30. What I have said of extension (28), applies also to counter-extension. The strap, which was formerly placed for this purpose in the groin of the affected side, by compressing the adductores, and the rectus internus, produced in them a contraction, which, by drawing the lower fragment towards the pelvis, opposed obstacles to the reduction, which are seldom experienced, when, like Desault, the surgeon contents himself with having the trunk held by assistants, either exclusively at the hips, or both at the hips and under the arm-pits. The resistance being always easily overcome in this affection, renders it unnecessary to have recourse to more powerful means.

31. Hippocrates advises, in fractures of the os femoris, to aid extension by coaptation, performed with the hand. All practitioners, since his time, have added this third manœuvre or process to the two first, namely, extension and counter-extension. But, what effect can the hands produce, in most cases, on the bone through the thick covering of the soft parts? Are we able to communicate to it through such a mass whatever lateral movement we please? Being quite lost in the intervening soft parts, will our efforts reach the bone, in the direction which we give them? The muscles bring the fragments into contact, much better than we can, as soon as extension has removed their overlapping. Indeed, if well executed extension makes the lower fragment return along the same track which it pursued in becoming displaced, it will then be inevitably brought into contact with the upper one by the contraction of the muscles. Besides, in most oblique fractures, is it not evident, that the lower fragment must be made to slide from above downward, on the inclined plain presented by the upper one, and on which it has slided from below upward, in becoming displaced? Is it while extension is making that coaptation ought to be performed? Certainly not: because, if the extension be well directed, an attempt at coaptation will derange it; and if it be not well directed, its course ought to be changed. Is it after extension is finished that recourse ought to be had to coaptation? By no means: because if there be then any remains of deformity, it must be owing to extension having been improperly directed. The remedy, therefore, is, to renew the extension, and direct it properly.

32. Hence, it follows, in general, that coaptation is here a feeble assistant towards reduction; that if it renders any service, it is only in cases of displacement laterally, or in the direction of the cross-diameter of the bone; and that it is by giving the proper direction to extension, by managing it according to the disposition of the muscles, and by knowing when to augment and when to slacken it, that the fragments are brought into regular contact.

33. If the inferior fragment has experienced a rotatory motion on its own axis outwards or inwards (18), the assistant ought, in making extension, to turn the limb very gradually in the opposite direction.

34. Extension was formerly attended with difficulties, which are rarely met with at the present day. Oftentimes, if we give credit to authors, it was altogether useless to endeavour, in the first instance, to reduce the fracture, and restore the limb to its natural length, as the contraction of the muscles rendered the operation absolutely impracticable. Hence, applications of a soothing and sedative nature were employed, previously to an attempt at reduction. The following circumstances have been assigned as the cause of these difficulties. The upper strap, irritating and drawing upwards the adductores and the rectus internus, drew the lower fragment in the same direction, while the semi-tendinosus, semi-membranosus, biceps, &c. being drawn downwards by the lower strap applied over them, drew the pelvis also downwards, and, consequently, the superior fragment connected with it. From this double action arose a double motion directly opposed to that which ought to be produced by extension.

35. There are still cases, where the muscles, in consequence of being irritated by projections or points of bone, by the efforts of the assistants, and by a morbid state of the nerves, increase their contraction to such a pitch that no practicable force can bring the fragments into apposition. What means are then to be employed? All those, in general, that diminish irritability, varied according to circumstances, such as diet, venesection, &c. In such cases, Desault obtained the most happy effects, by placing the limb in a state of continued extension; fatigued by the permanent tension in which they are thus kept, the muscles relax by degrees; their force diminishes; at length they yield, and the reduction is accomplished.

§ VI.

OF THE MEANS OF MAINTAINING THE REDUCTION.

36. The mere reduction of a fracture of the os femoris, is but one step towards the cure. In this, more than in the fracture of any other bone, causes which act incessantly (13) tend to subvert the momentary work of art; it is here, then, in particular, that means ought to be devised for maintaining this work. But, the first of these means is a suitable position of the limb. I have already mentioned the inconveniences that result, both as to the reduction and subsequent treatment, from that proposed by Pott (24...26). The patient must, then, be laid horizontally on a plain exactly even, and not capable of being affected or rendered uneven by the weight of the body. Instead of feather beds generally used in other cases at the Hotel-Dieu, Desault, in cases of fractures, substituted firm and hard mattresses, which, not sinking in the least, by the pressure of the body, give no cause to apprehend those continual displacements, to which a soft bed exposes the patient. These mattresses supersede the advice of certain authors who direct a plank to be placed under the patient.