In a recent study of 100 cases of tuberculosis of the spine, undertaken to determine the presence or absence of psoas abscess, only fifteen cases showed such a condition clinically. Fourteen other cases showed the presence of perivertebral abscesses by roentgenographic study, making a total of twenty-nine cases of abscess, or an incidence of 29 per cent. This is a little higher percentage than most observers give, but their observations were clinical and not checked in most instances by roentgenograms.
It is probable that, in a large majority of all cases of tuberculosis of the spine, an abscess of greater or lesser extent exists at the site of the disease. To find an abscess associated with definite bone destruction should not excite any particular curiosity; not to find one with evidence of like bone destruction should be a matter of considerable interest.
The abscess may increase in size, and generally