Topography and landmarks for the nerve supply to the levator ani and its relevance to pelvic floor pathologies.

The aim of this study was to explore the anatomical variations of the nerve to the levator ani (LA) and to relate these findings to LA dysfunction. One hundred fixed human female cadavers were dissected using transabdominal, gluteal, and perineal approaches, resulting in two hundred dissections of the sacral plexus. The pudendal nerve and the sacral nerve roots were traced from their origin at the sacral foramina to their termination. All nerves contributing to the innervation of the LA were considered to be the nerve to the LA. Based on the spinal nerve components, the nerve to the LA was classified into the following categories: 50% (n = 100) originated from S4 and S5 (type I); 19% (n = 38) originated from S5 (type II); 16% (n = 32) originated from S4 (type III); 11% (n = 22) originated from S3 and S4 (type IV); 4% (n = 8) originated from S3, S4, and S5 (type V). Two patterns of nerve termination were observed. In 42% of specimens, the nerve to the LA penetrated the coccygeus muscle and assumed an external position along the inferior surface of the LA muscle. In the remaining 58% of specimens, the nerve crossed the superior surface of the coccygeus muscle and continued along the superior surface of the iliococcygeus muscle. Damage to the nerve to LA has been associated with various pathologies. In order to minimize injuries during surgical procedures, a thorough understanding of the course and variations of the nerve to the LA is extremely important.

Matteo Realdo Colombo (c. 1516-1559): the anatomist and surgeon.

Matteo Realdo Colombo (c. 1516-1559) was one of the great anatomists and teachers of the Renaissance period. He has created a lasting reputation by both challenging incorrect medical convention and influencing the great artwork of the time. Although Colombo's contemporaries are often held in greater esteem, the accomplishments of this anatomist helped set the stage for modern medicine. The story of Colombo's life provides the modern surgeons and anatomist with valuable lessons regarding the nature of orthodoxy, conflict, and the evolving nature of "truth" in science.

Anatomy and biomechanics of the vertebral aponeurosis part of the posterior layer of the thoracolumbar fascia.

There is significant paucity in the literature regarding vertebral aponeurosis. We were able to find only a few descriptions of this specific fascia in the extant medical literature. To elucidate further the anatomy of this structure, forty adult human cadavers were dissected. Both quantitation and anatomical observations were made of the vertebral aponeurosis. The vertebral aponeurosis was identified in 100% of specimens. This fascia was identified as a thin fibrous layer consisting of longitudinal and transverse connective tissue fibers blended together deep to the latissimus dorsi muscle. It attached medially to the spinous processes of the of the thoracic vertebrae; laterally to the angles of ribs; inferiorly to the fascia covering the serratus posterior inferior muscle (superficial lamina of the posterior layer of thoracolumbar fascia); superiorly it ran deep to the serratus posterior superior and splenius capitis muscles to blend with the deep fascia of the neck. At the level of the serratus posterior inferior muscle, the vertebral aponeurosis fused to form a continuous layer descending toward the sacrotuberous ligament covering the erector spinae muscle. Morphometrically, the mean length of the vertebral aponeurosis was 38 cm and the mean width was 24 cm. The mean thickness was three mm. There was no significant difference between left and right sides, gender or age with regard to vertebral aponeurosis length, width, or thickness (P > 0.05). During manual tension of the vertebral aponeurosis, the tensile force necessary for failure had a mean of 38.7 N. In all specimens, the vertebral aponeurosis was capable of holding sutures placed through its substance. We hope that these data will be of use for descriptive purposes and may potentially add to our understanding of the biomechanics involved in movements of the back. As back pain is perhaps the most common reason patients visit their physicians, additional knowledge of this anatomical region is important.

Jacobus Sylvius (1478-1555): physician, teacher, and anatomist.

Jacques Dubois (1478-1555), better known by his Latin cognomen Jacobus Sylvius was one of the great anatomists and teachers of the Renaissance period. His legacy today, however, is marred by his feud with pupil Andreas Vesalius. The story of Sylvius's life provides the modern clinical anatomist with valuable lessons regarding the nature of orthodoxy, conflict, and the evolving nature of "truth."

Surgical and clinical anatomy of the interclavicular ligament.

Dislocation of the sternoclavicular joint can be associated with life-threatening complications; therefore, a thorough knowledge of the ligaments contributing to sternoclavicular joint stability is essential for the clinician dealing with this anatomical area. The aim of our study was to examine the anatomy of the interclavicular ligament. We examined 50 human cadavers. The interclavicular ligament was identified in 90% of the specimens. The interclavicular ligament was located at the base of the sternal notch in 50% of the cases and connected the superior portions of the capsule of the sternoclavicular joints of each side. The interclavicular ligament connected with the posterior superior aspect of each medial end of the clavicle and with the fibers of the posterior and anterior interclavicular ligaments forming a continuous ligamentous layer. The mean length of this ligament was 2.1 cm, the mean width was 0.72 cm and the mean thickness was 0.36 cm. With the elevation of the shoulder joint and the abduction of the humerus, the interclavicular ligament remained lax. With the depression of the shoulder joint and the adduction of the humerus, this ligament became fully taut. As a result, the interclavicular ligament prevented the upward displacement of the clavicle during forceful depression of the humerus and the shoulder. The tensile force necessary for failure was >53.7 N/cm(2) in all the specimens. These data may be useful to surgeons for instituting techniques for surgical procedures that reconstruct the sternoclavicular joint. Moreover, a future study aimed at evaluating the long-term consequences of surgical transection of this ligament may be in order.

Gimbernat y Arbós, Antonio de (1734-1816).

Don Manuel Louise Antonio de Gimbernat y Arbós, Spanish anatomist and surgeon, was one of the pioneers during the "age of dissection" (late eighteenth century). A bright young mind, Gimbernat was confident and audacious, which allowed him to become a recognized surgeon with a famed reputation that influenced his colleagues internationally. The Spaniard was most widely recognized for his advancements in the treatment of strangulated femoral hernias, and the lacunar ligament was named "Gimbernat's ligament" in his honor. In 1793, he published Nuevo Método de operar en la Hernia Crural dedicated to King Charles IV, which was translated into English by Thomas Beddoes 2 years later. Gimbernat's daring procedures helped improve safety and efficiency of hernia surgery. A person of great determination, he was known as a brilliant, meticulous, and creative man who exemplified the importance of surgeons. His devoted study of anatomy, especially of inguinal anatomy, allowed him to devise a legendary surgical technique in repairing femoral hernias, influencing renowned surgeons of his time and thereafter.