No excellent results were obtained in the group which had no treatment except for fracture when a fracture was present. Some of these patients improved considerably following fracture, but either deformity or a residual cavity was present as the end result in every case. No lesion in this group healed spontaneously with an excellent result.

Some patients treated by irradiation alone were definitely improved. Pain was relieved in almost all patients, when pain was present. Some patients were able to continue through life without any further treatment after the use of irradiation. In others, very little if any benefit was obtained. In a fairly large group of cases treated by irradiation, some form of surgery was resorted to later because of unsatisfactory results. There is definite evidence that surgery is less satisfactory when performed after irradiation has failed than it is when done alone. There is no evidence that preoperative or postoperative irradiation is of any benefit. Epiphyseal-growth arrest was fairly common in this group, and a malignant change took place in the bone in two cases many years after irradiation had been used. These two instances of malignant change were the only ones noted in this series.

Resection without replacement in unessential bones certainly seems to be the method of choice; this is especially true in the upper shaft of the fibula, and in the ribs. Resection and replacement with a massive bone graft, even in the essential weight-bearing bones, gave excellent results in a very small group of cases. This method of treatment may be more widely used in selected cases as surgical technique improves.

The results from simple curettage alone seem to be just as good as the results from curettage and chemical cauterization of the cavity. If cauterization is to be used, it would seem that thermal cauterization would be preferable because it can be more exactly controlled, and would not affect transplanted bone in the cavity.

In comparing the two groups of cases treated by curettage and the use of bone chips in the cavity on the one hand, and curettage with the use of a massive graft in the cavity on the other, there seems to be little choice between the two methods. The use of the massive graft in this group of cases, however, gave slightly better results than the use of multiple small chip grafts in the cavity. The combined use of the massive graft and multiple chip grafts in the cavity was not used in any case. It is possible that this method might yield better results than either of the others.

It is of interest to compare the surgical method in which no transplanted bone is used—such as simple curettage or curettage with cauterization of some form—with the method of cleaning out the cavity and transplanting either small chip grafts or the massive graft into the cavity. In the combined groups of curettage and curettage-cauterization, there are thirty-five cases, the end results of which are known. In the combined groups of bone chip and massive graft, there are twenty-eight cases in which the results are known.

Of the thirty-five cases treated by simple curettage or by curettage and cauterization, there were thirteen excellent results from every standpoint, and seven recurrences, which later required reoperation in six, and irradiation in one.

Of the twenty-eight cases in which bone chips or massive grafts were used, there were seventeen excellent results from every standpoint and only two required reoperation. The remaining results in each group were, in general, about the same.

From this study there can be no doubt that better results were obtained when transplanted bone was used in the cavity than when no bone was transplanted into the cavity.

The results of this study seem to narrow the choice of treatment in operable cases down to two methods,—that is, resection, or the use of transplanted bone after thorough cleaning out of the cavity. Irradiation should be reserved for use in inoperable cases, and should then be used only under the strictest precautions, as definite harm may result from its use.

Since most of the cases are seen in childhood, and almost all of them are operable, it is clear that no one method of treatment could be classed as the best method to use in every case. It has been shown that poor results may follow the use of any method that has been used up to this time, except resection. In the non-essential bones, such as the shaft of the fibula and the ribs, resection is the method of choice, routinely. In growing children when the lesions are near the epiphyseal line, especially in the essential weight-bearing bones, resection is not adaptable. In these cases, thorough unroofing of the cavity, curettage, and the use of transplanted bone would seem to be the method of choice. In cases of long standing where the lesion has grown away from the epiphysis, resection and replacement by a massive bone transplant should probably be used more often.