80. A fracture produced by a gun-shot wound, always renders large incisions necessary, for the purpose of extracting foreign bodies, and relaxing the aponeurosis of the fascia lata, which suffers too great a degree of tension in this place, and might, if not dilated, produce a very troublesome stricture. A fracture complicated by splinters, but without an external wound, and produced by a body striking against the part, seldom requires any particular apparatus, because, adhering as yet to the periosteum, the separated portions of the os femoris may unite again, either among themselves, or with the fragments. FRACTURES OF THE NECK OF THE OS FEMORIS. § XII. OF THE CAUSES. 81. The neck of the os femoris, being surrounded by a large mass of soft parts, and protected by the great trochanter, which forms its external boundary, is almost completely secured from the immediate action of external bodies, and consequently from direct fractures. Whenever it sustains a fracture, it is always by a true counter-stroke, resulting from a fall, sometimes on the great trochanter, and at other times on the sole of the foot or the knee. But fractures produced in the first mode, are much more frequently met with in practice, than those produced in the second, doubtless because, in the latter, the motion is weakened by the extent of parts through which it is distributed, previously to its arrival at the neck of the os femoris. Out of thirty observations made by Desault, on fractures of this description, twenty-four of them were produced by falls on the side. All those recorded by Sabatier, in his interesting memoir, appear to have been produced by similar falls. § XIII. OF THE VARIETIES. 82. Fractures of the neck of the os femoris may occur, 1st, in the middle part of it, where it is smallest, and where nature has not thrown together, as she does in the middle of the long bones so often exposed to fractures, a great quantity of compact substance: 2dly, at its upper end, where it is united to the head of the bone: 3dly, at its junction with the great trochanter, where the solution of continuity may be outside of the joint, a circumstance which doubtless happens much more frequently than has been hitherto suspected. 83. The division, rarely oblique, is almost always transverse: sometimes, in the latter case, the neck remains enclosed or imbedded, as it were, in the body of the bone, being fractured in such a way, as to present a hollow or notch of greater or less depth. Several cases of this kind occurred to Desault; one of them, modelled in wax, is deposited in the collection of the School of Health, and the original preparation is in my possession. The fracture, though frequently simple, is sometimes complicated with that of the great trochanter.