" In posterior positions, on the contrary, when the sacrum is towards the right or the left sacro-iliac synchondrosis, the legs form with the fcetal ventral surface an angle, the apex of which looks almost directly upward. This is strictly true, only when the breech is at the inferior strait. Trac non made with the filet must be perpendicular to the leg, and it is appar ent why fracture is likely. This is produced when the limb descends and it then becomes perpendicular to the tractor, especially since, coin cidently with the descent of the leg, the pelvis rises. Therefore, Olivier advises, during traction, to apply the fingers of the free hand to the sa crum, and by pushing the breech forward prevent its rising, and the ex tension of the leg." As for the forceps, Olivier, basing his opinion on the experiments of Jacquemier, Baluchi, and on the clinical data of Stoltz, Tarnier, Depaul and others, claims that it is, in the vast majority of cases, inoffensive to the child, although the instrument slips. The cause of this slipping, in his opinion, depends either on the fact that the handles are not com pressed, or else that the blades are applied to the iliac crests instead of on the foetal limbs. The pelvis, he says, offers an insufficient hold, because " when we compress the iliac crests, the bi-iliac diameter diminishes, and the crests shrink, and therefore a firm hold is not possible. But the limbs, close together, make a cone with base downward, and apex above. The diameter of the base is the bi-trochanteric. If the forceps is ap plied here, the blades may slip a little, but they are stopped by the in creasing volume of the cone. We thus have a firm hold, and expose the child to less risk." "Olivier has determined that: 1. The forceps may be applied to the limbs. 2. The hold is firm. 3. No lesion is produced.
" The application of the forceps to the limbs is easy. Is it applied as well in every position? With Tarnier's forceps, thanks to the curve, which is the same as that of Levret, when the position is posterior, S.I.L.P. or S.I.R.P., the blades adapt themselves well to the limbs in the bi-trochanteric diameter, and the forceps cannot slip, or only a trifle, owing to the increase in the cone downwards. When, however, the foetus is in one of the anterior positions, S.I.R.A. or S.I.L. A., the blades do not adapt themselves as well, although the bi-trochanteric diameter is firmly grasped, for the extremity of the blades extends beyond the ante rior surface of the limb, and compresses the abdominal walls, and the hold is less firm. This is why in the majority of our experiments, made with the foetus in anterior positions, the forceps has begun to slip before bringing down the bieech.
" The breech does not come down until the ends of the blades have reached the groin. There they meet the bi-trochanteric diameter, and they can slip no further. The recognition of this fact explains why, in
certain cases where, when it only remained to extract the posterior hip, we have endeavored to do this with the forceps, carrying it above and for wards, it has unlocked. In thus carrying the forceps the extremity of the anterior blade is brought into the groin, and, the breech not descend ing at once, the extremity of the posterior blade passes beyond the bi trochanteric diameter, and the instrument slips." Hence, in anterior positions, Olivier recommends the forceps which Tr Mat has constructed for extracting the breech, but he rejects it for the posterior positions, where, he thinks, the Tarnier forceps is the best, and in none of his experiments did he injure the pelvis or the foetal limbs.
Finally Olivier draws the following conclusions: L During Pregnancy.—The breech is engaged, or not. When en gaged, no interference; when not engaged, version by external manipula tions, and, in case of success, application of a binder, to be worn till labor.
2. During Labor.—A. The breech at the superior strait. B. The breech more or less engaged. C. The breech at the vulva.
A. If the membranes are unruptured, when dilatation is complete, rup ture them, bring down a foot and wait; if the cord prolapses, if it is com pressed, if . after an interval the breech does not engage, extract. If the membranes are ruptured, and intervention is called for, try to bring down a foot, and, in case of success, extract; if this fails, apply the forceps; if it slips, extract by a filet in the groin. The forceps should be applied as far as possible to the limbs, and not to the pelvis.
B. In anterior positions apply the forceps according to the above rules; if it slips, re-apply; in case it slips again, extract by a filet passed around the anterior groin.
In posterior positions, apply the forceps; if it slips twice in succession. and this is very exceptional, extract by the filet and use the complemen tary mancenvre of Lefour, finger in parturient's anus.
In transverse positions extract by a filet in anterior groin. One appli cation of forceps might succeed.
When the infant is dead, if the preceding manoeuvres do not succeed, resort to the cephalotribe or the cranioclast, or any other instrument which will hold well.
C. Resort to the method Ritgen devised for the vertex, and, if this fail, the bi-rectal of Lefour. Act with great care.
The results of these experiments are: The forceps may be of great utility in breech presentations, but it should be applied to the limbs and not to the foetal pelvis. It is often inefficient, and we have to resort to the filet.
We have no change to make, then, in the opinion expres3ed under the subject of labor in pelvic presentations. Wait as long as possible; then, in case of absolute necessity, resort to the forceps and to the filet, in ac cordance with the rules laid down by Olivier.