Variations and Malformations

  • H. K. Uhthoff

Abstract

In our collection we have observed an unsually high number of developmental abnormalities. We believe that this high incidence is related to the fact that our collection consists exclusively of spontaneously aborted embryos and fetuses. The highest number of abnormalities was seen at the level of the spine. In an earlier report [8] we described 11 malformations in 266 specimens. Since then we have found five more vertebral malformations. In all but one specimen the malformations were observed before the process of ossification had started. Our observations are limited to the level of vertebral bodies. Malformations are divided into three types: type 1, failure of formation; type 2, failure of segmentation; and type 3, mixed malformations [7]. Type 1, failure of formation, is subdivided into defect of formation and error of formation. Type 2, failure of segmentation, is similarly subdivided into defect of segmentation and error of segmentation. Defect denotes either an incomplete formation or an incomplete segmentation. Error, on the other hand, is characterized by an abnormal formation or by an abnormal direction of segmentation. Type 3 groups all malformations in which failure of formation and failure of segmentation are observed simultaneously. An example of a defect in formation is a hemivertebra (Figs. 15.1, 15.2) whereas an abnormally shaped vertebra represents an error of formation (Fig. 15.3). A defect of segmentation can be seen as an unsegmented bar (Fig. 15.4) or a block vertebra (Fig. 15.5). A V-shaped segmentation leading to an oblique intervertebral disk space (Fig. 15.6) represents an error in segmentation. Type 3, representing the simultaneous presence of failure of formation and failure of segmentation, can be seen in Figs. 15.7 and 15.8.

Keywords

Crest Azan 

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References

  1. 1.
    Goto S, Uhthoff HK (1985) Notochord action on spinal development. Acta Orthop Scand 57:85–90Google Scholar
  2. 2.
    Goto S, Uhthoff HK (1986) Notochord and spinal malformations. Acta Orthop Scand 57:149–153PubMedCrossRefGoogle Scholar
  3. 3.
    Kawashima T, Uhthoff HK (1990) Prenatal development around the sustentaculum tali and its relation to talocalcaneal coalitions. J Pediatr Orthop 10:238–243PubMedGoogle Scholar
  4. 4.
    Ogata S, Uhthoff HK (1989) The early development and ossification of the clavicle. Acta Orthop Scand (submitted for publication)Google Scholar
  5. 5.
    Schmorl G, Junghanns H (1971) The human spine in health and disease, 2nd edn. Grune and Stratton, New YorkGoogle Scholar
  6. 6.
    Shapiro F, Eyre D (1981) Congenital scoliosis. A histopathologic study. Spine 6:107–117PubMedCrossRefGoogle Scholar
  7. 7.
    Tanaka T, Uhthoff HK (1981) Significance of resegmentation in the pathogenesis of vertebral body malformation. Acta Orthop Scand 52:331–338PubMedCrossRefGoogle Scholar
  8. 8.
    Tanaka T, Uhthoff HK (1981) The pathogenesis of congenital vertebral malformations. Acta Orthop Scand 52:413–425PubMedCrossRefGoogle Scholar
  9. 9.
    Tanaka T, Uhthoff HK (1983) Coronal cleft of vertebrae, a variant of normal enchondral ossification. Acta Orthop Scand 54:389–395PubMedCrossRefGoogle Scholar

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© Springer-Verlag Berlin Heidelberg 1990

Authors and Affiliations

  • H. K. Uhthoff

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