An approach to the functional anatomy of the sacroiliac joints in vivo.

This first part of this paper is a review of the literature on the functional anatomy of the sacroiliac joint followed by a preliminary biomechanical study of the fresh post mortem pelvis. The latter was done in order to determine the coefficients of the screw matrix and the position of the instantaneous centers of rotation during the symmetrical movements of nutation and contranutation simulated in the biomechanics laboratory. The main part of this work deals with the spatial analysis in vivo of the relative displacements of the iliac bones with respect to the sacrum in the course of dissymmetrical movements of the pelvis. In the different phases of movement, the roentgenographic observation of the position of the bony components with respect to a three-dimensional orthonormal reference system required the use of material based on the principles of photogrammetry. This technique was used to achieve spatial reconstruction of the data recovered from a series of orthogonal x-ray films of the sacroiliac joints. Data retrieval was carried out on a digital table linked to a computer with a graphic terminal so that the information could be displayed in the form of rectangular coordinates of defined points on the bone. Owing to the limited amplitude of articular displacement, a statistical study was required to retrieve the coordinates from the projection of these points on the X-ray film with an estimated threshold of significance of 0.1 and an error of +/- 0.1 mm.(ABSTRACT TRUNCATED AT 250 WORDS)

[Congenital or acquired unilateral nevoid stellar telangiectasias. About 5 cases (author's transl)]. / Télangiectasies stellaires naevoïdes unilatérales acquises ou congénitales. A propos de 5 cas.

Based on five personal cases (one neo-natal case, one in childhood, and three cases in pregnant women) and sixteen published cases, this study remind us of the essential caracteristics of unilateral nevoid telangiectasis. Prevalence in women is noticeable appearance during pregnancy, with complete regression during post-partum, is quasi constant. If their nosological place is not clear among the essential telangiectasias, they seem to be quite different from Hutchinson's serpiginious angioma (verrucous telangiectasis), from Osler-Rendu's disease, from Brocq's telangiectasias and from generalizated telangiectasias. The true signification of all these diseases is still completely unknown.