If the leg stump

Attempts have been made to attach to the pelvis, by means of a waist
belt or braces, a wooden artificial limb whose upper end is fitted
directly on to the tuberosity of the ischium. So far these have met
with little success. In our opinion, the only really practical method
is to enclose the whole stump and pelvis in a regular corset, and to
attach the artificial limb to this corset.[8]

[8] Amongst English limb makers this moulded corset with the steel hip
attachments is usually known as the “tilting table.”–(ED.)

The moulding of this corset upon the stump must be accurate.

The tuberosity of the ischium is the only bony point in the stump upon
which pressure can be taken. The corset may be made of leather, but,
until a new order is issued, the material of choice is celluloid,
moulded upon a plaster of Paris cast, in spite of the disadvantage
mentioned on page 4.

The limb is an articulated peg leg, with convertible knee joint and
double lock, exactly the same as in the limb for amputation through
the thigh.

It is attached to the pelvis (_i.e._ to the tilting table), as shown
in figures 100 and 101, by a joint with a double anterior lock, which
allows the patient to sit down by flexing the hip.

[Illustration: FIG. 100.

FIG. 101.]

This general description and an examination of figures 100 and 101
will suffice to explain this appliance. It is comparatively rarely
required, and its construction is difficult; we consider that the
forms shown in the illustrations are the best. It is only possible
to fit such an appliance when the conditions are good, when the scar
is above and in front of the ischium, and when the latter is well
covered.

If the leg stump is ten centimetres long, if the knee joint is freely
mobile and capable of complete, or almost complete, active extension,
and if there are no adherent scars around the tuberosities of the
tibia, the American apparatus with free knee joint should be adopted.

_Walking on the bent knee_ (as stated on page 63) with the “poor man’s
peg” may be allowed as a temporary measure, but the patient must be
advised to give his knee a rest frequently in order to lessen the risk
of stiffness in a flexed position.

There are two methods of fitting, corresponding with those we have
described for the thigh.

1. For the ordinary amputations with bearing upon the top of the leg.

[Illustration:

FIG. 102.–Limb fitted upon the patient. Note that he
stands upon the toe, and that the knee is flexed. ]

[Illustration:

FIG. 103.–Posterior view of the same limb.]

[Illustration:

FIG. 104.–Anterior view of the same limb.]

2. For amputation very low down with end bearing upon the extremity
of the stump.

I. APPLIANCES WITH BEARING UPON THE TUBEROSITIES OF THE TIBIA

An artificial limb for amputation through the leg with a free knee
joint is composed of two parts: a leg piece (with foot) which is
fitted to the bony prominences around the top of the stump and
supports them; and a suspensory apparatus which consists of a lacing
thigh corset.

A. LEG BUCKET.–The points on which the top of the bucket
must be fitted are the internal tuberosity and the anterior
tubercle of the tibia, and the head of the fibula, so that hollows
corresponding to these must be carved out.

Pressure upon the head of the fibula is often painful, and a deep
concavity is therefore carved out for it. The pressure then comes upon
the external tuberosity of the tibia which, however, ordinarily bears
little weight.

Whenever possible direct end bearing upon the termination of the
stump should be used as an accessory to relieve the weight upon the
tuberosities of the tibia; this is obtained as described on page 7.
It is only possible if the scar is lateral and if there is a good
thick posterior or external flap (in the upper third of the leg). An
anterior flap is the least satisfactory.

It is also advisable–

That the inner surface and the anterior border of the tibia be divided
obliquely, and that the fibula be divided at a higher level than the
tibia.

The fibula must not take weight, it is too slender. In high
amputations it has a tendency to tilt outwards, causing the double
inconvenience of widening the stump and of projecting through the
skin. If only 4 or 5 cms. of the fibula remain it is perhaps best to
disarticulate and remove it.

With a fitting arranged in this way, we consider that the convenience
of walking with a free knee can be assured to patients whose stumps
measure only 10 cms. from the lower border of the patella.

These principles can be applied to a limb constructed either of wood
or of leather.

_The leather appliance_ (French method) is formed of a leather
cylinder, strengthened by two laternal steels which articulate at the
level of the knee joint with two similar steels in the thigh corset.
Its upper edge may be strengthened anteriorly by a metal plate, but
in practice the latter cannot be made to fit with precision the bony
prominences enumerated above. It is actually the edge of the leather,
adjusted by lacing, which supports tibial tuberosities, and therefore
the precision of the fit is soon lost.

For this reason, for amputation below the knee, the American method of
construction with a wooden bucket is demonstrably superior.

These limbs are infinitely more durable than the French. They may
last three years, whereas the French limb used by a young and active
patient is worn out at the end of the first year, and it was for this
reason that a limb with a free knee joint used to be considered a
luxury.[9]

[9] That is the reason that amputation at four fingers’ breadth below
the knee used to be called for the working class, amputation at “the
seat of election,” a name which is no longer applicable and which is
liable to mislead the operator.

This wooden bucket is shaped very accurately to the bony prominences,
and by passing the fingers over its inner surface the three hollows
corresponding to the points of pressure enumerated above can be
distinctly felt.

It is important to describe the shape of the upper edge of the bucket
in order to guard against two points which may interfere with flexion–

I. Pinching of the tissues behind the knee.

II. The tendency of the stump, when it is short, to tilt forward
in the bucket (Fig. 108).

_Pinching of the flesh behind the knee_ in flexion takes place between
the edge of the leg piece and that of the thigh corset.

If the top of the bucket is horizontal, it must inevitably occur, even
if the edge of the thigh corset is well cut away (Fig. 106).

It can be avoided by cutting away these two edges into concavities
opposite each other.

[Illustration:

FIGS. 105 and 106.–Limb in which the upper edge of the leg
bucket is almost horizontal; in the sitting position (Fig. 106) the
flesh at the back of the thigh is pinched even if the lower end of the
thigh corset is well cut away.]

In the French limbs made of leather it is usual to make the leg piece
very high in front, _i.e._ as high as the middle of the patella.
This is quite useless. The posterior border is cut down to a depth
of two fingers’ breadth below the axis of the joint. Pinching is
thus avoided, but the posterior support is insufficient, the stump
tilts forward as described above and the bucket gapes in front (Fig.
108). If the top of the bucket is horizontal–as in certain American
limbs–there is, as we have already said, pinching of the popliteal
tissues and compression of the popliteal vessels and nerves (Fig.
106). A concavity is therefore necessary, but one reaching to one
finger’s breadth below the axis of the joint is sufficient. In front
the edge of the bucket reaches up to the joint line, this is quite
sufficient to enclose the bony prominences (Fig. 109).

The posterior concavity of the leg piece is combined with a concavity
in the thigh piece varied in accordance with the thickness of the
popliteal soft parts.

[Illustration:

FIGS. 107 and 108.–If the leg bucket is hollowed out too
much at the back, the stump is tilted obliquely forward (Fig. 108),
the knee loses contact with the bucket, and the flesh at the back of
the thigh is pinched.]

To diminish further the tendency of the stump to tilt forward the
posterior edge of the bucket is flattened so that the shape of the top
of the bucket is triangular with curved sides and angles much rounded
(the anterior angle over the tuberosity of the tibia being obtuse).
This is the natural shape of a section of the top of the calf. In this
way the posterior muscles are flattened and no longer tend to escape
from the bucket when the knee is flexed. In figures 110 and 111 are
shown two ways in which this flattened posterior margin may be shaped.

[Illustration: FIG. 109.]

[Illustration: FIG. 110. FIG. 111.]

B. SUSPENSION APPARATUS.–The leg is attached (_a_) by a
thigh corset taking its hold on the femoral condyles, and (_b_) by
braces over the shoulders.

(_a_) _The thigh corset_ is made of leather laced in front. Two
lateral steels curving in sharply against the upper part of the
condyles (Fig. 112) form the most effective part of the support. At
their lower ends they are articulated with two steels passing up from
the top of the leg to which they are attached. The joint (Fig. 113)
is composed of a nut, A, into which fits a screw. Around the nut
is a copper ring made to move with the femoral steel by means of a
stop-notch. When the knee flexes and extends the wear comes upon this
copper ring. The steels remain intact. If the joint works loose it is
sufficient to renew the ring.

[Illustration: FIG. 112.

FIG. 113.

FIG. 112.–The thigh steels, curved in above the condyles,
hold the limb on very securely.[10]

FIG. 113.–Details of the joint at the knee.]

[10] In this illustration the joints are placed too low. They should
be opposite the centre of rotation of the knee joint, _i.e._ a
transverse line passing through the femoral condyles. (ED.)

(_b_) _The braces_ are a very useful addition which French
orthopædists should employ systematically.

They increase the stability of the limb and allow the thigh piece to
be laced less tightly, so that contraction of the thigh muscles is
facilitated.

[Illustration: FIG. 114.]

[Illustration: FIG. 115.]

Support may be given by a strap from a waist belt as shown in figure
117, but proper braces are better. These braces pass over the shoulder
of the sound side and are attached either to the thigh corset or to
the leg piece of the artificial limb. Attachment to the thigh corset
is made by a single strap either in front and behind (Fig. 114) or on
either side of the front lacing, the ends of the strap crossing in
front of the groin (Fig. 115). It is a simple matter to add to the
brace an extending strap, such as we have described for the artificial
limb for amputation through the thigh (page 44). It is only necessary
to terminate the brace in a strap from which two branches pass down
in an inverted V and are fixed to the sides of the front of the leg
piece (Figs. 116 and 117). This is unnecessary if the stump is long,
for its leverage will then be good. It is, however, very useful for
short stumps which give little power to the action of the quadriceps.
In the case of patients with a long stump an attempt has been made to
abolish the thigh piece and suspend the limb exclusively by braces.
This method, we believe, is inadequate even if it is completed by a
transverse band above the knee (Figs. 118 and 119).

[Illustration: FIG. 116.]

[Illustration: FIG. 117.]

[Illustration: FIG. 118.]

[Illustration: FIG. 119.]

C. THE FOOT.–The foot, usually articulated, is fixed in
exactly the same way as in a limb for an amputation through the thigh,
_i.e._ it is mounted in the equinus position. But in this case,
however, precautions must be taken against stretching of the posterior
ligaments of the knee joint, because the equinus mechanically produces
hyperextension of the knee, and a genu recurvatum may result. For this
reason a strap must be fixed posteriorly between the thigh corset and
the leg piece to prevent full extension of the knee (popliteal check
cord). This means that we make the patient stand and walk with slight
flexion of the knee and with a corresponding elevation of the heel of
the shoe (2-3 centimetres).

II. APPLIANCES WITH END BEARING ONLY

These appliances are suitable for certain amputations very low down in
the leg which we must first define.

The orthopædist should consider the following operations as very low
amputations of the leg, allowing of walking with end bearing only, and
suitable for the same type of appliance:–

Supra-malleolar amputation.[11]

Disarticulation at the ankle joint.

Sub-astragaloid amputation.

Osteoplastic amputations through the os calcis (or amputation
in which the os calcis is retained entire after removal of the
astragalus).

[11] In England, of course, this is always called Syme’s amputation.
It constitutes the type _par excellence_ of the end-bearing stump.
Upon a good Syme stump a patient may be able to walk ten miles without
an artificial foot, wearing simply an “elephant boot.” Amputations
above the Syme level are not end bearing, however long the stump may
be. The other amputations in this region seen in English war surgery
are the various types of osteoplastic amputations in which a part of
the os calcis is retained (Pirogoff’s amputation, etc.). These have
the following defects:–

(1) There is often sepsis between the tibia and the os calcis,
necessitating re-amputation. Osteoplastic amputations are unsuitable
for septic surgery.

(2) Ankylosis between the os calcis and the tibia is often imperfect
so that the bulbous end of the stump is unstable.

(3) The stump is too long to allow of the fixation of a good
artificial ankle joint beneath it. A Syme’s amputation leaves two to
two and a half inches clearance between it and the ground.

I have not yet seen a sub-astragaloid amputation in war surgery, and
only once a disarticulation through the ankle joint, the latter could
not bear pressure and it was necessary to convert it into a Syme’s
amputation. In fact, in this region there is Syme’s amputation and
a number of other far inferior amputations which should never be
considered when a Syme’s amputation is possible. (Ed.)

Certain limb makers consider these operations are bad for the same two
reasons that we have already refuted in connection with amputation
through the condyles of the femur, viz.–

(1) The stump being enlarged at its lower end will not fit into a
wooden bucket.

(2) The stump is too long to allow an artificial foot to be fixed
below it.

From this it simply follows: 1. That complete enclosure of the stump
in a wooden bucket is impossible; 2. That pressure must be placed
directly and exclusively upon the end of the stump.

The latter condition is only possible if the state of the soft parts
allows the cutting of a thick plantar flap to cover the cut surface of
the bone and if care be taken to resect the posterior tibial nerve in
the flap.

We therefore draw special attention to the excellent elliptical
supra-malleolar amputation with posterior flap (Guyon’s method) in
which it is sufficient to retain a bare finger’s breadth of skin from
the plantar surface in front of the point of the heel. It bears direct
pressure well, perfectly if a layer of the os calcis is cut with the
scissors from the area adjacent to the tendo-Achillis and applied
under the cut end of the tibia.

For all these amputations the anterior flap is bad. The thin dorsal
skin of the foot is incapable of withstanding the direct pressure
which is indispensable for this method of fitting.

Even if it were true that under these long stumps it is impossible to
insert an artificial foot for lack of space, the operations which we
have enumerated above should be recommended if the flap can be cut in
the way we have indicated.

[Illustration: FIGS. 120 and 121.]

Their great advantage–and the reason for retaining as much length of
bone as possible–is that they allow walking directly on the stump
without an apparatus. It is sufficient to have a circular shoe made by
any shoemaker consisting of a heel more or less thickened surmounted
by a lacing gaiter reaching halfway up the leg. Guyon’s amputation
constitutes the limit up to which this “elephant boot” is possible.

It is an unsightly apparatus, but its simplicity and cheapness should
be taken into consideration, for it is quite possible that a manual
labourer, especially a countryman, to whom an artificial foot and an
“elephant boot” are given, will reserve the former for Sunday and use
the other for his daily work.

APPLIANCES WITH ARTIFICIAL FOOT.–The wooden piece which
partly encloses the stump consists of a block carved to the shape of
the stump and padded with felt, it is prolonged in front by an instep
reaching to the level of the middle of the metatarsus, and above by
a grooved piece which reaches halfway up the leg and encloses the
anterior half of the latter. A leather gaiter is fixed at the sides
and back and extends up the leg, being laced in front over the wooden
piece as a field boot is laced over the leather tongue. The foot
may be mounted at right angles to the leg, but it is better mounted
slightly in equinus.

The sole and toes are of rubber as described on page 35.

In studying figures 120 and 121 the following should be noted:–

1. The shape of the leg bucket in which an aperture behind permits the
introduction of the stump which is enlarged at its lower end.

2. The mechanism by which the posterior gaiter laced in front fixes
this leg bucket.

3. The articulation of the foot on a transverse axis.