Chapter 8 PELVIS

Fig. 8.1. Female pelvis/female pelvic inlet: 1 - sacroiliac joint; 2 - sacral promontory; 3 - diagonal conjugate (12 cm); 4 - transverse (13 cm); 5 - oblique (12.5 cm); 6 - ischial spine; 7 - iliopubic eminence; 8 - pubic symphysis; 9 - ischial tuberosity; 10 - pubic arch

Fig. 8.2. Pubic symphysis, front view: 1 - interpubic disc; interpubic fibrocartilage; 2 - symphysial cavity; 3 - hyaline cartilage; 4 - inferior pubic ligament; 5 - inferior pubic ramus; 6 - superior pubic ramus; 7 - superior pubic ligament

8.1. TOPOGRAPHICAL ANATOMY

OF PELVIS

8.1.1. BONE PELVIS

External pelvic bone reference points: upper margin of the symphysis, horizontal branches of pubic bones with pubic tubercles, upper anterior iliac spines; the lower part is limited: coccyx, sciatic tubercles, large trochanters of the femurs. The pelvic outlet is closed by the muscles that form the pelvic diaphragm.

The large pelvis is bounded laterally by the wings of the ilium, and behind by the lower lumbar vertebrae and the base of the sacrum. The lower border of the large pelvis is the border line (linea terminalis), formed by the promontorium, the arcuate line of the ilium, the pubic ridges and the upper edge of the pubic symphysis.

The place of transition of the large pelvis to the small one, bounded by the boundary line, is the upper opening of the pelvis. The lower opening of the pelvis is bounded laterally by the ischial tubercles, behind the coccyx, in front by the pubic symphysis, and below by the lower branches of the pubic bones.

The bone basis of the lateral walls of the pelvis consists of those parts of the pelvic bones that are located below the boundary line.

The weak point of the posterior section of the pelvic ring is the line of the sacral openings of the sacrum. In these places, there are pelvic fractures, especially when the pelvis is compressed in the lateral or anteroposterior direction.