Part 13

ON THE FRACTURES OF THE UPPER END OR NECK OF THE HUMERUS.

For a very important improvement made by Dr. Physic in the treatment of an old fracture of the os humeri, and which may be applied also to similar fractures of other bones, see Article I. of the Appendix. TRANS.

1. The language of the surgeon differs, in this case, from that of the anatomist, and by the expression, “fracture of the neck of the humerus,” is here meant not that of the slight circular depression, which separates the head from the tuberosities of the bone, but rather that of the contracted or diminished portion of the bone, which commences at the tuberosities above, and being continued down the body of the bone, receives at its lower end the insertion of the tendons of the pectoralis major, the latissimus dorsi, and the teres major. Many practitioners consider this neck or contracted portion as extending even to the insertion of the deltoid muscle.

2. Several facts, the truth of which it is difficult to call in question, attest the possibility of a fracture of the neck of the bone, so called in anatomical language. I have myself seen, in the humerus of a young man, aged seventeen years, the head of the bone exactly separated from its body, by a division which had but slightly affected the upper extremity of the tuberosities. But the examples of this nature which occur in the annals of surgery are too few, to enable us to lay down any general principles for the treatment of such fractures.

§ II.

OF THE VARIETIES AND THE CAUSES.

3. The operation of external bodies, active, when they are thrown against the shoulder, passive, when the shoulder, or the arm, is forcibly driven against them, is always the cause of a fracture of the neck of the humerus. From the mechanism of the part, the division is sometimes direct, and sometimes the effect of a counter-stroke.

The first of these arises very generally from a fall on the point of the shoulder, and as in such a case, the commotion or shock must be very great, to extend with sufficient force through the thick mass which forms the deltoid muscle, that muscle sometimes suffers both contusion and an echymosis. Blood may even escape from a rupture of some of the arteries or veins of the joint, and form, as Desault has observed, a collection or tumour which it would be imprudent to open.

The other is the effect of a fall on the elbow, separated, at the time, some distance from the trunk, or on the hand, which, by a natural instinct, is thrown out, together with the arm and fore-arm, in order to break the violence of the fall.

4. The varieties of this kind of fracture originate, 1st, from the spot which it occupies, being either the middle or the lower part, rarely the upper part, of the neck of the humerus: 2dly, from the state of the surrounding soft parts, which sometimes remain quite natural, and at other times become distended and tumefied. This circumstance always involves the diagnosis in more or less uncertainty; 3dly, from the direction of the fracture, which is sometimes transverse, but usually oblique, particularly when produced in the second mode, that is, by a counter-stroke (3); 4thly, from the relative situation of the fragments, which may remain in contact, an occurrence however but very rare, or may separate from one another in a direction inwardly or upward; and, 5thly, from different complications, with which it may be attended.

§ III.

OF THE SIGNS AND THE DISPLACEMENT.

The whole of the signs of a fracture of the neck of the humerus, taken together, characterize its existence in a manner sufficiently evident. But it is not always an easy matter to take a view of them all at once, and in such a case, there are more difficulties attending the diagnosis here, than in any other fracture of the humerus.

An acute pain is felt at the instant of the fall; and sometimes a crack or report is plainly heard. There is always a sudden inability to move the limb, which, being left to itself, hangs motionless. But if any external force act on it, it yields to it without resistance, and may be moved by it with great ease in every direction.

These motions are accompanied with severe pain, and, if carried too far, may give rise to very troublesome affections, as has been observed in patients, where the fracture was mistaken for a luxation.

Beneath the acromion, is discovered a depression, always situated lower down, than that which accompanies the fracture of that apophysis. If one hand be placed on the head of the bone, while the other is employed in moving the lower fragment in different directions, or, while an assistant, engaged in making the necessary extension, communicates to this fragment a rotatory motion, 1st, the head will be perceived to remain motionless; 2dly, the friction of the two divided ends will produce a crepitation more or less perceptible. This twofold sign is always decisive as to the existence of a fracture; but the swelling of the joint may occasionally prevent the practitioner from availing himself of it.

The fragments remain sometimes in contact, without experiencing any displacement, in which case, most of the signs not manifesting themselves, the diagnosis is rendered more difficult. But most frequently a displacement occurs, and then it is the inferior fragment that is deranged, and not the superior one which is so short that it can be but little effected by the action of the muscles.

7. The displacement is in general but slightly perceptible in the longitudinal direction of the bone, unless when, in a very oblique fracture, the fragments present points which irritate the muscles, excite them to contraction, and augment their force; or, when a blow of great violence, continuing to act after the bone is broken, causes the fragments to overlap each other. Thus has the body of the bone been forcibly drawn upwards, or driven in the same direction, till having passed through the deltoid muscle, and the external integuments, it has even risen considerably above the level of its head.

But in general, as Petit observes, the weight of the limb hanging down the side, opposes to the action of the muscles a sufficient degree of resistance; and it is in the direction of the cross-diameter or thickness of the bone, that the displacement most frequently occurs. It is to be observed, that the lower fragment is driven either inward or outward, rarely in any other direction. In the first case, which is by far the most common, the elbow is somewhat removed from the body, and cannot be brought near to it without pain; in the second, which is more rarely met with, it is moved in an opposite direction.

In the one, the contractions of the deltoid muscle and the natural curve of the humerus, in the other, the united action of the pectoralis major, the latissimus dorsi, and the teres-major, appear to have an essential influence on the displacement.

In each case, the displacement is facilitated by the mobility of the lower fragment, and of the shoulder, when an apparatus from being improperly constructed, fails to prevent the movements of the whole extremity.

8. The signs which have just been detailed, do not always furnish such luminous evidence, particularly to an inexperienced practitioner, as to prevent the occurrence of very serious mistakes. Of this Desault related many examples in his lectures.

CASE. J. M*** Est*** falling on his elbow, fractured the neck of the humerus. A surgeon was immediately called, who, finding a depression beneath the acromion, a protuberance in the hollow of the arm-pit, and the humerus directed outwards, pronounced, without further examination, that there existed a luxation in a downward direction. Wishing to reduce it immediately, he employed, to no purpose, the common processes. Acute pains were the consequence. The opening in the capsule being too narrow was irritated, and the member subjected to great violence of motion. At length the pains became insupportable; the operators gave over their fruitless efforts, and Desault was called.

He discovered the mistake from the immobility of the head; from the depression beneath the acromion being lower down than in a luxation; and from the existence of a crepitation. A reduction was effected without loss of time; the apparatus was applied, but in the evening a considerable swelling occurred around the arm-pit; soon afterwards inflammation was superadded; a vast collection of matter succeeded, and, notwithstanding the utmost attention, it was five months before the patient was restored to health.

9. To this example, I could add others, where the most serious accidents have resulted from a similar mistake. It must be acknowledged, however, that, if, in a fracture, the displacement be inward and a little forward, the greater part of the signs herein detailed (5) apply equally to a fracture and a luxation: but then, as we have just seen in the preceding case, the immobility of the head, the place of the depression beneath the acromion, and the crepitation, will remove any doubts that may be excited in the mind of the surgeon, by the protuberance in the arm-pit, the direction of the arm, &c. &c.

§ IV.

OF THE PROGNOSIS.

10. A fracture of the neck of the humerus assumes, in general, a character not very troublesome; and if, as Heister says, “a fracture near the head is worse, and more difficult to be cured,” this is less owing to the nature and seat of the disease, than to the difficulty of keeping the fragments in contact.