The science and art of obstetrics / by Theophilus Parvin.

  • Parvin, Theophilus, 1829-1898.
Date:
1886
Catalogue details

Licence: Public Domain Mark

Credit: The science and art of obstetrics / by Theophilus Parvin. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    thicker upon the latter than upon the former; that which is upon the innominate is fibro-cartilage; that of the sacrum consists, first, of carti- lage adhering to the bone, and, second, of fibro-cartilage. The existence of a synovial membrane, especially distinct in case of pregnancy, is taught by some authors.1 Morris, however, holds that the cartilaginous mass uniting these bones is single, and not composed of two plates with a synovial space between them, stating that such may be the case some- times, but that it is not constant, certainly not in the male, though more frequent in the female; if two plates are present, the joint is arthi odial. The joint is further secured by the following six ligaments: theilio-lum- bar, extending from the transverse process of the last lumbar vertebra to the crest of the ilium,is afirm bandof fibrous tissue which not only greatly strengthens the joint, but helps to form the posterior wall of the false pelvis; the antero-superior, the anteroinferior, the postero-superior, the postero-inferior, and the inter-osseous ligament complete the direct means by which this joint is made one of the strongest in the body. But additional strength is given to it by the sacro sciatic ligaments. The great sacro-sciatic ligament arising from the posterior part of the superior curved line of the dorsum of the ilium, from the postero- inferior ilio-sacral ligament, from the side of the sacrum and of the coccyx, is attached to the lower portion of the ischium and to its ramus; this ligament is broad at first and then in its middle is narrowed, but again widens as it approaches its points of attachment. The less sacro- sciatic ligament is in front of the former, and is triangular in shape; it arises from the sides of the sacrum and the coccyx, and is at first confounded with the great ligament; afterwards it becomes distinct from the former in making the lower boundary of the great sciatic foramen, and passes to its attachment to the spinous process of the ischium. When in labor the head has descended into the pelvic cavity, the expulsive force drives it against the lower portion of the sacrum, and hence results a strain upon the sacro-iliac joints tending to throw the lower part of the sacrum backward; but nature guards against such dislocation by these strong fibrous bands which unite the sacrum and the ischium. The Sacro-Coccygeal Joint.—This is composed of two articular sur- faces, an interosseous fibro-cartilage, and four peripheral ligaments. The retrocession of the coccyx thus secured adds materially to the antero-posterior diameter of the outlet. Sappey states that, prior to their consolidation, all the inter-coccygeal articulations are symphyses, and Lenoir that the backward movement referred to takes place be- tween the first two bones of the coccyx, as between the first and the sacrum; exceptionally this motion is found to be between the second and the third, or between the third and fourth. Verneau2 says that he has frequently found even in young subjects complete synostosis of the sacrum and the coccyx, and describes the two as a single bone. The Pubic Joint.—Fibro-cartilage similar to that of the inter-vertebral disks is firmly fastened to the articulating surface of each pubic bone. This fibro-cartilage is soft in the middle, firm externally; it is much thicker in front than it is behind—thicker, too, in females than it is in 1 Anatomy of the Joints. 2 Le Bnssin dans lcs Sexes et dans les Races.