Weber M, Johannissón T, Thomsen M, Rehder H, Niethard F U
Orthopaedic University Hospital, Rheinische Westfäliche Technische Hochschule Aachen, Germany.
J Pediatr Orthop B. 1998 Jan;7(1):1-9.
A comprehensive seven-step study on THANATOPHORIC DYSPLASIA without cloverleaf skull (TD Type I) was carried out postmortem on three aborted fetuses of 19, 26-27, and 34 weeks and one preterm neonate of 35 weeks gestation, respectively. The characteristic x-ray configuration of the spine in TD Type I presenting with H-, U- or reversed U-shape vertebrae were shown to correlate with the inclination or reclination of the vertebral bodies within a kyphotic or lordotic segment. The bowing of the tubular bones in TD Type I is explained by a diminished mechanical stability that is causally related to a specific cartilage structure. The perichondral spurs are defined by their morphologic structure, and their origin is attributed to a normal perichondral ossification in the presence of an impaired enchondral ossification. Impairment of enchondral ossification was more evident in the periphery than in the center of the metaphyses leading to a tongue-shaped osseous cone directed toward the epiphysis. The perichondral spurs and the linguiform enchondral growth plate resulted in a three-phase maple leaf-like contour of the metaphyses of tubular bones and acetabular roof. The nature of the perichondral fibrous bands, the fibrovascular bundles, and the fibrovascular bands of the growth plate and their significance in atypical ossification processes are discussed in detail. It is suggested that the diminished longitudinal growth of the skeleton is caused by a reduced mitotic activity of cartilage cells in the proliferative zone leading to a reduction of cell numbers in the columnar zone transversely oriented spongiosa bars resulting from desmal ossification of the metaphyseal fibrovascular structures.
对三例分别为19周、26 - 27周和34周的流产胎儿以及一例妊娠35周的早产新生儿进行了死后全面的七步研究，研究对象为无三叶形颅骨的致死性骨发育不良（TD I型）。TD I型脊柱呈现H形、U形或倒U形椎体的特征性X线构型，显示与脊柱后凸或前凸节段内椎体的倾斜或后倾相关。TD I型管状骨的弯曲是由机械稳定性降低所解释的，这与特定的软骨结构存在因果关系。骨膜骨刺由其形态结构定义，其起源归因于软骨内骨化受损时正常的骨膜骨化。软骨内骨化的损害在干骺端周边比中心更明显，导致形成一个朝向骨骺的舌形骨锥。骨膜骨刺和舌形软骨生长板导致管状骨和髋臼顶干骺端呈现三相枫叶样轮廓。详细讨论了骨膜纤维带、纤维血管束以及生长板的纤维血管带的性质及其在非典型骨化过程中的意义。研究表明，骨骼纵向生长减少是由于增殖区软骨细胞有丝分裂活性降低，导致横向排列的海绵状骨小梁柱状区细胞数量减少，这是由干骺端纤维血管结构的膜内骨化引起的。
