broom-stick, terminating in a flat metal plate which could be rivetted into the empty shoe of the patient. A still later development was the use of a hinged joint corresponding to the knee (see Fig. 133), in cases of amputation of the thigh, so that the patient could learn early to utilize the joint of the

artificial limb instead of striding with a stiff leg. All of these contrivances served their purpose in helping to educate the stump and in teaching the patient how to walk.

To Mommsen belongs the credit of evolving what is, in my experience, the most practical and efficient provisional artificial

limb. Assume that the patient has been amputated six inches below the knee. An exact plaster impression is taken of the stump by enveloping it with a plaster-of-Paris bandage. The plaster should not be thicker than 16 inch. While it is hardening, the operator should carefully mould the tuberosity

FIG. 133. A provisional artificial limb (Spitzy) with movable knee joint. The transverse pieces marked 11 are easily bent, so that they conform to the curve of the thigh and are easily attached to the plaster dressing which encircles the stump. The foot piece is rivetted to the patient's boot.

of the tibia (see Fig. 134), since this bony projection forms the chief weight-bearing area. The head of the fibula and the condyles of the tibia are not subjected to pressure, since experience has shown that they are not adapted to weight

bearing. The plaster negative is then turned over to the bracemaker, who makes the corresponding foot, steel supports, knee-joint, and thigh-piece, just as though he were making an artificial limb for a patient whose stump had assumed its final definite form.

The one difference between the final

FIG. 134-Making a provisional artificial limb for an amputation of the calf. (Mommsen.) The figure illustrates the first step in the process when the exact plaster impression is taken of the patient's stump. Note that the surgeon is bringing pressure to bear on each side of the tuberosity of the tibia. The condyles and the head of the fibula should not be exposed to pressure.

prosthesis and this provisional one, lies in the fact that the plaster shell has been substituted for the usual leather socket (see Fig. 135). The steel uprights are firmly fixed to the plaster by means of two rivets, and a series of bandages soaked in a

mixture of plaster-of-Paris and bone glue (see footnote).1 In other words, the patient is given at once the same type of artificial limb which he is to wear after the stump has attained its constant shape. During the stump's transition period, the

FIG. 135. The provisional artificial limb for an amputation of the calf. It is exactly like the finished prosthesis, except that the socket into which the stump fits is of plaster-of-Paris instead of leather.

plaster negative can be changed whenever necessary, since the cost is minimal and the labor involved comparatively slight.

1 This mixture, which though light is extremely hard, is prepared as follows: 400 grams of bone glue, broken into small chips, are dissolved in half a liter of water, heated over a water-bath. When boiling, 400 grams of alabaster plaster-of-Paris in the form of a thin plaster cream are added slowly to the glue. The mixture is constantly stirred during the process, and the preparation kept as near 100°C. as possible. When thoroughly mixed and boiled, the requisite number of starched bandages of appropriate width are immersed in the fluid, and when saturated are wound about the plaster shell, so as to strengthen it and hold the steel upright of the artificial limb firmly in place. Complete by a few turns of a plain gauze bandage. Dry in a warm room one to two days.

For amputations of the thigh, the technic is similar. In these cases, the surgeon must lay stress upon an accurate moulding of the tuberosity of the ischium, since this bone is to bear the weight of the patient's body (see Fig. 136).

When the stump has, after many months, assumed a form which no longer changes, then leather is substituted for the plaster-of-Paris, and the patient is equipped with a finished prosthesis.

FIG. 136.

Making the provisional artificial limb for an amputation of the thigh. (Mommsen.) An exact plaster impression is taken of the stump. The surgeon's fist brings pressure to bear just below the tuberosity of the ischium, so as to mold the support for the weight of the body.

Types of Artificial Limbs for the Lower Extremities.It would far exceed the limits of this book were even mention to be made of the hundreds of different varieties of artificial limbs designed for amputations of the lower extremities which have been devised during preceding centuries, or which are now on the market. Study of about fifty different specimens has impressed me with certain conclusions which are, I think, of greater importance than the details of each particular invention.