THIS CASE is being reported because of the unusual type of congenital defect that existed in the insertion of the rectus abdominis muscle and the pathology that developed secondarily to it which necessitated surgical correction.
The normal insertion of the rectus abdominis muscle1 is by three portions of unequal size into the cartilages of the fifth, sixth, and seventh ribs. The upper portion, attached principally to the cartilage of the fifth rib, usually has some fibers of insertion into the anterior extremity of the rib itself. Some fibers are occasionally connected with the costoxiphoid ligaments and the side of the xiphoid process. The rectus sheath is formed normally by the aponeurosis of the obliquus externus, obliquus internus, and the transversus muscles. At the lateral border of the rectus muscle they form two membranes, the anterior and posterior lamellae of the sheath. The aponeurosis of the internus, above