Evaluating Haversian canal-to-osteon ratios for reconstructing bone remodelling activity: balancing precision and...

In cortical bone histology, the ratio of Haversian canal and secondary osteon areas reflects bone resorption and formation during metabolic events executed by Basic Multicellular Units (BMUs). Area data can be pooled where they are collected independently, and the ratio calculated from the mean of each measure. They can also be paired, where they are measured from the same secondary osteon at once and the mean of individual ratios is calculated. We evaluate the impact of pooling and pairing on the resulting ratio values and their interpretation of bone remodelling.

Using both approaches, we calculated the area ratio of 551 Haversian canals and secondary osteons from measurements of existing midshaft femur histology slides. The sample represents n = 38 young and middle-aged females of different social backgrounds from a historical osteological collection. Univariate and bivariate statistics were used to compare and evaluate paired and pooled values and their differences.

The pooled method usually returned a lower canal-to-osteon value than paired data across the whole sample, ages, and social groups. These methods differed in the ratios they produced, independently of the number of measurements per sample.

The pooling technique indicated the presence of thicker lamellar bone within secondary osteons, suggesting greater quantities of bone formed during BMU activity, than the paired technique results, which suggested less bone formed per BMU. While pooling offers efficiency in data collection and analysis, we show that paired data yield more biologically precise and analytically flexible results at an individual BMU level.