AUTOMATIC-INTERACTIVE MEASUREMENT OF RESORPTION CAVITIES IN TRANSILIAC BONE BIOPSIES AND CORRELATION WITH DEOXYPYRIDINOLINE

Measuring bone resorption accurately by histomorphometry of bone biops ies is a challenge. Several techniques have been proposed including th e measurement of eroded surfaces and resorption depth, but they have n ot been compared between themselves nor with biochemical assessment of bone resorption. In addition, there is a need for a rapid method that could be used more routinely. We describe here an automatic interacti ve method using a color analyzer (Visiolab(R), BIOCOM(R), France) with a specific software for the evaluation of erosion depth, eroded volum e, eroded surface, osteoclast number, and surface. Thirty transiliac u ndecalcified bone biopsies stained with Goldner's trichrome were used in this study, taken from subjects suffering from osteoporosis or prim ary hyperparathyroidism. At the time of the biopsy a 2 h fasting morni ng urine sample was collected for measurement by HPLC of total deoxypy ridinoline, the most sensitive marker of bone resorption. There was a highly significant correlation between maximum erosion depth measured directly and the one calculated according to the count of eroded lamel lae (E. F. Eriksen, et al. Metab Bone Dis Relat Res 5:243-252; 1984) ( r = 0.76; p = 0.0001). A significant correlation was found between uri nary deoxypyridinoline and eroded volume/bone volume in cancellous and endocortical bone measured with the automatic interactive technique ( r = 0.48; p = 0.007). In contrast, other histological indexes of bone resorption did not correlate with urinary deoxypyridinoline. The volum e of resorption cavities appears to be the most valid index of bone re sorption rate as it was correlated with the urinary excretion of total deoxypyridinoline. This histological parameter of bone resorption can be measured with a convenient automated method using an image analyze r.