Choufani Elie, Jouve Jean-Luc, Pomero Vincent, Adalian Pascal, Chaumoitre Kathia, Panuel Michel
Service d'Orthopédie Pédiatrique, CHU Timone, 264 rue Saint Pierre, 13385, Marseille Cedex 05, France.
Eur Spine J. 2009 Sep;18(9):1342-8. doi: 10.1007/s00586-009-1012-y. Epub 2009 Apr 24.
Many believe that the fetus spine had only one curvature from cranial to caudal which is a global kyphosis and that the lumbosacral lordosis appears with the erect posture. They agree that the sacrum of Homo sapiens is not positioned posteriorly at birth and that it is during the first few years that the sacrum, in humans, moves dorsally in relation with the progressive acquisition of erect posture and the ontogeny of bipedal locomotion. Nevertheless, there is no biometric study assessing these parameters in vivo in utero during the fetal life. Cross-sectional biometric study of the lumbosacral junction of the spine in in utero fetuses was to document the presence of a lumbosacral lordosis in the fetal population in utero long before standing and walking and its change during growth. Forty-five MRIs (magnetic resonance imaging) of fetuses aged of 23-40 weeks of gestation were analyzed. The measurements were performed on computerized MRI DICOM images using a professional software to calculate the curvature and radius of the lumbosacral junction. The presence or absence of visual lumbosacral lordosis was noted for each case. Correlation tests were performed in order to disclose a correlation between the gestational age and the curvature calculated. A test was considered significant for P < 0.01. There were 14 males, 17 females and 14 undetermined. All the curves (100%) showed mathematically the presence of a lordosis in the lumbosacral region. The visual lumbosacral lordosis was present in 60% of cases. The measurement of the lumbosacral curvature varies between -0.133 and -0.033 mm(-1) and a mean of -0.054 mm(-1) with a corresponding radius ranging from -7 to -303 mm with a mean of -18.7 mm. The statistical analysis showed no correlation between the gestational age and the lumbosacral curvature (R (2) = 0.11). The hypothesis of increased lumbosacral lordosis with gestational age is rejected. It is difficult to accurately determine the role played separately by genetics and by erect posture. A visual lumbosacral lordosis was noted in 60% of cases with mean radius of -18.6691 mm. This lordosis was not correlated statistically to gestational age which means that it is not related to growth and might be genetically determined. Mechanical factors may play a major role in the determination of the shape of the growing pelvis. One can ask if the pelvis morphology is genetically determined or if it is mechanically determined under muscular and ligamentous stresses. This study shows that the sacrum of human fetuses is oriented posteriorly mathematically in 100% of cases, and in 60% of cases based on the morphologic appearance of the lumbosacral junction. So beside the effect of progressive acquisition of erect posture and bipedalism in determining the formation of lumbosacral angle, we believe that genetics play an important role in the formation of the lumbosacral angle.
许多人认为，胎儿的脊柱从头部到尾部只有一种弯曲，即整体脊柱后凸，而腰骶前凸是随着直立姿势出现的。他们一致认为，智人的骶骨在出生时并非位于后方，而是在出生后的头几年里，随着直立姿势的逐渐获得和双足行走的个体发育，人类的骶骨相对于脊柱逐渐向后移动。然而，尚无生物测量研究在胎儿期对这些参数进行子宫内活体评估。对子宫内胎儿脊柱腰骶交界处进行横断面生物测量研究，旨在记录胎儿在站立和行走之前很久就已存在的腰骶前凸及其在生长过程中的变化。分析了45例妊娠23 - 40周胎儿的磁共振成像（MRI）。使用专业软件在计算机化的MRI DICOM图像上进行测量，以计算腰骶交界处的曲率和半径。记录每个病例是否存在明显的腰骶前凸。进行相关性测试以揭示胎龄与计算出的曲率之间的相关性。当P < 0.01时，测试被认为具有显著性。其中有14例男性、17例女性和14例性别未确定。所有曲线（100%）在数学上均显示腰骶部存在前凸。60%的病例存在明显的腰骶前凸。腰骶曲率的测量值在 - 0.133至 - 0.033 mm(-1)之间，平均为 - 0.054 mm(-1)，相应半径在 - 7至 - 303 mm之间，平均为 - 18.7 mm。统计分析表明胎龄与腰骶曲率之间无相关性（R (2) = 0.11）。随着胎龄增加腰骶前凸增大的假设被否定。很难准确确定遗传因素和直立姿势分别所起的作用。60%的病例观察到明显的腰骶前凸，平均半径为 - 18.6691 mm。这种前凸与胎龄无统计学相关性，这意味着它与生长无关，可能是由遗传决定的。机械因素可能在生长中的骨盆形状的决定中起主要作用。人们不禁要问，骨盆形态是由遗传决定的，还是在肌肉和韧带应力作用下由机械因素决定的。这项研究表明，100%的人类胎儿骶骨在数学上向后定向，60%的病例基于腰骶交界处的形态学表现也是如此。因此，除了逐渐获得直立姿势和双足行走在决定腰骶角形成中的作用外，我们认为遗传因素在腰骶角的形成中也起着重要作用。
