ON THE LIFE-HISTORY OF ASCARIS LUMBRICOIDES

CONCLUSION. Recapitulating in brief, it may be said that, whatever particular theory of osteogenesis may be the true one, the following points have proved valuable in practice: Tlhe area of the graft must be kept scrupulously aseptic, and free from unnecessary blood clot. Adequate blood supply is necessary to the growth of the graft. T'lhe graft nmust be placed in close apposition to raw surfaces of tlle bone witlh wlhiclh it is to unite. The wlhole region must be kept fixed for a long period for undisturbed organiization to take place. Tlle bone graft slhould be autogenous, and it is better that it slhould include both periosteum and medulla wllerever this is possible, for both these aspects of tlle bonie afford facilities for the growtlh of new blood vessels. Surgeons should have patience, for union is often delayed, and lhasty conclusions that union is not going to take place, and consequent relaxation of strict fixation of the part, mnay convert a case of delayed union into one of non-union. After aniy of thlese procedures it is essential to fix the linmb absolutely to let new vessels grow undisturbed by chlance movements, for the idea of the operation is that all the transplanted bits of bone shall become vascularized. As a aeneral rule, the limb shouild be kept fixed aind undisturbed for at least twice tlle time necessary for union of the same bone in an ordinary simple fracture. I often see cases whichi lhave been operated on, often plated, by some other surgeon, in which splints have been removed at the end of a few weeks, and the case has been regarded as a failure because union has not taken place. Thlere is no definite time within which a fracture will *unite. The timies given in textbooks are understated as applied to the majority.of cases. For example, I may quote the case of a patient, seen in 1908, with an ununited fractuLre of the humerus of twelve months' duration, which -was treated by the "hammer and dam " metlhod, but had to be kept still for nearly six montlhs before thie bones united. The ultimate union was absolutely satisfactory. Operative procedures hed previously failed. Thlis question of tlle consolidation of fractures has been discussed in a previous paper. The wounds received in this war have brought the surgery of septic bones very much into the foreground, and bone grafting will have to be very extensively practised. We must be careful to allow a sufficient time to 'lapse before proceeding to this operation. It is difficult to formulate an exact rule as to when the operation should be performed, for we seem never to be quite free from tlle danger of recrudescent sepsis. My habit is to wait for at least six montlhs after a sinus is closed, during which time and for a variable period afterwards efforts can be made to improve the general nutrition of the limb. It frequently happens that during this delay union of the fragments takes place, and no transplantation is needed. Early operation is to be discouraged from every point of view, and failure to observe tllis fact has resulted in many a tragedy. It is very exceptional, unless there lhas been a great loss of bone, for non-union to persist in fractures which are the seat of the type of suppuration met with at this time.