We studied 300 wrists from cadavera and the wrists of forty patients
with de Quervain disease to determine the variation in the pattern of the
tendons and septa in the first extensor compartment. In 75 per cent of the
wrists from cadavera, we found that the number of tendons within the
compartment differed from what is considered standard; there was complete
or partial septation in 40 per cent. In about a third of the specimens from
cadavera, the first extensor compartment was divided by a septum and two
tendons or more were present within the major subcompartment. These
features might readily result in inadequate decompression of the
compartment in the treatment of de Quervain disease. In our prospective
study of forty patients with de Quervain disease, septation was found in
twenty-seven. There was no significant difference between the number of
patients and the number of specimens from cadavera that had no, one, or two
accessory abductor tendons.