vascularization of symphysis pubis in the albino RAT

ABSTRACT

Little attention has been paid to study the vascular nutritional pathways to the symphysis pubis. Knowledge regarding the nutrient sources and degree of vascularisation of the fibrocartilaginous structures especially the articular discs of symphysis pubis in virgins and during late period of pregnancy is fundamental for physiotherapists and physicians for clinical decision making. This work was undertaken to describe the vascular nutritional pathway to the symphysis pubis in rats using light microscopy and immunohistochemistry and to describe the structural transformation observed in the symphysis pubis during the intrapartum period. 20 rats [8 males and 12 females] 80 - 100 days of age were used in this study. The symphysis pubis was excised and specimens were prepared for light microscopy and immunohistochemistry. The interpubic disc has two distinct portions an inner bearing portion made up of cartilage and a peripheral portion made up of dense connective tissue. Blood vessels that supply the medial extremity of each pubic bone, penetrate the muscle attachments and the articular tissue to supply the pubic ligaments and the fibrous rim of the interpubic disc. The subchondral bone also share in giving blood supply to the symphysis pubis as it shows several marrow contacts linking the marrow space of the pubic bones with the interpubic disc. Histological examination revealed more intense factor VIII staining in the joint in intrapartum specimens indicating more angiogenesis. The lengthening of the articular gap is seen in intrapartum specimens. The symphyseal gap changes morphologically in intrapartum specimens as a result of pregnancy. Its width increased and it assumed the structure of a ligament. Mononuclear cellular infiltration was demonstrated in the interpubic tissue around parturition. As a result of delivery, traumatic changes occur leading to progressive loosening of the symphysis pubis and production of cartilaginous nodules. Changes in the symphysis pubis noticed as an effect of pregnancy are increased vascularity, increased deposition of collagen, mononuclear cellular infiltration and formation of cartilaginous nodules. These results are of interest to physiotherapists and physicians. Knowledge regarding the degree of vascularisation of the symphysis pubis in virgins and during late period of pregnancy is fundamental for clinical decision making. A clear understanding of the changes that occur in the symphysis pubis at term would be of great benefit to the diagnosis and management of any pathophysiological condition that may happen at parturition