124. Most of these phenomena will fail to occur, if the upper division, passing only half way through the bone, break off but one of the condyls, or if, passing through even the whole of the bone, it be perfectly transverse; but cases of this description are seldom met with. § XX. OF THE PROGNOSIS. 125. I have little to add to the observations already made on the prognosis in fractures of the condyls of the os humeri. All that I have there said is applicable to the os femoris. As is the case with regard to the former fractures, so also here, the apprehensions of authors have been greatly exaggerated by their visionary doctrine respecting injuries of the joints: both reason and experience unite in showing such apprehensions to be unfounded. I shall only observe, that in the present case, even more particularly than in fractures of the condyls of the os humeri, most of the unfortunate events that take place, are owing to the insufficiency of the means employed for effecting a cure. Indeed, as I have already observed (45), all those means can have no effect in opposing the continual tendency of the fragments to become displaced, if the upper fracture[29] of the os femoris be oblique. And in most cases, this fracture is oblique: hence it follows, 1st, that the bony points of the fragments being constantly pushed, during their displacement, against the ligaments that surround the joint, will perpetuate in them the irritation first produced by the fracture, and thus give rise to swelling, inflammation, and all the other morbid affections of the part, so much dreaded by authors, and attributed by them to the mere communication of the fracture with the joint: 2dly, that the best expedient to prevent such affections, is an apparatus that shall retain the divided surfaces in perfect contact with each other by means of permanent extension. [29] That which forms the superior boundary of the longitudinal fracture by which the condyls are separated from each other. TRANS. 126. It is obvious that this extension will be less necessary, if the upper division of the os femoris be transverse, because, then, the condyls and the body of the bone will find a mutual point of support against each other. § XXI. OF THE MEANS OF CONTACT BETWEEN THE FRAGMENTS. 127. Since the same causes, as in the preceding cases, tend here to destroy this contact, when the superior fracture is oblique (122), the apparatus ought, therefore, to be so constructed as to counteract these causes, that is, it ought, 1st, to draw the two condyls down; 2dly, to retain the pelvis up, and with it the superior fragment. This twofold indication relates only to the upper division of the bone, without any reference to that which separates the condyls; 3dly, it is necessary to counteract the tendency which the condyls may have to separate from each other.