JExtra-Capsular Fracture of the Areck of t]~e Femur. 499

The nasal passages are the natural channels for the introduction of air into the lungs, and its expulsion therefrom; they are, by their construction and organisation, admirably adapted to serve as such, and, if judiciously employed and in a healthy condition, are adequate for this purpose under the varying conditions of weather and climate unaided by artificial appliances of any kind.

The mouth and fauces constitute the natural passage for aliment; they are not designed for use as air-passages, and should not be employed to supersede the nares in breathing.

By their communication with the laryax they are, however, obviously designed to serve as alternative air-passages, supple- mentary of the nares when the latter are obstructed, or from any cause incapable of conducting air to the lungs.

The use of oral respirators, is based upon a misconception of the functions of the mouth in regard to respiration, and they should not be employed, because they are not only unnecessary, but positively mischievous, by the habit whiah they induce of breathing through the mouth.

:Nasal respirators may be useful, under special circumstances, to exclude dust from the air-passages.

Muffle-respirators may be used to protect s draughts of cold air, but the muffler alone will serve equally w.ell for this purpose.

Finally--respirators for the occasional exhibition of certain medicines by inhalation are often useful, and may for this purpose be either oral or nasal

ART. XIX.--Extra-Capsular Fracture of the zVec]r of the Femur. a By ALEXANDER GORDON, M.D.; :Professor of Surgery, Queen's College, Belfast~

AN extra-capsular fracture is defined as a fracture of the neck of the femur external to the capsule.. I t would, however, convey a more accurate idea of the nature of the accident to define it as a fracture through the base of the neck. Usually in front the frac- ture runs along the anterior inter-trochanteric line, above where the neck joins the apex of the trochanter, thence internal to the digital fossa, and downwards along the internal margin of the pos- terior inter-trochanteric line, till it passes through or above the lesser trochanl~r. The fracture is thus seen to follow a course which corresponds to the circumference of the base of the neck,

a Read before the Ulster Medical Society, Session 1880-81.

500 Extra-Capsular Fracture of the 2XTeck of the Femur.

which is quadrilateral in form, as described by anatomists, and widens slightly in its antero-posterior diameter as we proceed from above downwards. When a person advanced in life falls upon the outer part of the great trochanter, the limb comes to be at rest; the weight of the body through the pelvis being in projectile force strikes the head, and drives the base of the neck into the trochan- ter. The direction of the force is nearly parallel to the long axis of the neck, and in the direction in which the neck is mechanically strongest and its base weakest. I have no hesitation in stating that this is the mode in which the extra-capsular fracture is pro- duced. If we examine carefully a good collection of these frac- tures it will be found that no two of them are exactly alike, differing slightly from each other, but generally presenting a remarkable resemblance. In all of them the fracture may be said to consist of three fragments--one formed by the head and neck, a second by the apex of the trochanter, the posterior inter-trochau- teric ridge, and more or less of the outer and posterior part of the trochanter, and the third by the upper end of the shaft, with a portion of the trochanter attached. If the reader has before him a femur, and if he draws horizontally a figure, leaving the curve of the outer surface of the trochanter extending from the anterior to the posterior inter-trochanteric line, this figure will approach closely to a semicircle. Draw across this semicircle a diameter, which may be regarded as the base of the neck. I t will be at once seen that the diameter or base of the neck can scarcely pene- trate the semicircle without tending to flatten it more or less. If a force be applied to the diameter or base of the neck which drives it into tile semicircle or trochanter, the effect of such a force will be at once apparent. In the act of breaking, the base of the neck or diameter widens the semicircle, and the broad base of the neck widens the diameter of the trochanter, which then rapidly dimi- nishes. The effect will be a fracture of the trochanter varying in different cases according to circumstances, such as the direction, amount of force, and the fragility of the bone. Women are much more subject to extra-capsular fractures than men, for several reasons--1. Females generally lead a more sedentary life, and there- fore their bones are more atrophied, and are, in consequence, more easily broken. 2. The angle approaches more nearly to a right angle than in males, and therefore a force acting on the trochanter has more power in driving the base of the neck into the tro- chanter. 3. As we advance in age, the posterior inter-trochanteric

By DR. ALEXANDER GORDON. 501

ridge becomes widened, and the angle of reflection of the compact tissue becomes more a right angle, and penetration is thereby facilitated. Old age is the main predisposing cause of both extra- and intra-capsular fractures, and the comparative frequency is owing to the manner of falling. Falls upon the trochanter are the most common causes of this accident. The extra-capsular fracture will be found to be more frequent in extreme old age than the intra-capsular. If the direction of the force be parallel, or nearly so, to the axis of the neck, the fracture will be found to be extra-capsular. On the other hand, if the force has been at right angles to the axis of the neck, as in forcible abduction of the limb, the fracture will be the ordinary intra-capsular, and from the nature of the force attendant there will be great lacera- tion of the periosteum ; and for want of the periosteum there will be upward and downward movements as well as those of rotation, and on this account there will be no osseous union. ]f a force be applied from before backwards, or at right angles to the neck, there will be a trifling laceration of the periosteum and osseous union, if matters have not been aggravated by attempts to elicit crepitus by rotation and extension to enable us to diagnose a frac- ture. The weakest point of the neck of the femur, to a force applied at right angles to its axis, is at the point where it changes from the quadrilateral to the circular form; this is about one- third of an inch from the head, and is the weakest point of the neck when force is applied with the limb abducted.

In leaping, the extremities are approximated, and the weight of the body at the ilio-femoral articulation is received upon the upper and outer part of the head of the femur, through which it is obliquely transmitted thence to the inner surface of the neck. The chief force of the shock is received by the lower part of the base, between the lesser trochanter and the ridge which forms the boundary between the anterior and internal surfaces of this part. But the upper end of the femur is bent forwards, the effect of which is to strengthen this part of the bone in a remarkable manner against shocks, which are thereby diffused over the strong base of the neck internally, and also over the anterior and internal ridge and the compact tissue forming the anterior surface of the upper end of the shaft. The effect of the momentum from leaping or lifting heavy weights is to force the head into the acetabulum and diffuse the shock against that part of the neck and upper end of the shaft to which nature has given it special strength to resist.

502 Extra-Capsular Fracture of the Neck of the Femur.

If we now direct our attention to the upper and posterior part of the neck it will be at once apparent that this part of the neck suffers very little pressure. I think, when the limbs are approxi- mated, and when force is applied vertically to the upper end of the femur, it is not likely to suffer either dislocation or fracture. I have not met with a single instance of extra-capsular fracture caused in any way but by a fall on the great trochanter. Abduct the femur even to a slight degree, the point of impact becomes more external, and the weight of the body falls upon it almost at a right angle to its axis, and breaks easily--the production of the ordinary intra-capsular fracture being the result. The specimens which I have of extra-capsular fracture resolve themselves into five Forms, each of which presents some character slightly differing from the others, thus affording us an explanation of the various signs which might puzzle us in forming a correct diagnosis if we took only a general view of the accident.

First Forra.--ln the first form the force is received upon the upper and posterior part of the base of the neck, which gives way, and at the same moment the fracture in front takes place. Above and behind, the line of fracture varies very little, but in front it may pass through the anterior inter-trochanteric line, external to it or even nearly to the outer border of the anterior surface. Below, it passes into or above the lesser trochanter.

The trochanteric fragment is small in comparison to that of the second form. The eversion of the limb is usually well marked, but sometimes to such an extent that the toe looks directly outwards. I f we examine a specimen of this form the rotation outwards of the shaft of the femur upon the neck appears so plain as not to admit of doubt. This theory has always appeared unsatisfactory to me. I have taught for many years that the eversion was due to the rotation of the shaft of the femur upon the base of the neck. I always thought that there was more than I had observed. I therefore determined to pursue my inquiries by commencing with the cause of the accident. All my inquiries taught me that it was produced by a fall upon the outer surface of the femur. The extremity is usually extended, and lying with its outer surface upon the ground. The extremity will be fixed, and cannot turn outwards, as the outer margin of the foot lies in contact with the ground. Therefore, so far as inquiry into the history of the accident was concerned, the theory of rotation outwards of the shaft upon the base of the neck was no longer tenable. I t is a

By DR. ALEXANDER GORDON. 308

physical impossibility. I next commenced an examination of the specimens. I took the sound femur, and placed it on its anterior surface, with the aspect of the linea aspera looking directly towards the ceiling; then, taking one of the specimens in which there was the greatest amount of rotation outwards, I was surprised to see that the aspects of the bead and linea aspera were the same, and that in the specimens the head had undergone a rotation back- wards to a little more than a right angle, probably to the extent of 92 ~ or 93 ~ . Other specimens showed similar rotation, varying in amount from 80 ~ and upwards. This examination revealed the true explanation of the eversion in this accident. I t is not a rota- tion of the shaft of the femur upon the neck, but of the base of the neck upon the shaft, whilst it lies with its outer side on the ground, fixed by the weight of the body and in contact with the ground. The theory of eversion of the extremity by rotation of the shaft upon the base of the neck is therefore untenable, as the position of the limb renders such rotation impossible. When the patient falls upon the outer surface of the thigh the extremity comes to be at rest, and the head of the femur looking upwards receives the weight of the pelvis on the inner side of the bead, which from its position looks directly upwards; the weight thus received upon the head is transmitted through the neck to its base--that being the weakest part to a force thus applied--=gives way, and breaking penetrates the trochanters. The neck being broken, the pelvis losing its support falls backwards, carrying with it the head, causing rotation from before backwards of the base of the neck upon the shaft. This rotation will continue until the posterior surface of the pelvis comes in contact with the ground.

In order to form a true estimate of the views set forth regarding the mode by which the fracture is produced, and to explain its various forms and their signs, let the femur be placed on its outer surface, the head will look upwards, and it will also be extended, and what- ever movement takes place at the ilio-femoral articulation will be that of the pelvis upon the head. The momentum of the pelvis will be received upon the head, and transmitted from it to the neck, and thence to the base of the neck. I t must always be borne in mind that the head fits accurately into the acetabulum, and also that the momentum of the pelvis will be transmitted in a line perpendicular to the point of impact. As the head receives a general support from the acetabulum, it is not broken, though it may be in a state of extreme atrophy. When the pelvis is placed

504 .Extra-Capsular Fracture of the Neck of the Femur.

upon the head, with its inlet looking upwards and forwards, the point of impact will fall behind the axis of the neck, and the fracture will be the First For,,. If the inlet looks directly forwards, the impact will be in front of the axis of the neck, and the Second Form will be the result. I f the ground upon which the patient falls inclines downwards, the upper part of the neck will receive the greatest shock, and deep penetration of the neck above will take place, with an increase in the angle of the neck. This unnatural increase of the angle of the neck is the main ground upon which the Third Form is based. If the impact be upon the lower part of the head, the lower part of the base of the neck will receive the greatest degree of shock, and the base, being dense at this part, splits the shaft, and produces the Fourth Form.

A very slight movement of the pelvis upon the head of the femur, in the various directions above mentioned, suffices to throw the shock upon the back, fore, upper, or under part of the neck respectively, prodficing fractures having results widely different from each other. I may here remark, that although the various forms of fracture of the base of the neck may be primarily the same, yet the secondary or subsequent lesions and displacements will be very different, according to the direction and amount of force and the fragility of the bone.

In this, the first form, when the patient is placed supine, we see that the injured thigh is in a plane anterior to that of the other side to a greater degree than in any of the other forms, while the limb is shortened and the toes very much everted, and the upper end of the shaft nearer to the anterior superior spine of the ilium, resembling in a remote degree the approximation that occurs in dislocation, upwards and backwards on the dorsum ilii, but with the toes remarkably everted. That this accident could be mistaken for a dislocation on the dorsum ilii is difficult to understand, as in fracture the outer surface of the femur and external condyle look backwards and outwards, whereas in a dislocation it looks forwards and inwards; and to produce the amount of rotation outwards in the healthy femur would require the head of the bone to have left the acetabulum and be placed on the pubes. In most instances of this form of fracture the neck forms a right angle with the shaft, but in some the angle is not much altered, but the anterior aspect of the neck, instead of looking directly forwards, looks forwards and upwards, the neck being rotated on its axis as much as 15 ~ or 20 ~ . The fracture through the base in front is

By DR. ALEXANDER GORDON. 505

external to the anterior inter-trochanterie line, where it might be easily felt very prominent behind and external to the tendon of the rectus femoris muscle. This prominence with the fulness in the groin is so easily felt, and contrasts so remarkably with that of the opposite side, that the diagnosis might be based upon it alone. As the base of the neck has penetrated behind obliquely outwards and forwards, the trochanteric fragment is usually not large, nor is it displaced much out, but a little backwards and mostly inwards, lying within a short distance of the head and acetabulum ; but this inward displacement of the trochanteric fragment is more apparent than real, for were we to deduct the amount of penetration by the neck it will be found very little displaced therefore prominence of the base of the neck in front, widening and displacement of the trochantel~c fragment, would be diagnostic.

Diagnos i s . - -So the diagnostic signs of this, the most frequent of all the forms of extra-capsular fracture, are as follows :--

1. The history of a fall on the great trochanter. 2. Well-marked shortening. 3. Eversion of the foot. 4. Prominence of the base of the neck easily detected by manual

examination, external to, or behind the tendon of the rectus femoris muscle.

5. Increase of the autero-posterlor diameter of the upper end of the femur.

6. Pain on pressure at the upper part and front of the shaft. 7. The shaft is approximated to the anterior superior spine of

the ilium. 8. The injured femur is on a plane anterior to that of the

opposite side. Although this form scarcely presents a single sign in common

with dislocation of the head of the femur on the dorsum ilii, yet, as the latter is the only luxation with which it is possible to con- found it, subjoined I give the differential diagnosis : - -

Extra-Capsular Fracture.

1. Cause.---A direct fall upon the trochanter.

2. Most common in advanced life.

8. Foot much everted, sometimes pointing directly outwards.

4. Limb shortened.

Dislocation on the Dorsura Ilii.

1. Cavse.--Forced rotation inwards of the femur.

2. Extremely rare, almost un- known in advanced life.

8. Foot inverted.

4. Limb shortened.

506 Extra-Capsular Fracture

5. The head may be easily shown to be within the acetabulum by gently flexing and extend- ing the femur by the hand placed behind the lower end of the femur.

6. The outer surface of the tro- chanter looks backwards.

7. The base of the neck may be felt prominent in front~ and there is great increase in the antero-posterior diameter of the trochanter.

8. Acute pain on pressure along the line of fractur% in front~ above and behind.

of the Neck of the Femur.

5. The head rests on the dorsum ilii behind and above the acetabu- lum~ and the movements are restrained and difficult.

6. The trochanter is approximated to the anterior superior spinet its outer surface looking for- wards.

8. ~o pain, or very slight pain, when pressure is made over the posterior part of the tro- chanter.

9. The displacement of the tro- chanterie fragment may be easily felt by passing the fin- gers along the posterior branch of the liuea aspera.

10. A groove may often be felt when the trochanteric frag- ment is separated.

11. The inter-trochanteric line be- hind cannot be felt.

12. In cases of great eversion of the foot in aged persons~ from a fall upon the great trochanter, this form may be diagnosed~ as in none of the other varieties does the same amount of ever- sion take place.

Treatment.--I have often asked myself, as well as others, upon wha t principle can a long splint be serviceable in this form of f r ac tu re ? T h e head and neck are firmly fixed in the acetabulum, by the capsular l igament. The base of the neck is deeply driven into the cancellated tissue behind, whilst it is prominent in front. T h e t rochanter ic f r agment , to which are a t tached the gluteus minimus, pyriformis, the internal and external obturators, is

By DR. ALEXANDER GORDON. 507

approximated to the acetabulum behind, and is fixed in this position by these muscles, and the only medium of connexion between it and the shaft is the tendon of the gluteus medius and fibrous tissue on the outer surface of the trochanter. The foot being greatly everted, in order to apply the splint we must rotate it so as to make it look forwards. Now in this movement the base of the neck forms the fixed point upon which the shaft must move in this rotation, thereby separating the base of the neck entirely from the trochanter, except in front. The limb being shortened, when extension is made it separates the shaft from the head and neck, which is fixed by the capsule, as already stated. The trochanteric fragment being also fixed by the muscles previously mentioned, would also be separated by extension; indeed the effects of extension would be to draw the three fragments from each other, and render a limb which would otherwise be useful into one that was comparatively useless. I could hardly conceive a more useless or irrational practice, and one without a particle of sound anatomical knowledge in its favour, not to speak of con- fining the patient in a recumbent posture, thereby entailing certainly very serious consequences, and often fatal results.

The treatment which I have adopted is that of putting the patient into a comfortable and easy position, and allowing him to move as he may wish. I know of no instance in which the frag- ments were detached or separated from each other by any rash or imprudent movement on the part of the patient. The accident is usually extremely painful, and any movement made by the patient aggravates that pain, and therefore when they change their position, to relieve the organic suffering from pressure, they do so with the greatest gentleness and caution. Some will experience the greatest relief by lying midway between the side and back positions, the outer and posterior surface of the femur resting on and supported by the bed; others cannot suffer the limb to be extended, but will have it bent at right angles to the pelvis, as affording to them the greatest freedom from pain; others will adopt an intermediate position. The rule which I adopt is to let them select their own position, and support the limb as they find it most comfortable.