Technical note: Application and potentiality of quantitative ultrasonometry for the evaluation of bone mineral density status.

The evaluation of bone mineral density (BMD) is an important task in paleopathology. Techniques commonly applied in bone quantity assessment, such as DXA or radiogrammetry (XR), suffer from several limitations when applied to skeletal remains. In recently published research, we developed a new methodology and new reference curves for the evaluation of BMD on human skeletal remains, applying for the first time Quantitative Ultrasonometry (QUS), a user-friendly, portable, and reliable clinical technique. This study aims to apply this new methodology to an archeological sample and to compare the results with those obtained through XR. We apply QUS and XR to a sample of 104 adults from Medieval Italian cemeteries. Fragility fractures were recorded. Descriptive statistics and comparisons between sexes, age-at-death cohorts, and individuals with and without fragility fractures were performed. Moreover, univariate and multivariate logistic regression models were used to define the parameters most predictive of fracture risk in past populations. The comparison between sexes showed no significant results concerning BMD parameters, whereas a decrease in BMD with increasing age is confirmed. The comparison between fracture and non-fracture individuals and the logit model demonstrated that QUS parameters, especially UBPI, are more reliable predictors of fracture risk in comparison to XR. Our results confirmed that QUS is a valuable technique that can be efficiently applied to archeological remains, also considering its portability. We also propose a modification of the previously published QUS standard curves, to easily assess osteopenia and osteoporosis in archeological material.