动，并对每个步骤所需的力进行测量。从十个尸体标本得到的力-活动度曲线中，分别针对垂直（y-）方向和矢状（z-）方向的十个测量点计算出所需的平均力（及其标准差）。将这些值以图形方式转换，并创建了一条回归曲线。这条曲线可以估算耻骨联合每次运动时的作用力：在单腿站立时，诱导平均活动度所需的平均力在垂直方向为169牛，在矢状方向为148牛；对于最大活动度，在垂直方向需要398牛的力，在矢状方向需要148牛的力。在行走时，诱导耻骨联合平均运动所需的力在垂直方向为120牛，在矢状方向为68牛；对于最大活动度，在垂直方向需要333牛的力，在矢状方向需要136牛的力。对于部分负重的耻骨联合破裂（Tile B 1型）患者的活动，必须通过适当的固定装置抵消单腿站立时的平均作用力（垂直方向169牛，矢状方向68牛）。在需要完全负重的情况下，例如依从性有限的患者，只有通过抵消行走时的最大作用力（垂直方向333牛，矢状方向136牛）才能实现稳定。
