David E. Tate, Jr.

1 The Story of Hand Anatomy

Progress in knowledge of anatomy of the human hand has paralleled that of knowledge of human anatomy in general. This chapter will serve as an overview to select areas of a very broad topic.

Scientists and scholars studied anatomy in rather desultory fashion until the 16th century CE, at which time Leonardo da Vinci and Andreas Vesalius ushered in a contemporary era of inquiry based on direct observation. From being scorned or even punished in earlier times, anatomical dissections became honorable, festive civic occasions, best exemplified by Rembrandt’s painting The Anatomy Lesson of Nicolaes Tulp. Unfortunately, the journey from furtive, forbidden study to grand public occasion has been tortuous, as societal and religious prohibitions eased only grudgingly. However, once the genie of inquiry was released, during the Renaissance, anatomical studies gained momentum, with further refinements in anatomical knowledge arising after the introduction of anesthetics in the 1840s, along with Baron Joseph Lister’s antiseptic and later aseptic surgery, in 1867. ¹ The ability to patiently operate and dissect, free from fear of infliction of distress or infection, ushered in the era of modern surgical care. Exemplified by Kocher, Billroth, Halsted, Cushing, and Kanavel, modern surgical care became increasingly refined, depending not just on gross anatomy, but also on increasingly fine gradations of functional anatomy. Deliberate pacing of dissection as demonstrated by these pioneers yielded improved results and stimulated still further study. “Smash and grab” surgery on unprepped, unanesthetized patients went by the wayside. Anatomical precision, gross and functional, became paramount to effective operative patient care. While considerable progress has occurred since the 1840s anesthetic advent of William T.G. Morton and Crawford Long, these gains did not occur in a vacuum. Medical inquiry can be traced to Egypt, 4,600 years before Morton and Long presented the world with the possibility of pain-free surgical care.

In keeping with this line of thought, the chapter will discuss not only the gross anatomical study of the hand, but will also delve into various functional aspects of hand anatomy, such as studies of Tinel on behavior of nerve wounds, Destot for carpal mechanics, Kanavel for synovial fluid circulation, Carl Manchot, Michel Salmon, and G. Ian Taylor for circulation of the skin, Harold Kleinert for behavior of flexor tendons, Andrew Koman for dynamics of hand circulation, and Charles Sherrington, Wilder Penfield, and Goran Lundborg for cerebral cortical aspects of the hand, to name a few.

The starting point of any discussion of contemporary medicine is Imhotep. As described in 1913 by Sir William Osler, Imhotep is the “…first figure of a physician to stand out clearly from the mists of antiquity.” ² This Egyptian prodigy was a physician, architect, and vizier to Pharaoh Zoser of the Third Dynasty, circa 2980 BCE. Imhotep was eventually promoted to demigod, and then to the status as a full god of medicine (▶Fig. 1.1). ³

The Edwin Smith Papyrus was written around 1500 BCE, but it is attributed to Imhotep, and others, circa 2800 BCE (▶Fig. 1.2). The papyrus contains the first documented cause-and-effect medical case histories recorded by humans. The papyrus describes nonmagical treatments for these ailments, most of which were head injuries. ⁴

In India, Sushruta (circa 600 BCE) ▶Fig. 1.3 urged doctors to study the human body to become more effective practitioners. Dissection with a knife, though, was prohibited. Sushruta over-came this restriction by wrapping a body in a shroud of grass and then placing it in a river (▶Fig. 1.4a and b). After 7 days, a grass whisk could sweep away outer tissue layers. Sushruta used his findings to describe “Marmas,” points on the upper limb, and elsewhere in the body, where penetrating injuries could inflict serious harm ^{5 , 6} (▶Figs. 1.4a, b).

In Greece, Hippocrates and Aristotle studied human illnesses. Hippocrates commented on splinting of upper limb fractures in The Genuine Works of Hippocrates: “The forearm is to be placed at right angles to the arm, in a state intermediate between pronation and supination….” ⁷

Of all the Greek physicians, Galen of Pergamon is best known. With the dissection prohibitions of his time, he studied human bodies as he could. Galen also made considerable study of animal bodies, thus becoming an early paragon of comparative anatomy. While his diligence was commendable, Galen made many unfortunate and unfounded extrapolations from animal to human anatomy. Galen was considered infallible, so numerous errors persisted to the time of Andreas Vesalius (1514–1564), such as imaginary fibers within veins, sought in vain by Vesalius: “…I had separated the substance of the veins, in search of the fibers, I dissected it raw and boiled, and by Hercules, to tell the truth, the fibers had come from the imagination of our authors (i.e., Galen) ….” ⁸

By 476 CE, the Dark Ages descended upon Western Europe. Odoacer, a Germanic chief, defeated Romulus Augustus as the Germanic troops sacked Rome. Leadership in medical studies then passed to Arab physicians. Chief of these Arabic physicians was Avicenna (980–1037 CE). Avicenna was born in Afshona, at the time a town in the Persian Empire, now in present-day Uzbekistan. Aviecenna’s Canon of Medicine (circa 1020 CE) synthesized medical knowledge of the time, combining Hippocrates and Aristotle with Avicenna’s own observations. Translated into Latin, the Canon served as a prime medical textbook for several centuries. At present, there is not a full English translation of the work. In the Canon, Avicenna made numerous incisive observations pertaining to the hand: “The seven carpal bones in the wrist joint form two rows. Proximal carpal row consists of three bones and the distal carpal row consists of four bones. The three proximal bones taper and form a wedge proximally. They articulate with the lower end of the radius and ulna and provide flexion and extension of the wrist.” Avicenna also differentiated between tendons and nerves and cautioned against excessively tight dressings. ⁹

As Western Europe’s reawakening took hold in the 15th and 16th centuries, a spirit of medical inquiry was part of this scientific and intellectual flowering. Leonardo da Vinci and Andreas Vesalius represent two of the high points of this era. da Vinci (▶Fig. 1.5) was a spectacular polymath, skilled in art and numerous natural sciences, including human and animal anatomy. Based on personal observation and dissection of human specimens, da Vinci started, but did not complete, a survey of the entirety of human anatomy. His plan was outlined, in part, as follows: “This work should begin with the conception of man and describe the nature of the womb and how the child lives in it … next describe a grown male and female … composed of vessels, nerves, muscles and bones ….” ¹⁰

At first, da Vinci may have been interested in human anatomy from the standpoint of an artist, but interest in anatomy for its own sake soon developed. In the drawings which he did complete, he drew the same part from four views. He also pioneered the use of cross-sectional images, and injected wax into the ventricles of the brain to better study their shape. da Vinci represents the acme of the artist as an anatomist. Thereafter, the two fields diverged, with anatomists enlisting skilled artists to depict structures of interest. O’Malley and Sanders expertly critique da Vinci’s strengths and weaknesses as an anatomist. In their estimation, da Vinci’s iconic depictions of bones and muscles were the high point of the work, with depictions of other body areas suffering from flaws and incomplete renderings. ¹⁰

Leonardo da Vinci depicted the hand (▶Figs. 1.6a, b) in a dorsal projection:

“The first bone of the thumb [metacarpal I] and the first bone of the index finger [metacarpal II] are placed upon the basilar bone [multangulum majus] in immediate support ….” ¹⁰

Similarly, he describes the soft tissues of the hand on the palmar surface, “Show and describe what cord in each finger is the most powerful and the largest … the cords of the palm of the hand together with their muscles are very much larger than those of its dorsum.” ¹⁰ da Vinci’s plan to depict the whole of human development remained incomplete, but he was clearly anticipating future directions with the work that he did complete.

Miraculously, the da Vinci drawings survived, drifting around Europe for centuries, making a miraculous reappearance at Windsor castle, not unlike the surfacing of Franz Schubert’s unpublished, unplayed musical manuscripts “… shoved in cupboards and drawers all over Europe.”

The paradigm for artist-anatomist collaboration was set with anatomist Andreas Vesalius (▶Figs. 1.7a, b), and artist Johann van Kalkar in De Fabrica Corporis Humani (published in 1543), with their Swiss publisher Johannes Oporinus (▶Fig. 1.8) setting a similarly exacting standard for superlative printing of an epoch-making book. ¹¹

A native of Brussels, Vesalius was only 29 when the Fabrica was published. From an early age, Vesalius demonstrated an insatiable appetite for primary anatomical knowledge. By age 22, he had robbed a gibbet of the corpse of a deceased criminal in Louvain, Belgium: “… I was … looking for bones where executed criminals are usually placed along the country roads … I came upon a dried cadaver …. the birds had cleansed this one … which had been partially burned and roasted over a fire of straw and then bound to a stake …. I climbed the stake and pulled the femur away from the hipbone. Upon my tugging, the scapulae and arms and hands also came away. After I had surreptitiously brought the arms and legs home in successive trips—leaving the head and trunk behind—I allowed myself to be shut out of the city in the evening so that I might obtain the thorax, which was held securely by a chain. So great was my desire to possess these bones, that in the middle of the night, alone and in the midst of all these corpses, I climbed the stake with considerable effort and did not hesitate to snatch away that which I so desired.” ^{12 , 13}

With a stroke, the days of a teacher standing on high, droning out of a book, while the lowly barber performed the actual dissection, were over. Instead, Vesalius the teacher was also Vesalius the prosector, front and center, as the famous image from the cover of the Fabrica demonstrates (▶Fig. 1.9).

The Fabrica is a revolutionary work, covering the whole of human anatomy, based on primary dissections. The work is divided into seven books: Book I: The Bones and Cartilages (English translation by William F. Richardson and John B. Carman and published by Norman; ▶Fig. 1.10a), Book II: The Ligaments and Muscles (English translation by William F. Richardson and John B. Carman and published by Norman; ▶Fig. 1.10b), Book III: The Veins and Arteries, Book IV: The Nerves, Book V: The Organs of Nutrition and Generation, Book VI: The Heart and Associated Organs, and Book VII: The Brain.

In discussing the upper limbs in the Fabrica, Vesalius uses the terms “radius” and “ulna” for the two forearm bones. The teleology of the triangular fibrocartilage is charming: “… Nature did not want the rest of the epiphysis to touch the carpus without the intervention of something else, and she therefore drew out … a cartilage which ascends the epiphysis of the ulna and separates it from the carpus … the ulna supports the carpus without touching it ….” Metacarpals are referred to as metacarpals by Vesalius, with various names for phalanges: “The fingers contain three bones each … sometimes known as internodes, joints, phalanges, cudgels, and knuckles.” ¹⁴

For Vesalius, nomenclature of hand-based muscles was numeric, with an explanation for each muscle’s function. For example, muscles 26 to 29 are the lumbricals: “… they are thin, rounded muscles that stretch out from the four individual tendons of the second muscle (flexor digitorum profundus) … they proceed … and insert into the root of the fingers … to incline the four fingers sideways toward the thumb ….” ¹⁵

Vesalius depicts the brachial plexus in Book IV: he uses a numeric system to describe the nerves: the median nerve is the third nerve; the ulnar nerve is the fifth. “…the third nerve… sits on the anterior side of the inner tubercle of the humerus …the fifth nerve…reaches the inner tubercle of the humerus; it bends around the rear of this, having its own special groove through which it may fitly travel into the forearm.” ¹⁶

Vesalius and da Vinci are the giants upon whose shoulders all the other anatomy scholars stand, up to and including today. Their insistence on primary investigation and accurate rendering of their results furnished the template for all investigations to follow.

In terms of artistic depiction of anatomic study, Rembrandt’s iconic The Anatomy Lesson of Dr. Nicolaes Tulp (painted in 1632) documents the prestige associated with quality scientific inquiry (▶Fig. 1.11).

This Dutch painting depicts Nicolaes Tulp, physician, anatomic demonstrator, and Amsterdam civic leader, conducting an anatomical dissection of a recently executed criminal. William Heckscher’s book-length study of the painting discusses the history of artistic depictions of anatomic dissections. Heckscher vividly describes the civic atmosphere of the Netherlands at the time, rich with a spirit of logic, learning, and scholarly inquiry. ¹⁷ While some, including Heckscher, have reported anatomic errors in the painting, likely based on surveys of anatomy atlases, Dutch surgeons clarified the situation using an actual anatomic dissection to investigate Rembrandt’s painted depiction. The famous “misplaced muscle” is likely an accurate rendering of a reflected flexor carpi radialis, although Rembrandt does depict anomalous nerve and tendon structures in the hand (▶Fig. 1.12). ^{17 , 18}

A similar artistic-anatomic connection took place in the Netherlands in 1690. The anatomist was Govaert Bidloo, the artist was Gerard de Lairesse, and the engraver was Abraham van Bloetling. While the resulting Atlas Humani Corpori was unsuccessful commercially, one of its images has lived on as a memento of a stylish intersection of anatomy and art (▶Fig. 1.13). ¹⁹

Jacob Benignus Winslow (1669–1760) was born in Odense, Denmark but moved to France where he worked for the rest of his life. In France, he changed his name to Jacques Benigne Winslow (Fig. 1.10a). His famous anatomical text “Exposition Anatomique de la Structure du Corps Humain” was published in French in 1732 (Fig. 1.10b) and translated into English by G. Douglas M.D ²⁰ . Apart from the eponymous epiploic foramen in the abdomen, he made important contributions to hand anatomy: he described the extensor tendon rhombus (described in Chapters 2 and 29), the sagittal band (see Chapter 29). Winslow described, for the first time, the trapeziometacarpal joint as “double ginglymus”, that “both curved surfaces in opposite directions”.

Another Dutch prodigy in the tradition of Nicolaes Tulp was Petrus Camper. While best known for the eponymous “chiasma” in the flexor digitorum sublimis, Ijpma and coworkers documented the wide range of Camper’s interests and intellect in a 2010 article. Camper was a comparative anatomist in the style of John Hunter, lecturing at the illustrious Amsterdam Guild of Surgeons, literally following in the footsteps of Nicolaes Tulp and other luminaries of Dutch medicine. Like Tulp, Camper was also commemorated in a painting during an “anatomy.” In the Anatomy Lesson of Prof. Petrus Camper, painted by Tibout Regters (painted in 1758), Camper is on the far right (▶Fig. 1.14). ²¹

On the heels of Rembrandt came Josias Weitbrecht, a German anatomist who worked in Russia, sponsored by Peter the Great. His masterwork, Syndesmology represents a summation of his life’s work, and a partnership with artist Andreas Grecow, along with Grecow’s students Gregorius Katschalow and Johannes Sokolow. As Bartoníček and Naňka mentioned in their insightful biographical article of Weitbrecht, the original book was in Latin, featuring “…more than 10 different font styles and sizes. Each paragraph is followed by references to works of individual authors, including a brief commentary. References to figures can be found on the page margins. Each double-page ends in a footnote that contains a word representing the first word of the following page.” In addition to the distinctive layout of the book, the anatomic depictions are masterful: “…A number of views presenting individual articular structures have been used in the standard anatomical literature until today…although their names …differed significantly from the current anatomical terminology….” Unfortunately, the book suffered from a series of truncating, subpar translations, shortening the book, and casting aside the illustrations as well. Emmanuel Kaplan redeemed the work with a masterful English translation in 1969 which restored the work to full length, and also reincorporated the illustrations. ²²

Here is Weitbrecht himself, via Kaplan, on the triangular fibrocartilage complex: “A band or very strong retinaculum, which holds the ulna in its lower end, is the intermediate triangular cartilage that covers the sinuosity of the lower end of the radius. It was very well described by Vesalius…the base is so perfectly attached to the radius by a cartilaginous contact that it forms only one sinus. Two of the angles that form the tip of the process of the base of the radius are covered by the short ligaments, which are fused with the capsular ligament that unites the carpus with the radius. That is how it is attached to the ulna. The tip of the cartilage…inserts into the base of the styloid process of the ulna directly opposite to it. This insertion is the center of motion of the radius. A straight line drawn from this insertion to the styloid process of the radial bone represents the radius of this portion of a circle made by the tip of the radial styloid process when it turns around the styloid process of the ulna.” ²³

In the spirit of comparative anatomical investigation, Charles Bell (▶Fig. 1.15) produced a tour de force, in 1833.

The product was The Hand, Its Mechanism and Vital Endowments as Evincing Design (▶Fig. 1.16). It was one of a set of treatises commissioned by the Royal Society for “…a work… On the Power, Wisdom, and Goodness of God, as manifested in the creation….” Other works in the series included studies of geology, astronomy, and physiology of plants and animals. Bell’s book is a masterful survey of the hand, with exhaustive comparative anatomical surveys of humans, horses, bats, anteaters, and various dinosaurs. Take, for example, the upper limb of the bat: “the phalanges of the fingers are elongated… for the purpose of sustaining a membranous web, and to form a wing….on the fine web of a bat’s wing, nerves are distributed, which enable it to avoid objects in its flight, during obscurity of night when both eyes and ears fail….”

As for the ant-eater: “…the distinctiveness of the spines and processes declares the strength of the muscles…in the development of one grand metacarpal bone, which gives attachment to a strong claw… a very distinct provision for scratching and turning aside the ant-hill….”

Bell tied in these discussions with the human upper limb: “…When a man strikes with a hammer, the muscle near the shoulder, acts upon the humerus in raising the extended lever of the arm and hammer….” Bell, in explaining his theme of the ingenious design of the hand as reflecting the undoubted input of the creator, offers a quote which encapsulates the essence of the theme: “…Some animals have horns, some have hoofs, some teeth, some talons, some claws, some spurs and beaks: man hath none of these, but is weak and feeble, and sent unarmed into the world—Why, a hand, with reason to use it, supplies the use of all these.” ²⁴

This intellectual tour de force of natural history is also exemplified by brothers and rivals, William and John Hunter. The brothers were predecessors of Bell at London’s Great Windmill Street School of Anatomy. Neither of the Hunters studied the hand in particular, but they are luminaries in anatomy’s ascent as a vital part of medical science.

Of the Hunters, William was the more polished brother. William was a capable anatomist and teacher, especially in obstetrics. Additionally, William was a sought-after society doctor. In contrast, John was an insatiable and indefatigable master of human and animal anatomy. John was keen to dissect anything on which he could put his hands, and to that end, he was on familiar terms with the underworld of London’s pre-Anatomy Act resurrectionists and body-snatchers.

As a sidelight to any discussion of anatomical study, body-snatchers are a fascinating, if repellent, collection of characters, and a necessary digression to this narrative. As there was no provision to legally obtain “material” for human dissections, villainous gangs worked on moonless nights, harvesting the dead. Londoners were terrified of being harvested, and church graveyards were often pockmarked with mazes of empty graves. Children were priced by the inch. Unfortunately, shortage of cadavers for dissection, coupled with a need for expansion of anatomic knowledge, made body-snatching a necessary, if unappealing, feature of London life in the 18th and 19th centuries. Sir Astley Cooper, first a pupil of John Hunter, and later a distinguished surgeon in his own right, characterizes the resurrectionists: “…the lowest dregs of degradation. I do not know that I could describe them better; there is no crime they would not commit…a dissolute and ruffianly gang.” While condemning them, Cooper did have to make use of their services as he sought to hone his anatomical knowledge and surgical skill. Cooper testified to Parliament regarding the reach of the body-snatchers: “There is no person, let his situation in life be what it may, whom if I were disposed to dissect, I could not obtain. The law only enhances the price and does not prevent exhumation….” ²⁵

As surgical care improved, and treatment for more conditions became feasible, refinements of functional anatomy became increasingly important. Across the English Channel from the Hunters, Baron Guillaume Dupuytren (1777–1835) pioneered treatment of a functional anatomical problem, now named for him: Dupuytren contracture. It was first mentioned by Felix Platter, a Swiss physician in 1614, while Henry Cline, an English surgeon, performed dissection on two hands with the condition. Astley Cooper, in 1824, attributed the abnormality to a derangement of the palmar fascia, but the eponym went to Dupuytren. Wylock presents an account by a colleague of Dupuytren at work: “After the hand was fully immobilized, Dupuytren made a transversal incision of 2.5 cm at the MP joint of the fifth finger in the palm of the hand. After this incision, the aponeurosis was severed with an audible scratching noise. In this manner, a good extension was achieved.” ^{26 , 27}

Back in England, by the 1830s, a combination of realization of the need for improved anatomic instruction and improved access to anatomical material led to the Anatomy Act of 1832. The Act did not eliminate abuses but did augment the supply of legally obtained corpses. Prior to the act, only bodies of murderers retrieved from the gallows were legally available for dissection. After the Act, bodies from Victorian workhouses that went unclaimed were also made available. This had its own problems with anatomy inspectors pressuring clergy in charge of workhouses to avoid mentioning to residents the option of stating their wishes regarding burial versus dissection; the notion of being dissected rather than being buried was a considerable source of distress in Victorian England. ²⁸

Regardless of the rather unappetizing manner of obtaining corpses for dissection, the momentum for improved anatomical instruction was unstoppable. This momentum led to the creation of a publishing landmark: Gray’s Anatomy. This text was released in 1858, and it took anatomic illustration and discussion to a new level of excellence. The book was jointly produced by Henry Gray (writer) (▶Fig. 1.17), and Henry van Dyke Carter (artist) (▶Fig. 1.18).

Using Carter’s iconic depictions of dissections by the authors, combined with terse but elegant verbal summation, Gray’s Anatomy yielded an elegant summation of human anatomical knowledge at that time. The text was revolutionary in its readability, practicality, and visual presentation. The book combined the talents of Gray, Carter, and the publishing house of J.W. Parker and Son, and the printing firm of John Wertheimer, to yield a physical product which became and remains to this day (41st Edition published in 2015), a classic of medical education and medical edification. Indeed, this coalescence of skill to produce Gray’s is reminiscent of the partnership of Vesalius, Kalkar, and Oporinus in producing the Fabrica. In each case, writer, artist, and publisher came together to yield a peerless physical manifestation of knowledge. ²⁸

Gray’s is an overview of all of human anatomy, but the hand receives generous attention from its masterful producers. Carter’s drawings had beautifully rendered, hand-lettered labels placed directly upon the subjects, while Gray deftly and logically described the structures in question: “…The articulation between the two rows of the carpus consists of an enarthroidial joint in the middle, formed by reception of the os magnum into a cavity formed by the scaphoid and the semilunar bones, and of an arthroidial joint on either side, the outer one formed by the articulation of the scaphoid with the trapezium and trapezoid, the internal one by the articulation of the cuneiform and the unciform.” ²⁹

Similarly, the interossei are masterfully and clearly represented visually by Carter, while Gray delivers a concise description: “…The interossei muscles are so named from their occupying their intervals between the metacarpal bones. They are divided into two sets, a dorsal and a palmar, the former are four in number, one in each metacarpal space, the latter, three in number lie upon the metacarpal bones….” ²⁹

Gray’s Anatomy is a landmark, as it represents a dramatic elevation in the quality and quantity of anatomical instruction, yielding a product of exceeding high standard, and widely available. It foreshadows such advances as Robert Acland’s monumental Practice Manual for Microvascular Surgery. This course combined written and video instructions, using Acland’s microsurgical skill, meticulous presentation standards, and his dry, but droll, verbal narration, to yield a standardized and superlative instructional product which has helped train several generations of microsurgical practitioners, over 100 years after the appearance of Gray’s Anatomy. ³⁰

As we note the names of structures in Gray’s Anatomy, we can shift attention to anatomical nomenclature. Anatomical terminology has slowly become codified; initially each investigator coined a novel name for each bone described, as discussions of da Vinci, Vesalius, and Gray illustrate. In 1895, the introduction of the Basel Nomina Anatomica (BNA) represented an attempt to standardize anatomic terminology. Interrupted by World Wars I and II, a widely accepted BNA revision known as the Nomina Anatomica was ratified in Paris in July 1955. A second edition was released in 2011, representing the latest effort at a worldwide set of terms for human anatomical structures. ³¹

For nomenclature of the carpal (Greek, karpos, wrist) ³² bones, McMurrich in 1914 and Johnson in 1990 provide informative and entertaining summaries of the twists and turns of carpal bone nomenclature. Their articles take the journey from the numbers of Vesalius to present-day naming schemes. The origins of today’s system of carpal nomenclature originated with Vesalius. He numbered the bones 1 through 8, starting with the scaphoid as 1, lunate 2, triquetrum 3, pisiform 4, trapezium 5, trapezoid 6, capitate 7, hamate 8. Interestingly, the numbers live on to the time of the ICD-9, with carpal bone fractures classified as 814.01, scaphoid fracture, 814.02, lunate fracture, and onward, up to fracture of the hamate, 814.08. ^{33 , 34}

In 1653, Michael Lyser, a German who worked in Denmark, wrote a five-volume anatomy text. The fifth volume contained suggestions for preparing skeletons for display. In this volume, he proposed names for the carpal bones. Starting radially on the first row: cotyloid (Greek: cup shaped), lunatum (Latin: crescent-shaped), cuneiform (Latin: wedge-shaped), ossiculum magnitudine pisi sativi (Latin: a bone small in magnitude like a cultivated pea), then the distal row: trapezoides (Latin: trapezoid), trapezium (Greek: table), os maximum et crassissimum, in postcaparte capitulum obtinenens (a bone large and thick, held against the back portion of the head), and unciform (Latin: possessing a hook). McMurrich documents the popularity of Lyser’s book, but also documents ongoing flux and controversy in naming of carpal bones. By 1726, Alexander Monro (primus), a Scotsman, had named the carpals: scaphoiudes/naviculare (scaphion [Greek]: boat; naviculare [Latin]: boat), lunare, cunieforme, pisiforme (cartilaginosum), trapezia, trapezoids, magnum, unciform, with Monro transposing the trapezium and the trapezoid.

Also, in 1726, Bernard Siegfried Albinus named the carpals: naviculare, lunatum, triquetrum, subrotundum (Latin: approximately, beneath the round area), multangulum majus (having many angles, large), multangulus minor (having many angles, small), capitatum (Latin: having or forming a head), and cunieforme. In 1871, Henle, a German anatomist, added hamate to the list (hamulus [Latin]: hook). McMurrich includes a table in his article, while Johnson provides serial drawings of the carpus depicting the evolution of the names ^{33 , 34} (▶Fig. 1.19).

With the advent of anesthesia (Crawford Long 1842, William TG Morton 1846), applied anatomy took on new importance, as anesthesia eliminated intraoperative pain and allowed for more patient, deliberate, and delicate dissection, as exemplified by Halsted’s approach to inguinal hernia. ^{35 – 37} The ability to safely render patients insensible of pain was an epochal breakthrough. Coupled with this advance, Baron Lister’s antiseptic surgery, later to evolve into aseptic surgery, further freed surgeons to work patiently, and with respect for anatomy, by reducing fear of the scourge of infection. ³⁸ The combination of freedom from intraoperative pain, and reduction of fear of infection, yielded a new importance of not just gross, but functional aspects of anatomy: how do body parts work, and how can their functions be repaired and restored? By 1900, surgical interventions were becoming increasingly sophisticated—improved anesthetic management (Codman and Cushing: “ether chart”) with ever-enhanced anatomical knowledge and precision led inevitably from the necessary lightning speed of Victor Horsley (1890s neurosurgery), to Harvey Cushing’s meticulous, deliberately paced interventions of 1910. Cushing observed Horsley firsthand: “He found Horsley living in seemingly great confusion, dictating letters to a male secretary during breakfast… patting dogs between letters, operating like a wild man. HC gave him a copy of his paper on the Gasserian ganglion, where-upon Horsley said he would show him how to do a case. They drove off the next morning in Horsley’s cab, after sterilizing the instruments in H’s house, and packing them in a towel, went to a well-appointed West End mansion. Horsley dashed upstairs, had his patient under ether in 5 minutes, and was operating within 15 minutes after entering the house; made a great hole in the woman’s skull, pushed up the temporal lobe, blood everywhere, gauze packed into the middle fossa, the ganglion cut, the wound closed, and he was out of the house less than an hour after he entered it.” ³⁹ In contrast, Cushing refined a deliberate approach to operating on the brain: “…chief advances… were of technical nature. The introduction of blood pressure recording during operations had added to the safety of neurosurgical procedures in general, and he had added a number of ingenious devices for diminishing hemorrhage….” ⁴⁰ . In addition to neurosurgery, these anesthetic and infection control advances led to broad surgical progress, rendering previously untreatable, virtual death sentences such as breast carcinoma, appendicitis, and cholecystitis into entities which could, in fact, be treated with reasonable hope of success. ^{32 , 40 , 41}

In step with these new surgical vistas, functional systems of the hand became important. The ability to operate in a patient and deliberate manner offered a boon to surgeons and patients but posed new challenges as well. Areas of anatomy, previously inaccessible, and of little interest, suddenly became vitally important.

In association with anesthetic and surgical progress, Wilhelm Roentgen’s discovery of X-rays in 1895 “Ueber eine neue Art von Strahlen” (strahlen, German for beam or ray), the discovery of “X-strahlen,” became a vital part of the study of functional anatomical systems. ^{42 , 43} Etienne Destot of France (▶Fig. 1.20) was a prime exponent of the use of this new technology to study the functional behavior of body systems, specifically, the wrist. Within 2 months of the announcement of the discovery of the X-ray of Roentgen, he was “…already making radiographs of patients in l’Hotel Dieu.” ⁴⁴

Destot masterfully defined carpal behavior, normal and pathologic in his masterwork Injuries of the Wrist, translated into English in 1926. In this book, Destot clearly defined various derangements and maladies of the wrist which continue to bedevil surgeons and patients alike to the present day. Among the discussions are those of proximal pole scaphoid fractures, and what would later come to be known as SLAC (scapholunate advanced collapse). “I desire to draw only one conclusion… when we find a fracture of the upper extremity of the scaphoid combined with an alteration of the glenoid cavity of the radius, …it is not rare to observe stiffness and loss of function passing on to anchylosis between the radius and the scaphoid…it is often in these complications in the radius that we must seek for the principal factors in the seriousness of carpal lesions which appear simple.” ⁴⁴

Across the Atlantic, Kansas-native Allen Buckner Kanavel (▶Fig. 1.21) made his own innovative use of Roentgen’s “X-Strahlen.” Circa 1900, infection was perhaps the most pressing problem pertaining to the hand. At the time, mechanisms of spread, and methods to treat infections of the hand were sorely lacking. Poorly executed attempts to drain hand infections frequently left patients with a useless hand, no hand, or worse, as surgeons blundered through multiple trips to the operating theater, making multiple ill-advised incisions on the hands of their hapless patients.

Kanavel worked in Chicago, Illinois. Among the many industries in booming Chicago was the meatpacking industry. Centered at the Union Stockyards, the 475-acre complex on Chicago’s South Side, it processed as many as 18 million animals a year. ⁴⁶ Described in rather lurid, but likely not too exaggeratedly, by Upton Sinclair in his muckraking The Jungle, the stockyards were a veritable injury factory, featuring speedy transit of large animals, and innumerable blunt and sharp instruments of all varieties. In turn, this recipe for mayhem yielded numerous hand infections, often in advanced stages of distress: “…one constantly meets cases in which the patient has been subjected to incision at some swollen or tender area, under the assumption that if there is not pus there ‘the drainage will do good anyway.’ A general rule should be laid down not to incise unless the surgeon has an accurate appreciation of the condition and an absolute diagnosis made.” Here, he summarizes a complex case which presented to him: “The immense size to which these infected hands may grow can hardly be believed unless they are seen. I recall particularly a patient who presented himself with such a hand which had been treated for four weeks without the surgeon having diagnosticated and opened a typical middle palmar abscess…the size of the infected hand…could be compared to the appearance of a large turtle. The patient had had ten or fifteen incisions on the fingers and the dorsum of the hand when I saw him. Only one incision—that of the middle palmar space—was necessary for drainage. A cupful of pus was evacuated, and the patient ultimately recovered complete function of his hand…. he had been advised by several surgeons to have his hand amputated.” ⁴⁷

Using X-rays, Kanavel injected radio-opaque barium paste into flexor sheaths and deep spaces, thereby mapping patterns of synovial fluid drainage. With knowledge of the drainage pattern, a precise and accurate delineation of when to incise, and where, became available to assist the surgeon and patient alike. Instead of dozens, or more incisions, one or two judiciously applied, and carefully planned, incisions would clear tendon sheath and deep space infections. The book graphically demonstrates the contrast between ill-advised, essentially blind attempts at drainage, leaving the patient with a ruined limb, versus the excellent results available in timely, anatomically precise interventions, even in severe infections. Demonstrating his patient, methodical approach, Kanavel documents essential preparation for success: “Operation should always be done under general anesthesia and in a bloodless field.” ⁴⁷ Kanavel is perhaps best known for the “cardinal signs” of flexor tenosynovitis. The first three were described in 1912: “The three cardinal symptoms and signs are: 1. Excessive tenderness over the course of the sheath. This symptom is by all odds the most important. 2. Flexion of the finger. 3. Excruciating pain on extending the finger, most marked at the proximal end.” By the fifth edition of the book, in 1925, the fourth cardinal sign had taken its place: 4. “Symmetrical enlargement of the whole finger.” ⁴⁷

Further refinements of functional properties of the human form came from the landmark studies of cutaneous and muscular circulation, initially by Carl Manchot, of Switzerland, followed by Frenchman Michel Salmon. Both authors performed injection studies. As a medical student, the precocious Manchot performed a survey of the entire human cutaneous circulation, using an unknown dye, and dissecting the injected areas via an open technique in the time before X-rays were known. Manchot demonstrated that cutaneous perfusion is not a random occurrence, but rather that cutaneous perfusion is an ordered set of overlays, each supplied by a named vessel. In France, Michel Salmon took advantage of Roentgen’s rays and performed injections with radio-opaque agents, followed by radiographic images, to map perfusion of skin and muscle. Salmon observed: “The cutaneous territory of the radial artery corresponds to the radial side and a smaller portion of the flexor side of the forearm. The remainder of the forearm skin receives its arterial supply from the ulnar artery…Posterior Compartment: in general, these muscles are supplied by the system of interosseous arteries. According to the classic authors, the anterior interosseous artery divides below the pronator quadratus into two terminal branches, anterior and posterior. The anterior… terminates in the pronator quadratus…the posterior branch pierces the interosseous membrane and enters the posterior compartment of the forearm….” ^{48 , 49}

Manchot and Salmon proved to be far ahead of their time, however, and their works languished until more refined clinical techniques could make use of these key observations. As William Morain observed, it is tantalizing to think of what might have been had Sir Harold Gilles, master of the random pattern flap for facial reconstruction in World War I, been able to read French and German, in order to apply the findings of Manchot and Salmon to his clinical cases. Over half a century passed until clinical medicine caught up to these two laboratory paragons, with their work reflected in the world’s first free tissue transfer in 1973. ^{48 – 50} Taking this work into the 21st century, G. Ian Taylor and coworkers have made spectacular studies of human and animal cutaneous circulation, the angiosome concept: “…each nerve is associated with a longitudinally oriented system of arteries and veins. The ‘inductive’ effect of the nerves is very obvious, especially in the skin, where the vessels or their branches ‘peel off’ to accompany the nerve. The nervous system is one of the first to differentiate in the vertebrate embryo, and it is interesting to speculate what role its peripheral fibers may have played in the organization of the germ layers….” ⁵¹

Additional refinements of study have allowed investigation into vessels of increasingly small caliber, along with dynamic behavior of these vessels in health, and in sickness. A leader in these studies is L. Andrew Koman, using modalities including digital plethysmography, laser Doppler flowmetry, and vital capillaroscopy to assess hand perfusion and hand ischemia. ⁵²

Study of the anatomy of the hand, in the meantime, continued for both gross and functional anatomy. In 1892, Legueu and Juvara of France described a now-eponymous set of vertical fascial septations in the palm at the proximal end of the flexor tendon pulley system. The septae assist with partitioning of flexor tendons and neurovascular bundles in the palm. Bilderback and Rayan presented a further study of these septae in 2004. ⁵³

In 1861, Jean C.F. Guyon of France described the anatomic passageway of the ulnar nerve at the wrist which now bears his name. “…On the underside of the wrist, just inside the pisiform, at the base of the hypothenar area, there is a small intralaminar section…Another interesting fact when describing this small space is the presence in the cavity of the ulnar artery and the nerve lying on the posterior wall, that is to say, on the anterior ligament of the carpus….” ⁵⁴ Gross and Gelberman, quoted in Maroukis et al, delivered a landmark follow-up study in 1985, defining three zones of Guyon’s canal: “Zone I: Begins from the proximal edge of the palmar carpal ligament and ends distally at the bifurcation of the ulnar nerve. Zone II: Runs from just distal to the bifurcation of the ulnar nerve to the fibrous arch of the hypothenar muscles and contains the deep branch of the ulnar nerve. Zone III: Begins just distal to the bifurcation of the ulnar nerve and contains the superficial branch of the ulnar nerve.” ⁵⁵

In analogous fashion, Ulrich Lanz of Germany, in 1977 defined vital patterns of variation in median nerve motor branch takeoff. The report documents the seemingly capricious, and potentially hazardous takeoff points of the motor branch: radial, ulnar, proximal, distal, and all points in between. ⁵⁶ This point is reinforced by Green and Morgan in 2008, a report in which they document that the finding of muscle crossing the midline of a carpal tunnel dissection may portend the presence of an aberrant motor branch of the median nerve. ⁵⁷ To reinforce the notion of variability of what might be found in the carpal tunnel, Galzio and coworkers documented the presence of the entire ulnar nerve, bilaterally, within the carpal tunnels of a single patient. ⁵⁸

A giant in the field of dynamic behavior of peripheral nerves was Jules Tinel of France. Tinel summarized his extensive World War I nerve repair experiences in his 1918 book, Nerve Wounds. He described formication (Latin, formica: ant), defined in the Oxford English Dictionary as: “An abnormal sensation, as of ants creeping over the skin.” Tinel describes formication as “… provoked by pressure: When compression or percussion is lightly applied to the injured nerve trunk, we often find, in the cutaneous region of the nerve a creeping sensation usually compared by the patient to electricity.” ⁵⁹ Pietrzak and coworkers report that Paul Hoffman of Germany described the sign first, but World War I prevented his work from reaching the global medical community. ⁶⁰ Much like Newton and Liebniz, Tinel and Hoffman arrived at the same conclusion independently of one another. ⁶¹

J. William Littler (▶Fig. 1.22), a New York City hand surgeon, devoted much of his lengthy career to the study of the thumb. A gifted surgeon, talented artist, ⁶² and American Society for Surgery of the Hand founding member, Littler described the refinements of pollicization, and summarized efforts to overcome thumb deficiency in a fascinating 1976 review. ⁶³ Joseph Upton and colleagues recently reported on the unique nature of the thumb and on pollicization. This report summarized Upton’s own extensive experience, while offering an elegant synthesis of the early work of Littler and others, works which have led to the theoretical and technical practices for managing thumb deficiency, attempting to replace the irreplaceable. ⁶⁴

The 20th century saw a flowering of applied hand anatomy scholarship. Paul Brand (▶Fig. 1.23) was a brilliant scientist, surgeon, and humanitarian. While working as a missionary surgeon in India, he helped define the pathoanatomy of the hand in leprosy. He also defined numerous surgical correctives for the resultant deformities, to the infinite benefit to these otherwise shunned victims of M. leprae. Brand’s keen interest in mechanics led to detailed studies of functional properties of muscles. In turn, these studies helped codify a rational basis for tendon transfers. By matching excursion of the fibers, and cross-sectional area of the muscles, Brand optimized techniques for substitution of muscles for one another. ^{65 , 66}

Enhanced understanding of peripheral nerve anatomy was spearheaded by Sir Sidney Sunderland. Among his many contributions was a massive study of full-length fascicular architecture of upper limb nerves in 1945. ⁶⁷ Hand in hand, enhanced understanding of peripheral nerve entrapment also occurred. Learmonth described the now-eponymous submuscular transposition of the ulnar nerve in 1942, McGowan graded degrees of ulnar nerve entrapment in 1950, and Osborne described the ligament that bears his name in 1957. ^{68 – 70}

In analogous fashion to these ulnar nerve investigators, G.S. Phalen clarified and advanced treatment for median nerve entrapment in the 1950s and 1960s. Here Phalen describes the test that now bears his name: “In performing the so-called wrist flexion test, the patient is asked to hold the forearms vertically and to allow both hands to drop into complete flexion at the wrist for approximately one minute. In this position the median nerve is squeezed between the proximal edge of the transverse carpal ligament and the adjacent flexor tendons and radius. Maintaining this position for a long time eventually causes numbness and tingling over the distribution of the median nerve in the normal hand. However, when the median nerve is already somewhat compressed within the carpal tunnel, further compression by this maneuver causes almost immediate aggravation of the numbness and paresthesia in the fingers (▶Fig. 1.24).” ^{71 , 72} In an added refinement, Szabo and Gelberman defined pathophysiology of peripheral nerve entrapment in association with distal radius fracture, in 1987, while Green and Rayan studied static and dynamic behavior of the cubital tunnel in 1999. ^{73 , 74}

Functional anatomical investigation continued across the full width and breadth of hand anatomy. Flexor tendon injuries have represented, and continue to represent, a severe challenge to patient and surgeon alike. Sterling Bunnell (▶Fig. 1.25) pioneered and refined techniques for tendon grafting. This focus eventually led to publication in 1944 of his landmark Surgery of the Hand, a summary of his life’s work not just in tendon repair, but also a virtuoso discussion of comparative anatomy, and a summation of hand care as it existed at the time. This book replaced Kanavel’s as the accepted hand surgery resource in English. ⁷⁵ In addition to his formidable scientific and surgical skills, Bunnell was also a talented organizer and leader.

In World War II, Bunnell oversaw the formation of a set of nine specialized hand surgery hospitals in the United States. ⁷⁶ In turn, this group of pioneers formed the core of the American Society for Surgery of the Hand, founded in 1946. ⁷⁷

Taking Bunnell’s work a step further, Harold Kleinert (▶Fig. 1.26) had a revolutionary vision of direct repair of flexor tendons, with rehabilitation incorporating immediate controlled motion. This concept met with initial skepticism and in fact overt hostility: “…Primary repair in no man’s land is not recommended by the authors for the occasional operator in hand surgery. However, the authors concluded that the results were obtainable by the experienced surgeon in selected patients, support their contention that no man’s land is some man’s land. Dr. J.H. Boyes, in discussing this paper noted that these were the most outstanding results obtained by any one in flexor-tendon repair. One gathered that he questioned the percentage of good results without any failures.” ⁷⁸ In spite of this formidable opposition, the excellence of Kleinert’s concepts and clinical skills won the day and created a “one-man revolution in hand surgery.” ⁷⁹ Kleinert, a native of Sunburst, Montana was a charismatic prodigy, urged to attend medical school at Temple (“go as far east as you can, you need the polish”), who was basically self-taught: “…he made his own fellowship, for himself….” ^{80 , 81} Kleinert’s work in Louisville, KY spanned more than a half-century, spanning a broad spectrum of expertise: high-volume small vessel repair, replantation, free tissue transfers, and a host of other interventions which expanded treatment for the injured human upper limb. Kleinert’s startling advances attracted a host of additional skilled teachers and practitioners to Louisville, perhaps none more formidable than Robert Acland (▶Fig. 1.27).

Acland was a skilled plastic surgeon, microsurgeon, anatomist, and multimedia educational expert. Acland devised instruments to standardize microsurgical care, and an iconic written and video course on microsurgical training, known and loved by generations of microsurgical trainees: “…scenes like this needn’t be a part of the human condition; let’s see how….” A spectacular postscript to Acland’s clinical time was creation of a video atlas, surveying the entire human frame. ^{82 – 88}

Claude Verdan of Switzerland (▶Fig 1.28), who was also a collaborator of Kleinert, provided standardization of tendon care at the level of organized medicine, and defined the quadrigia effect, a tendon dysfunction seen in certain cases of finger amputation, where a tethered profundus stump of an amputated digit can prevent excursion of flexor digitorum profundus (FDP) tendons of the other three digits in the ipsilateral hand, secondary to their common muscle origin. ^{89 , 90}

Other investigators studied dynamic aspect of systems involving combined hard and soft tissue systems. Building on Destot’s foundation, Linscheid and Dobyns clarified patterns of wrist injury and consequent deformity, leading to adoption of standardized recognition and terminology for wrist injury, initially dorsal intercalated segment instability (DISI) and volar intercalated segment instability (VISI), later expanded by the Mayo Clinic hand group to include CID (carpal instability, dissociative) and CIND (carpal instability, nondissociative). ^{90 , 91} Taleisnik performed a landmark study on wrist ligaments in 1976, while Berger and coworkers from the Mayo Clinic have offered further refinements of such study, with works on magnetic resonance imaging characteristics of anterior radiocarpal ligaments (1994), along with gross and histologic analyses of scapholunate (1996) and lunotriquetral ligaments (1998). ^{93 – 96}

Further expanding microsurgical frontiers, Chase and coworkers documented functional flap transfers, thereby covering damaged structures. Chase summarized his life’s work in his 1984 ASSH Presidential Address. ^{97 , 98}

Eduardo A. Zancolli of Argentina (▶Fig. 1.29) defined his own concept of functional hand anatomy, and of hand surgery, in the two editions ^{99 , 100} of the iconic Structural and Dynamic Bases of Hand Surgery. Cementing his legacy is the spectacular 1991 collaboration with Elbio Cozzi, Atlas of Surgical Anatomy of the Hand, a large-format, high-resolution triumph of anatomical exposition. ¹⁰¹ On a smaller scale, but of similar quality, is Lee Milford’s 1968 Retaining Ligaments of the Digits of the Hand. ¹⁰²

While functional anatomical concepts have assumed greater and greater importance, gross anatomy remains a vital focus of interest. To name just a pair, von Schroeder and Botte collaborated on defining studies of juncturae tendinum, and extensor tendons of the digits in the early 1990s—the two articles remain benchmark anatomical references. ^{103 , 104}

Another area of functional hand anatomy that is coming into its own is application of cerebral cortical localization. In the late 19th and early 20th centuries, Charles Sherrington performed pioneering cortical mapping via electrical stimulation studies performed on primates. His studies defined reflexes, as well as sensory, motor, and visual parameters of the brain. ¹⁰⁵

In a logical extension of Sherrington’s work, Wilder Penfield, a trainee of Harvey Cushing, carried out spectacular human cerebral cortical mapping while performing epilepsy surgery under local anesthesia at McGill University in Montreal, Canada. These findings were summarized in his 896 -page collaboration with Herbert Jasper: Epilepsy and the Functional Anatomy of the Human Brain (1954). ¹⁰⁶

Goran Lundborg has studied the hand in relation to its cerebral control center in great detail: “A nerve transection, isolated or in association with an amputation injury, represents an acute deafferentiation with immediate and long-standing influence on the corresponding representational areas in the brain cortex as well as in adjacent cortical territories.” ¹⁰⁷

A true new frontier in application of the work of Sherrington and Penfield is the development of “brain-powered” prostheses which can allow bypass of damaged spinal cord or brachial plexus segments. Researchers are now documenting the effectiveness of the “brain-machine interface” (BMI), with a sensor picking and disseminating the signals from the motor strip of the cerebral cortex to motor a prosthesis. ^{108 , 109} While motor functions have been an initial focus, Yadav and coworkers describe a proposed interface to transfer artificial sensory information via dorsal column stimulation, in yet another tantalizing advance. ¹¹⁰

Over time, anatomical knowledge of the hand has advanced in step with anatomy as a whole, from Imhotep and Sushruta to the present, with Vesalius representing a massive leap forward. Since the time of Vesalius, studies have become increasingly refined, directed toward ever-sharpening gradations of topography and function, as the chapter has discussed. While research is always advancing, some truths remain as constants. To paraphrase Harvey Cushing, accidents and injuries will never go away, and we must always be ready to care for them. To do so requires a proper knowledge of anatomy, but medical science is constantly evolving, so there must be a commitment to master and renew what is known, all the while staying abreast of new discoveries. Undoubtedly, much has been left out of this chapter, but I am hopeful that it will serve as a useful overview of the massive efforts over the centuries to understand hand and upper limb anatomy to properly care for conditions of the human hand in disease and health.

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