Part 14

These two objections are not valid, and, on the other hand, this amputation allows us to fit an artificial limb with complete end bearing, and this is a great advantage.

1. Fitting of the bucket.--The first difficulty is easily got over. All that is necessary is to cut away the front of the lower half of the bucket, and to cover in this opening with a lacing piece of leather. The stump passes into the top of the bucket, comes out of this opening and then falls back into the enlarged lower end where it takes a direct bearing (Fig. 99).

2. Level of the knee joint.--It is clear that if the stump is too long it is impossible to fit a knee joint with a bolt right through at the same level as the opposite knee. The thigh piece would have to be prolonged downwards in order to allow of the insertion of this bolt.

This arrangement would not affect walking, but would be unsightly in sitting because of the inequality in the length of the thighs.

It is easy to overcome the difficulty by attaching the leg by two independent lateral hinge joints, without a bolt right through, using the stirrup-shaped fork and the double lock, if a peg is used. This method, as we have already stated, is not so strong, but this is to a large extent compensated for by the possibility of getting a direct end bearing.

3. Direct end bearing and suspension.--If the stump is well covered with a good anterior flap and if the lower end of the bucket is accurately moulded upon it with an interposed layer of felt, the patient can walk directly upon the end of the stump, without it being necessary to carry the bucket up against the ischium, simple braces being used as the means of suspension.

4. There is nothing special about the braces or about the extending strap if the knee is free, nor about the method of attaching the foot.

These limbs for long stumps do not require any spring to extend the knee, if one is wanted an artificial muscle is quite easily fitted.

We have taken as our type an amputation through the femoral condyles.

The covering of the stump is excellent, and pressure is taken upon tissues which are naturally adapted to it (the thick skin and fibrous tissue over the patella), specially if it has been possible to keep the patella in the flap and fix it across the cut surface of the femur (Gritti's operation).

The mechanical points in the fitting of an artificial limb for an amputation through the knee joint are the same. But this amputation seems to us to be inferior to that through the condyles. The sacrifice of three centimetres in length is of no importance in an appliance with direct end bearing; and, on the other hand, disarticulation has several disadvantages:--

1. The enlargement of the femoral condyles, without any compensating advantage.

2. The bearing upon the two condyles, separated by a groove.

3. The insufficient covering of the condyles by the thin skin of the front of the leg.

The principles of fitting a limb are the same in amputations of the leg in which we are obliged to make the patient walk upon the bent knee (too short a stump, the position of the scars, persistent osteitis, the impossibility of straightening the knee when it is ankylosed or stiff in a flexed position), as in the old-fashioned kneeling pin leg.

A posterior transverse band, passing over the bent stump helps to hold the limb on.

CHAPTER IV

ARTIFICIAL LIMB FOR DISARTICULATION AT THE HIP JOINT

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.

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.

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.

CHAPTER V

ARTIFICIAL LIMBS WITH FREE KNEE JOINT FOR AMPUTATION THROUGH THE LEG