THE WALKING CALIPER SPLINT AND

ITS USES.

By W. L. HARNETT, m.a., m.b., f.r.c.s. (Eng.), LIEUT.-cot., I.M.S.,

Officiating Professor of Surgery, Medical College, ! Calcutta.

When a fractured femur has consolidated so

that no mobility at the site of fracture remains, the new hone is not at first strong enough to bear the weight of the body. If it is subjected to this it may break or more frequently it may bend. It is necessary at first to support it and to relieve it of weight-bearing. This can be done by the

simple method of carrying the weight through a

ring, which fits closely around the top of the

thigh,- on to two lateral uprights of steel which end in a socket in the heel of the boot. Provided that the ring fits closely beneath the tuberosity of the ischium, which must rest upon it and that the lateral steels are made of such a length that the heel does not reach quite to the bottom of the boot, the whole of the body weight will be carried to the ground through the appliance. The patient is first fitted with a pair of light

boots and the boot of the injured side has a hole drilled obliquely through the heel of sufficient diameter to take the, bars of the splint, usually about f inch. The obliquity of the tunnels should be such that the outer hole is one rnch nearer to the toe than the inner. The heel and sole of the other boot are raised by whatever amount is necessary to equalise the two legs when the apparatus is in use. The splint is the ordinary Thomas knee splint, the ring of which must be a close fit, so that it rests firmly pressed against the

Nov., 1927.] USES OF WALKING CALIPER SPLINT: HARNETT. 617

tuberosity of the ischium. If the ring be too

arge it will pass over the tuberosity and press gainst the perineum, rendering weight-bearing Impossible. The ring should be kept lovy on the jnner side and on the outer it should rise to a

level just over the top of the great trochanter. ^ should be well padded, especially at the back, where the tuberosity of the ischium rests upon it. * he lower end of the splint is cut off and the last inch of each side bar turned inwards at a right

angle- to fit into the ends of the tunnel in the heel

?/ the boot. The point at which the ends of the

^de bars are turned over must be very carefully determined. The boot is put on and the splint ls fitted and pressed home against the tuberosity of the ischium. With the laces loose, the boot is then partly drawn off, so that there is a } inch clearance between the sole of the patient s heels and that of the boot. The points for turning oyer and cutting are then marked with a file on the side )ars of the splint. The efficient functioning of the splint depends entirely on this clearance and 't should be fitted in the rough with the greatest Care, a trifling extra length being allowed, so that the splint can be altered later, if, as sometimes

happens, the padding of the ring is rather soft

?nd allows of some " settling." A type of splint Js made with sliding bars to admit of lengthening, ut this of course adds to the expense besides

Weakening the apparatus. It is only necessary in eases where the splint is to be worn for a long tune by a growing child, as in the treatment of

tuberculosis of the knee joint. A broad leather band behind the knee and another in front, in

which a hole is cut exactly fitting the patella and astened by straps secure the limb in the splint. strap connecting the side bars just above

the

ankles and passing behind the leg prevents them from springing out of the sockets in the heel. It ls sometimes necessary to cut away the leathei ?t* the boot at the back of the heel to prevent abrasion of the skin in walking. The slight obli-

quity at which the bars are placed in the heels

throws the foot out a little and facilitates walking.. Jn such a splint the patient can walk with ease ana all weight is necessarily borne by the ischial

tuberosity. The length of time during which the

caliper should be worn is very variable. Four

nionths from the date of injury is about _

the

average which should be allowed to elapse in a ease of fracture of the femur before full weight- bearing is permitted, but radiograms at regular _j mtervals will enable the surgeon to determine the

Progress of consolidation; in cases where end-to- end apposition of transverse fractures is secured and in children this period may be considerably shortened.

Functional use of the limb is one of the best

Ways of assisting union, it improves the circula- tjon and the nutrition of the muscles, ensures the removal of waste products and prevents the

orrnation of adhesions in joints. In cases of

delayed union in the bones of the lower limb its

value is inestimable, cases which have been

stationary for weeks will commence to form

callus soon after starting to walk in a caliper splint. It is suitable for the later stages of treat- ment of any fracture of the femur from neck to condyles and for osteotomies at either end of the hone. It is equally suitable for fractures of the tibia or an apparatus based on the same

principle may be constructed to take its bearing from the tibial condyles, in which case the bone carries a larger proportion of the weight than in the long models. This splint may also be used to keep the knee

straight in the extended position or to force it

straight if it be flexed. By the application of suitable pads, straps and short Jones' malleable iron gutter splints, it may be utilised for the cor- rection of backward luxation of the tibia, genu valgum or lateral deviation. Sir Robert Jones advocates its use in the ambulant treatment of tuberculosis of the knee joint. In the concluding stages of treatment the splint may be used to give lateral support to the limb without relieving it of

weight-bearing, which is accomplished by shorten- ing the side bars, so as to allow the heel to reach the sole of the boot.

Figs. 1 and 2 show front and back views of the splint applied to a case of separation of the

upper epiphysis of the femur after preliminary reduction and immobilisation in plaster of paris. The piece of leather at the hack of the femur showed in the photograph is not necessary and is now omitted. is now omitted.

The necessity of fitting boots is a disadvantage when dealing with patients who are in the habit of o-oing barefoot, and in whom boots are liable to produce pressure sores on the feet. Fig. 3 shows an attempt to dispense with their use. A Jones' extension anklet was fitted to the foot and at-

tached by cords to the end of the splint, which

Fig. 1. Fig. 1.

618 THE INDIAN MEDICAL GAZETTE. [Nov., 1927.

was covered by rubber and on which the patient walked. A wood patten was placed on the sounu foot to balance the length of splint requisite to

take the extension. A strap over the shoulder

was found necessary to support the weight of the splint. This type of splint, though useful, is not to be recommended, the attachment is never so

firm as in the usual form and the patient has not the same freedom of locomotion. In practice it has been found that Indian patients readily adapt themselves to the use of the boot and soon learn

to get about in the splint with only the aid of a stick. The caliper splint was evolved during the Great

War and widely used at Home. Its great utility in shortening the period of disability after fracture of the femur deserves to be more widely known in this country than it appears to be. By its use the patient is enabled to resume any occu- pation except hard manual labour about two months after his injury, a result which cannot be achieved by any other method of treatment.

El. .*2

Fig. 2. Fig. 2.

Fig. 3. Fig. 3.