1. This study shows that the treatment of spinal tuberculosis is not satisfactory, because healing as here defined occurred in only 35 per cent. of the cases studied, while in 45 per cent. of these cases healing failed to occur. Even if the 20 per cent. of questionable results is credited to the healed group, this still leaves the chance of healing only a little more than even.
2. In general, the operative treatment offers no advantage over the non-operative plan, since it is found that healing occurred in 34 per cent. of the cases operated upon and in 36 per cent. of those treated without posterior spinal bridging.
3. The dominant factor in the healing of Pott's disease lies in the occurrence, the behavior, and the disposal of the abscess. While healing occurred in 35 per cent. of the total cases, it only took place in 19 per cent. of the cases in which a persistent abscess was recorded. The dominance of the abscess is further shown by the finding that in all cases in which an abscess was recorded the percentage of healing following disposal of the abscess increased to 59 per cent.
4. The evidence inescapably points to the conclusion that the greatest need is further study of the abscess factor. To improve the results of treatment it is essential that there should be a better understanding of the nature of the abscess. There is need for knowledge of the constitutional and local factors which influence the occurrence and the disposal of the abscess. There also is need for some understanding of the conditions which prevent abscess formation and for the development of those techniques which will be most useful for dealing with the persistent abscess.
5. Until these basic matters are understood, it is probable that it would be good surgical practice to undertake early aseptic evacuation of the abscess wherever it may be located.