Skiagraphic atlas showing the development of the bones of the wrist and hand : for the use of students and others / by John Poland.

  • Poland, John, 1855-1937.
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: Skiagraphic atlas showing the development of the bones of the wrist and hand : for the use of students and others / by John Poland. Source: Wellcome Collection.

Provider: This material has been provided by University of Bristol Library. The original may be consulted at University of Bristol Library.

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    The lower margin of this is separated from the inferior articular surface by a thin edge, to which is attached the thin base of the triangular fibro-cartilage of the wrist-joint. The anterior epiphysiary crest ends at the outer side towards the base of the styloid process in a sharp tubercle, which is the lower end of the pronator crest on the diaphysis, and which limits the attachment of the lower and outer part of the pronator quadratus. Posterior to this is a shallow groove divided into two for the tendons of the extensor ossis metacarpi poUicis and the extensor primi inter- nodii pollicis. Behind the groove is a ridge, the external thecal tubercle, passing downwards to the apex of the styloid process. To the lower end of the pronator crest, and to the surface of bone running backwards to this ridge, the supinator longus is inserted. Posterior to the external thecal tubercle is another broad, shallow groove, divided into two by a slight ridge, for the transmission of the tendons of the extensor carpi radialis longior and extensor carpi radialis brevior. Still more internal to this on the posterior surface of the epiphysis is the prominent middle thecal tubercle, on the inner side of which is a deep oblique, narrow groove for the extensor secundi internodii pollicis. This prominent ridge, therefore, forms a good guide to the epiphysial line on this aspect of the bone, the line running across the bone an eighth of an inch below the posterior end of the ridge. The inner ridge of this groove is the less prominent internal thecal tubercle. Between this and the posterior extremity of the sigmoid surface is the wide groove for the tendons of the extensor indicis and the extensor communis digitorum (see frontispiece). The epiphysis, as seen at the seventeenth to eighteenth year of age, is 3 centimetres 2 millimetres in width from side to side and 2 centimetres in width antero-posteriorly; 8 millimetres in thickness about its centre. Its anterior lip is 6 millimetres in depth about the middle, and the posterior lip 10 millimetres at the same point; in the centre it is 5 millimetres thick vertically. On the outer side from the epiphysial line of cartilage to the apex of the styloid process it measures 2 centimetres. At its ulnar border, the sigmoid cavity, it is 6 milhmetres thick vertically. At fourteen years of age the vertical measurements are from epi- physial cartilage, outer side, to apex of styloid process, 7 millimetres ; ulnar border, 4^ milhmetres; anterior Hp, 6 milhmetres; posterior lip, 9 milhmetres, each about the middle. This epiphysis is not united to the shaft till the nineteenth or twentieth year. Union takes place first towards the middle of the epiphysis—its thinnest part. M. Voillemier has quoted instances in which the conjugal cartilage still persisted in subjects aged twenty-four and twenty-five years.