John M'Lachlan.

Applied anatomy: surgical, medical and operative online

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great muscular masses at each side; and (4) the great transverse
breadth of the joint.

ULNA ALONE.

The only dislocation of this bone is backward, and it is very
rare. The head of the radius bears its normal relation to the
external condyle; the length of the outer side of the arm is
unaltered, but the inner side is shortened. The olecranon process
is displaced backward, and its distance from the internal condyle
much increased.

The Treatment is the same as for both bones backward.

RADIUS ALONE.

The usual dislocations of the head of this bone are — (1) For-
wards ; (2) Backwards ; (3) Outwards.

1. Forwards. — This is by far the most common of the three,
and is, in fact, the second most common dislocation occurring at
the elbow joint. It is caused by indirect violence, as a fall on the
hand in supination, with the elbow joint extended; it may also be
caused by direct violence to the bone behind. It occurs very often
in young persons. The same form of violence applied to the arm
of a person in the prime of life would probably produce fracture
of the lower end of the humerus, dislocation of the shoulder, or
fracture of the middle of the clavicle; in an old person it ordinarily
produces fracture of the lower end of the radius (Colles's); but
in young persons the usual result is either a dislocation of the head
of the radius forwards, or of both bones backwards; not infre-
quently, however, it is a fracture of the lower end of the humerus,
immediately above the condyles. The Symptoms are — (a) The head
of the radius lies in front of the external condyle, and there is a
hollow where it ought to be; (&) the fore-arm is fixed in a state of
semiflexion, and either pronated or midway between pronation and
supination, on account of the relaxation of the biceps allowing the
pronators to act; (c) flexion of the joint is suddenly checked by
the head oi the radius coming into contact with the lower end



Surgical, Medical, and Operative. 381

of the humerus — it heing impossible to flex the joint beyond
an obtuse angle — and this is present whether the dislocation is
complete or incomplete; (d) any forcible attempts at supination
or extension of the arm cause severe pain ; and (e) the whole
fore-arm is twisted, with the outer side somewhat upwards. The
orbicular ligament is torn.

The other two dislocations are rare, and may be diagnosed by
feeling the head of the radius in its new position, and, as in all
dislocations of the radius, the outer side of the fore-arm is shortened,
and the movements of the joint restricted. They are often accom-
panied with fracture of the external condyle into the joint.

Treatment. — Extension and counter -extension by assistants,
while the Surgeon presses the head of the bone into position. As
the strength of this joint is due to ligaments, it is necessary to keep
it at rest for a lengthened period to allow the ligaments to re-unite,
otherwise the action of the biceps will reproduce the displacement.
It should be kept perfectly quiet for four or five weeks. In dislo-
cation forward, the joint must be flexed and a pad applied over the
head of the bone, and kept in position by a divergent figure-of-eight
bandage, which not only keeps the pad in position, but keeps the
elbow joint flexed at the same time. Some Surgeons advise that
the arm should be extended and the head of the bone kept in
position by a pad and straight anterior splint. If preferred, as in
other injuries about the elbow joint, two lateral well-padded angular
splints may be used.

The treatment of the other dislocations, not specially mentioned,
will readily suggest itself from a study of the two common forms.

THE WKIST.

The Wrist Joint. — Glass, Diarthrosis ; Suh-Olass, An oblong
form of hinge, with two axes of movement — a long (as in bending
the hand backwards and forwards), and a short (as in moving the
hand towards the ulnar or radial sides); by some it is called a
condyloid articulation. The bones entering into its formation are
— the under surface of the radius above, and the scaphoid, semi-
lunar, and cuneiform bones below; the ulna is shut out from the
joint by the triangular fibro-cartilage.



382 Applied Anatomy:

The Synovial Membrane sometimes communicates with the
membrane at the end of the ulna (jnemhrana sacciformis). The
Arteries of the joint are the anterior and posterior carpal, anterior
and posterior interosseous, and branches from the deep palmar
arch ; the Nerves come from the ulnar and posterior interosseous.
The Ligaments are four — The anterior, posterior, internal, and
external lateral.

Movements. — 1. Flexors — (a) The palmaris longus, {h) the
flexor carpi radialis, and (c) the flexor carpi ulnaris. 2. Extensors —
(a) The extensor carpi radialis longior, (h) extensor carpi radialis
brevior, and (a) extensor carpi ulnaris. 3. To bend to ulnar side —
(a) The flexor carpi ulnaris, and (b) extensor carpi ulnaris. 4. To
bend to radial side — (a) The flexor carpi radialis, (b) extensor carpi
radialis longior, and (c) the extensors of the thumb. Relations. —
In Front — (1) Radial artery, (2) flexor longus pollicis, (3) flexor
carpi nlnaris, (4) palmaris longus, (5) tendons of flexor sublimis,
(6) tendons of flexoT profundus, (7) median nerve, (8) ulnar artery
and nerve, and (9) flexor carpi ulnaris. Behind — (1) Extensores
carpi radialis longior et brevior, (2) extensor secundi internodii
pollicis, (3) extensor communis digitorum, (4) extensor indicis,
(5) extensor minimi digiti; and (6) extensor carpi ulnaris. On the
outer side — (1) The extensor ossis metacarpi pollicis, (2) extensor
primi internodii pollicis, (3) radial artery, and (4) the radial nerve.
On the inner side merely the integumentary structures.

The strength of the wrist is mainly due to the numerous strong
tendons surrounding it, aided by its own ligaments, the numerous
articulations in the neighbourhood, and the presence of the trian-
gular fibro-cartilage. For these reasons dislocation of this joint is
very rare, as most of the so-called dislocations of the wrist joint
have usually been found to be fractures. The guide is to be found
in the relation of the base of the metacarpal bone of the thumb
to the styloid process of the radius; just as in like injuries about
the elbow, the guide is found in the relation of the inner condyle
of the humerus to the olecranon process. If the styloid process
of the radius and the metacarpal bone of the thumb retain their
normal relation, the case cannot be one of dislocation. The styloid
process of the radius is more anterior, and passes further down
than the styloid process of the ulna> In effusion into the joint,



Surgical, Medical, and Operative. 383

as in Acute Synovitis, the swelling is best seen on the dorsal
aspect of the wrist, showing a general fulness, and some bulging
between the tendons. The pain is very acute, and, as the joint
is so superficial, there will be heat and redness j it is fixed in,
a slightly-flexed position, and any attempt at movement causes
great pain. When, however, the wrist joint is firmly fixed, the
fingers may be moved without causing pain; this shows that the
inflammation is not in the sheaths of the tendons {tenosynovitis).
But if, on the other hand, when the wrist joint is fixed, the move-
ments of the fingers give rise to pain, there is strong reason for
believing that the synovial lining of the sheaths of the tendons
is inflamed. The wrist joint may be dislocated — 1. Backwards.
2. Forwards. The usual cause is a fall on the palm, or by the
hand being bent forcibly backwards.

1. Bacl<wards. — Symptoms — This is the most common form
and is characterised by (a) the presence on the back of the wrist
of a prominence with a convex upper margin; (6) the radius and
idna form a projection on the palmar aspect, but the styloid
processes retain their normal relationship; and (c) the length of
the fore-arm is unaltered, but the distance between the styloid
processes and the base of the metacarpus is shortened.

2. Forwards. — Symptoms — The whole hand is displaced to the
palmar aspect, and there is a prominence on the dorsum with a
concave lower margin, caused by the radius and ulna, the styloid
processes of which can be readily felt.

Treatment. — Draw the hand forcibly downwards, and press
the projection into its proper place; it usually slips in with a
snap. Then keep the arm in a sling, but be careful that the
fingers, thumb, and wrist joint do not stiffen.

Any of the bones composing the Tiiumb may be dislocated,
but the most frequent form is dislocation baci<wards of tiie
first phaianx from the metacarpal bone, the base of the first
phalanx lying on the dorsal surface of the head of the metacarpal
bone. It should be reduced either by extending the displaced
phalanx, or else by forcibly bending it backwards and pressing
the head into position, while the metacarpal bone is flexed as
much as possible into the palm to relax the flexor brevis. In
many cases, however, great diSiculty is experienced in effecting



384 Applied Anatomy

reduction J the cause of thie difficulty is not perfectly understood.
Some, following Hey, believe that the difficulty is due to the
strong lateral ligaments of the joint, which grasp the head of the
bone; but the great majority of Surgeons believe that the tendons
of the flexor brevis muscle, with the abductor on the one side and
the adductor on the other, together with the sesamoid bones into
which they are inserted, is the great obstacle. It is believed that
the narrow neck of the metacarpal bone is grasped between the
two tendon groups, like a stud between the sides of a botton hole.
The Treatment will obviously depend on the view the Surgeon
takes as to the cause — either subcutaneous section of one or both
lateral ligaments of the joint, or one or both tendons of the flexor
brevis muscle.

In falls upon the knuckles and dorsum of the metacarpus,
besides a possible dislocation of the wrist other three events may
happen, viz.: — (a) Dislocation of the head of the os magnum
backwards; {h) Smith's fracture (see " Fractures of Wrist"); or
(c) sprain of the wrist.



Surgical, Medical, and Operative. 385



CHAPTER XXII.
DISLOCATIONS OF THE LOWER EXTREMITY.

The Hip Joint. — Glass, Diarthrosis; Sub-Class, Enarthrosis.
The Synovia! IVJembrane covers the anatomical neck of the
femur, lines the inner surface of the capsule, covers the cotyloid
ligament, forms a tuhular prolongation around the ligamentum
teres, and covers the mass of fat (Haversian gland) lying at the
bottom of the acetabulum; it sometimes communicates with the
bursa beneath the psoas and iliacus. The Bones entering into
its formation are the acetabulum and head of the femur. The
acetabulum is formed by all the three parts of the os innominatum
— the ilium forming a little less than two -fifths, the ischium a
little more than two -fifths, and the pubic bone the remaining
fifth. These three pieces unite, through the Y-shaped epiphysis
in the acetabulum, about puberty. The acetabulum consists of a
horse-shoe-shaped articular surface, which is deficient opposite the
cotyloid notch, and a central non-articular depression continuous
with the notch. The strongest and deepest part of the cavity is
at its upper and posterior part, the lower and inner part being
very shallow and weak. The Arteries of the joint come from
the obturator, sciatic, internal and external circumflex, and the
gluteal arteries ; the nerves are derived from the sacral plexus,
great sciatic, obturator, and accessory obturator nerves.

Ligaments. — 1. The Cotyloid, a tire of white fibro-cartilage,
attached to the rim of the acetabulum and transverse ligament;
it deepens the cavity, closely embracing the head of the femur.
2. The transverse, bridges over the notch, converting it into a
foramen, and is continuous at each end with the ligamentum
teres; beneath it the nutrient vessels pass into the joint. 3. The

2b



386 Applied Anatomy :

ligamentum teres, or round ligament, is a Y-shaped structure,
passing from the two ends of the cotyloid notch to a depression
in the head of the femur. 4. The Capsular. The capsular
ligament is attached above to the margin of the cotyloid cavity
and transverse ligament; and helow — in fi-ont, to the anterior
inter-trochanteric line; above, to the inner side and upper edge
of the great trochanter; behind and below, to the junction of the
middle and outer thirds of the neck of the bone. It consists of
circular and longitudinal fibres, and, on the posterior and inferior
aspects of the capsule, the fibres are almost all circular, so as
not to interfere with the swinging movements of the limb as in
walking, and in these situations also the capsule is very thin and
very loosely attached. On the anterior aspect of the capsular
ligament there is a specially thickened part, known as the ilio-
femoral band, or Y-shaped ligament of Bigelow. It is attached
above to the anterior inferior iliac spine, and below the two
limbs diverge — one to be attached to the upper end of the inter-
trochanteric line, the other to the root of the lesser trochanter.
The inner slip specially limits extension, and the outer slip,
eversion, of the femur. There are also other specially thickened
parts of the capsule — (a) The ilio-troehantej'ic on the superior
aspect, passing from the anterior surface of the root of the great
trochanter to the ilium, immediately above the anterior inferior spine.
(6) The inchio-capsular on the under surface, passing from the
ischium below the acetabulum to blend with the capsular ligament,
(c) The pubo-femoral ligament, a specially thickened part in front
and below. By flexing the thigh upon the trunk and rotating
the femur inwards, the Y- ligament is rendered lax; this is of
importance in the reduction of dislocations. The centre of gravity
falls behind the centre of rotation of the hip joint, and the trunk,
therefore, naturally tends to fall backwards, but this is prevented by
the ilio-femoral band. By this wise provision of Nature,, muscular
eifort is not required to maintain the erect attitude, so that energy
is economised. There is another part of the capsular ligament
that requires special notice, viz., the cervical reflexion. This con-
sists of bands of fibres which come off from the inner surface
of the capsule, and are reflected upwards on to the neck of the
femur, especially towards the anterior and lower, and the posterior



Surgical, Medical, and Operative. 387

and upper aspects. This reflexion is not necessarily ruptured in
intra-capsular fracture, and conveys blood across the fractui'ed
point, and hy this means wiU tend to a certain extent to aid the
union of the broken parts.

The Movements at the Hip Joint. — Flexors. — These muscles
flex the thigh on the trunk, or the trunk on the femur. Direct
flexors (i.e., those that pass from the trunk over one joint only)
— (1) The psoas, (2) iliacus, and (3) pectineus. Indirect flexors
(i.e., muscles passing over two joints, and only acting secondarily
on the hip joint — (1) The rectus, and (2) sartorius. Extensors. —
Direct — The three glutei muscles. It should be observed that in
the extension movements required at the hip joint in ordinary
walking the gluteus maximus is not used; it only comes into play
when greater energy is required. Indirect — The three hamstrings
(biceps, semi-tendinosus, and semi-membranosus). Abductors. —

(1) The gluteus medius, (2) gluteus minimus, (.3) tensor fasciae
femoris, and (4) sartorius. Adductors. — (1) The three adductors,

(2) gracilis, (3) pectineus, (4) quadratus femoris, and (5) obturator
externus. External Rotators. — (1) Gluteus maximus, (2) gluteus
medius (posterior part), (3) pyriformis, (4) obturator internus and
the two gemelli, (5) quadratus femoris, (6) obturator externus, and
(7) psoas and iliacus. Internal Rotators. — (1) Gluteus minimus,
(2) gluteus medius (anterior part), and (3) tensor fascise femoris.
It wUl -be noticed that the external rotators are much more
numerous and powerful than the internal, so that the foot
naturally tends to fall outwards when one assumes the supine
position.

IVIuscles in direct contact with the Capsule of the Hip Joint.
— In Front — The psoas and the iliacus. Above — (1) The rectus
(reflected tendon), and (2) the gluteus minimus. On its inner
side — (1) The pectineus, and (2) the obturator externus. Behind
it — (1) The pyriformis, (2) the obturator internus and the two
gemelli, (3) part of the gluteus minimus, (4) the obturator externus,
and (5) the quadratus femoris.

The range of motion of the joint in its various directions is
limited, in a general way, as follows: — Exietision, by the anterior
fibres of the capsule and Uio-femoral band; Flexion, by the contact
of the neck of the femur with the acetabulum and soft parts of



388 Applied Anatomy :

the groin; Ahduation, by the puho-femoral hand and lower part
of the capsule ; Adduction, by the ilio-trochanteric band and the
upper part of the capsule in extension, and the ligamentum teres
in the flexed position; External Rotation, by the inner limb of
the Y-shaped ligament during extension, and the outer Hmb and
ligamentum teres during flexion; Internal Rotation, by the ischio-
femoral and Y-ligament. The ligamentum teres is rendered tense
either when the thigh is partly flexed and adducted, or when the
limb is flexed and rotated outwards — i.e., flexion with adduction
or external rotation.. Mr Savory also maintains that it is always
made tense in the upright position, and is stiU further tightened
in standing on one leg.

In effusion into the joint, as in Acute Synovitis (a rather rare
condition, pure and simple), the swelling wOl be difiicult to detect,
on account of the depth of the joint from the surface, and the
thick capsule. As in other joints, it will tend to show itself where
the capsule is thinnest — in front, internal to the inner head of the
Y- shaped ligament, and behind at the posterior and lower part of
the capsule. In these parts, therefore, any swelling and tenderness
must be first looked for; the joint at the same time will be flexed,
abducted, and rotated outwards, as in the position of flexion the
joint holds most fluid with the least tension, and abduction and
eversion relax the outer and inner bands, respectively, of the
ilio-femoral ligament.

Bursa under the Psoas Tendon.— Inflammation of this bursa
gives rise to symptoms somewhat like those of hip joint disease.
It may be possible to feel a fluctuating swelling deep in the groin ;
the thigh is held in a position of flexion and abduction, the patient
is unable to extend it, and should he or the Surgeon attempt to do
so there is marked pain, the anterior superior spine follows the
movements of the femur, and there is arching forwards of the
lumbar spine (lordosis) as by this movement the inflamed structure
is pressed upon. The joint, however, can be readily flexed, and
when so held the pain disappears ; there is an absence of all
rigidity, and there is perfect smoothness of all the movements at
the hip joint, as in this position all pressure is removed from the
bursa in question. The only movement that cannot be properly
performed, therefore, is extension.



Surgical, Medical, and Operative. 389

DISLOCATIONS OF THE HIP JOINT.

The dislocations of this joint are various, hut whatever position
the head of the hone ultimately assumes, the primary dislocation,
just as in the shoulder joint, is always in a downward direction.
The forms of regular dislocation in the order of frequency are —

(1) Backwards and upwards, upon the dorsum Uiij (2) hackwards,
into the great sacro-sciatic notch; (3) forwards and downwards, into
the foramen ovale; and (4) forwards and upwards, upon the pubes.
The first two forms are the most common; in aU the four forms
the ligamentum teres is usually ruptured, hut the ilio-femoral hand
remains intact.

We have to notice the influence exerted (1) by the Y- ligament ;

(2) by the tendon of the obturator internus, as it is found in the
gluteal region, on the various forms of regular dislocation of this
joint : —

1. The Y- Ligament. — If this ligament escape rupture, we may
get any of the four regular forms of dislocation enumerated above;
if it be wholly ruptured, the dislocation will be of an irregular
form.- In no case do muscles (except perhaps the obturator
internus) exercise any direct influence on the displacement. In
dislocation on to the dorsum Uii, and into the great sacro-sciatic
notch there is marked inversion of the limb ; this is because the
iHo-femoral band is not ruptured, and the external rotators are
powerless to rupture it, and are therefore unable, so long as the
ligament remains intact, to evert the limb. For the same reason,
in dislocation into the foramen ovale the limb is flexed. In
dislocation on to the pubes the ligament is lax, and hence the
external rotators are at liberty to act, and, having nothing to
oppose them, produce marked eversion.

2. The Tendon of the Obturator Internus. — Bigelow has
pointed out that the muscular body of this muscle is usually mixed
with tendinous structure; by this means it acquires great strength,
and when contracted acts as a powerful accessory ligament on the
posterior aspect of the hip joint. It has also been pointed out by
the same Surgeon that in dislocations on to the dorsum ilii, and
into the great sacro-sciatic notch, the bone passes in exactly the
same direction in the first instance; but in dislocation on to the



390 Applied Anatomy:

dorsum ilii, the head, in passing upwards and backwards, passes
between the tendon of the ohturator internus and the pelvis,
whereas in dislocation into the great sacro-sciatic notch, the head
of the hone as it passes backwards, passes heliind the tendon of
the obturator internus, the tendon lying over the neck of the bone
and preventing its ascent.

Mr MoBBis states that when the limb is flexed, abducted,
and rotated inwards, the backward dislocations are produced ; in
moderate flexion, the head rests on the dorsum ilii; in extreme
flexion, it comes to rest near the sciatic notch. When the limb is
abducted, extended, and rotated outwards, the dislocation upon the
pubes occurs. In very forcible abduction, the head of the bone is
sent into the perinseum. If there be neither rotation, forced flexion,
nor extension, the head of the bone rests in its primary position
— in the thyroid foramen. The dislocations, therefore, it wUl be
observed, all occur in the abducted position of the limb, because
(1) during abduction the head of the bone passes to the shallowest
and weakest part of the acetabulum, and presses on the least sup-
ported part of the capsule; and (2) during abduction the ligamentum
teres is loose. The same condition of parts is also brought about,
even when the limb is not abducted, if the body be forced over to
the dislocated side. The reverse is true in regard to the adducted
position. Just as in tlie shoulder, there is but one primary form of
dislocation of the hip joint, and in both cases that dislocation is
downwards ; in the shoulder the rent in the capsule is at the lower
and anterior part, but in the hip it is at the lower and posterior
part. Further, observe that in the shoulder, the forward disloca-
tions are the most common, but in the hip it is the backward forms.
The point at which the head of the bone will ultimately come to
rest depends on the direction and amount of the violence, as well
as on the position of the limb. Dislocations occur chiefly in men
during the middle period of life (twenty to fifty), and is specially
apt to be produced in certain occupations, as miners and navvies.
The same application of violence in an old person wiU produce
intra-capsular fracture of the neck of the bone ; in young persons,
fracture of the shaft.

There are Special Test Lines made use of in the diagnosis of
dislocations of the femur and fractures of the neck of the bone.



Surgical, Medical, and Operative. 391

1. Nelaton's Test Line. — Draw a line from the anterior superior
spinous process of the ilium over the oiiter side of the hip to the
most prominent part of the tuberosity of the ischium. In health,
the top of the great trochanter should just touch this line in every
position of the joint. The disadvantage of this measurement is
that the patient has to be rolled over towards the sound side, a
movement which may not only be very painful to the patient, but
may be actually injurioiis, as it may loosen an impacted fracture



Online LibraryJohn M'LachlanApplied anatomy: surgical, medical and operative → online text (page 34 of 54)