In such a case the operation of excision of the head of the femur is by no means difficult, and not excessively dangerous, especially in young children.
Operation.—It is hardly necessary, or indeed possible, to lay down exact rules for the performance of this operation, in so far as the external incisions are concerned, for the sinuses which exist ought in general to be made use of.
When the surgeon has his choice, a straight incision ([Plate II.] fig. a.), parallel with the bone, extending from the top of the great trochanter downwards for about two inches, and also from the same point in a curved direction with the concavity forwards, upwards towards the position of the head of the bone (see diagram), will be found most convenient. The incisions should be carried boldly down to the bone, which will often be felt exposed and bathed in pus, any remains of the ligamentous structures must be cautiously divided with a probe-pointed bistoury, and then by bringing the knee of the affected side forcibly across the opposite thigh, with the toes everted, the head of the bone is forced out of the wound. The head, neck, and great trochanter should be fully exposed, and the saw applied transversely below the level of the trochanter, so as to remove it entire. If this is not done, it prevents discharge, protrudes at the wound, and besides this it is almost invariably diseased along with the head. Chain saws are quite unnecessary, it being in most cases easy to apply an ordinary one to the bone, if it is properly everted.
Great care in the after-treatment is required to prevent undue shortening of the limb, or in the event of a cure to secure the most favourable position for the anchylosis. The femur occasionally tends to protrude at the wound, and hence may require to be counter-extended by splints. If required at all, the splint should be made with an iron elbow opposite the wound to admit of its being easily dressed. In most cases counter-extension may be best managed by a weight and pulley.
Various forms of hammock swings to support the whole body, and slings of leather or canvas to support the limb only, have been found to aid recovery, and render the patient much more comfortable.
When the acetabulum is also diseased the prognosis is much more unfavourable than when it is sound.
The experiments of Heine and Jäger on the dead body, and operations by Hancock, Erichsen, and Holmes, on patients, have shown that in cases of extensive disease of the acetabulum it is quite possible by a prolonged and careful dissection to remove it all without injury of the pelvic viscera.
The details of incisions for such an operation need scarcely be given, as they must vary in each case with the amount of bone diseased, and the position of the already existing sinuses. The amount of bone that may be removed varies much. Erichsen in one case excised "the upper end of the femur, the acetabulum, the rami of the pubis, and of the ischium, a portion of the tuber ischii, and part of the dorsum ilii."[61]
A less formidable proceeding may be useful in cases where the acetabulum is diseased, but not deeply. The moderate use of an ordinary gouge may succeed in removing the diseased bone.
Experience and the cold evidence of statistics prove, however, that the prognosis in any case is modified very much for the worse by the presence of any disease of the acetabulum, more than one-half of the cases proving fatal in which it is diseased, whether attempts to remove the disease of the acetabulum be made or not, and that those cases do best in which the head of the femur has been displaced, and lies outside the joint almost like a loose sequestrum among the soft parts.