Pubic symphysis

The upper segment is the distance from the top of the head to the top of the pubic symphysis the iower segmen t is the distance from the top of the pubic symphysis to the fioor. The upper segment to lower segment ratio in persons with Marfan syndrome is iow (< 0.9) because the arms and iegs are iong reiative to the torso. 

Pinheiro, M. C., Moraes, S. G., Battlehner, C. N., Caldini, E. G., Toledo, O. M. S., and Joazeiro, P. P. (2004). Histochemical and ultrastructural study of collagen fibers in mouse pubic symphysis during late pregnancy. Micron. 35, 685-693. 

FIGURE 1 Female reproductive system and related structures vagina (1), cervix (2), uterus (3), ovary (4), fallopian tube (5), urinary bladder (6), urethra (7), anus (8), rectum (9), colon (10), vestibule (11), and pubic symphysis (12). (Courtesy of Lufs Pauperio.)... 

Relaxin is a peptide hormone that is synthesized and stored in the corpus luteum and is responsible for the relaxation of the pubic symphysis in mammals prior to parturition. Porcine relaxin (MW 5600) is composed of an A and a B chain linked by disulfide bonds, and its amino acid sequence is consistent with these links having the same disposition as those in insulin (Schwabe et al, 1976 1977 Kwok et a/., 1977) (see Table I). Using its sequence homology with insulin, Bedarkar et al (1977) postulated a three-dimensional structure for relaxin with the crystal structure of insulin as a basis (Fig. 6). A similar model has been proposed by Isaacs et al (1978). 

The borders of the anterior compartment are the pubic symphysis ventrally the components of the levator ani muscle laterally (Fig. 1.1b) and the perineal membrane (see Table 1.1) caudally. There is no distinct border between the anterior and middle compartment in the female. The contents of the anterior compartment are bladder and urethra (Fig. 1.1b). 

Anteriorly the sacroiliac, sacro-spinous and sym-physeal ligaments are transversely orientated to support the pelvic floor and resist external rotation. There are superior symphyseal ligaments which support the pubic symphysis. 

There are a number of anatomical differences between children and adults. The paediatric skeleton is more elastic than in adults, particularly around the sacroiliac joints and pubic symphysis which allows greater absorption of energy before the joint and ligaments become disrupted. A high energy impact may cause deformity of the bones rather than the fractures and joint disruption that occurs in adulthood. 

These relate to fractures or disruption of the pubic symphysis and are associated with anterior sacroiliac joint disruption. The posterior iliac ligament complex is unaffected and pelvic stability is maintained. In the older child, widening of the pubic symphysis beyond 2.5 cm is associated with disrup-... 

Fig. 12.17. Widening of the pubic symphysis with a fracture of the superior pubic ramus and avulsion injury from the iliac spine on the right...

The next most abundant form of cartilage in the body is hbrocartilage. Examples of hbrocartilage include the meniscus, intervertebral disc (IVD), pubic symphysis, and temporomandibular joint, all which aid in bone—bone load transmission and cartilage protection. In addition to type 11 collagen and chondroitin sulfate, hbrocartilage has... 

II Single breaks in the ring near the pubic symphysis or a sacroiliac joint... 

The pelvis consists of two innominate bones that meet at the midline anteriorly at the pubic symphysis and end posteriorly in a wedge-shaped opening that is filled by the sacrum. The sacrum completes the ring-like shape of the pelvis. 

The pubic tubercles are located on the anterior superior aspects of the pubic bones (Fig.59-4). The pubic symphysis is located medially. 

FIG. 66-4 HVIA thrusting technique for restriction of pubic symphysis. 

The finding of somatic dysfunction at the T12-L1 region is common in the presence of prostate disease. Dysfunctions of the pubic symphysis and congestion of the ischiorectal fossa should be explored. These should be treated to relieve or prevent discomfort in this area. 

FIG. 116-4 Deep inhibiting pressure on tissues over-lying the pubic symphysis. 

Pigure 1. The effect of relaxin on pubic symphysis a) without relaxin b) with relaxin... 

The determination of hiological activity is based on the opening of pubic symphysis. The figure 1 shows the effect of relaxin on pubic symphysis. 

Relaxin causes an increase in the biosynthesis of thyrotropic hormone as PLUNKETT (14) could confirm by radiological methods. Mechanism of action of relaxin was up till now not very clear. There is a reciprocal action between the other hormones and relaxin as pretreatment of estrogen is necessary for achievement of maximum activity of relaxin. STEINETZ (7) has published a hypothesis for the mode of action of relaxin on pubic symphysis, which is not applicable for other endocrine organs and particularly for general effects of relaxin. 

An AP radiograph of the entire abdomen is taken unless one has been obtained recently for any reason and there was no breakthrough event. An additional film in upright position is unnecessary. Abnormal calcification, nephrocalcinosis, spinal deformation, bony abnormality, spinal surgery, pubic symphysis abnormality, and the position of prosthesis (VP shunt, JJ tube, bladder catheter, nephrostomy tube or other) all can easily be shown prior to administration of contrast medium. Attention should be paid to extra urinary anatomy (think of congenital hip dislocation). 

Fig. 6.1. AP radiograph of the pelvic cavity showing widening of the pubic symphysis in a girl with vesical exstrophy...

Epispadia is part of the heterogeneous exstrophy-epispadia complex. It may occur in males and females. Widening of the pubic symphysis is usually associated. Continence is variable in those patients, so imaging and urodynamic studies in these patients should be directed towards this handicap and the detection of associated anomalies. Duplication of the bulbous urethra is extremely rare. It may be complete or blind-ended, ventral or dorsal (Barbagli et al. 1996). Finally, megalourethra (Stephens and Fortune 1993) is an enlargement of the pendulous urethra with no evidence of distal obstruction. It... 

---