Chapter II: Part 2

48. =Median furrow.=--In a muscular man, a furrow, caused by the prominence of the erector spinæ on each side, runs down the middle of the back. The lower end of the furrow corresponds with the interval between the spine of the last lumbar and that of the first sacral vertebra.

49. =Spines of vertebræ.=--A little friction with the fingers down the backbone will cause the spines of the vertebræ to be tipped with red, so that they can be easily counted, and any deviation from the straight line detected. Still it is worth remembering that the spine of the third dorsal is on a level with the commencement of the spine of the scapula--that the spine of the seventh dorsal is on a level with the inferior angle of the scapula--that the spine of the last dorsal is on a level with the head of the last rib.

=Division of the trachea.=--The division of the trachea is opposite the spine of the third, in some cases the fourth, dorsal vertebra. In front this division is on the level of the junction of the first with the second bone of the sternum.

The root of the spine of the scapula is marked by a slight dimple in the skin. This is on a level with the third intercostal space. A stethoscope placed on the inner side of this dimple would cover the bronchus, more especially the right, since it is nearer to the chest wall.

Make a man lean forwards, with his arms folded across the chest; this will make prominent the spines of the vertebræ. The lower border of the trapezius will guide you to the spine of the twelfth dorsal vertebra.

50. The place where the kidney is most accessible to pressure is below the last rib, on the outer edge of the erector spinæ.

51. The highest part of the ilium is about the level of the fourth lumbar spine. The best incision for opening the descending colon is in a slightly sloping line beginning at the outer edge of the erector spinæ, midway between the crest of the ilium and the last rib, and continued across the flank for three inches or more, according to the amount of subcutaneous fat.

52. In the pit of the neck we can feel the trapezius and the ligamentum nuchæ. By pressing deeply we detect the forked and prominent spine of the second cervical vertebra.

53. The spines of the third, fourth, and fifth cervical vertebræ recede from the surface to permit free extension of the neck, and cannot often be felt. But the spines of the sixth and seventh (v. prominens) stand out well.

54. Notice that most of the spines of the dorsal vertebræ, owing to their obliquity, do not tally with the heads of their corresponding ribs. Thus, the spine of the second dorsal corresponds with the head of the third rib; the spine of the third dorsal with the head of the fourth rib, and so on till we come to the eleventh and twelfth dorsal vertebræ, which do tally with their corresponding ribs. All this, however, is best seen in the skeleton.

55. The spines of the vertebræ may be useful as landmarks indicative of the levels of important organs. I have therefore arranged them in a tabular form, thus:--

TABULAR PLAN OF PARTS OPPOSITE THE SPINES OF THE VERTEBRÆ.

{ 5th. Cricoid cartilage. Œsophagus begins.
CERVICAL. { 7th. Apex of lung: higher in the female than in the
{ male. (30)

{ 1st.
{ 2nd.
{ 3rd. Aorta reaches spine. Apex of lower lobe of lung.
{ Angle of bifurcation of trachea. (49)
{ 4th. Aortic arch ends. Upper level of heart.
{ 5th.
{ 6th.
DORSAL. { 7th.
{ 8th. Lower level of heart. Central tendon of diaphragm.
{ 9th. Œsophagus and vena cava through diaphragm. Upper edge
of spleen.
{ 10th. Lower edge of lung. Liver comes to surface
posteriorly. Cardiac orifice of stomach.
{ 11th. Lower border of spleen. Renal capsule.
{ 12th. Lowest part of pleura. Aorta through diaphragm.
Pylorus.

{ 1st. Renal arteries. Pelvis of kidney. (83)
{ 2nd. Termination of spinal cord. Pancreas. Duodenum just
below. Receptaculum chyli.
LUMBAR. { 3rd. Umbilicus. Lower border of kidney.
{ 4th. Division of aorta. (65) Highest part of ilium.
{ 5th.

56. =Origins of the spinal nerves.=--It is useful to know opposite what vertebræ the spinal nerves in the different regions arise from the spinal cord. They arise as follows:--

The origins of the eight cervical nerves correspond to the interval between the occiput and the sixth cervical spine.

The origins of the first six dorsal nerves correspond to the interval between the sixth cervical and the fourth dorsal spines.

The origins of the six lower dorsal nerves correspond to the interval between the fourth and the eleventh dorsal spines.

The origins of the five lumbar nerves correspond to the interval between the eleventh and twelfth dorsal spines.

The origins of the five sacral nerves correspond to the spines of the last dorsal and the first lumbar vertebræ.

57. =Movements of the spine.=--The movements of which the spine is capable are threefold: 1. Flexion and extension; 2. Lateral inclination; 3. Torsion. Flexion and extension are freest between the third and the sixth cervical vertebræ, between the eleventh dorsal and the second lumbar, and between the last lumbar and the sacrum. This is well marked in severe cases of opisthotonos, where the body is supported on the back of the head and heels.[4]

Still better may it be observed when a mountebank bends backwards, and touches the ground with his head.

The lateral movement is freest in the neck and the loins.

The movement of torsion or rotation round its own axis may be proved by the following experiment:--Seated upright, with the back and shoulders well applied against the back of a chair, we can turn the head and neck as far as 70°. Leaning forwards so as to let the dorsal and lumbar vertebræ come into play, we can turn 30° more.

58. =Position and motions of scapula.=--There are a few points worthy of observation about the scapula. It covers the ribs from the second to the seventh inclusive. We can feel its superior angle covered by the trapezius. The inferior angle is covered by the latissimus dorsi, which keeps it well applied against the ribs in the strong and athletic; but in weak and consumptive persons the lower angles of the scapulæ project like wings--hence the term ‘scapulæ alatæ.’

A line drawn horizontally from the spine of the sixth dorsal vertebra over the inferior angle of the scapula gives the upper border of the latissimus dorsi. Another line drawn from the root of the spine of the scapula to the spine of the last dorsal vertebra gives the lower border of the trapezius, which stands a little in relief.

59. The sliding movement of the scapula on the chest can be properly understood only on the living subject. It can move not only upwards and downwards as in shrugging the shoulders--backwards and forwards as in throwing back the shoulders--but it has a rotatory movement round a movable centre. This rotation is seen while the arm is being raised from the horizontal to the vertical position, and is effected by the co-operation of the trapezius with the serratus magnus. The glenoid cavity is thus made to look upwards, the inferior angle slides forwards, and is well held under the latissimus dorsi.

60. For the medical examination of the back, the patient should sit with the arms hanging between his thighs, to lower the scapulæ as much as possible. In this position the spine of the scapula corresponds (nearly) with the fissure between the upper and lower lobes of the lung; the apex of the lower lobe being about the level of the third rib.

_THE ABDOMEN._

The student is assumed to be familiar with the conventional lines dividing the abdomen into regions.

61. =Abdominal lines.=--The linea alba, or central line of the abdomen, marks the union of the aponeuroses of the abdominal muscles. It runs from the apex of the ensiform cartilage to the symphysis pubis. As this line is the thinnest and least vascular part of the abdominal wall, we make our incision along it in ovariotomy, and in the high operation of lithotomy; in it, we tap the abdomen in ascites, and the distended bladder in retention of urine.

The so-called ‘linea semilunaris,’ at the outer border of the sheath of the rectus, corresponds with a line, drawn slightly curved (with the concavity towards the linea alba), from the lowest part of the seventh rib to the spine of the pubes. This line would be in an adult about three inches from the umbilicus; but in an abdomen distended by dropsy or other cause, the distance is increased in proportion.

It is important to know the position of the ‘lineæ transversæ,’ or tendinous intersections across the rectus abdominis. There are rarely any below the umbilicus, and generally three above it. The first is about the level of the umbilicus. The second is about four inches higher--that is, about the level of the lowest part of the tenth rib. These are the principal lines, and they divide the upper part of each rectus into two nearly quadrilateral portions, an upper and a lower: of these, those on the right side are a trifle larger than on the left. We see these muscular squares pretty plainly in some athletic subjects. Much more frequently we see them, too much exaggerated, on canvas and in marble. Artists are apt to exaggerate them, and make the front of the belly too much like a chess-board. It is lucky for them that all the world do not see with anatomical eyes.

A familiarity with the shape and position of these divisions of the rectus is of importance, lest we should, in ignorance, make a mistake in our diagnosis. A spasmodic contraction of one of these divisions, particularly the upper, or a collection of matter within its sheath, has been frequently mistaken for deep-seated abdominal disease.

In the erect position, the anterior superior spines of the ilia are a little below the level of the promontory of the sacrum. The bifurcation of the aorta is on about the level of the highest part of the crest of the ilium.

62. =Umbilicus.=--The umbilicus is not midway between the ensiform cartilage and the pubes, but rather nearer to the pubes. In all cases it is situated above the centre of a man’s height. It is a vulgar error to say that when a man lies with legs and arms outstretched, and a circle is drawn round him, the umbilicus lies in the centre of it. This central point is in most persons just above the pubes.

In very corpulent persons two deep transverse furrows run across the abdomen. One runs across the navel and completely conceals it. The other is lower down, just above the fat of the pubes. In tapping the bladder above the pubes in such a case, the trochar should be introduced where this line intersects the linea alba.

Although the position of the umbilicus varies a little in different persons, as the abdomen is unusually protuberant or the reverse, still, as a general rule, it is placed about the level of the body of the third lumbar vertebra. Now, since the aorta divides a little below the middle of the fourth lumbar, it follows that the best place to apply pressure on this great vessel is one inch below the umbilicus, and slightly to the left of it (65). That the aorta can, under favourable circumstances, be compressed under chloroform sufficiently to cure an aneurysm below it, is proved by recorded cases, and by none more effectually than by a case related in the second volume of the ‘Reports of St. Bartholomew’s Hospital.’

It may be asked, why not apply pressure on the aorta above the umbilicus? The answer is, that the aorta above the umbilicus is farther from the surface, and is, moreover, covered by important structures upon which pressure would be dangerous.

63. =Parts behind linea alba.=--Let us next consider what viscera lie immediately behind the linea alba. For two or three fingers’ breadth below the ensiform cartilage there is the left lobe of the liver, which here crosses the middle line. Below the edge of the liver comes the stomach, more or less in contact with the linea alba, according to its degree of distension. In extreme distension the stomach pushes everything out of the way, and occupies all the room between the liver and the umbilicus. When empty and contracted, it retreats behind the liver, and lies flat in front of the pancreas at the back of the abdomen; thus giving rise to the hollow termed the ‘pit of the stomach.’ But as the stomach distends, it makes a considerable fulness where there was a pit. The middle of the transverse colon lies above the umbilicus, occupying space (vertically two or three inches) according to its distension. Behind and below the umbilicus, supposing the bladder contracted, are the small intestines, covered by the great omentum.

64. =Peritoneum.=--The peritoneum is in contact with the linea alba all the way down to the pubes, when the bladder is empty. But when the bladder distends, it raises the peritoneum from the middle line above the pubes; so that with a bladder distended half-way up to the umbilicus, there is a space of nearly two inches above the symphysis where the bladder may be tapped without risk of injury to the peritoneum. For the same reason, we have space sufficient for the successful performance of the high operation for stone. This fact in anatomy must have been well understood by Jean de Dot, the smith at Amsterdam, who, in the seventeenth century, cut himself in the linea alba above the pubes, and took out of his bladder a stone as large as a hen’s egg. The stone, the knife, and the portrait of the operator, may be seen to this day in the museum at Leyden.

65. =Division of Aorta.=--The aorta generally divides at a point one inch and a half below the umbilicus. A more reliable guide to this division than the umbilicus, is a point (a very little to the left) of the middle line about the level of the highest part of the crest of the ilium. A line drawn with a slight curve outwards from this point to the groin, where the pulsation of the common femoral can be distinctly felt (rather nearer to the pubes than the ilium), gives the direction of the common iliac and external iliac arteries. About the first two inches of this line belong to the common iliac, the remainder to the external. Slight pressure readily detects the pulsation of the external iliac above ‘Poupart’s ligament.’

As a rule, the length of the common iliac is about two inches, but it should be remembered there are frequent deviations. It may be between three-quarters of an inch and three inches and a half long. These varieties may arise either from a high division of the aorta, or a low division of the common iliac, or both. It is impossible to ascertain during life what is its length in a given instance, for there is no necessary relation between its length and the height of the stature. It is often short in tall men, and _vice versâ_. Anatomists generally describe the right as a trifle longer than the left; but their average length is pretty nearly the same.

66. Mr. Abernethy, who in the year 1796 first put a ligature round the external iliac, made his incision in the line of the artery. But the easiest and safest way to reach the vessel is by an incision (recommended in the first instance by Sir Astley Cooper, and now generally adopted), beginning just on the inner side of the artery, a little above Poupart’s ligament, and continued upwards and outwards a little beyond the spine of the ilium. The same incision extended farther in the same direction would reach the common iliac.

67. =Bony prominences.=--The anterior superior spine of the ilium, the spine of the pubes, and the line of Poupart’s ligament, are landmarks with which every surgeon should be thoroughly familiar.

68. =Spine of ilium.=--The spine of the ilium is the spot from which we measure the length of the lower extremity. It is a valuable landmark in determining the nature of injuries to the pelvis and the hip. The thumb easily feels the spine, even in fat persons. Its position with regard to the trochanter major should be carefully examined. The best way to do this is to place the thumbs firmly on the opposite spines, and to grasp the trochanters with the fingers. Any abnormal position on one side is thus easily ascertained with the sound side as a guide.

69. =Spine of pubes.=--The spine of the pubes is the best guide to the external abdominal ring. It cannot easily be felt by placing the finger directly over it, since it is generally covered by fat. To feel it distinctly, we should push up the skin of the scrotum and get beneath the subcutaneous fat. If there be any difficulty in finding it, abduct the thigh, and the tense tendon of the adductor longus will lead up to it.

The position of the spine of the pubes is appealed to as a means of diagnosis in doubt between inguinal and femoral hernia. The spine lies on the outer side of the neck of an inguinal hernia, on the inner side of the neck of a femoral.

The spine of the pubes is nearly on the same horizontal line as the upper part of the trochanter major. In this line, about one full inch external to the spine, is the femoral ring. Here is the seat of stricture in a femoral hernia.

70. =Poupart’s ligament, or crural arch.=--The line of Poupart’s ligament (crural arch) is in most persons indicated by a slight crescent-like furrow along the skin. It corresponds with a line drawn not straight, but with a gentle curve downwards from the spine of the ilium to the spine of the pubes. With the help of the preceding landmarks it is easy to find the exact position of the external and internal abdominal rings, and the direction of the inguinal canal.

71. =Abdominal rings.=--The external abdominal ring is situated immediately above the spine of the pubes. It is an oval opening with the long axis directed obliquely downwards and inwards. Though its size varies a little in different persons, yet as a rule it will admit the end of the little finger, so that we can tell by examination whether it be free or otherwise. To ascertain this, the best way is to push up the thin skin of the scrotum before the finger; then, by tracking the spermatic cord, the finger readily glides over the crest of the pubes and feels the sharp margins of the ring.

The position of the internal ring is about midway between the spine of the ilium and the symphysis of the pubes, and about two-thirds of an inch above Poupart’s ligament.

72. =Inguinal canal.=--The position of the external and internal abdominal rings being ascertained, it is plain that the direction of the inguinal canal must be obliquely downwards and inwards, and that its length in a well-formed adult male is from one and a half to two inches, according as we include the openings or not. In very young children the canal is much shorter and less oblique, the inner ring being behind the outer. With the growth of the pelvis in its transverse direction, the anterior spines of the ilia become farther apart, and thus draw the internal ring more and more away from (_i.e._ to the outer side of) the external.

73. =Spermatic cord.=--The spermatic cord can be felt as it emerges through the external ring, and its course can be tracked into the scrotum. The vas deferens can be distinctly felt at the back of the cord, and separated from its other component parts.

74. =Epigastric artery.=--The direction of the deep epigastric artery corresponds with a line drawn from the inner border of the internal ring up the middle of the rectus muscle, towards the chest.

In thin persons the absorbent glands which lie along Poupart’s ligament can be distinctly felt. They are usually oval, with their long axes parallel to the line of the ligament.

75. =Abdominal viscera.=--Now let us see how far we can make out externally the position and size of the abdominal viscera.

To make this examination with anything like success, it is desirable to relax the abdominal muscles. The man should be on his back, the head, shoulders and thorax being well raised, to relax the recti muscles; and the thighs bent on the abdomen, to relax the several fasciæ attached to the crural arch. To induce complete relaxation, where a very careful examination is desired, chloroform should be given.

In manipulating the abdomen we should not use the tips of the fingers. This is sure to excite the contraction of the muscles. The flat hand should be gently pressed upon it, and with an undulating movement.

76. It is well to bear in mind that the central tendon of the diaphragm is about the level of the lower end of the sternum at its junction with the seventh costal cartilage; that the right half of the diaphragm rises to about the level of the fifth rib--that is, about an inch below the nipple; that the left half does not rise quite so high. In tranquil breathing the diaphragm descends about half an inch.

The position of the abdominal viscera varies, to a certain extent, in different persons. In some of them, especially the stomach, their position varies in the same person at different times.

Let us take, first, the largest of the abdominal viscera--the liver.

77. =Liver.=--The liver lies under the right hypochondrium, and passes across the middle line over the stomach into the left hypochondrium, generally speaking, as far as the left mammary line. The extent to which it can be felt below the edges of the ribs depends upon whether it is enlarged or not, as well as upon its texture, and also upon the amount of flatus in the stomach and intestines. As a rule, in health its lower thin border projects about half an inch below the costal cartilages, and can be felt moving up and down with the action of the diaphragm; but it requires an educated hand to feel it. An uneducated hand would miss it altogether. That part of it, however, which crosses the middle line below the ensiform cartilage is much more accessible to the feel; here it lies immediately behind the linea alba, and in front of the stomach, nearly half-way down to the umbilicus. Here, therefore, is the best place to feel whether the liver be enlarged or pushed down lower than it ought to be. If it be much enlarged and much lower, even the most untutored hand could detect its edge.

Even if the edge of the liver be felt very much lower than is normal below the ribs, it does not necessarily follow that the liver is enlarged, since it may be pressed down by other causes--for instance, the habit of wearing tight stays.

To what height does the liver ascend? This can only be ascertained by careful percussion of the chest-wall. The highest part of its convexity on the right side is about one inch below the nipple, or nearly on a level with the external and inferior angle of the pectoralis major. Posteriorly the liver comes to the surface below the base of the right lung, about the level of the tenth dorsal spine.

Roughly speaking, the upper border of the liver corresponds with the level of the tendinous centre of the diaphragm; that is, the level of the lower end of the sternum. Thus a needle thrust into the right side, between the sixth and seventh ribs, would traverse the lung, and then go through the diaphragm into the liver.

78. =Gall bladder.=--The gall bladder, or rather the fundus of it, is situated, but cannot be felt, just below the edge of the liver about the ninth costal cartilage, outside the edge of the right rectus muscle.

79. =Stomach.=--The stomach varies in size more than any organ in the body. When empty and contracted (63) it lies at the back of the abdomen, overlapped by the left lobe of the liver, and in front of the pancreas. When very full, it turns on its axis and swells up towards the front, coming close behind the wall of the abdomen, occupying most of the left hypochondrium and epigastrium, displacing the other contiguous organs, pushing in every direction, and often interfering with the action of the heart and left lung. Hence the palpitation and distressing heart-symptoms in indigestion and flatulence.

The cardiac orifice of the stomach lies to the left of the middle line, just below the level of the junction of the seventh costal cartilage with the sternum.

80. =Pylorus.=--The pylorus lies under the liver, on the right side, near the end of the cartilage of the eighth rib; but it cannot be felt unless occasionally when enlarged and hardened by disease.

81. =Spleen.=--The spleen, if healthy, cannot be felt, so completely is it sheltered by the ribs. It lies on the left side, connected to the great end of the stomach, beneath the ninth, tenth, and eleventh ribs, between the axillary lines--lines drawn vertically downwards from the anterior and posterior margins of the axilla. Its upper edge is on a level with the spine of the ninth dorsal vertebra, its lower with the spine of the eleventh.

Its position and size, therefore, in health can only be ascertained, and not very accurately, by the extent of dulness on percussion. The greatest amount of dulness would be over the tenth and eleventh ribs; above this the thin edge of the lung would intervene between the spleen and the abdominal wall. If, therefore, the spleen can be distinctly felt below the ribs, it must be enlarged. In proportion to its enlargement, so can its lower rounded border be detected below the tenth and eleventh ribs, especially when forced downwards by a deep inspiration.[5]

82. =Pancreas.=--The pancreas lies transversely behind the stomach, and crosses the aorta and the spine about the junction of the first and second lumbar vertebræ. The proper place to feel for it, therefore, would be in the linea alba about two or three inches above the umbilicus. Is it perceptible to the touch?--only under very deep pressure, and very favourable circumstances, such as an emaciated and empty abdomen. It is worth remembering that it may be felt under such conditions. The pancreas of normal size, in thin persons, has been mistaken for disease--disease of the transverse arch of the colon, or aneurysm of the abdominal aorta.

83. =Kidney.=--The kidney lies at the back of the abdomen, on the quadratus lumborum and psoas muscles, opposite the two lower dorsal and two upper lumbar spines. The right, owing to the size of the liver, is a trifle--say, three-quarters of an inch--lower than the left. The pelvis of the kidney is on about the level of the spine of the first lumbar vertebra: the upper border is on about the level of the space between the eleventh and twelfth dorsal spines; the lower border comes as low as the third lumbar spine. During a deep inspiration both kidneys are depressed by the diaphragm nearly half an inch.

Can we feel the normal kidney? The only place where it is accessible to pressure is just below the last rib, on the outer edge of the ‘erector spinæ.’ I say accessible to pressure, for I have never succeeded in satisfying myself that I have distinctly felt its rounded lower border in the living subject, nor even in the dead, with the advantage of flaccid abdominal walls and the opportunity of making hard pressure with both hands, placed simultaneously, one in front of the abdomen, the other on the back. For these reasons, although we can easily ascertain its degree of tenderness, we cannot actually feel it unless it be considerably enlarged.

We must be on our guard not to mistake for the kidney an enlarged liver or spleen, or an accumulation of fæces in the lumbar part of the colon.

84. =Large intestine.=--Let us now trace the large intestine and see where it is accessible to pressure. The ‘cæcum,’ or ‘caput coli,’ and the ileo-cæcal valve lie in the right iliac fossa. The ascending colon runs up the right lumbar region over the right kidney. The transverse colon crosses the abdomen two or three inches above the umbilicus. The descending colon lies in the left lumbar region in front of the left kidney. The sigmoid flexure occupies the left iliac fossa.

Throughout this tortuous course, except at the hepatic and splenic flexures, the colon is accessible to pressure, and we could, under favourable circumstances, detect hardened fæces in it. In a case which occurred in St. Bartholomew’s Hospital, a collection of fæces in the transverse colon formed a distinct tumour in the abdomen. All the symptoms yielded to large and repeated injections of olive oil. In another case an accumulation of fæcal matter in the sigmoid flexure during life was mistaken for a malignant disease.

85. =Colotomy.=--The operation of opening the colon (colotomy) may be done in the right or left loin, below the kidney, in that part of the colon not covered by peritoneum.

The landmarks of the operation are:--(1) The last rib, of which feel the sloping edge; (2) the crest of the ilium; (3) the outer border of the ‘erector spinæ.’ The incision should be about three inches long, midway between the rib and the ilium. It should begin at the outer border of the ‘erector spinæ,’ and should slope downwards and outwards in the direction of the rib. The edge of the ‘quadratus lumborum,’ which is the guide to the colon, is about one inch external to the edge of the ‘erector spinæ,’ or three full inches from the lumbar spines. The line of the gut is vertical, and runs for a good two inches between the lower border of the kidney and the iliac crest on the left side; rather less on the right.

=Small intestines.=--All the room below the umbilicus is occupied by the small intestines. The coils of the jejunum lie nearer to the umbilicus (one reason of the great fatality of umbilical herniæ). Those of the ilium are lower down.

On the right side, a little below the ninth rib, the colon lies close to the gall bladder, and is, after death, sometimes tinged with bile. Posteriorly, this part of the colon is in contact with the kidney and duodenum.

86. =Bladder.=--When the bladder distends, it gradually rises out of the pelvis into the abdomen, pushes the small intestines out of the way, and forms a swelling above the pubes, reaching in some instances up to the navel. The outline of this swelling is perceptible to the hand as well as to percussion. More than this, fluctuation can be felt through the distended bladder by tapping on it in front with the fingers of one hand, while the forefinger of the other passed up the rectum feels the bottom of the ‘trigone.’

_THE PERINEUM._

The body is supposed to be placed in the usual position for lithotomy.

87. =Bony framework.=--We can readily feel the osseous and ligamentous boundaries of the perineum; namely, the rami of the pubes and ischia, the tuberosities of the ischia, the great sacro-ischiatic ligaments, and the apex of the coccyx. This framework forms a lozenge-shaped space. If we draw an imaginary line across it from the front of one tuber ischii to the other, we divide this space into an anterior and a posterior triangle. The anterior is nearly equilateral, and, in a well-formed pelvis, its sides are from three to three and a half inches long. It is called the urethral triangle. The posterior, containing the greater part of the anus and the ischio-rectal fossa on each side, is called the anal triangle.

88. =Raphé.=--A slight central ridge of skin, called the ‘raphé,’ runs from the anus up the perineum, scrotum, and penis. This ‘raphé,’ or middle line of the perineum, is the ‘line of safety’ in making incisions to let out matter or effused urine, or to divide a stricture.

89. =Central point of perineum.=--It is very important to know that a point of the raphé about midway between the scrotum (where it joins the perineum) and the centre of the anus, corresponds with the so-called ‘central tendon’ where the perineal muscles meet. The bulb of the urethra lies above this point, and never, at any age, comes lower down. The artery of the bulb, too, never runs below this level. Therefore the incision in lithotomy should never commence above it. A knife introduced at this point, and pushed backwards with a very slight inclination upwards, would enter the membranous part of the urethra just in front of the prostate gland; pushed still farther it would enter the neck of the bladder. This point, then, is a very good landmark to the urethra in lithotomy, or, indeed, in any operations on the perineum.

The incision in the lateral operation of lithotomy, beginning below the point indicated, should be carried downwards and outwards between the anus and the tuberosity of the ischium, a little nearer to the tuberosity than the anus. The lower end of the incision should reach a point just below the anus.

90. =Triangular ligament.=--In a thin perineum, we can feel the lower border of the deep perineal fascia or the ‘so-called’ triangular ligament of the urethra. The urethra passes through it about one inch below the lower part of the symphysis pubis, and about three-quarters of an inch higher than the central tendon of the perineum. It is important to bear in mind these landmarks in introducing a catheter. If the catheter be depressed too soon, its passage will be resisted by the triangular ligament; if too late, it will be likely to make a false passage by running through the bulb.

91. =Anus.=--One of the most important landmarks which guide a surgeon in his operations about the anus, is a white line[6] at the junction of the skin and mucous membrane. It is easily recognised and is of especial interest, because it marks with great precision the linear interval between the external and internal sphincter muscles. From this line the internal sphincter extends upwards, beneath the mucous membrane, for about an inch, becoming gradually more and more attenuated.

The wrinkled appearance of the anus is caused by the contraction of the external sphincter. At the bottom of these cutaneous folds, especially towards the coccyx, we look for ‘fissure of the anus.’

92. =Landmarks in the rectum.=--Many valuable landmarks may be felt by introducing the finger into the rectum, with a catheter at the same time in the urethra. The principal of these landmarks are the following:--

_a._ The finger can feel the extent and powerful grasp of the internal sphincter for about one inch up the bowel. (91)

_b._ =Urethra.=--Through the front wall of the bowel it can most distinctly feel the track of the membranous part of the urethra, exactly in the middle line. This is very important, because you can ascertain with precision whether the catheter has deviated from the proper track.

_c._ =Prostate gland.=--About an inch and a half or two inches from the anus, the finger comes upon the prostate gland. The gland lies in close contact with the bowel, and can be detected by its shape and hard feel. The finger, moved from side to side, can examine the size of its lateral lobes, their consistence and sensibility.

_d._ The finger, introduced still farther, can reach beyond the prostate, as far as the apex of the trigone of the bladder. More than this, it can feel the angle between the ‘ductus communes ejaculatorii,’ which forms the apex of the trigone. This is the precise spot where the distended bladder should be punctured through the rectum. The more distended the bladder, the easier can this spot be felt. Fluctuation is at once detected by a gentle tap on the bladder above the pubes (86). The trochar must be thrust in the direction of the axis of the distended bladder; that is, roughly speaking, in a line drawn from the anus through the pelvis to the umbilicus.

_e._ The fold of peritoneum, called the recto-vesical pouch, is about four inches from the anus, therefore it is not within reach of the finger; and we run no risk of wounding it in tapping the bladder if the trochar be introduced near the angle of the trigone.

_f._ The finger can feel one of the ridges or folds of mucous membrane which are situated at the lower part of the rectum. This fold projects from the side, and sometimes from the upper part of the rectum, near the prostate. When thickened or ulcerated, this fold occasions great pain in defæcation; and great relief is afforded by its division.

_g._ Lastly, the finger can examine the condition of the spaces filled with fat on either side of the rectum, called the ischio-rectal fossæ, with a view to ascertain the existence of deep-seated collections of matter, or the internal communications of fistulæ.

=Introduction of catheters.=--In the introduction of catheters the following are good rules. Keep the point of the instrument well applied against the upper surface of the urethra;--depress the handle at the right moment (90);--keep the umbilicus in view;--in cases of difficulty feel the urethra through the rectum, to ascertain whether the instrument be in the right direction. Attention to these rules diminishes the risk of making a false passage, an injury which under great delicacy in manipulation ought never to happen.

=Urethra in the child.=--In children the membranous part of the urethra is, relatively speaking, very long, owing to the smallness of the prostate. It is also more sharply curved, because the bladder in children is more in the abdomen than in the pelvis. It is, moreover, composed of thin and delicate walls. The greatest gentleness, therefore, should be used in passing a catheter; else the instrument is likely to pass through the coats and make a false passage. Hence the advantage of being able to ascertain through the rectum whether the instrument be in the right track and moving freely in the bladder, which can also be easily felt in children.

_THE THIGH._

93. =Poupart’s ligament, or crural arch.=--Mark the anterior superior spine of the ilium, the spine of the pubes, and define the line of ‘Poupart’s ligament’ which extends between them. This line is one of our guides in the diagnosis of inguinal and femoral herniæ. If the bulk of the tumour be above the line, the hernia is probably inguinal; if below it, femoral. The line is not a straight one drawn from the spine of the ilium to the spine of the pubes, but slightly curved, with the convexity downwards, owing to its close connection with the fascia lata of the thigh. In many persons it can be distinctly felt; in nearly all its precise course is indicated by a slight furrow in the skin.

For the points about the spine of the pubes, refer to paragraph 69.

94. =Furrow at the bend of the thigh.=--When the thigh is even slightly bent, there appears a second furrow in the skin below that at the crural arch. This second furrow begins at the angle between the scrotum and the thigh, passes outwards, and is gradually lost between the top of the trochanter and the anterior superior spine of the ilium. It runs right across the front of the capsule of the hip-joint. For this reason it is a valuable landmark in amputation at the hip-joint. The point of the knife should be introduced externally where the furrow begins, should run precisely along the line of it, and come out where it ends; so that the capsule of the joint may be opened with the first thrust. In suspected disease of the hip pressure made in this line, just below the spine of the ilium, will tell us if the joint be tender. Effusion into the joint obliterates all trace of the furrow, and makes a fulness when contrasted with the opposite groin.

95. =Saphenous opening.=--In most persons there is a natural depression over the saphenous opening in the fascia lata, where the saphena vein joins the femoral. The position of this opening is just below the inner third of Poupart’s ligament, and about an inch and a half external to the spine of the pubes. This is the place where the swelling of a femoral hernia first appears: therefore it ought to be carefully examined in cases of doubt.

96. =Femoral ring.=--The position of the femoral ring, through which the hernia escapes from the abdomen, is on a deeper plane, about half an inch higher than the saphenous opening, and immediately under Poupart’s ligament. As the plane of the ring is vertical in the supine position of the body, the way in which we should try to reduce a femoral hernia is by pressure, applied first in a downward direction, afterwards in an upward. The intestine protruded has to pass back under a sharp edge of fascia, namely, the upper horn of the saphenous opening (known as Hey’s ligament). At the same time we bend the thigh, to relax the fascia as much as possible.

A good way to find the seat of the femoral ring with precision is the following:--Feel for the pulsation of the femoral artery on the pubes; allow half an inch (on the inner side) for the femoral vein; then comes the femoral ring.

In performing the operation for the relief of the stricture in femoral hernia the incision through the skin should be about an inch and a half external to the spine of the pubes. Its direction should be vertical, and its middle should be just over the femoral ring.

97. =Lymphatic glands in the groin.=--The cluster of inguinal and femoral lymphatic glands can sometimes be felt in thin persons. The inguinal lie for the most part along the line of Poupart’s ligament: they receive the absorbents from the wall of the abdomen, the urethra, the penis, the scrotum, and the anus. The femoral glands lie chiefly over the saphenous opening and along the outer side of the saphena vein: they receive the absorbents of the lower extremity; they receive some also from the scrotum--of which we have practical evidence in cases of chimney-sweepers’ cancer.

98. =Trochanter major.=--The trochanter major is a most valuable landmark, to which we are continually appealing in injuries and diseases of the lower extremity. There is a natural depression over the hip (in fat persons) where it lies very near the surface, and can be plainly felt, especially when the thigh is rotated. Nothing intervenes between the bone and the skin except the strong fascia of the gluteus maximus and the great bursa underneath it.

The top of the trochanter lies pretty nearly on a level with the spine of the pubes, and is about three-fourths of an inch lower than the top of the head of the femur. A careful examination of the bearing of the great trochanter to the other bony prominences of the pelvis, and a comparison of its relative position with that of the opposite side, are the best guides in the diagnosis of injuries about the hip, and the position of the head of the femur.

99. =Nélaton’s line.=--‘If in the normal state you examine the relations of the great trochanter to the other bony prominences of the pelvis, you will find that the top of the trochanter corresponds to a line drawn from the anterior superior spine of the ilium to the most prominent part of the tuberosity of the ischium. This line also runs through the centre of the acetabulum. The extent of displacement in dislocation or fracture is marked by the projection of the trochanter behind and above this line.’[7]

‘Nélaton’s line,’ as it is termed, theoretically holds good. But in stout persons it is not always easy to feel these bony points so as to draw the line with precision. A surgeon must, after all, in many cases trust to measurement by his eyes and his flat hands--his best guides. Thus, let the thumbs be placed firmly on the spines of the ilia, while the fingers grasp the trochanters on each side. Having the sound side as a standard of comparison, the hand will easily detect any displacement on the injured side. Hippocrates bids us compare the sound parts with the parts affected (in fractures) and observe the inequalities.

The top of the great trochanter is the guide in an operation recently introduced by Mr. Adams, namely, the ‘subcutaneous section of the neck of the femur.’ ‘The puncture should be made one inch above and nearly one inch in front of the top of the trochanter. The neck of the bone is to be sawn through at right angles to its axis, the saw working parallel to Poupart’s ligament, and about one inch below it.’

=Spine of the ilium.=--The anterior superior spine of the ilium is the point from which we measure the length of the lower limb. By looking at the spines of opposite sides we can detect any slant in the pelvis. By pressure on both spines simultaneously we examine if there be a fracture of the pelvis, or disease at the sacro-iliac joint.

100. ‘In reducing a dislocation of the hip by manipulation it is important to bear in mind that, in every position, the head of the femur faces nearly in the direction of the inner aspect of its internal condyle.’[8]

101. =Compression of femoral artery.=--About a point midway between the spine of the ilium and the symphysis pubis, the femoral artery can be felt beating, and effectually compressed, against the pubes. How should the pressure be applied when the patient lies on the back? In accordance with the slope of the bone--that is, with a slight inclination upwards. A want of attention to this point is the reason why so many fail when they undertake to command the circulation through the femoral artery in an amputation, or to cure an aneurysm by digital compression.

If the Italian tourniquet be used, we should be careful to adjust the counter-pad well under the tuberosity of the ischium. If digital pressure be used, it is easy to command the femoral by slight pressure of the thumb, provided the fingers have a firm hold on the great trochanter.

102. =Sartorius.=--The sartorius is the great fleshy landmark of the thigh, as the biceps is of the arm, and the sterno-cleido-mastoideus of the neck. Its direction and borders may easily be traced by asking the patient to raise his leg, a movement which puts the muscle in action. The same action defines the boundaries of the triangle (of Scarpa) formed by Poupart’s ligament, the adductor longus and sartorius.

=Line of femoral artery.=--To define the course of the femoral artery, draw a line from midway between the anterior superior spine of the ilium and the symphysis pubis to the (spur-like) tubercle for the adductor magnus on the inner side of the knee. The femoral artery lies under the upper 2/3 of this line.

The sartorius begins to cross the artery, as a rule, from three to four inches below Poupart’s ligament. The point at which the profunda artery arises is about one and a half or two inches below the ligament. Therefore the incision for tying the femoral in Scarpa’s triangle should commence about a hand’s breadth below Poupart’s ligament, and be continued for three inches in the line of the artery.

To command the femoral in Scarpa’s triangle, the pad of the tourniquet should be placed at the apex, and the direction of the pressure should be, not backwards, but outwards, so that the artery may be compressed against the femur.

In the middle third of the thigh the femoral artery lies in Hunter’s canal, overlapped by the sartorius. About the commencement of the lower third the artery leaves the canal through the oval opening in the adductor magnus, and, under the name of popliteal, enters the popliteal space. The line for finding the artery in Hunter’s canal has been already traced (102). The incision to reach the artery in this part of its course would fall in with the outer border of the sartorius.

To command the femoral artery in Hunter’s canal, the pressure should be directed outwardly, so as to press the vessel against the bone.

_THE BUTTOCKS._

103. =Buttocks.--Bony landmarks.=--The bony landmarks of the buttocks which can be distinctly felt are: 1, the posterior superior spines of the ilia; 2, the spines of the sacral vertebræ; 3, the two tubercles of the last sacral vertebra; 4, the apex of the coccyx in the deep groove leading to the anus; 5, the tuberosities of the ischia on each side of the anus.

The posterior spines of the ilia are about the level of the second sacral spine, and correspond with the middle of the sacro-iliac symphysis.

The third sacral spine marks the lowest level to which the membranes of the cord and the cerebro-spinal fluid descend in the spinal canal.

The tuberosities of the ischia, in the erect position, are covered by the gluteus maximus. In the sitting position they support the weight of the body, and are only covered by a thick pad of coarse fat. Between this pad and the bones there is a bursa, which becomes occasionally enlarged and inflamed in coachmen.

The prominence of the nates is one of the characteristics of man in connection with his erect attitude. ‘Les fesses n’appartiennent qu’à l’espèce humaine.’ They are formed of an accumulation of fat over the great muscle of the buttock (gluteus maximus). From their appearance we may gather some indication of the state of the constitution. They are firm and globose in the vigorous; loose and flaccid in the infirm. Wasting and flattening of one, compared with the other, is an early symptom of disease in the hip.

104. =Fold of the buttock.=--The deep furrow, termed ‘the fold of the buttock,’ which separates the nates from the back of the thigh, corresponds with the lower border of the gluteus maximus. Its altered direction in disease of the hip is very characteristic. This is the best place to feel for the great ischiatic nerve. We find it by pressing deeply between the trochanter and the tuber ischii, rather nearer to the latter. When we sit upright, the nerve is not liable to pressure; but it becomes numbed when we sit long sideways.

105. =Gluteal artery.=--To find at what point the gluteal artery comes out of the pelvis, draw a line from the posterior superior spine of the ilium to the top of the trochanter major, rotated inwards. The junction of the inner with the middle third of this line lies over the artery as it emerges from the upper border of the great ischiatic notch.

The point of exit of the ischiatic artery from the pelvis is about half an inch lower than that of the gluteal.

106. =Pudic artery.=--The pudic artery crosses the spine of the ischium. To find it, draw a line from the outer side of the tuber ischii to the posterior superior spine of the ilium. The junction of the lower with the middle third gives the position of the artery. The ischiatic artery lies close to it, but nearer the middle line.

Looking at the course of these arteries it appears that when we sit on hard seats the pressure is sustained by the bones; when we recline on soft seats the pressure is sustained more by the soft parts, and reaches the arteries; hence the tendency of modern modes of reposing to drive the blood into the interior of the pelvis and favour the production of piles and uterine disorders. A celebrated French accoucheur used to say that the fashion of high waists, tight lacing, and easy chairs brought him many thousands a year.

_THE KNEE._

107. =Bony points.=--The patella; the tuberosities of the two condyles; the tubercle of the tibia for the attachment of the ligamentum patellæ; another (the lateral) tubercle, on the outer side of the head of the tibia; and the head of the fibula are the chief bony landmarks of the knee.

Observe that the head of the fibula lies at the outer and back part of the tibia, and that it is pretty nearly on a level with the tubercle for the attachment of the ligamentum patellæ.

We can also feel the adductor tubercle or spur-like projection of bone above the internal condyle which gives attachment to the tendon of the adductor magnus. This spur-like projection corresponds with the level of the epiphysis of the lower end of the femur, and also with the level of the highest part of the trochlea for the patella: facts worth notice in performing excision of the knee.

‘In reducing a dislocation of the hip, it is important to bear in mind that the inner aspect of the internal condyle in every position of the limb faces nearly in the direction of the head of the femur.’ (100)